The following lists only preprints without a corresponding final revised paper.
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19 Mar 2025
Carbon soil stock change in an intensive crop field near Paris reveals significant carbon losses
Benjamin Loubet, Nicolas P. Saby, Maryam Gebleh, Pauline Buysse, Jean-Philippe Chenu, Céline Ratie, Claudy Jolivet, Carmen Kalalian, Florent Levavasseur, Jose-Luis Munera-Echeverri, Sebastien Lafont, Denis Loustau, Dario Papale, Giacomo Nicolini, Bruna Winck, and Dominique Arrouays
EGUsphere, https://doi.org/10.5194/egusphere-2025-592, https://doi.org/10.5194/egusphere-2025-592, 2025
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Soil is a large pool of carbon storing globally from two to three times more carbon than the atmosphere and vegetation. We compute the soil stock evolution from 2005 to 2019 for a wheat-maize-barley-oilseed-rape crop rotation at a French crop site. The soil carbon stock decreased by around 70 ± 16 g C m-2 yr-1 over the period, leading to a total loss of around 8 % of the initial soil stock. This strong destocking is primarily explained by a decrease in the residue return to the site.
18 Mar 2025
Variability in oxygen isotopic fractionation of enzymatic O2 consumption
Carolina F.M. de Carvalho, Moritz F. Lehmann, and Sarah G. Pati
EGUsphere, https://doi.org/10.5194/egusphere-2025-1193, https://doi.org/10.5194/egusphere-2025-1193, 2025
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Using O2 stable isotope analysis, we determined the isotopic fractionation of biological O2 consumption by 10 flavin-dependent and 6 metalloenzymes. Metalloenzymes displayed a narrower range and lower values of isotopic fractionation than flavin-dependent enzymes. This work expands our understanding of the variability of oxygen isotopic fractionation at the enzyme level, improving the ability to study O2 dynamics from molecular to ecosystem scales.
18 Mar 2025
Influence of Carbon Source and Iron Oxide Minerals on Methane Production and Magnetic Mineral Formation in Salt Marsh Sediments
Kaleigh R. Block, Amy Arbetman, Sarah P. Slotznick, Thomas E. Hanson, George W. Luther III, and Sunita R. Shah Walter
EGUsphere, https://doi.org/10.5194/egusphere-2025-822, https://doi.org/10.5194/egusphere-2025-822, 2025
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Although thermodynamic considerations and modelling studies predict low methane emissions from salt marshes, significant methane emissions can be observed. We investigate the roles of methylated carbon sources and interspecies electron transfer through conductive iron minerals in promoting methane production by salt marsh microbial communities. We find that a methylated carbon substrate in conjunction with conductive or semi-conductive iron minerals yield the highest rates of methane production.
17 Mar 2025
Surface area and Ω-aragonite oversaturation as controls of the runaway precipitation process in ocean alkalinity enhancement
Niels Suitner, Jens Hartmann, Selene Varliero, Giulia Faucher, Philipp Suessle, and Charly A. Moras
EGUsphere, https://doi.org/10.5194/egusphere-2025-381, https://doi.org/10.5194/egusphere-2025-381, 2025
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Alkalinity leakage limits the efficiency of ocean alkalinity enhancement. Drivers of this process remain unquantified, restricting accurate assessments. The induced runaway process can be modeled using surface area and aragonite oversaturation as key factors. This study proposes a framework for improving predictability of alkalinity loss due to runaway precipitation, emphasizing the need for field experiments to validate theoretical models concerning dilution and particle sinking processes.
14 Mar 2025
A niche for diverse cable bacteria in continental margin sediments overlain by oxygen-deficient waters
Caroline P. Slomp, Martijn Hermans, Niels A. G. M. van Helmond, Silke Severmann, James McManus, Marit R. van Erk, and Sairah Malkin
EGUsphere, https://doi.org/10.5194/egusphere-2025-817, https://doi.org/10.5194/egusphere-2025-817, 2025
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Cable bacteria couple oxidation of sulfide at depth in sediments with reduction of oxygen, nitrate or nitrite near the sediment surface, thereby preventing release of toxic hydrogen sulfide to the overlying water. We show evidence for a diversity of cable bacteria in sediments from hypoxic and anoxic basins along the continental margin of California and Mexico. Cable bacteria activity in this setting is likely periodic and dependent on the supply of organic matter and/or oxygen.
14 Mar 2025
The incubation history of soil samples strongly affects the occlusion of particulate organic matter
Frederick Büks, Sabine Dumke, and Julia König
EGUsphere, https://doi.org/10.5194/egusphere-2025-771, https://doi.org/10.5194/egusphere-2025-771, 2025
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Ultrasonication followed by density fractionation is a frequently used method to determine soil structural stability and the amount of occluded particulate organic matter. Our analyses of three sandy, silty and loamy soils showed that air-drying and gentle rewetting changes SOM fractions depending on the subsequent time of reincubation compared to field-fresh samples. This is important, since e.g. the measurement of archived soils require the handling of air-dried samples.
14 Mar 2025
20th-century ecological disasters in central European monoculture pine plantations led to critical transitions in peatlands
Mariusz Bąk, Mariusz Lamentowicz, Piotr Kołaczek, Daria Wochal, Michał Jakubowicz, Luke Andrews, and Katarzyna Marcisz
EGUsphere, https://doi.org/10.5194/egusphere-2025-1008, https://doi.org/10.5194/egusphere-2025-1008, 2025
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We integrated palaeoecological and geochemical data to discern the impact of catastrophic events on the development of peatlands within pine monocultures. An approach that integrates these methods is not commonly employed but offers a more comprehensive understanding of past ecosystem transformations. We used multi-proxy research of the peat core and neodymium isotope record. We support the results of our analyses with the recognition of statistically significant critical transitions.
14 Mar 2025
How does nitrogen control soil organic matter turnover and composition? – Theory and model
Chun Chung Yeung, Harald Bugmann, Frank Hagedorn, Margaux Moreno Duborgel, and Olalla Díaz-Yáñez
EGUsphere, https://doi.org/10.5194/egusphere-2025-1022, https://doi.org/10.5194/egusphere-2025-1022, 2025
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To address the uncertain interactions between soil nitrogen (N) and carbon (C), we set up a model “experiment” in silico to test several hypothesized responses of decomposers to N. We found that decomposers were stimulated by N when decomposing high C:N detritus, but inhibited when decomposing low C:N, processed organic C. The consequence is that under exogenous N addition (e.g., contemporary N deposition), forests may accumulate light fraction C predominantly, at the expense of coarse detritus.
14 Mar 2025
On the Challenges of Retrieving Phytoplankton Properties from Remote-Sensing Observations
J. Xavier Prochaska and Robert J. Frouin
EGUsphere, https://doi.org/10.5194/egusphere-2025-927, https://doi.org/10.5194/egusphere-2025-927, 2025
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Satellites monitor ocean health globally, but we discovered a fundamental physics limitation in measuring phytoplankton – tiny plants essential to marine ecosystems. Our analysis shows even advanced satellites can't reliably distinguish phytoplankton from other ocean components. This challenges decades of research and suggests existing measurements have greater uncertainties than realized. Combining satellite data with direct ocean sampling is needed for better monitoring these vital organisms.
14 Mar 2025
Seasonality of the North Pacific Ocean Desert area in the past two decades and a modelling perspective for the 21st century
Siyu Meng, Xun Gong, Benjamin Webber, Manoj Joshi, Xiaokun Ding, Xiang Gong, Mingliang Gu, and Huiwang Gao
EGUsphere, https://doi.org/10.5194/egusphere-2025-13, https://doi.org/10.5194/egusphere-2025-13, 2025
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The North Pacific Ocean Desert (NPOD), with low phytoplankton biomass, covers about 40 % of the North Pacific. The variations in NPOD seasonal cycle, which have a greater impact than its annual mean changes, are influenced by the El Niño-Southern Oscillation from 1998 to 2021. However, from 2021 to 2100, a weakened NPOD seasonal cycle is expected due to climate change. These changes in NPOD seasonal cycle could affect fisheries and marine ecosystems.
14 Mar 2025
Mineral Formation during Shipboard Ocean Alkalinity Enhancement Experiments in the North Atlantic
Mohammed Hashim, Lukas Marx, Frieder Klein, Chloe Dean, Emily Burdige, Matthew Hayden, Daniel McCorkle, and Adam Subhas
EGUsphere, https://doi.org/10.5194/egusphere-2025-988, https://doi.org/10.5194/egusphere-2025-988, 2025
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Ocean alkalinity enhancement (OAE) is a CO2 removal approach that involves the addition of alkaline substances to seawater that would allow it to absorb more atmospheric CO2. Increasing seawater alkalinity, however, can trigger mineral precipitation that decreases OAE efficiency. We conducted experiments to constrain the thermodynamic and kinetics of mineral precipitation.
13 Mar 2025
Phytoplankton community succession and biogeochemistry in a bloom simulation experiment at an estuary-ocean interface
Jenna Alyson Lee, Joseph H. Vineis, Mathieu A. Poupon, Laure Resplandy, and Bess B. Ward
EGUsphere, https://doi.org/10.5194/egusphere-2025-871, https://doi.org/10.5194/egusphere-2025-871, 2025
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Concurrent sampling of environmental parameters, productivity rates, photopigments, and DNA were used to analyze a 24–L estuarine diatom bloom microcosm. Biogeochemical data and an ecological model indicated that the bloom was terminated by grazing. Comparisons to previous studies revealed (1) additional community and diversity complexity using 18S amplicon vs. traditional pigment–based analyses, and (2) a potential global productivity–diversity relationship using 18S and carbon transport rates.
13 Mar 2025
Tree Growth and Water-Use Efficiency at the Himalayan Fir Treeline and lower altitudes: Roles of Climate Warming and CO2 Fertilization
Xing Pu and Lixin Lyu
EGUsphere, https://doi.org/10.5194/egusphere-2025-952, https://doi.org/10.5194/egusphere-2025-952, 2025
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This study explores how rising CO₂ and increasing temperatures affect the growth of Himalayan fir trees on the Tibetan Plateau, particularly in relation to water availability. We found that while tree growth in wet, high-elevation areas improved with increased CO₂, growth in dry, low-elevation areas declined due to water stress. These findings suggest that while CO₂ may boost growth in some areas, the negative effects of drought may outweigh these benefits.
13 Mar 2025
Terrestrial browning from Colored Dissolved Organic Matter (CDOM) changes the seasonal phenology of the coastal Arctic carbon cycle
Clement Bertin, Vincent Le Fouest, Dustin Carroll, Stephanie Dutkiewicz, Dimitris Menemenlis, Atsushi Matsuoka, Manfredi Manizza, and Charles E. Miller
EGUsphere, https://doi.org/10.5194/egusphere-2025-973, https://doi.org/10.5194/egusphere-2025-973, 2025
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We adjusted a model of the Mackenzie River region to account for the riverine export of organic matter that affects light in the water. We show that such export causes a delay in the phytoplankton growth by two weeks and raises the water surface temperature by 1.7 °C. We found that temperature increase turns this coastal region from a sink of carbon dioxide to an emitter. Our findings suggest that rising exports of organic matter can significantly affect the carbon cycle in Arctic coastal areas.
13 Mar 2025
Assessing terrestrial carbon fluxes and stocks in South America and its major biomes using CMIP6 Earth System Models
Marcos B. Sanches, Manoel Cardoso, Celso von Randow, Chris Jones, and Mathew Williams
EGUsphere, https://doi.org/10.5194/egusphere-2025-942, https://doi.org/10.5194/egusphere-2025-942, 2025
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This study examines South America's role in the global carbon cycle using flux and stock analyses from CMIP6 Earth System Models. We discuss the continent’s relevance, model-observation agreement, and the impacts of dry and wet years on major biomes. Additionally, we assess model results indicating that parts of South America could shift from carbon sinks to emitters, significantly affecting the global carbon balance.
12 Mar 2025
Sedimentary organic carbon dynamics in a glaciated Arctic fjord: tracing contributions of terrestrial and marine sources in the context of Atlantification over recent centuries
Dahae Kim, Jung-Hyun Kim, Youngkyu Ahn, Matthias Forwick, and Seung-Il Nam
EGUsphere, https://doi.org/10.5194/egusphere-2025-957, https://doi.org/10.5194/egusphere-2025-957, 2025
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The Arctic is warming rapidly, altering carbon storage in Svalbard’s Kongsfjorden. Our study analyzed sediment cores to track organic carbon shifts over time. We found that increasing Atlantic Water inflow enhanced marine carbon while reducing land-derived inputs. These findings suggest that Atlantification is reshaping carbon sequestration in Arctic fjords, with broader implications for the Arctic carbon cycle.
12 Mar 2025
Long-term ecosystem dynamics of an ice-poor permafrost peatland in eastern Eurasia: paleoecological insights into climate sensitivity
Zhengyu Xia, Fengtong Chen, Mengyang Guo, and Zicheng Yu
EGUsphere, https://doi.org/10.5194/egusphere-2025-946, https://doi.org/10.5194/egusphere-2025-946, 2025
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We conducted a paleoecological analysis of multiple cores from an ice-poor permafrost peatland in eastern Eurasia to understand its long-term ecosystem dynamics. Our findings highlight that climate-permafrost interactions and their feedbacks play a key role in controlling peatland processes, including its formation, development, and ongoing trajectory. The studied peatland shows historical stability as well as resilience in maintaining hydrology and carbon sink amid ongoing climate change.
11 Mar 2025
Does increased spatial replication above heterogeneous agroforestry improve the representativeness of eddy covariance measurements?
José Ángel Callejas-Rodelas, Alexander Knohl, Ivan Mammarella, Timo Vesala, Olli Peltola, and Christian Markwitz
EGUsphere, https://doi.org/10.5194/egusphere-2025-810, https://doi.org/10.5194/egusphere-2025-810, 2025
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The spatial variability of CO2 and water vapour exchanges with the atmosphere was quantified above an agroforestry system, and further compared to a monocropping system, using a total of four eddy covariance stations. The variability of fluxes within the agroforestry was found to be as large as the variability between agroforestry and monocropping, induced by the heterogeneity of the site, which highlights the need for replicated measurements above such ecosystems.
11 Mar 2025
Benthic ostracod diversity and biogeography in an urban semi–enclosed eutrophic riverine bay
Jialu Huang, Moriaki Yasuhara, He Wang, Pedro Julião Jimenez, Jiying Li, and Minhan Dai
EGUsphere, https://doi.org/10.5194/egusphere-2025-138, https://doi.org/10.5194/egusphere-2025-138, 2025
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We investigated the abundance, diversity, composition, and distribution of ostracod (a meiobenthic group) and their interactions with eutrophication and pollution through high resolution sampling of surface sediment in Deep Bay, a small semi-enclosed riverine bay adjacent to two of the world’s most populated cities, Hong Kong and Shenzhen. The results support the idea that ostracod is a useful bioindicator of coastal benthic ecosystems shaped by distinct environmental problems.
10 Mar 2025
Drone-based multispectral differentiation of subalpine vegetation at the treeline in the Southern Alps of New Zealand
Fabian Döweler and Martin K.-F. Bader
EGUsphere, https://doi.org/10.5194/egusphere-2025-926, https://doi.org/10.5194/egusphere-2025-926, 2025
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Monitoring subalpine ecosystems is challenging due to their remote terrain. Using drones with multispectral sensors and machine learning, we classified vegetation in New Zealand’s Southern Alps. Results show that plant texture affects spectral responses, with dense, uniform vegetation like tussock grass achieving higher accuracy than structurally complex shrubs. This work highlights how drones can support landscape scale vegetation mapping, supporting conservation efforts in alpine environments.
07 Mar 2025
Preservation and degradation of ancient organic matter in mid-Miocene Antarctic permafrost
Marjolaine Verret, Sebastian Naeher, Denis Lacelle, Catherine Ginnane, Warren Dickinson, Kevin Norton, Jocelyn Turnbull, and Richard Levy
EGUsphere, https://doi.org/10.5194/egusphere-2025-786, https://doi.org/10.5194/egusphere-2025-786, 2025
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15 million years ago, the McMurdo Dry Valleys of Antarctica were dominated by a tundra environment. In contrast, the modern environment is amongst the coldest and driest on Earth. Using a permafrost core, this paper investigates the shift from a tundra- to a bacteria-dominated landscape. By differentiating between ancient and modern organic material, we further our understanding of preservation of ancient organic material and its response and contribution to future climate change.
07 Mar 2025
Extreme carbon fluxes may result from autochthonous particulate organic carbon regulated by the interactions between picophytoplankton and heterotrophic bacteria in river-reservoir systems
Fang Luo, Zhe Li, Qiong Tang, Yan Xiao, Lunhui Lu, Dianchang Wang, Chong Li, and Xinghua Wu
EGUsphere, https://doi.org/10.5194/egusphere-2025-156, https://doi.org/10.5194/egusphere-2025-156, 2025
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Freshwater systems are key sources of CH4 and CO2, influenced by particulate organic carbon (POC). The trophic interaction between picophytoplankton (PP) and heterotrophic bacteria (HB) plays a crucial role in the carbon cycle within the aquatic system. This study found that autochthonous POC was more likely to drive extreme carbon emissions via PP-HB interactions. These findings highlight the importance of PP-HB interactions in predicting extreme carbon emissions in river-reservoir ecosystems.
07 Mar 2025
Improving Marine Sediment Carbon Stock Estimates: The Role of Dry Bulk Density and Predictor Adjustments
Mark Chatting, Markus Diesing, William Ross Hunter, Anthony Grey, Brian P. Kelleher, and Mark Coughlan
EGUsphere, https://doi.org/10.5194/egusphere-2025-661, https://doi.org/10.5194/egusphere-2025-661, 2025
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Marine sediments store carbon and are critical in the global carbon cycle, but data gaps reduce the accuracy of carbon stock estimates. This study improves estimates in the Irish Sea by refining key data inputs. Using machine learning and bias adjustments, the new model suggests previous estimates overestimated carbon stocks by 31.4 %. The findings highlight the need for more accurate sediment measurements to guide environmental policies and better protect carbon storage in marine ecosystems.
06 Mar 2025
Tracing the contribution of dust sources on deposition and phytoplankton carbon uptake in global oceans
Yaxin Liu, Yunting Xiao, Lehui Cui, Qinghao Guo, Yiyang Sun, Pingqing Fu, Cong-Qiang Liu, and Jialei Zhu
EGUsphere, https://doi.org/10.5194/egusphere-2025-763, https://doi.org/10.5194/egusphere-2025-763, 2025
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Dust carries iron deposits into the ocean, providing essential nutrients for the growth of marine phytoplankton, influencing their carbon uptake capacity. A model constrained by global datasets on dust iron content, ocean iron solubility, and dissolved iron concentrations was used to assess the contributions of 11 major dust sources to carbon uptake in 8 marine areas, enhancing understanding of the impact of global dust emissions on marine deposition and carbon cycle with decreased uncertainty.
05 Mar 2025
Global patterns and drivers of climate-driven fires in a warming world
Hemraj Bhattarai, Maria Val Martin, Stephen Sitch, David H. Y. Yung, and Amos P. K. Tai
EGUsphere, https://doi.org/10.5194/egusphere-2025-804, https://doi.org/10.5194/egusphere-2025-804, 2025
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Wildfires are becoming more frequent and severe due to climate change, posing various risks. We explore how future climate conditions will influence global wildfire activity and carbon emissions by 2100. Using advanced computer modeling, we found that while some regions remain stable, boreal forests will see a major rise in burned area and emissions. These changes are driven by drier conditions and increased vegetation growth, highlighting the urgent need for better fire management strategies.
04 Mar 2025
Assessing Carbon Flux Variability in an Alpine Steppe: Insights from Dual-Height Measurements
Nithin D. Pillai, Christian Wille, Felix Nieberding, Manuel Helbig, and Torsten Sachs
EGUsphere, https://doi.org/10.5194/egusphere-2025-530, https://doi.org/10.5194/egusphere-2025-530, 2025
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The Tibetan Plateau is warming rapidly, affecting carbon cycles in its ecosystems. Using two measurement heights (3 m and 19 m) in an alpine steppe near Nam Co, we explored how spatial scale impacts CO2 fluxes. CO2 fluxes varied with spatial scale due to landscape heterogeneity. This variability shows that the measurement scale can shift the ecosystem's carbon balance from CO2 sink to either carbon neutral or CO2 source, highlighting the importance of considering spatial scale in carbon studies.
04 Mar 2025
Physiological responses to ultra-high CO2 levels in an evergreen tree species
Ben-El Levy, Yedidya Ben-Eliyahu, Yaniv-Brian Grunstein, Itay Halevy, and Tamir Klein
EGUsphere, https://doi.org/10.5194/egusphere-2025-807, https://doi.org/10.5194/egusphere-2025-807, 2025
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As atmospheric CO2 increases globally, plants increase the rate of photosynthesis. Still, leaf gas exchange can be downregulated by the plant. Here we tested the limits of these plant responses in a fruit tree species under very high CO2 levels, relevant to future Earth and to contemporary Mars. Plant water use decreased at 1600 ppm CO2 and remained low at 6000 ppm. Photosynthesis significantly increased at 6000 ppm. In summary, ultra-high CO2 may partly compensate for water shortage.
04 Mar 2025
Part 2: Quantitative contributions of cyanobacterial alkaline phosphatases to biogeochemical rates in the subtropical North Atlantic
Noelle A. Held, Korrina Kunde, Clare E. Davis, Neil J. Wyatt, Elizabeth L. Mann, E. Malcolm S. Woodward, Matthew McIlvin, Alessandro Tagliabue, Benjamin S. Twining, Claire Mahaffey, Mak A. Saito, and Maeve C. Lohan
EGUsphere, https://doi.org/10.5194/egusphere-2024-3996, https://doi.org/10.5194/egusphere-2024-3996, 2025
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Microbial enzymes are critical to marine biogeochemical cycles, but which microbes are producing those enzymes? We used a targeted proteomics method to quantify how much Prochlorococcus and Synechococcus contribute to surface ocean alkaline phosphatase activity. We find that alkaline phosphatase abundance is limited by the availability of iron, zinc and cobalt (which may substitute for zinc).
28 Feb 2025
Air-sea gas exchange measurements helped derive in-situ organic and inorganic carbon fixation in response to Ocean Alkalinity Enhancement in a temperate plankton community
Julieta Schneider, Ulf Riebesell, Charly André Moras, Laura Marín-Samper, Leila Kittu, Joaquín Ortíz-Cortes, and Kai George Schulz
EGUsphere, https://doi.org/10.5194/egusphere-2025-524, https://doi.org/10.5194/egusphere-2025-524, 2025
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Ocean Alkalinity Enhancement (OAE) is an approach to sequester additional atmospheric CO2 in the ocean and may alleviate ocean acidification. A large-scale mesocosm experiment in Norway tested Ca- and Si-based OAE, increasing total alkalinity (TA) by 0–600 µmol kg-1 and measuring CO2 gas exchange. While TA remained stable, we found mineral-type and/or pCO2/pH effects on coccolithophorid calcification, net community production and zooplankton respiration, providing insights for future OAE trials.
28 Feb 2025
Ideas and Perspectives: Potentially Large but Highly Uncertain Greenhouse Gas Emissions Resulting from Peat Erosion
Thomas C. Parker, Chris Evans, Martin G. Evans, Miriam Glendell, Richard Grayson, Joseph Holden, Changjia Li, Pengfei Li, and Rebekka R. E. Artz
EGUsphere, https://doi.org/10.5194/egusphere-2025-287, https://doi.org/10.5194/egusphere-2025-287, 2025
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Many peatlands around the world are eroding and causing carbon losses to the atmosphere and to freshwater systems. To accurately report emissions from peatlands we need to understand how much of the eroded peat is converted to CO2 once exposed to the atmosphere. We need more direct measurements of this process and a better understanding of the environmental conditions that peat is exposed to after it erodes. This information will help quantify the emissions savings from peatland restoration.
28 Feb 2025
Utilizing Probability Estimates from Machine Learning and Pollen to Understand the Depositional Influences on Branched GDGT in Wetlands, Peatlands, and Lakes
Amy Cromartie, Cindy De Jonge, Guillemette Ménot, Mary Robles, Lucas Dugerdil, Odile Peyron, Marta Rodrigo-Gámiz, Jon Camuera, Maria Jose Ramos-Roman, Gonzalo Jiménez-Moreno, Claude Colombié, Lilit Sahakyan, and Sébastien Joannin
EGUsphere, https://doi.org/10.5194/egusphere-2025-526, https://doi.org/10.5194/egusphere-2025-526, 2025
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BrGDGT are a molecular biomarker utilized for paleotemperature reconstructions. One issue, however, with utilizing brGDGTs is that the distribution differs in relation to sediment environments (i.e., peat, lake, soil) which change overtime. We utilize the probability estimate outputs from five machine learning algorithms, and a new modern brGDGTs database to track change and apply these models’ to two downcore records utilizing pollen and non-pollen polymorphs to confirm the model’s accuracy.
25 Feb 2025
Technical note: Measurements of fluorescent dissolved organic matter (FDOM) in seawater (Filter blanks, pore sizes, and storage)
Junhyeong Seo, Heejun Han, Intae Kim, and Guebuem Kim
EGUsphere, https://doi.org/10.5194/egusphere-2025-501, https://doi.org/10.5194/egusphere-2025-501, 2025
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This study examines methodological uncertainties in FDOM (fluorescent dissolved organic matter) measurements due to filter blanks, pore sizes, and storage conditions. Results show that pre-cleaning filters and optimizing storage improve measurement reliability. These finding minimize procedural errors and provide clear guidelines for FDOM analysis, emphasizing the need for method standardization in marine biogeochemical research.
25 Feb 2025
Enhanced isotopic approach combined with microbiological analyses for more precise distinction of various N-transformation processes in contaminated aquifer – a groundwater incubation study
Sushmita Deb, Mikk Espenberg, Reinhard Well, Michał Bucha, Marta Jakubiak, Ülo Mander, and Dominika Lewicka-Szczebak
EGUsphere, https://doi.org/10.5194/egusphere-2025-754, https://doi.org/10.5194/egusphere-2025-754, 2025
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This study investigates nitrogen cycling in groundwater from agricultural area using organic fertilizer. Research combines isotope and microbial studies to track transformations. High-nitrate samples were incubated with a low addition of ¹⁵N tracer. Results showed a shift from archaeal nitrification to bacterial denitrification under low oxygen with glucose, confirmed by isotope and microbial analysis. Findings offer insights for improving water quality and pollution management.
25 Feb 2025
Impact of wheat cultivar development on biomass production and carbon input in tillage-eroded soils
Luis Alfredo Pires Barbosa, Martin Leue, Marc Wehrhan, and Michael Sommer
EGUsphere, https://doi.org/10.5194/egusphere-2025-746, https://doi.org/10.5194/egusphere-2025-746, 2025
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Healthy soils need plant biomass, especially roots, to function properly. Our study examined how different wheat varieties and soil erosion impact root growth and carbon storage. We found that tillage erosion significantly reduced total wheat biomass, while newer wheat varieties produced more grain but contributed less carbon to the soil. Simulations showed that modern varieties are more sensitive to dry conditions, highlighting a trade-off between higher yields and long-term soil health.
24 Feb 2025
From Ground Photos to Aerial Insights: Automating Citizen Science Labeling for Tree Species Segmentation in UAV Images
Salim Soltani, Lauren E. Gillespie, Moises Exposito-Alonso, Olga Ferlian, Nico Eisenhauer, Hannes Feilhauer, and Teja Kattenborn
EGUsphere, https://doi.org/10.5194/egusphere-2025-662, https://doi.org/10.5194/egusphere-2025-662, 2025
Preprint under review for BG (discussion: open, 1 comment)
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We introduce an automated approach for generating segmentation masks for citizen science plant photos, making them applicable to computer vision models. This framework effectively transforms citizen science data into a data treasure for segmentation models for plant species identification in aerial imagery. Using automatically labeled photos, we train segmentation models for mapping tree species in drone imagery, showcasing their potential for forestry, agriculture, and biodiversity monitoring.
21 Feb 2025
Technical note: Acidification methodology impacts sediment decarbonation as revealed by bulk and serial oxidation measurements
Songfan He, Huiyuan Yang, and Xingqian Cui
EGUsphere, https://doi.org/10.5194/egusphere-2025-701, https://doi.org/10.5194/egusphere-2025-701, 2025
Preprint under review for BG (discussion: open, 0 comments)
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Acidification is used to measure organic carbon in sediments, but its effects on carbon properties are unclear. We studied how acid rinsing and fumigation impact carbon measurements using advanced techniques. Results show both methods and acid strength influence outcomes, with rinsing preserving natural states better. This research highlights the importance of method choice in accurate carbon analysis, crucial for understanding environmental processes.
18 Feb 2025
Lake anoxia, primary production and algal community shifts in response to rapid climate changes during the Late-Glacial
Stan Jonah Schouten, Noé Raymond Marie Marcel Schmidhauser, Martin Grosjean, Andrea Lami, Petra Boltshauser-Kaltenrieder, Jacqueline F. N. van Leeuwen, Hendrik Vogel, and Petra Zahajská
EGUsphere, https://doi.org/10.5194/egusphere-2025-440, https://doi.org/10.5194/egusphere-2025-440, 2025
Preprint under review for BG (discussion: open, 2 comments)
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Climate warming speeds up lake eutrophication, creating 'dead zones' where aquatic life suffocates due to oxygen depletion. The sediments of Amsoldingersee, a Swiss lake, revealed how climate shifts impacted the lake around 10,000–18,000 years ago. 1. Algal composition differed between both cold & warm periods. 2. Nutrient additions from dust controlled algal growth more than temperature. 3. Cold periods with ice cover lead to oxygen depletion. 4. Algal communities recovered after anoxic phases.
14 Feb 2025
Can atmospheric chemistry deposition schemes reliably simulate stomatal ozone flux across global land covers and climates?
Tamara Emmerichs, Abdulla Al Mamun, Lisa Emberson, Huiting Mao, Leiming Zhang, Limei Ran, Clara Betancourt, Anthony Wong, Gerbrand Koren, Giacomo Gerosa, Min Huang, and Pierluigi Guaita
EGUsphere, https://doi.org/10.5194/egusphere-2025-429, https://doi.org/10.5194/egusphere-2025-429, 2025
Preprint under review for BG (discussion: open, 0 comments)
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The risk of ozone pollution to plants is estimated based on the flux through the plant pores which still has uncertainties. In this study, we estimate this quantity with 9 models at different land types worldwide. The input data stems from a database. The models estimated mostly reasonable summertime ozone deposition. The different results of the models varied by land cover which were mostly related to the moisture deficit. This is an important step for assessing the ozone impact on vegetation.
13 Feb 2025
Toward a typology of river functioning: a comprehensive study of POM composition at multi-rivers scale
Florian Ferchiche, Camilla Liénart, Karine Charlier, Jonathan Deborde, Mélanie Giraud, Philippe Kerhervé, Pierre Polsenaere, and Nicolas Savoye
EGUsphere, https://doi.org/10.5194/egusphere-2025-158, https://doi.org/10.5194/egusphere-2025-158, 2025
Preprint under review for BG (discussion: open, 0 comments)
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This study examines particulate organic matter (POM) composition and dynamics in 23 temperate rivers. Carbon and nitrogen isotope analysis revealed four river types based on dominant POM sources (phytoplankton, terrestrial material). Watershed characteristics influence POM composition while seasonal variations in river flow and sediment resuspension drive POM dynamics. This study improves the understanding of river systems and calls for further studies exploring downstream estuarine functioning.
13 Feb 2025
Reviews and syntheses: Potential and limitations of oceanic carbon dioxide storage via reactor-based accelerated weathering of limestone
Tom Huysmans, Filip J. R. Meysman, and Sebastiaan J. van de Velde
EGUsphere, https://doi.org/10.5194/egusphere-2025-447, https://doi.org/10.5194/egusphere-2025-447, 2025
Preprint under review for BG (discussion: open, 2 comments)
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To examine the potential of "Accelerated Weathering of Limestone" as a carbon capture and storage technique, we compared the different available reactor designs, and assessed their CO2 sequestration efficiencies, resource usage and limitations. We find that large water volumes are required to efficiently remove CO2 from the gas stream and that very small CaCO3 particle sizes and long residence times are required to achieve reasonable CaCO3 dissolution efficiencies.
13 Feb 2025
Accelerated export of terrestrial organic carbon to the Chukchi Sea since pre-industrial times
Bassem Jalali, Marie-Alexandrine Sicre, Jian Ren, Zhongqiao Li, Youcheng Bai, Liang Su, Vincent Klein, and Jianfang Chen
EGUsphere, https://doi.org/10.5194/egusphere-2025-325, https://doi.org/10.5194/egusphere-2025-325, 2025
Preprint under review for BG (discussion: open, 1 comment)
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This work investigates the spatiotemporal variations of terrestrial material from surface and core sediments from the Chukchi Sea using bulk parameters and biomarkers. We found a growing imprint of terrestrial material at higher latitudes resulting from the transport of eroded matter or remobilized from shelf sediments by sea ice. The 300 year TERR-alkanes and ACL27-31 composites from 5 cores evidence increasing export of terrestrial carbon since the early 20th century accelerating after 1980.
13 Feb 2025
A fresh look at the pre-industrial air-sea carbon flux using the alkalinity budget
Alban Planchat, Laurent Bopp, and Lester Kwiatkowski
EGUsphere, https://doi.org/10.5194/egusphere-2025-523, https://doi.org/10.5194/egusphere-2025-523, 2025
Preprint under review for BG (discussion: open, 0 comments)
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Disparities in ocean carbon sink estimates derived from observations and models raise questions about our ability to accurately assess its magnitude and trend. Essential for isolating the anthropogenic component of the total air-sea carbon flux estimated from observations, the pre-industrial air-sea carbon flux is a key source of uncertainty. Thus, we take a fresh look at this flux using the alkalinity budget, alongside the carbon budget which had previously been considered alone.
12 Feb 2025
Distribution of alkylamines in surface waters around the Antarctic Peninsula and Weddell Sea
Arianna Rocchi, Mark F. Fitzsimons, Preston Akenga, Ana Sotomayor, Elisabet L. Sà, Queralt Güell-Bujons, Magda Vila, Yaiza M. Castillo, Manuel Dall’Osto, Dolors Vaqué, Charel Wohl, Rafel Simó, and Elisa Berdalet
EGUsphere, https://doi.org/10.5194/egusphere-2025-407, https://doi.org/10.5194/egusphere-2025-407, 2025
Preprint under review for BG (discussion: open, 0 comments)
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During the Polar Change expedition, volatile alkylamines, important players in nitrogen cycling and cloud formation, were measured in Antarctic waters using a high-sensitivity method. Trimethylamine was the dominant alkylamine in marine particles, associated with nanophytoplankton. Dissolved dimethylamine likely originated from trimethylamine degradation, while diethylamine sources remain unclear. These findings confirm the biological origin of alkylamines in polar marine microbial food webs.
11 Feb 2025
Methanogenesis by CO2 reduction dominates lake sediments with different organic matter compositions
Guangyi Su, Julie Tolu, Clemens Glombitza, Jakob Zopfi, Moritz F. Lehmann, Mark A. Lever, and Carsten J. Schubert
EGUsphere, https://doi.org/10.5194/egusphere-2025-437, https://doi.org/10.5194/egusphere-2025-437, 2025
Preprint under review for BG (discussion: open, 0 comments)
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In Lake Geneva, we studied how different types of organic matter affect methane production. Despite varying sources—like algae and land-based materials, both deep and delta areas are significant methane sources and methane was mainly produced through CO2 reduction. Surprisingly, the origin of organic matter didn’t strongly influence methane production rates or pathways. Our findings highlight the need to better understand microbial processes to predict methane emissions from lakes.
11 Feb 2025
A Novel Approach to Estimate Carbon and Nitrogen Flux from In Situ Optics: Application to Cyclonic Eddies off the Cape Verde Islands
Nasrollah Moradi, Lili Hufnagel, Simon Ramondenc, Clara Flintrop, Rainer Kiko, Tim Fischer, Helena Hauss, Arne Körtzinger, Gerhard Fischer, and Morten Iversen
EGUsphere, https://doi.org/10.5194/egusphere-2025-347, https://doi.org/10.5194/egusphere-2025-347, 2025
Preprint under review for BG (discussion: open, 0 comments)
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Mesoscale eddies are suggested to enhance deep-sea carbon export, but quantifying carbon flux in these eddies remains challenging. This study combines in-situ camera particle profiles, carbon flux data, particle settling velocities, and respiration rates, while accounting for water temperature and oxygen concentration. Applied to Cape Verde's cyclonic eddies, it revealed a funnel-shaped flux pattern with doubled flux at the eddy core, highlighting their regional carbon sequestration impacts.
11 Feb 2025
Influences on Chemical Distribution Patterns across the west Greenland Shelf: The Roles of Ocean Currents, Sea Ice Melt, and Freshwater Runoff
Claudia Elena Schmidt, Tristan Zimmermann, Katarzyna Koziorowska, Daniel Pröfrock, and Helmuth Thomas
EGUsphere, https://doi.org/10.5194/egusphere-2025-291, https://doi.org/10.5194/egusphere-2025-291, 2025
Preprint under review for BG (discussion: open, 0 comments)
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This study explores how ocean currents, melting sea ice, and freshwater runoff alter biogeochemical cycles on the west Greenland shelf. By analyzing water samples on a high-resolution, large-scale grid, we found that these factors create distinct regional and spatial distribution patterns and significantly impact biological productivity during late summer. The study highlights the need for ongoing monitoring to understand the effects of climate change in this sensitive area.
10 Feb 2025
Process-based modelling of multi-decade carbon dynamics of a cool temperate swamp
Oluwabamise Lanre Afolabi, He Hongxing, and Maria Strack
EGUsphere, https://doi.org/10.5194/egusphere-2024-4049, https://doi.org/10.5194/egusphere-2024-4049, 2025
Preprint under review for BG (discussion: open, 0 comments)
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This modelling study elucidated the multi-decade carbon dynamics of a temperate swamp peatland and the important biotic and abiotic interactions and feedbacks that drive the carbon biogeochemical cycle of this ecosystem which is currently lacking. The carbon balance of the swamp reflected the strong relationship between the swamp’s carbon flux and controlling biotic processes, hydrological and thermal conditions that imprinted on carbon assimilation and losses at different time scales.
10 Feb 2025
Isotope discrimination of carbonyl sulfide (34S) and carbon dioxide (13C, 18O) during plant uptake in flow-through chamber experiments
Sophie L. Baartman, Steven M. Driever, Maarten Wassenaar, Linda M. J. Kooijmans, Nerea Ubierna Lopez, Leon Mossink, Maria E. Popa, Ara Cho, Lisa Wingate, Thomas Röckmann, Steven M. A. C. van Heuven, and Maarten C. Krol
EGUsphere, https://doi.org/10.5194/egusphere-2025-215, https://doi.org/10.5194/egusphere-2025-215, 2025
Preprint under review for BG (discussion: open, 2 comments)
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Carbonyl sulfide (COS) and carbon dioxide (CO2) uptake fluxes and isotope discrimination was measured in sunflower and papyrus plants, using a plant chamber approach and varying light availability. COS and CO2 isotope discrimination in plants have never been jointly measured before. COS isotope discrimination did not differ between the species, nor with changing light. CO2 fluxes and isotope values provided additional useful information for data interpretation.
07 Feb 2025
Groundwater-CO2 Emissions Relationship in Dutch Peatlands Derived by Machine Learning Using Airborne and Ground-Based Eddy Covariance Data
Laura M. van der Poel, Laurent V. Bataille, Bart Kruijt, Wietse Franssen, Wilma Jans, Jan Biermann, Anne Rietman, Alex J. V. Buzacott, Ype van der Velde, Ruben Boelens, and Ronald W. A. Hutjes
EGUsphere, https://doi.org/10.5194/egusphere-2025-431, https://doi.org/10.5194/egusphere-2025-431, 2025
Preprint under review for BG (discussion: open, 0 comments)
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We combine two types of carbon dioxide (CO2) data from Dutch peatlands in a machine learning model: from fixed measurement towers and from a light research aircraft. We find that emissions increase with deeper water table depths (WTD) by 4.6 tonnes CO2 per hectare per year, per 10 cm deeper WTD on average. The effect is stronger in winter than in summer and varies between locations. This variability should be taken into account when developing mitigation measures.
07 Feb 2025
Soils signal key mechanisms driving greater protection of organic carbon under aspen compared to spruce forests in a North American montane ecosystem
Lena Wang, Sharon Billings, Li Li, Daniel Hirmas, Keira Johnson, Devon Kerins, Julio Pachon, Curtis Beutler, Karla Jarecke, Vaishnavi Varikuti, Micah Unruh, Hoori Ajami, Holly Barnard, Alejandro Flores, Kenneth Williams, and Pamela Sullivan
EGUsphere, https://doi.org/10.5194/egusphere-2025-70, https://doi.org/10.5194/egusphere-2025-70, 2025
Preprint under review for BG (discussion: open, 2 comments)
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Our study looked at how different forest types and conditions affected soil microbes, and soil carbon and stability. Aspen organic matter led to higher microbial activity, smaller soil aggregates, and more stable soil carbon, possibly reducing dissolved organic carbon movement from hillslopes to streams. This shows the importance of models like the Microbial Efficiency – Matrix Stabilization framework for predicting CO2 release, soil carbon stability, and carbon movement.
06 Feb 2025
Technical Note: Pondi – a low-cost logger for long-term monitoring of methane, carbon dioxide, and nitrous oxide in aquatic and terrestrial systems
Martino E. Malerba, Blake Edwards, Lukas Schuster, Omosalewa Odebiri, Josh Glen, Rachel Kelly, Paul Phan, Alistair Grinham, and Peter I. Macreadie
External preprint server, https://doi.org/10.31219/osf.io/54rd2, https://doi.org/10.31219/osf.io/54rd2, 2025
Preprint under review for BG (discussion: open, 0 comments)
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The Pondi is a cost-effective, lightweight logger designed for long-term monitoring of carbon dioxide, methane, and nitrous oxide emissions in both terrestrial and aquatic ecosystems. It addresses key challenges in greenhouse gas monitoring by providing an automated, low-cost, solar-powered solution with cloud connectivity and real-time analytics. Its robust design enables deployment in diverse environmental conditions, supporting large-scale, high-resolution emission assessments.
06 Feb 2025
Pathways of CH4 formation and emission in the subsaline reed wetland of Lake Neusiedl
Pamela Alessandra Baur, Thiago Rodrigues-Oliveira, Karin Hager, Zhen-Hao Luo, Christa Schleper, and Stephan Glatzel
EGUsphere, https://doi.org/10.5194/egusphere-2025-443, https://doi.org/10.5194/egusphere-2025-443, 2025
Preprint under review for BG (discussion: open, 1 comment)
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In the subsaline reed wetland of Lake Neusiedl, we found the highest CH4 emissions in summer and via plant-mediated transport in each season. A clear diel cycle of CH4 emission was only identified for plant-mediated transport in summer. The isotopic source signature of CH4 differed between seasons, with the most 13C-depleted signature in fall. Desiccation reduced methanogenic diversity in the sediments and resulted in a marked increase and dominance of the O2-tolerant Methanomicrobiales.
06 Feb 2025
Adaptation of methane oxidising bacteria to environmental changes: implications for coastal methane dynamics
Tim R. de Groot, Julia C. Engelmann, Pierre Ramond, Julia Diorgio, Judith van Bleiswijk, and Helge Niemann
EGUsphere, https://doi.org/10.5194/egusphere-2025-316, https://doi.org/10.5194/egusphere-2025-316, 2025
Preprint under review for BG (discussion: open, 1 comment)
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In the ocean, the potent greenhouse gas methane is largely produced – but also consumed – in coastal systems before reaching the atmosphere. Rising temperatures and shifting precipitation patterns will likely impact the community composition of aerobic methanotrophic bacteria (MOB). Experiments with North Sea and Wadden Sea water showed that methane availability increased MOB abundance but that different MOB types could thrive under drastically changed environmental conditions.
06 Feb 2025
Forestation tends to create favourable conditions for convective precipitation in the Mediterranean Basin
Jolanda J. E. Theeuwen, Sarah N. Warnau, Imme B. Benedict, Stefan C. Dekker, Hubertus V. M. Hamelers, Chiel C. van Heerwaarden, and Arie Staal
EGUsphere, https://doi.org/10.5194/egusphere-2025-289, https://doi.org/10.5194/egusphere-2025-289, 2025
Preprint under review for BG (discussion: open, 4 comments)
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The Mediterranean Basin is prone to drying. This study uses a simple model to explore how forests affect the potential for rainfall by analyzing the lowest part of the atmosphere. Results show that forestation amplifies drying in dry areas and boosts rainfall potential in wet regions, where it also promotes cooling. These findings suggest that the impact of forestation varies with soil moisture, and may possibly mitigate or intensify future drying.
05 Feb 2025
Plant community composition controls spatial variation in year-round methane fluxes in a boreal rich fen
Eeva Järvi-Laturi, Teemu Tahvanainen, Eero Koskinen, Efrén López-Blanco, Juho Lämsä, Hannu Marttila, Mikhail Mastepanov, Riku Paavola, Maria Väisänen, and Torben Røjle Christensen
EGUsphere, https://doi.org/10.5194/egusphere-2025-217, https://doi.org/10.5194/egusphere-2025-217, 2025
Preprint under review for BG (discussion: open, 2 comments)
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Our research investigates how plant community composition influences methane emissions in a northern boreal rich fen. We measured methane fluxes year-round using manual chambers across 36 plots. Our findings suggest that sedges, particularly Carex rostrata, significantly impact the fluxes throughout the year. This study enhances our understanding of vegetation-driven methane emissions, providing valuable insights for predicting future changes in peatland methane emissions.
05 Feb 2025
Part 1: Zonal gradients in phosphorus and nitrogen acquisition and stress revealed by metaproteomes of Prochlorococcus and Synechococcus
Claire Mahaffey, Noelle Held, Korinne Kunde, Clare Davis, Neil Wyatt, Matthew McIlvin, Malcolm Woodward, Lewis Wrightson, Alessandro Tagliabue, Maeve Lohan, and Mak Saito
EGUsphere, https://doi.org/10.5194/egusphere-2024-3987, https://doi.org/10.5194/egusphere-2024-3987, 2025
Preprint under review for BG (discussion: open, 0 comments)
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Picocyanobacteria fix over 50 % of carbon in the subtropical ocean, but which nutrients control their growth and activity? Using a states, rates and metaproteomic approach alongside targeted proteomics in experiments, we reveal picocyanobacteria are phosphorus stressed in the west Atlantic and nitrogen stressed in east Atlantic. We find evidence for trace metal and organic phosphorus control on alkaline phosphatase activity.
04 Feb 2025
Treeline species Betula ermanii are more adaptable to alpine environments than non-treeline species Picea jezoensis: evidence from leaf functional traits
Renkai Dong, Na Li, Mai-He Li, Yu Cong, Haibo Du, and Hong S. He
EGUsphere, https://doi.org/10.5194/egusphere-2025-369, https://doi.org/10.5194/egusphere-2025-369, 2025
Preprint under review for BG (discussion: open, 0 comments)
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This study examines how two tree species, B. ermanii (treeline species) and P. jezoensis (non-treeline species), respond to climate change. B. ermanii adopts a resource-acquisition strategy and may expand to higher elevations, while P. jezoensis, with a resource-conserving strategy, is less likely to spread. These findings offer new insights into the future dynamics of subalpine forests under climate change.
04 Feb 2025
The primacy of dissolved organic matter to aquatic light variability
Henry F. Houskeeper and Stanford B. Hooker
EGUsphere, https://doi.org/10.5194/egusphere-2024-4163, https://doi.org/10.5194/egusphere-2024-4163, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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The manuscript assesses the dominant spectral patterns in the aquatic light field and relates the patterns observed to fluctuations in relevant environmental variables. The key finding is that the dominant light patterns in the ocean depend more strongly on variability in dissolved organic matter compared to phytoplankton.
04 Feb 2025
Optimisation of the World Ocean Model of Biogeochemistry and Trophic-dynamics (WOMBAT) using surrogate machine learning methods
Pearse James Buchanan, P. Jyoteeshkumar Reddy, Richard J. Matear, Matthew A. Chamberlain, Tyler Rohr, Dougal Squire, and Elizabeth H. Shadwick
EGUsphere, https://doi.org/10.5194/egusphere-2024-4026, https://doi.org/10.5194/egusphere-2024-4026, 2025
Preprint under review for BG (discussion: open, 1 comment)
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We developed a cost-effective method to improve ocean models for studying the global carbon cycle. Using machine learning, we optimized parameters in the WOMBAT-lite model, enhancing its accuracy in predicting chlorophyll levels, air-sea carbon dioxide exchange, and phytoplankton nutrient use. This approach increases model reliability and offers a pathway for scientists to better understand and predict ocean changes, contributing to improved insights into Earth's climate system.
03 Feb 2025
Modeling the impact of drainage on peatland CO2 and CH4 fluxes and its underlying drivers
Thu Hang Nguyen, Philippe Ciais, Liyang Liu, Yi Xi, Chunjing Qiu, Elodie Salmon, Aram Kalhori, Christophe Guimbaud, Matthias Peichl, Joshua L. Ratcliffe, Koffi Dodji Noumonvi, and Xuefei Li
EGUsphere, https://doi.org/10.5194/egusphere-2025-352, https://doi.org/10.5194/egusphere-2025-352, 2025
Preprint under review for BG (discussion: open, 0 comments)
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We simulate virtual drainage at 10 pristine peatland sites. Over time, the emission factors of CO2 flux decrease and the reduction of CH4 emissions is amplified. The sensitivities of flux changes to drainage are primarily controlled by initial CO2 and CH4 fluxes, initial soil carbon content, peat vegetation community, air temperature and initial water table depth. Using GWP100, our simulation suggested only very small net GHG emission changes when peatland is drained for 50 years.
03 Feb 2025
Anaerobic biodegradation of Miocene lignites from an opencast mine by autochthonous microorganisms stimulated under laboratory conditions
Michal Bucha, Piotr Siupka, Anna Detman-Ignatowska, Sushmita Deb, Agnieszka Bylina, Daria Kaim, Aleksandra Chojnacka, Dominika Kufka, Dominika Lewicka-Szczebak, Anna Sikora, and Leszek Marynowski
EGUsphere, https://doi.org/10.5194/egusphere-2025-236, https://doi.org/10.5194/egusphere-2025-236, 2025
Preprint under review for BG (discussion: open, 0 comments)
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In this work, we show the evidences of anaerobic activity of nitrogen-processing microorganisms that naturally occurred in outcropped organic-rich sediments as Miocene lignites. The results presented in this paper indicate the important role of nitrogen supply processes in environments depleted in this element and at the same time rich in humic substances, such as peat bogs, wetlands, immature sediments containing organic carbon (e.g. gyttja, fossil wood, coal).
31 Jan 2025
Orbital-scale variability in the contribution of foraminifera and coccolithophores to pelagic carbonate production
Pauline Cornuault, Luc Beaufort, Heiko Pälike, Torsten Bickert, Karl-Heinz Baumann, and Michal Kucera
EGUsphere, https://doi.org/10.5194/egusphere-2025-198, https://doi.org/10.5194/egusphere-2025-198, 2025
Preprint under review for BG (discussion: open, 0 comments)
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We present new high-resolution data of the relative contribution of the two main pelagic carbonate producers (coccoliths and foraminifera) to the total pelagic carbonate production from the tropical Atlantic in past warm periods since the Miocene. Our findings suggests that the two groups responded differently to orbital forcing and oceanic changes in tropical ocean, but their proportion changes did not drive the changes in overall pelagic carbonate deposition.
30 Jan 2025
Aquatic metabolism influences temporal variations of water carbon and atmospheric carbon dioxide fluxes in a temperate salt marsh
Jérémy Mayen, Pierre Polsenaere, Aurore Regaudie de Gioux, Jonathan Deborde, Karine Collin, Yoann Le Merrer, Élodie Foucault, Vincent Ouisse, Laurent André, Marie Arnaud, Pierre Kostyrka, Éric Lamaud, Gwenaël Abril, and Philippe Souchu
EGUsphere, https://doi.org/10.5194/egusphere-2025-335, https://doi.org/10.5194/egusphere-2025-335, 2025
Preprint under review for BG (discussion: final response, 3 comments)
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In a salt marsh, we performed seasonal 24-h cycles to look for aquatic metabolism influence on water carbon dynamics and net ecosystem CO2 exchanges (NEE). From high to low tide in winter, marsh anaerobic respiration induced the highest levels of dissolved inorganic carbon and alkalinity. On the contrary, in spring and summer, marsh primary production led to CO2-depleted water exportations downstream. Aquatic heterotrophy at high tide can influence NEE during the highest immersion levels only.
30 Jan 2025
Bioconcentration as a key driver of Hg bioaccumulation in high trophic level fish
David Amptmeijer and Johannes Bieser
EGUsphere, https://doi.org/10.5194/egusphere-2025-312, https://doi.org/10.5194/egusphere-2025-312, 2025
Preprint under review for BG (discussion: open, 0 comments)
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The mercury (Hg) form of most concern is monomethylmercury (MMHg⁺) due to its neurotoxicity and ability to bioaccumulate in seafood. Bioaccumulation in seafood occurs via bioconcentration (direct uptake) and biomagnification (trophic transfer). Our study separates these processes, showing that bioconcentration increases MMHg⁺ in high trophic level fish by 15 % per level, contributing 28–48 % of MMHg⁺ in Atlantic cod. These findings can be used to inform efficient Hg modeling strategies.
30 Jan 2025
Previous integrated or organic farming affects productivity and ecosystem N balance rather than fertilizer 15N allocation to plants and soil, leaching, or gaseous emissions (NH3, N2O, and N2)
Fawad Khan, Samuel Franco Luesma, Frederik Hartmann, Michael Dannenmann, Rainer Gasche, Clemens Scheer, Andreas Gattinger, Wiebke Niether, Elizabeth Gachibu Wangari, Ricky Mwangada Mwanake, Ralf Kiese, and Benjamin Wolf
EGUsphere, https://doi.org/10.5194/egusphere-2025-292, https://doi.org/10.5194/egusphere-2025-292, 2025
Preprint under review for BG (discussion: open, 0 comments)
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Crop rotations with legumes and use of organic and mineral fertilizers show potential to reduce agricultural N losses. This study examined N losses, including direct N2 flux, on two adjacent sites with different management history: organic farming (OF) with legume cultivation and integrated farming (IF) using synthetic and organic N inputs. IF increased soil organic carbon and nitrogen content, 15N recovery and showed a balanced N budget, i.e., more efficient N cycling compared to OF.
30 Jan 2025
Environmental drivers constraining the seasonal variability of satellite-observed methane at Northern high latitudes
Ella Kivimäki, Tuula Aalto, Michael Buchwitz, Kari Luojus, Jouni Pulliainen, Kimmo Rautiainen, Oliver Schneising, Anu-Maija Sundström, Johanna Tamminen, Aki Tsuruta, and Hannakaisa Lindqvist
EGUsphere, https://doi.org/10.5194/egusphere-2025-249, https://doi.org/10.5194/egusphere-2025-249, 2025
Preprint under review for BG (discussion: open, 1 comment)
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We investigate how environmental variables influencing natural methane fluxes explain the large-scale seasonal variability of satellite-observed methane at Northern high latitudes. Our findings show that soil moisture, snow cover, and soil temperature have the strongest influence, with snowmelt playing a surprisingly significant role, likely through soil isolation and wetting. This study highlights the value of multi-satellite observations for understanding large-scale wetland emissions.
30 Jan 2025
Plant phenology evaluation of CRESCENDO land surface models. Part II: Trough, peak, and amplitude of growing season
Daniele Peano, Deborah Hemming, Christine Delire, Yuanchao Fan, Hanna Lee, Stefano Materia, Julia E. M .S. Nabel, Taejin Park, David Wårlind, Andy Wiltshire, and Sönke Zaehle
EGUsphere, https://doi.org/10.5194/egusphere-2024-4114, https://doi.org/10.5194/egusphere-2024-4114, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Earth System Models are the principal tools for scientists to study past, present, and future climate changes. This work investigates the ability of a set of them to represent the observed changes in vegetation, which are vital to estimating the impact of future climate mitigation and adaptation strategies. This study highlights the main limitations in correctly representing vegetation variability. These tools still need further development to improve our understanding of future changes.
29 Jan 2025
Estimation of Metabolic Dynamics of Restored Seagrass Meadows in a Southeast Asia Islet: Insights from Ex Situ Benthic Incubation
Mariche Bandibas Natividad, Jian-Jhih Chen, Hsin-Yu Chou, Lan-Feng Fan, Yi-Le Shen, and Wen-Chen Chou
EGUsphere, https://doi.org/10.5194/egusphere-2024-4000, https://doi.org/10.5194/egusphere-2024-4000, 2025
Preprint under review for BG (discussion: open, 1 comment)
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Seagrass restoration serves as a nature-based solution for CO2 removal. We examined the organic carbon and carbonate dynamics of restored seagrasses (SG) and bare sediments (BS) using ex situ core incubations. SG exhibited higher net ecosystem metabolism compared to BS, while no significant difference was observed in net ecosystem calcification. Consequently, SG demonstrated a significantly enhanced overall capacity for carbon uptake.
29 Jan 2025
Grassland yield estimations – potentials and limitations of remote sensing, process-based modelling and field measurements
Sophie Reinermann, Carolin Boos, Andrea Kaim, Anne Schucknecht, Sarah Asam, Ursula Gessner, Sylvia H. Annuth, Thomas M. Schmitt, Thomas Koellner, and Ralf Kiese
EGUsphere, https://doi.org/10.5194/egusphere-2024-4087, https://doi.org/10.5194/egusphere-2024-4087, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Grasslands shape the landscape in many parts of the world and serve as the main source of fodder for livestock. There is a lack of comprehensive data on grassland yield, though highly valuable for authorities and research. By applying three approaches to estimate grassland yields, namely a satellite data model, a biogeochemical model and a field measurements approach, we provide annual grassland yield maps for the Ammer region in 2019 and highlight potentials and limitations of the approaches.
29 Jan 2025
Meta-metabolome ecology reveals that geochemistry and microbial functional potential are linked to organic matter development across seven rivers
Robert E. Danczak, Amy E. Goldman, Mikayla A. Borton, Rosalie K. Chu, Jason G. Toyoda, Vanessa A. Garayburu-Caruso, Emily B. Graham, Joseph W. Morad, Lupita Renteria, Jacqueline R. Hager, Shai Arnon, Scott Brooks, Edo Bar-Zeev, Michael Jones, Nikki Jones, Jorg Lewandowski, Christof Meile, Birgit M. Muller, John Schalles, Hanna Schulz, Adam Ward, and James C. Stegen
External preprint server, https://doi.org/10.1101/2024.01.10.575030, https://doi.org/10.1101/2024.01.10.575030, 2025
Preprint under review for BG (discussion: open, 0 comments)
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As dissolved organic matter (DOM) is transported from land to the ocean through rivers, it interacts with the environment and some is converted to CO2. We used high-resolution carbon analysis to show that DOM from seven rivers exhibited ecological patterns particular to the corresponding river. These results indicate that local processes play an outsized role in shaping DOM. By understanding these interactions across environments, we can predict DOM across spatial scales or under perturbations.
29 Jan 2025
Burn severity and vegetation type control phosphorus concentration, molecular composition, and mobilization
Morgan E. Barnes, Jesse Alan Roebuck Jr., Samantha Grieger, Paul J. Aronstein, Vanessa A. Garayburu-Caruso, Kathleen Munson, Robert P. Young, Kevin D. Bladon, John D. Bailey, Emily B. Graham, Lupita Renteria, Peggy A. O'Day, Timothy D. Scheibe, and Allison N. Myers-Pigg
EGUsphere, https://doi.org/10.5194/egusphere-2025-21, https://doi.org/10.5194/egusphere-2025-21, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Wildfires impact nutrient cycles on land and in water. We used burning experiments to understand the types of phosphorous (P), an essential nutrient, that might be released to the environment after different types of fires. We found that the amount of P moving through the environment post-fire is dependent on the type of vegetation and degree of burning which may influence when and where this material is processed or stored.
29 Jan 2025
Water chemistry and greenhouse gas concentrations in waterbodies of a thawing permafrost peatland complex in northern Norway
Jacqueline Kay Knutson, François Clayer, Peter Dörsch, Sebastian Westermann, and Heleen A. de Wit
EGUsphere, https://doi.org/10.5194/egusphere-2025-184, https://doi.org/10.5194/egusphere-2025-184, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Thawing permafrost at Iškoras in northern Norway is transforming peat plateaus into thermokarst ponds and wetlands. These small ponds show striking oversaturation of dissolved greenhouse gases like carbon dioxide (CO2) and methane (CH4), partly due to organic matter processing. Streams nearby emit CO2 driven by turbulence. As permafrost disappears, carbon dynamics will change, potentially increasing emissions of CH4. This study highlights the need to integrate these changes into climate models.
29 Jan 2025
Evaluating ocean alkalinity enhancement as a carbon dioxide removal strategy in the North Sea
Feifei Liu, Ute Daewel, Jan Kossack, Kubilay Timur Demir, Helmuth Thomas, and Corinna Schrum
EGUsphere, https://doi.org/10.5194/egusphere-2025-81, https://doi.org/10.5194/egusphere-2025-81, 2025
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Ocean Alkalinity Enhancement boosts oceanic CO₂ absorption, offering a climate solution. Using a regional model, we examined OAE in the North Sea, revealing that shallow coastal areas achieve higher CO₂ uptake than offshore, where alkalinity is more susceptible to deep-ocean loss. Long-term carbon storage is limited, and pH shifts vary by location. Our findings guide OAE deployment to optimize carbon removal while minimizing ecological effects, supporting global climate mitigation efforts.
27 Jan 2025
Timberline formation and relationship with climatic variables of Indian central Himalaya: role of topography
Priyanka Sah, Subrat Sharma, and Rehana Shaik
EGUsphere, https://doi.org/10.5194/egusphere-2024-3155, https://doi.org/10.5194/egusphere-2024-3155, 2025
Preprint under review for BG (discussion: open, 2 comments)
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Himalayan timberlines are distinct in the their formation which is influenced by mountainous topography and local climate but formation of geological landforms in the history of earth has plays a significant role in occurrence of the present time timberline in the Himalaya.
23 Jan 2025
Litter biomass as a driver of soil VOC fluxes in a Mediterranean forest
Manon Rocco, Julien Kammer, Mathieu Santonja, Brice Temime-Roussel, Cassandra Saignol, Caroline Lecareux, Etienne Quivet, Henri Wortham, and Elena Ormeno
EGUsphere, https://doi.org/10.5194/egusphere-2025-54, https://doi.org/10.5194/egusphere-2025-54, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Soil emissions of biogenic volatile organic compounds (BVOCs) play a significant role in ecosystems, yet the impact of litter accumulation on these emissions is often overlooked, particularly in Mediterranean deciduous forests. A study in downy oak forest identified over 135 BVOCs, many absorbed by the soil, while others were emitted and increased with litter biomass. This underscores the critical role of litter and microbial activity in shaping soil BVOC dynamics under changing climates.
23 Jan 2025
Radial growth of Picea abies is controlled by joint effects of temperature and nutrient availability at the lower part of treeline ecotone
Hana Kuzelova, Tomas Chuman, Jelena Lange, Jan Tumajer, and Vaclav Treml
EGUsphere, https://doi.org/10.5194/egusphere-2025-151, https://doi.org/10.5194/egusphere-2025-151, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Treeline ecotones are exposed to pronounced differences in irradiation and nutrient availability in complex mountain relief. We compared growth phenology and growth rate of Picea abies on north and south-facing slope at sites differing in nutrient availability at the lower part of the treeline ecotone. Our results suggest that temperature alone governs growth phenology, but nutrient availability modulates the growth rate in the peak season when temperature no longer limits cambial activity.
23 Jan 2025
Pelagic ecosystem responses to changes in seawater conditions during the Middle Pleistocene Transition in the Eastern Mediterranean
Konstantina Agiadi, Iuliana Vasiliev, Antoine Vite, Stergios Zarkogiannis, Alba Fuster-Alonso, Jorge Mestre-Tomás, Efterpi Koskeridou, and Frédéric Quillévéré
External preprint server, https://doi.org/10.1101/2024.12.28.630586, https://doi.org/10.1101/2024.12.28.630586, 2025
Preprint under review for BG (discussion: open, 2 comments)
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How did the different organisms respond to the Pleistocene glacial-interglacial cycles? We tried to answer this question by analysing the chemical and isotopic signals from marine organisms that lived in the Eastern Mediterranean at the time. Our results suggest that while changes in production by phyto- and zooplankton affected biomass in the ocean, temperature changes severely impacted the vertical migration of mesopelagic fishes.
23 Jan 2025
Active microbial sulfur cycling across a 13,500-year-old lake sediment record
Jasmine Sofia Berg, Paula Catalina Rodriguez, Cara Magnabosco, Longhui Deng, Stefano M. Bernasconi, Hendrik Vogel, Marina Morlock, and Mark Alexander Lever
EGUsphere, https://doi.org/10.5194/egusphere-2024-4158, https://doi.org/10.5194/egusphere-2024-4158, 2025
Preprint under review for BG (discussion: open, 1 comment)
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Our research explores microbial sulfur cycling in the 13,500-year sediment record of a sulfate-rich alpine lake. We present evidence for active sulfur cycling across sediment layers, even in sulfate-depleted zones, driven by uncultivated microorganisms. In addition, rapid organic matter sulfurization could contribute to its preservation. These findings enhance our understanding of the role of sulfur in organic matter preservation and deep biosphere processes.
22 Jan 2025
Quantifying the agricultural footprint on the silicon cycle: Insights from silicon isotopes and Ge/Si ratios
Sofía López-Urzúa, Louis Derry, and Julien Bouchez
EGUsphere, https://doi.org/10.5194/egusphere-2025-78, https://doi.org/10.5194/egusphere-2025-78, 2025
Preprint under review for BG (discussion: open, 1 comment)
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Silicon (Si) is essential for ecosystem health and Earth's climate, yet human activities such as agriculture have significantly disrupted its natural cycle. In a French agricultural catchment, we found that crop harvesting removes most of the Si released from rocks—1 to 4 times more than the dissolved Si transport downstream by rivers. Using geochemical tools, including Si isotopes and germanium-silicon ratio, we traced Si cycling and highlighted the impact of agriculture on Si exports.
21 Jan 2025
The response of small boreal catchments to extreme weather event: Hurricane Larry
Kavi Maruti Heerah, Kailee Clarke, and Heather Reader
EGUsphere, https://doi.org/10.5194/egusphere-2024-3843, https://doi.org/10.5194/egusphere-2024-3843, 2025
Revised manuscript under review for BG (discussion: final response, 4 comments)
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The boreal environment has been highlighted as an important source of carbon and iron to the ocean. Hurricanes rarely reach the boreal environment, but with climate change hurricanes can reach further north affecting carbon and iron export from this region. This paper sampled three rivers before and after a hurricane. We found the catchments buffered increases in carbon and iron from the hurricane. This study represents one of the first to investigate hurricanes in the boreal environment.
17 Jan 2025
Savanna ecosystem structure and productivity along a rainfall gradient: the role of competition and stress tolerance mediated by plant functional traits
Prashant Paudel, Stefan Olin, Mark Tjoelker, Mikael Pontarp, Daniel Metcalfe, and Benjamin Smith
EGUsphere, https://doi.org/10.5194/egusphere-2024-3977, https://doi.org/10.5194/egusphere-2024-3977, 2025
Preprint under review for BG (discussion: open, 1 comment)
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Ecological processes respond to changes in rainfall conditions. Competition and stress created by water availability are two primary components at two ends of the rainfall gradient. In wetter areas, plants compete for resources, while in drier regions, stress limits growth. The complex interaction between plant characters and their response to growth conditions governs ecosystem processes. These findings can be used to understand how future rainfall changes could impact ecosystems.
17 Jan 2025
Transporter gene family evolution in ectomycorrhizal fungi in relation to mineral weathering capabilities
Katharine Alice King, Petra Fransson, Roger Finlay, and Marisol Sánchez-García
EGUsphere, https://doi.org/10.5194/egusphere-2024-3930, https://doi.org/10.5194/egusphere-2024-3930, 2025
Preprint under review for BG (discussion: final response, 4 comments)
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Ectomycorrhizal (ECM) fungi form symbiotic associations with dominant trees in boreal forests. These fungi have an important role in mineral weathering in boreal forest, which is also a key process in the carbon cycle. The aim of this study is to characterise the diversity of base cation transporters in ECM fungi in relation to weathering capabilities, and to quantify base cation uptake by ECM fungi from pulverised rocks.
16 Jan 2025
The effect of a short oxygen exposure period on algal biomass degradation and methane release from eutrophic and oligotrophic lake sediments
Sigrid van Grinsven, Natsumi Maeda, Clemens Glombitza, Mark A. Lever, and Carsten J. Schubert
EGUsphere, https://doi.org/10.5194/egusphere-2024-3979, https://doi.org/10.5194/egusphere-2024-3979, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Algal blooms in lakes can cause large amounts of organic material to sink to the bottom, leading to low oxygen conditions and increased methane emissions. This study shows that adding oxygen to the bottom waters reduces methane emissions by 50 %, even after oxygen levels drop again. The effect was consistent across lakes with different nutrient levels. These findings suggest that oxygenation could be an effective strategy to reduce methane emissions in lakes.
16 Jan 2025
Fertilization turns a rubber plantation from sink to methane source
Daniel Epron, Rawiwan Chotiphan, Zixiao Wang, Ornuma Duangngam, Makoto Shibata, Sumonta Kumar Paul, Takumi Mochidome, Jate Sathornkich, Wakana A. Azuma, Jun Murase, Yann Nouvellon, Poonpipope Kasemsap, and Kannika Sajjaphan
EGUsphere, https://doi.org/10.5194/egusphere-2025-2, https://doi.org/10.5194/egusphere-2025-2, 2025
Preprint under review for BG (discussion: open, 2 comments)
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The rapid expansion of rubber cultivation constitutes a significant land-use change in Southeast Asia. Despite fertilization been a common practice in rubber plantations, its impact on soil methane (CH4) dynamics remained poorly understood. Our study demonstrates that fertilization not only reduces soil CH4 consumption but also increases CH4 production, transforming rubber plantations from a net CH4 sink into a source. Implementing rational fertilization could enhance atmospheric CH4 removal.
16 Jan 2025
Southern Hemisphere tree-rings as proxies to reconstruct Southern Ocean upwelling
Christian Blair Lewis, Rachel Corran, Sara Mikaloff-Fletcher, Erik Behrens, Rowena Moss, Gordon Brailsford, Andrew Lorrey, Margaret Norris, and Jocelyn Turnbull
EGUsphere, https://doi.org/10.5194/egusphere-2024-4107, https://doi.org/10.5194/egusphere-2024-4107, 2025
Preprint under review for BG (discussion: final response, 3 comments)
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The Southern Ocean carbon sink is a balance between two opposing forces: CO2 absorption at mid-latitudes and CO2 outgassing at high-latitudes. Radiocarbon analysis can be used to constrain the latter, as upwelling waters outgas old CO2, diluting atmospheric radiocarbon content. We present tree-ring radiocarbon measurements from New Zealand and Chile. We show that low radiocarbon in New Zealand’s Campbell Island is linked to outgassing in the critical Antarctic Southern Zone.
16 Jan 2025
Assessing the effect of forest management on above-ground carbon stock by remote sensing
Sofie Van Winckel, Jonas Simons, Stef Lhermitte, and Bart Muys
EGUsphere, https://doi.org/10.5194/egusphere-2024-4094, https://doi.org/10.5194/egusphere-2024-4094, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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Insights on management's impact on forest carbon stocks are crucial for sustainable forest management practices. However, accurately monitoring carbon stocks remains a technological challenge. This study estimates above-ground carbon stock in managed and unmanaged forests using passive optical, SAR, and LiDAR remote sensing data. Results show promising potential in using multiple remote sensing predictors and publicly available high-resolution data for mapping forest carbon stocks.
15 Jan 2025
Carbon and Nitrogen Dynamics in Subsoils After 20 years of Added Precipitation in a Mediterranean Grassland
Leila Maria Wahab, Sora Kim, and Asmeret Asefaw Berhe
EGUsphere, https://doi.org/10.5194/egusphere-2024-3607, https://doi.org/10.5194/egusphere-2024-3607, 2025
Revised manuscript under review for BG (discussion: final response, 6 comments)
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Soils are a large reservoir of carbon on land and there is uncertainty regarding how it will be affected by climate change. There is still active research about how changing precipitation patterns, a key aspect of climate change, will affect soil carbon and furthermore how vulnerable subsoils are to climate change. In this study, we studied subsoils after 20 years of experimentally manipulated precipitation shifts to see whether increasing precipitation would affect carbon amounts and chemistry.
15 Jan 2025
Long-term forest-line dynamics in the French Pyrenees: an accelerating upward shift related to forest context, global warming and pastoral abandonment
Noémie Delpouve, Laurent Bergès, Jean-Luc Dupouey, Sandrine Chauchard, Nathalie Leroy, Erwin Thirion, and Cyrille Barthélémy Karl Rathgeber
EGUsphere, https://doi.org/10.5194/egusphere-2024-4099, https://doi.org/10.5194/egusphere-2024-4099, 2025
Preprint under review for BG (discussion: open, 1 comment)
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Worldwide, the upper forest line has climbed over the past decades, shaping mountain landscapes in response to global changes. Thanks to historical land-use maps, we documented the forest-line rise across the entire French Pyrenees and over a long time span. The forest line has moved upward since the 1850s, driven by the regional abandonment of grazing and the presence of the mountain pine. However, despite a recent acceleration, the forest line has been unable to keep pace with global warming.
14 Jan 2025
Transformation Processes in the Oder Lagoon as seen from a Model Perspective
Thomas Neumann, Gerald Schernewski, and René Friedland
EGUsphere, https://doi.org/10.5194/egusphere-2024-3734, https://doi.org/10.5194/egusphere-2024-3734, 2025
Preprint under review for BG (discussion: open, 2 comments)
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We applied a 3D ecosystem model to the Oder Lagoon in the Baltic Sea and found that 30 % of nitrogen and 10 % of phosphorus are retained in the lagoon before entering the Baltic Sea. This is important for coarse-grained models that do not resolve such coastal structures. Moreover, the coastal filter supports the mitigation of eutrophication in the Baltic Sea.
14 Jan 2025
The significant role of snow in shaping alpine treeline responses in modelled boreal forests
Sarah Haupt, Josias Gloy, Luca Farkas, Katharina Schildt, Lisa Trimborn, and Stefan Kruse
EGUsphere, https://doi.org/10.5194/egusphere-2024-4036, https://doi.org/10.5194/egusphere-2024-4036, 2025
Revised manuscript under review for BG (discussion: final response, 5 comments)
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We studied alpine treeline migration in boreal forests using an enhanced vegetation model that includes snow processes. Our findings revealed site-specific migration drivers, with snow playing a dual role: supporting seedling establishment while increasing mortality risks. Results emphasize the need to include snow processes in vegetation models to better predict boreal forest responses.
13 Jan 2025
Oceanic enrichment of ammonium and its impacts on phytoplankton community composition under a high-emissions scenario
Pearse J. Buchanan, Juan J. Pierella Karlusich, Robyn E. Tuerena, Roxana Shafiee, E. Malcolm S. Woodward, Chris Bowler, and Alessandro Tagliabue
EGUsphere, https://doi.org/10.5194/egusphere-2024-3639, https://doi.org/10.5194/egusphere-2024-3639, 2025
Preprint under review for BG (discussion: open, 1 comment)
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Ammonium is a form of nitrogen that may become more important for growth of marine primary producers (i.e., phytoplankton) in the future. Because some phytoplankton taxa have a greater affinity for ammonium than others, the relative increase in ammonium could cause shifts in community composition. We quantify ammonium enrichment, identify its drivers, and isolate the possible effect on phytoplankton community composition under a high emissions scenario.
10 Jan 2025
Assessing the impact of landwater on the Northwest Pacific using normalized Total Alkalinity
Tatsuki Tokoro, Shin-Ichiro Nakaoka, Shintaro Takao, Shu Saito, Daisuke Sasano, Kazutaka Enyo, Masao Ishii, Naohiro Kosugi, Tsuneo Ono, Kazuaki Tadokoro, and Yukihiro Nojiri
EGUsphere, https://doi.org/10.5194/egusphere-2024-3792, https://doi.org/10.5194/egusphere-2024-3792, 2025
Preprint under review for BG (discussion: open, 1 comment)
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We studied how landwater from the mainland of Japan affects the ocean's carbon cycle using decades of Total Alkalinity (TA) data from the Northwest Pacific. Statistical analysis revealed landwater as a major TA source, reducing coastal acidification by 65 %, but with minimal impact on atmospheric CO2 absorption. Future work aims to refine results with depth-specific data and apply findings to global models.
09 Jan 2025
Human Activities Caused Hypoxia Expansion in a Large Eutrophic Estuary: Non-negligible Role of Riverine Suspended Sediments
Yue Nan, Zheng Chen, Bin Wang, Bo Liang, and Jiatang Hu
EGUsphere, https://doi.org/10.5194/egusphere-2024-4013, https://doi.org/10.5194/egusphere-2024-4013, 2025
Preprint under review for BG (discussion: final response, 4 comments)
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Human activities are changing the coastal water environment, but the role of suspended sediments in oxygen loss is not well understood. We used a model to compare dissolved oxygen levels and related factors in the 1990s and 2010s in the Pearl River Estuary. Reduced suspended sediments and increased pollution have expanded low-oxygen areas by 1.5 times. It highlights that declining suspended sediments increase hypoxia in estuaries, especially with rising nutrients, which need urgent attention.
09 Jan 2025
Inferring methane emissions from African livestock by fusing drone, tower, and satellite data
Alouette van Hove, Kristoffer Aalstad, Vibeke Lind, Claudia Arndt, Vincent Odongo, Rodolfo Ceriani, Francesco Fava, John Hulth, and Norbert Pirk
EGUsphere, https://doi.org/10.5194/egusphere-2024-3994, https://doi.org/10.5194/egusphere-2024-3994, 2025
Preprint under review for BG (discussion: open, 1 comment)
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Research on methane emissions from African livestock is limited. We used a probabilistic method fusing drone and flux tower observations with an atmospheric model to estimate emissions from various herds. This approach proved robust under non-stationary wind conditions and effective in estimating emissions as low as 100 g h-1. We also detected herd locations using spectral anomalies in satellite data. Our approach can be used to estimate diverse sources, thereby improving emission inventories.
08 Jan 2025
Future Forests: estimating biogenic emissions from net-zero aligned afforestation pathways in the UK
Hazel Mooney, Stephen Arnold, Benjamin Silver, Piers Forster, and Catherine Scott
EGUsphere, https://doi.org/10.5194/egusphere-2024-3895, https://doi.org/10.5194/egusphere-2024-3895, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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We simulate the potential changes in natural emissions of volatile gases from the land surface in the UK following afforestation from present-day woodland cover of 13 % to 19 % by 2050. We estimate present-day annual UK emissions of isoprene at 40 kt yr-1 and total monoterpenes at 46 kt yr-1, but emissions from afforested experiments show between a 4 % decrease and 131 % increase in emissions, explained by the variation in emissions activity between and within needleleaf and broadleaf trees.
07 Jan 2025
Characteristics of ecosystems under various anthropogenic impacts in a tropical forest region of Southeast Asia
Chansopheaktra Sovann, Torbern Tagesson, Patrik Vestin, Sakada Sakhoeun, Soben Kim, Sothea Kok, and Stefan Olin
EGUsphere, https://doi.org/10.5194/egusphere-2024-3784, https://doi.org/10.5194/egusphere-2024-3784, 2025
Preprint under review for BG (discussion: open, 2 comments)
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We offer pairwise observed datasets that compare the characteristics of tropical ecosystems, specifically pristine forests, regrowth forests, and cashew plantations. Our findings uncover some key differences in their characteristics, emphasizing the influence of human activities on these ecosystems. By sharing our unique datasets, we hope to improve the knowledge of tropical forest ecosystems in Southeast Asia, advancing tropical research, and tackling global environmental challenges.
06 Jan 2025
Photosynthetic electron, carbon and oxygen fluxes within a mosaic of Fe limitation in the California Current Upwelling System
Yayla Sezginer, Kate Schuler, Emily Speciale, Adrian Marchetti, Claire Till, Ralph Till, and Philippe Tortell
EGUsphere, https://doi.org/10.5194/egusphere-2024-3812, https://doi.org/10.5194/egusphere-2024-3812, 2025
Preprint under review for BG (discussion: final response, 2 comments)
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We recorded three metrics of photosynthesis in the California Current. Real-time observations of microalgae physiology and productivity revealed signs of iron limitation where the continental shelf rapidly dropped off. Iron limitation influenced how efficiently light was absorbed and used for carbon fixation but did not appear to affect net photosynthetic oxygen production. Our results offer useful insights towards efforts to model carbon fixation rates from microalgae optical properties.
19 Dec 2024
Marine heatwaves deeply alter marine food web structure and function
Vianney Guibourd de Luzinais, William W. L. Cheung, and Didier Gascuel
EGUsphere, https://doi.org/10.5194/egusphere-2024-3696, https://doi.org/10.5194/egusphere-2024-3696, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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Marine heatwaves(MHWs) are becoming more frequent and intense, yet their impacts on marine ecosystems globally remain unclear.Using a novel ecological model, we show that MHWs significantly reduced marine ecosystem biomass between 1998 and 2021, especially in the North Pacific Ocean.Marine predators are impacted more than organisms lower in the food chain.This study underscores the urgent need to integrate MHWs into developing climate-resilient marine ecosystem management and conservation plans.
17 Dec 2024
Review and Synthesis: Peatland and Wetland Models Simulating CH4 Production, CH4 Oxidation and CH4 Transport Pathways
Amey Tilak, Alina Premrov, Ruchita Ingle, Nigel Roulet, Benjamin R. K. Runkle, Matthew Saunders, Avni Malhotra, and Kenneth Byrne
EGUsphere, https://doi.org/10.5194/egusphere-2024-3852, https://doi.org/10.5194/egusphere-2024-3852, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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For the future model users, 16 peatland and wetland models reviewed to identify individual model operational scale (spatial and temporal), stabilization timeframes of different carbon pools, model specific advantages and limitations, common and specific model driving inputs, critical inputs of individual models impacting CH4 plant mediated, CH4 diffusion and CH4 ebullition. Finally, we qualitatively ranked the process representations in each model for CH4 production, oxidation and transport.
17 Dec 2024
Reduced microbial respiration sensitivity to soil moisture following long-term N fertilization enhances soil C retention in a boreal Scots pine forest
Boris Ťupek, Aleksi Lehtonen, Stefano Manzoni, Elisa Bruni, Petr Baldrian, Etienne Richy, Bartosz Adamczyk, Bertrand Guenet, and Raisa Mäkipää
EGUsphere, https://doi.org/10.5194/egusphere-2024-3813, https://doi.org/10.5194/egusphere-2024-3813, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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We explored soil microbial respiration (Rh) kinetics of low-dose and long-term N fertilization in N-limited boreal forest in connection to CH₄, and N₂O fluxes, soil, and tree C sinks. The insights show that N fertilization effects C retention in boreal forest soils through modifying Rh sensitivities to soil temperature and moisture. The key findings reveal that N-enriched soils exhibited reduced sensitivity of Rh to moisture, which on annual level contributes to enhanced soil C sequestration.
17 Dec 2024
Controls on Palaeogene deep-sea diatom-bearing sediment deposition and comparison with shallow marine environments
Cécile Figus, Johan Renaudie, Or M. Bialik, and Jakub Witkowski
EGUsphere, https://doi.org/10.5194/egusphere-2024-3768, https://doi.org/10.5194/egusphere-2024-3768, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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The compilation of Palaeogene deep-sea diatom-bearing sediment occurrences indicates that the deposition of diatom-bearing sediments is mainly controlled by nutrient availability and ocean circulation in the Atlantic, Pacific and Indian oceans. Comparison with shallow marine diatomites suggests that the peak in the number of diatom-bearing sites in the Atlantic may be related to tectonic reorganizations that caused the cessation of shallow marine diatomite deposition between ~46 and ~44 Ma.
16 Dec 2024
Subsurface CO2 dynamics in a temperate karst system reveal complex seasonal and spatial variations
Sarah Ann Rowan, Marc Luetscher, Thomas Laemmel, Anna Harrison, Sönke Szidat, and Franziska A. Lechleitner
EGUsphere, https://doi.org/10.5194/egusphere-2024-3775, https://doi.org/10.5194/egusphere-2024-3775, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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We explored CO2 from soil to subsurface at Milandre cave, finding very high concentrations at all depths. While forest soils produced modern CO2 year-round, cave and meadow soil CO2 influences varies with temperature controlled cave ventilation, with older CO2 input in winter from old organic matter stored underground. These findings show that CO2 fluxes in karst systems are highly dynamic, and a better understanding of them is important for accurate carbon cycle modelling.
16 Dec 2024
Drivers of soil organic carbon from temperate to alpine forests: a model-based analysis of the Swiss forest soil inventory with Yasso20
Claudia Guidi, Sia Gosheva-Oney, Markus Didion, Roman Flury, Lorenz Walthert, Stephan Zimmermann, Brian J. Oney, Pascal A. Niklaus, Esther Thürig, Toni Viskari, Jari Liski, and Frank Hagedorn
EGUsphere, https://doi.org/10.5194/egusphere-2024-3788, https://doi.org/10.5194/egusphere-2024-3788, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Predicting soil organic carbon (SOC) stocks in forests is crucial for assessing C balance, yet drivers of SOC stocks remain uncertain at large scales. Across a broad environmental gradient in Switzerland, we compared measured SOC stocks with those modelled by Yasso20, commonly used for GHG budgets. Our results show that soil mineral properties and climate are main controls of SOC stocks, indicating that better accounting of these processes will advance accuracy of SOC stock predictions.
16 Dec 2024
Ozone causes substantial reductions in the carbon sequestration of managed European forests
Per Erik Karlsson, Patrick Büker, Sam Bland, David Simpson, Katrina Sharps, Felicity Hayes, and Lisa Emberson
EGUsphere, https://doi.org/10.5194/egusphere-2024-3742, https://doi.org/10.5194/egusphere-2024-3742, 2024
Preprint under review for BG (discussion: final response, 3 comments)
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Stomatal ozone uptake and the negative impacts on forest growth rates were estimated for European forests. This was translated to annual increments in the forest living biomass carbon stocks, with and without ozone exposure. In the absence of O3 exposure, European forest growth rates would on average increase by 9 %, but the sequestration to the living biomass carbon stocks would increase by 31 %, since the sequestration depends on the difference between growth and harvest rates.
16 Dec 2024
Characterisation of uncertainties in an ocean radiative transfer model for the Black Sea through ensemble simulations
Loïc Macé, Luc Vandenbulcke, Jean-Michel Brankart, Pierre Brasseur, and Marilaure Grégoire
EGUsphere, https://doi.org/10.5194/egusphere-2024-3682, https://doi.org/10.5194/egusphere-2024-3682, 2024
Preprint under review for BG (discussion: open, 0 comments)
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The amount of light found in seawater influences water temperature and primary production and must be finely modelled in systems that aim at representing marine biogeochemical environments. We analyse results from a radiative transfer model accounting for absorption and scattering of light in the ocean and compare them with in situ and remote-sensed data, along with the associated uncertainties. We also highlight the benefits of using advanced representations of light in modelling frameworks.
13 Dec 2024
Nitrogen Fixation in Arctic Coastal Waters (Qeqertarsuaq, West Greenland): Influence of Glacial Melt on Diazotrophs, Nutrient Availability, and Seasonal Blooms
Isabell Schlangen, Elizabeth Leon-Palmero, Annabell Moser, Peihang Xu, Erik Laursen, and Carolin Regina Löscher
EGUsphere, https://doi.org/10.5194/egusphere-2024-3680, https://doi.org/10.5194/egusphere-2024-3680, 2024
Preprint under review for BG (discussion: final response, 6 comments)
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We explored nitrogen fixation in the Arctic Ocean, revealing its key role in supporting coastal productivity, especially near melting glaciers. By combining molecular data, rate measurements, and environmental analysis, we identified dominant microbes like symbiotic unicellular cyanobacteria and linked high nitrogen fixation to glacial melt. Our findings suggest that climate-driven changes may expand niches for these microbes, reshaping nitrogen cycles and Arctic productivity in the future.
12 Dec 2024
Quantifying the soil sink of atmospheric Hydrogen: a full year of field measurements from grassland and forest soils in the UK
Nicholas Cowan, Toby Roberts, Mark Hanlon, Aurelia Bezanger, Galina Toteva, Alex Tweedie, Karen Yeung, Ajinkya Deshpande, Peter Levy, Ute Skiba, Eiko Nemitz, and Julia Drewer
EGUsphere, https://doi.org/10.5194/egusphere-2024-3654, https://doi.org/10.5194/egusphere-2024-3654, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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We measured soil hydrogen (H2) fluxes from two field sites, a managed grassland and a planted deciduous woodland, with flux measurements of H2 covering full seasonal cycles. We estimate annual H2 uptake of -3.1 ± 0.1 and -12.0 ± 0.4 kg H2 ha-1 yr-1 for the grassland and woodland sites, respectively. Soil moisture was found to be the primary driver of H2 uptake, with the clay content of the soils providing a physical barrier which limited H2 uptake.
11 Dec 2024
Impact of clouds on vegetation albedo quantified by coupling an atmosphere and a vegetation radiative transfer model
Kevin Wolf, Evelyn Jäkel, André Ehrlich, Michael Schäfer, Hannes Feilhauer, Andreas Huth, Alexandra Weigelt, and Manfred Wendisch
EGUsphere, https://doi.org/10.5194/egusphere-2024-3614, https://doi.org/10.5194/egusphere-2024-3614, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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This paper investigates the influence of clouds on the vegetation albedo using a coupled atmosphere-vegetation radiative transfer model. Both models are iteratively linked to more realistically simulate cloud-vegetation-radiation interactions over canopies. Solar, spectral and broadband irradiances have been simulated under varying cloud conditions. The simulated irradiances were used to investigate the spectral and broadband effect of clouds on vegetation albedo.
09 Dec 2024
Projections of coral reef carbonate production from a global climate-coral reef coupled model
Nathaelle Bouttes, Lester Kwiatkowski, Elodie Bougeot, Manon Berger, Victor Brovkin, and Guy Munhoven
EGUsphere, https://doi.org/10.5194/egusphere-2024-3738, https://doi.org/10.5194/egusphere-2024-3738, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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Coral reefs are under threat due to warming and ocean acidification. It is difficult to project future coral reef production due to uncertainties in climate models, socio-economic scenarios and coral adaptation to warming. Here we have included a coral reef module within a climate model for the first time to evaluate the range of possible futures. We show that coral reef production decreases in most future scenarios, but in some cases coral reef carbonate production can persist.
09 Dec 2024
Nitrate reduction in groundwater as an overlooked source of agricultural CO2 emissions
Hyojin Kim, Julian Koch, Birgitte Hansen, and Rasmus Jakobsen
EGUsphere, https://doi.org/10.5194/egusphere-2024-3706, https://doi.org/10.5194/egusphere-2024-3706, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Nitrate pollution from farming is a global issue. Denitrification, a natural process that reduces nitrate, also releases CO2, contributing to climate change. This study found that groundwater denitrification is a significant CO2 source from Danish agriculture, and it is comparable to other reported sources. These emissions have been overlooked in greenhouse gas inventories, highlighting the need to update guidelines for more accurate reporting of agricultural emissions.
09 Dec 2024
Faithful transfer of radiolarian silicon isotope signatures from water column to sediments in the South China Sea
Qiang Zhang, George Edward Alexander Swann, Vanessa Pashley, and Matthew S. A. Horstwood
EGUsphere, https://doi.org/10.5194/egusphere-2024-3686, https://doi.org/10.5194/egusphere-2024-3686, 2024
Revised manuscript under review for BG (discussion: final response, 5 comments)
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We presents the first coupled record of radiolarian silicon isotopes (δ30Sirad) from paired water column and surface sediment samples in the South China Sea. No significant discrepancies in δ30Sirad values were observed between plankton and sediment samples, implying a minimal impact of dissolution on δ30Sirad during deposition of radiolarian shells. This demonstrates the faithful preservation of the δ30Sirad signature and its potential for studying past changes in the marine silicon cycle.
09 Dec 2024
The fungal collaboration gradient drives root trait distribution and ecosystem processes in a tropical montane forest
Mateus Dantas de Paula, Tatiana Reichert, Laynara Lugli, Erica McGale, Kerstin Pierick, João Paulo Darela-Filho, Liam Langan, Jürgen Homeier, Anja Rammig, and Thomas Hickler
EGUsphere, https://doi.org/10.5194/egusphere-2024-3259, https://doi.org/10.5194/egusphere-2024-3259, 2024
Revised manuscript accepted for BG (discussion: final response, 11 comments)
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This study explores how plant roots, with different forms and functions, rely on fungal partnerships for nutrient uptake. This relationship was integrated into a vegetation model and was tested in a tropical forest in Ecuador. The model accurately predicted root traits and showed that without fungi, biomass decreased by up to 80 %. The findings highlight the critical role of fungi in ecosystem processes and suggest that root-fungal interactions should be considered in vegetation models.
06 Dec 2024
Very-high resolution aerial imagery and deep learning uncover the fine-scale spatial patterns of elevational treelines
Erik Carrieri, Donato Morresi, Fabio Meloni, Nicolò Anselmetto, Emanuele Lingua, Raffaella Marzano, Carlo Urbinati, Alessandro Vitali, and Matteo Garbarino
EGUsphere, https://doi.org/10.5194/egusphere-2024-3757, https://doi.org/10.5194/egusphere-2024-3757, 2024
Preprint under review for BG (discussion: open, 1 comment)
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Alpine treelines reflect the impacts of climate and land use changes on ecosystems. Using low-cost drones and deep learning, we developed a method to map tree spatial patterns at fine scales across diverse environments. Our results reveal accurate detection and delineation of trees and spatial trends like clustering and size-class interactions. This efficient, adaptable approach enhances forest monitoring, aiding global efforts to assess treeline dynamics and their responses to global change.
06 Dec 2024
Organic Carbon, Mercury, and Sediment Characteristics along a land – shore transect in Arctic Alaska
Frieda P. Giest, Maren Jenrich, Guido Grosse, Benjamin M. Jones, Kai Mangelsdorf, Torben Windirsch, and Jens Strauss
EGUsphere, https://doi.org/10.5194/egusphere-2024-3683, https://doi.org/10.5194/egusphere-2024-3683, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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Climate warming causes permafrost to thaw, releasing greenhouse gases and affecting ecosystems. We studied sediments from Arctic coastal landscapes, including land, lakes, lagoons, and the ocean, finding that organic carbon storage and quality vary with landscape features and saltwater influence. Freshwater and land areas store more carbon, while saltwater reduces its quality. These findings improve predictions of Arctic responses to climate change and their impact on global carbon cycling.
06 Dec 2024
Sea ice and mixed layer depth influence on nitrate depletion and associated isotopic effects in the Drake Passage – Weddell Sea region, Southern Ocean
Aymeric Pierre Marie Servettaz, Yuta Isaji, Chisato Yoshikawa, Yanghee Jang, Boo-Keun Khim, Yeongjun Ryu, Daniel M. Sigman, Nanako O. Ogawa, Francisco J. Jiménez-Espejo, and Naohiko Ohkouchi
EGUsphere, https://doi.org/10.5194/egusphere-2024-3687, https://doi.org/10.5194/egusphere-2024-3687, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Phytoplankton blooms occur after sea ice retreats in the Southern Ocean. In this study we investigate the influence of seasonal cycle of sea ice concentration on nitrate depletion, testing the hypothesis that meltwater release stabilizes the water column and favors nutrient utilization. We find that, at a regional scale, nitrate depletion and vertical mixing are weakly correlated with sea ice cycle. Nitrate depletion is rather linked to other oceanographic processes controlling mixing depth.
05 Dec 2024
Estimating the variability of deep ocean particle flux collected by sediment traps using satellite data and machine learning
Théo Picard, Chelsey A. Baker, Jonathan Gula, Ronan Fablet, Laurent Mémery, and Richard Lampitt
EGUsphere, https://doi.org/10.5194/egusphere-2024-3292, https://doi.org/10.5194/egusphere-2024-3292, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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Ocean sediment traps measure the sequestrated sinking organic carbon. While sinking, the particles are affected by local currents, which presents a challenge in linking the deep flux with the surface. We present a machine learning tool that predicts the source location of the sinking particles based on satellite data. The predictions demonstrate a stronger correlation between surface and deep carbon fluxes, allowing a more comprehensive understanding of the deep carbon sequestration drivers.
05 Dec 2024
Decreasing foraminiferal flux in response to ongoing climate change in the Santa Barbara Basin, California
Emily Havard, Katherine Cherry, Claudia Benitez-Nelson, Eric Tappa, and Catherine V. Davis
EGUsphere, https://doi.org/10.5194/egusphere-2024-3374, https://doi.org/10.5194/egusphere-2024-3374, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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This study explores the impact of modern climate change on single-celled, marine organisms in the Santa Barbara Basin called foraminifera. We collect their shells as they sink to the seafloor and compare our record (2014–2021) to previous studies (1993–1998). We find substantial decreases in total foraminifera and warm-water species. Likely influenced by ocean acidification and regional water circulation, these changes have implications for the marine carbon cycle, ecosystem, and fossil record.
04 Dec 2024
Particulate inorganic carbon quotas by coccolithophores in low oxygen/low pH waters off the Southeast Pacific margin
Francisco Javier Díaz-Rosas, Cristian Antonio Vargas, and Peter von Dassow
EGUsphere, https://doi.org/10.5194/egusphere-2024-3463, https://doi.org/10.5194/egusphere-2024-3463, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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We studied Particulate Inorganic Carbon (PIC) and coccolithophores in low-oxygen, low-pH waters off the Southeast Pacific margin. We estimated how much PIC is produced by coccolithophores, which supports carbon transport to ocean depths. Results show coccolithophores can thrive in these zones, though their role in carbon export may lessen. This work advances understanding of coccolithophores’ role in carbon cycling as ocean acidification changes marine chemistry.
04 Dec 2024
A statistical global burned area model for seamless integration into Dynamic Global Vegetation Models
Blessing Kavhu, Matthew Forrest, and Thomas Hickler
EGUsphere, https://doi.org/10.5194/egusphere-2024-3595, https://doi.org/10.5194/egusphere-2024-3595, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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We developed a model to predict global wildfire patterns by examining weather, vegetation, and human activities. This tool helps forecast seasonal fire risks across diverse regions and focuses on seasonal changes, unlike existing models. Its simplicity makes it valuable for climate and fire management planning, as well as for use in global climate studies, helping communities better prepare for and adapt to rising wildfire threats.
02 Dec 2024
Physicochemical and urban land-use characteristics associated with resistance to precipitation in estuaries vary across scales
Anna B. Turetcaia, Nicole G. Dix, Hannah Ramage, Matthew C. Ferner, and Emily B. Graham
External preprint server, https://doi.org/10.31223/X50Q3S, https://doi.org/10.31223/X50Q3S, 2024
Preprint under review for BG (discussion: open, 1 comment)
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We investigate what physicochemical and urbanization factors are involved in estuarine resistance to precipitation events across scales and salinity gradient. We found that urban estuaries are more resistant to precipitation events. We also found that while water temperature, water column depth, turbidity, nitrogen, and chlorophyll-a are related to estuarine resistance on continental-scale, these trends interacted with estuarine salinity and differed on local-scale.
02 Dec 2024
Refining Marine Net Primary Production Estimates: Advanced Uncertainty Quantification through Probability Prediction Models
Jie Niu, Mengyu Xie, Yanqun Lu, Liwei Sun, Na Liu, Han Qiu, Dongdong Liu, Chuanhao Wu, and Pan Wu
EGUsphere, https://doi.org/10.5194/egusphere-2024-3221, https://doi.org/10.5194/egusphere-2024-3221, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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Our results reveal the effectiveness of probabilistic forecasting models in analyzing the uncertainty of marine NPP estimates. Both the Bayesian and neural network models demonstrate superior capabilities in capturing the dynamic trends and uncertainties inherent in NPP data, with the neural network model demonstrating superior accuracy and reliability. Furthermore, we successfully applied these models to forecast NPP in specific ocean regions, highlighting the interannual variability of NPP.
02 Dec 2024
Reviews and Syntheses: Trait-based approach to constrain controls on planktic foraminiferal ecology: key trade-offs and current knowledge gaps
Kirsty Marie Edgar, Maria Grigoratou, Fanny Monteiro, Ruby Barrett, Rui Ying, and Daniela Schmidt
EGUsphere, https://doi.org/10.5194/egusphere-2024-3295, https://doi.org/10.5194/egusphere-2024-3295, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Planktic foraminifera are microscopic marine organisms whose calcium carbonate shells provide valuable insights into past ocean conditions. A promising means of understanding foraminiferal ecology and their environmental interactions is to constrain their key functional traits relating to feeding, symbioses, motility, calcification and reproduction. Here we review what we know of their functional traits, key gaps in our understanding and suggestions on how to fill them.
29 Nov 2024
Reviews and syntheses: Contribution of sulfate to methane oxidation in upland soils: a mini-review
Rui Su, Kexin Li, Nannan Wang, Fenghui Yuan, Ying Zhao, Yunjiang Zuo, Ying Sun, Liyuan He, Xiaofeng Xu, and Lihua Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3347, https://doi.org/10.5194/egusphere-2024-3347, 2024
Revised manuscript under review for BG (discussion: final response, 8 comments)
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This research examines the effect of sulfate on methane oxidation in soil, finding that sulfate may facilitate methane oxidation. Considering methane's role as a greenhouse gas and rising sulfate deposition, the study aims to predict changes in methane oxidation due to acid deposition. Future experiments will explore microbial mechanisms, as sulfate reduces methane emissions while enhancing its consumption, providing insights for mitigation strategies.
29 Nov 2024
Role of air-soil temperature on the LAI course and role of height-DBH on the maximum LAI during foliation of Platanus orientalis L. along an urban-rural greenway system
Melih Öztürk, Turgay Biricik, and Rıdvan Koruyan
EGUsphere, https://doi.org/10.5194/egusphere-2024-3372, https://doi.org/10.5194/egusphere-2024-3372, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Oriental plane LAI values have changed with definite pattern compatible with phenological periods. Air-soil temperatures were significantly definitive on course of mean LAI particularly during foliation. However, tree height and DBH were not significantly correlated with point-based maximum LAIs. Point-based mean LAI increased from 0.80 m2 m-2 to 2.76 m2 m-2 during foliation period. Mean tree height and DBH for point-based canopies ranged between 17.0–26.7 m and 26.5–38.2 cm respectively.
29 Nov 2024
Measuring and modeling waterlogging tolerance to predict the future for threatened lowland ash forests
Eric Gustafson, Dustin Bronson, Marcella Windmuller-Campione, Robert A. Slesak, and Deahn Donner
EGUsphere, https://doi.org/10.5194/egusphere-2024-3332, https://doi.org/10.5194/egusphere-2024-3332, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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Black ash forests provide many ecological and tribal cultural benefits but may soon be killed by invasive insects. Black ash trees maintain forests on very wet sites by removing enough water to allow other species to survive. We combined results from physical experiments and a simulation model to project the ecological outcome of strategies to replace ash with species not killed by the insect. We found that this should work if ways can be found to ensure that planted trees survive to maturity.
29 Nov 2024
Simulating vertical phytoplankton dynamics in a stratified ocean using a two-layered ecosystem model
Qi Zheng, Johannes J. Viljoen, Xuerong Sun, and Robert J. W. Brewin
EGUsphere, https://doi.org/10.5194/egusphere-2024-3502, https://doi.org/10.5194/egusphere-2024-3502, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Phytoplankton contribute to half of Earth’s primary production, but not a lot is known about subsurface phytoplankton, living at the base of the sunlit ocean. We develop a two-layered box model to simulate phytoplankton seasonal and interannual variations in different depth layers of the ocean. Our model captures seasonal and long-term trends of the two layers, explaining how they respond to a warming ocean, furthering our understanding of how phytoplankton are responding to climate change.
27 Nov 2024
Aquatic and Soil CO2 Emissions from forested wetlands of Congo's Cuvette Centrale
Antoine de Clippele, Astrid C. H. Jaeger, Simon Baumgartner, Marijn Bauters, Pascal Boeckx, Clement Botefa, Glenn Bush, Jessica Carilli, Travis W. Drake, Christian Ekamba, Gode Lompoko, Nivens Bey Mukwiele, Kristof Van Oost, Roland A. Werner, Joseph Zambo, Johan Six, and Matti Barthel
EGUsphere, https://doi.org/10.5194/egusphere-2024-3313, https://doi.org/10.5194/egusphere-2024-3313, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Tropical forest soils as a large terrestrial source of carbon dioxide (CO2) contribute to the GHG budgets. Despite this, carbon flux data from forested wetlands is scarce in tropical Africa. The study presents three years of semi-continuous measurements of surface CO2 fluxes within the Congo Basin. Although no seasonal patterns were evident, our results showed a positive effect of soil temperature and soil moisture, while a quadratic relationship was observed with the water table level.
26 Nov 2024
Assimilating Multi-site Eddy-Covariance Data to Calibrate the CH4 Wetland Emission Module in a Terrestrial Ecosystem Model
Jalisha Theanutti Kallingal, Marko Scholze, Paul Anthony Miller, Johan Lindström, Janne Rinne, Mika Aurela, Patrik Vestin, and Per Weslien
EGUsphere, https://doi.org/10.5194/egusphere-2024-3305, https://doi.org/10.5194/egusphere-2024-3305, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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We explored the possibilities of a Bayesian-based data assimilation algorithm to improve the wetland CH4 flux estimates by a dynamic vegetation model. By assimilating CH4 observations from 14 wetland sites we calibrated model parameters and estimated large-scale annual emissions from northern wetlands. Our findings indicate that this approach leads to more reliable estimates of CH4 dynamics, which will improve our understanding of the climate change feedback from wetland CH4 emissions.
25 Nov 2024
Estimation of particulate organic carbon export to the ocean from lateral degradations of tropical peatland coasts
Hiroki Kagawa, Koichi Yamamoto, Sigit Sutikno, Muhammad Haidar, Noerdin Basir, Atsushi Koyama, Ariyo Kanno, Yoshihisa Akamatsu, and Motoyuki Suzuki
EGUsphere, https://doi.org/10.5194/egusphere-2024-3547, https://doi.org/10.5194/egusphere-2024-3547, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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This study elucidated the carbon export that has never been highlighted before, such as coastal peat mass movements and coastal erosion in tropical peatlands. The flux of POC exported to the ocean in the northern part of Bengkalis Island, Indonesia was estimated to range from 2.06 to 7.60 tC m-1 yr-1 due to coastal erosion and from 1.43 to 5.41 tC m-1 due to peat mass movement events. A significant amount of carbon is continuously released to the ocean.
21 Nov 2024
Pelagic coccolithophore production and dissolution and their impacts on particulate inorganic carbon cycling in the western North Pacific
Yuye Han, Zvi Steiner, Zhimian Cao, Di Fan, Junhui Chen, Jimin Yu, and Minhan Dai
EGUsphere, https://doi.org/10.5194/egusphere-2024-3492, https://doi.org/10.5194/egusphere-2024-3492, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Coccolithophore calcite accounts for a major fraction of particulate inorganic carbon (PIC) standing stocks in the western North Pacific, with a markedly higher contribution in the oligotrophic subtropical gyre than in the Kuroshio-Oyashio transition region, which highlights the importance of coccolithophores for PIC production in the pelagic ocean. We also found extensive dissolution of coccolithophore calcite in the oversaturated shallow waters primarily driven by microbial metabolic activity.
21 Nov 2024
Terrestrial and marine plastic pollution outlook in the Mediterranean region: a box-model approach based on OECD policy scenarios
Théo Segur and Jeroen E. Sonke
EGUsphere, https://doi.org/10.5194/egusphere-2024-3031, https://doi.org/10.5194/egusphere-2024-3031, 2024
Preprint under review for BG (discussion: open, 0 comments)
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Our paper provides a quantification of plastic pollution in the Mediterranean region, and several policy scenario projections based on OECD data toward 2100. We estimate a 4-fold increase of Mediterranean marine plastic stock by 2060 and that the implementation of terrestrial plastic cleanup can significantly help to reduce plastic pollution transfer from land to sea. Our results provide insight for policy makers, which is needed at the regional scale in a context of the UNEP plastic treaty.
20 Nov 2024
Promoted phosphorus transformation by increasing soil microbial diversity and network complexity – A case of long-term mixed-species plantations of Eucalyptus with N-fixing tree species
Jiyin Li, Yeming You, Wen Zhang, Yi Wang, Yuying Liang, Haimei Huang, Hailun Ma, Qinxia He, Angang Ming, and Xueman Huang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3456, https://doi.org/10.5194/egusphere-2024-3456, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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Monoculture of Eucalyptus can lead to soil degradation. In this study, we introduced nitrogen-fixing species in Eucalyptus plantations and investigated the effect of the introduction of nitrogen-fixing species on soil phosphorus transformation by soil microorganisms and their nitrogen-phosphorus cycling functional genes, which may be a promising forest management strategy to improve ecosystem phosphorus benefits.
20 Nov 2024
Variable organic matter stoichiometry enhances the biological drawdown of CO2 in the Northwest European shelf seas
Kubilay Timur Demir, Moritz Mathis, Jan Kossack, Feifei Liu, Ute Daewel, Christoph Stegert, Helmuth Thomas, and Corinna Schrum
EGUsphere, https://doi.org/10.5194/egusphere-2024-3449, https://doi.org/10.5194/egusphere-2024-3449, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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This study examines how variations in the ratios of carbon, nitrogen and phosphorus in organic matter affect carbon cycling in the Northwest European shelf seas. Traditional models with fixed ratios tend to underestimate biological carbon uptake. By integrating variable ratios into a regional model, we find that carbon dioxide uptake increases by 10–33 %. These results highlight the need to include variable ratios for accurate assessments of regional and global carbon cycles.
19 Nov 2024
Evaluating the consistency of forest disturbance datasets in continental USA
Laura Eifler, Franziska Müller, and Ana Bastos
EGUsphere, https://doi.org/10.5194/egusphere-2024-3534, https://doi.org/10.5194/egusphere-2024-3534, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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Forests provide ecosystem services and biodiversity, but they are increasingly affected by disturbances. Consistent global data on forest disturbances are lacking, impeding effective assessment. We compare four forest disturbance datasets for the continental USA, finding moderate agreement overall, with ground-based inventories more consistent than satellite data. This emphasizes the need for enhanced data quality assessment, integration, and accuracy to better understand forest disturbances.
19 Nov 2024
Assessing evapotranspiration dynamics across central Europe in the context of land-atmosphere drivers
Anke Fluhrer, Martin Baur, María Piles, Bagher Bayat, Mehdi Rahmati, David Chaparro, Clémence Dubois, Florian Hellwig, Carsten Montzka, Angelika Kübert, Marlin Mueller, Isabel Augscheller, Francois Jonard, Konstantin Schellenberg, and Thomas Jagdhuber
EGUsphere, https://doi.org/10.5194/egusphere-2024-3386, https://doi.org/10.5194/egusphere-2024-3386, 2024
Preprint under review for BG (discussion: final response, 2 comments)
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This study compares established evapotranspiration products in Central Europe and evaluates their multi-seasonal performance during wet & drought phases between 2017–2020 together with important soil-plant-atmosphere drivers. Results show that SEVIRI, ERA5-land & GLEAM perform best compared to ICOS measurements. During moisture limited drought years, ET is decreasing due to decreasing soil moisture and increasing vapor pressure deficit, while in other years ET is mainly controlled by VPD.
15 Nov 2024
Ozone pollution may limit the benefits of irrigation to wheat productivity in India
Gabriella Everett, Øivind Hodnebrog, Madhoolika Agrawal, Durgesh Singh Yadav, Connie O'Neill, Chubamenla Jamir, Jo Cook, Pritha Pande, and Lisa Emberson
EGUsphere, https://doi.org/10.5194/egusphere-2024-3371, https://doi.org/10.5194/egusphere-2024-3371, 2024
Preprint under review for BG (discussion: final response, 3 comments)
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Ground-level ozone (O3), heat, and water stress (WS) reduce wheat yields, threatening food security in India. O3, heat, and WS interact as stressed plants close stomata, limiting O3 entry and damage. This study models O3 uptake under rainfed (WS) and irrigated conditions for current and future climates. Results show little O3-related yield loss under wWS but higher losses with irrigation. Both climate scenarios increase O3-related losses, highlighting risks to India’s wheat productivity.
13 Nov 2024
Acidification and nutrient management are projected to cause reductions in shell and tissue weights of oysters in a coastal plain estuary
Catherine Czajka, Marjorie A. M. Friedrichs, Emily B. Rivest, Pierre St-Laurent, Mark J. Brush, and Fei Da
EGUsphere, https://doi.org/10.5194/egusphere-2024-3359, https://doi.org/10.5194/egusphere-2024-3359, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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Under future acidification, warming, and nutrient management, substantial reductions in shell and tissue weights of Eastern oysters are projected for the Chesapeake Bay. Lower oyster growth rates will be largely driven by reduced calcium carbonate saturation states and reduced food availability. Oyster aquaculture practices in the region will likely be affected, with site selection becoming increasingly important as impacts will be highly spatially variable.
13 Nov 2024
Old Carbon, New Insights: Thermal Reactivity and Bioavailability of Saltmarsh Soils
Alex Houston, Mark H. Garnett, Jo Smith, and William E. N. Austin
EGUsphere, https://doi.org/10.5194/egusphere-2024-3281, https://doi.org/10.5194/egusphere-2024-3281, 2024
Preprint under review for BG (discussion: final response, 3 comments)
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The organic carbon stored in saltmarsh soils can be up to 15,000 years old. We found that less energy is required to decompose young carbon than old carbon, i.e., young carbon tends to be more labile. We show that the labile carbon can still be up to 2,000 years old, implying that even old carbon in saltmarsh soils may contribute to greenhouse gas emissions. Protecting saltmarshes from degradation may help conserve these stores of old, labile organic carbon and hence limit CO2 emissions.
12 Nov 2024
Thermokarst lake change and lake hydrochemistry: A snapshot from the Arctic Coastal Plain of Alaska
Lydia Stolpmann, Ingmar Nitze, Ingeborg Bussmann, Benjamin M. Jones, Josefine Lenz, Hanno Meyer, Juliane Wolter, and Guido Grosse
EGUsphere, https://doi.org/10.5194/egusphere-2024-2822, https://doi.org/10.5194/egusphere-2024-2822, 2024
Preprint under review for BG (discussion: open, 1 comment)
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We combine hydrochemical and lake change data to show consequences of permafrost thaw induced lake changes on hydrochemistry, which are relevant for the global carbon cycle. We found higher methane concentrations in lakes that do not freeze to the ground and show that lagoons have lower methane concentrations than lakes. Our detailed lake sampling approach show higher concentrations in Dissolved Organic Carbon in areas of higher erosion rates, that might increase under the climate warming.
11 Nov 2024
Two different phytoplankton blooming mechanisms over the East China Sea during El-Niño decaying summers
Dong-Geon Lee, Ji-Hoon Oh, Jonghun Kam, and Jong-Seong Kug
EGUsphere, https://doi.org/10.5194/egusphere-2024-3406, https://doi.org/10.5194/egusphere-2024-3406, 2024
Preprint under review for BG (discussion: final response, 8 comments)
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During El Niño decaying summers, the East China Sea (ECS) experiences intensified phytoplankton blooms. Here, we suggest two different mechanisms. Atmospheric teleconnection induces increased rainfall, which elevates nutrient-rich runoff into the ECS. Additionally, the cyclonic wind patterns promote upwelling, delivering subsurface nutrients to surface waters. These two mechanisms operate concurrently, fueling robust phytoplankton blooms.
08 Nov 2024
Phylogeochemistry: exploring evolutionary constraints on belemnite rostrum element composition
Alexander Pohle, Kevin Stevens, René Hoffmann, and Adrian Immenhauser
EGUsphere, https://doi.org/10.5194/egusphere-2024-3383, https://doi.org/10.5194/egusphere-2024-3383, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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The belemnite rostrum geochemistry is used as proxy in paleoceanography. Evolutionary patterns in element ratios (Mg/Ca, Sr/Ca, Mn/Ca and Fe/Ca) from belemnite rostra based on a literature dataset are assessed. These proxy data reflect a complex interplay between evolutionary, ontogenetic, environmental, kinetic and diagenetic effects. We coin the new term ‘phylogeochemistry’ for this interdisciplinary research field.
07 Nov 2024
Marine snow morphology drives sinking and attenuation in the ocean interior
Yawouvi Dodji Soviadan, Miriam Beck, Joelle Habib, Alberto Baudena, Laetitia Drago, Alexandre Accardo, Remi Laxenaire, Sabrina Speich, Peter Brandt, Rainer Kiko, and Lars Stemmann
EGUsphere, https://doi.org/10.5194/egusphere-2024-3302, https://doi.org/10.5194/egusphere-2024-3302, 2024
Preprint under review for BG (discussion: final response, 5 comments)
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Key parameters representing the gravity flux in global models are the sinking speed and the vertical attenuation of the exported material. We calculate for the first time, these parameters in situ for 6 intermittent blooms followed by export events using high-resolution (3 days) time series of 0–1000 m depth profiles from imaging sensor mounted on an Argo float. We show that sinking speed depends not only on size but also on the morphology of the particles, density being an important property.
06 Nov 2024
Marine snow surface production and bathypelagic export at the Equatorial Atlantic from an imaging float
Joelle Habib, Lars Stemmann, Alexandre Accardo, Alberto Baudena, Franz Philip Tuchen, Peter Brandt, and Rainer Kiko
EGUsphere, https://doi.org/10.5194/egusphere-2024-3365, https://doi.org/10.5194/egusphere-2024-3365, 2024
Preprint under review for BG (discussion: open, 0 comments)
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This study investigates how carbon moves from the ocean surface to the depths in the equatorial Atlantic, contributing to long-term carbon storage. Using an Argo float equipped with a camera, we captured two periods with major carbon export events. By identifying particle types and their sinking behaviors, we found that smaller, compact particles are key drivers of carbon transport. Our findings underscore the value of using imaging tools on autonomous platforms in tracking carbon sequestration.
06 Nov 2024
Uncertainties in carbon emissions from land use and land cover change in Indonesia
Ida Bagus Mandhara Brasika, Pierre Friedlingstein, Stephen Sitch, Michael O'Sullivan, Maria Carolina Duran-Rojas, Thais Michele Rosan, Kees Klein Goldewijk, Julia Pongratz, Clemens Schwingshackl, Louise P. Chini, and George C. Hurtt
EGUsphere, https://doi.org/10.5194/egusphere-2024-3165, https://doi.org/10.5194/egusphere-2024-3165, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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Indonesia is 3 world's highest carbon emitter from land use change. However, there are uncertainties of the carbon emission of Indonesia that can be reduced with satellite-based datasets. But later, we found that the uncertainties are also caused by the difference of carbon pool in various models. Our best estimation of carbon emissions from land use change in Indonesia is 0.12 ± 0.02 PgC/yr with steady trend. This double when include peat fire and peat drainage emissions.
06 Nov 2024
Rising atmospheric CO2 concentrations: the overlooked factor promoting SW Iberian Forest development across the LGM and the last deglaciation?
Sandra Domingues Gomes, William Fletcher, Abi Stone, Teresa Rodrigues, Andreia Rebotim, Dulce Oliveira, Maria F. Sánchez Goñi, Fatima Abrantes, and Filipa Naughton
EGUsphere, https://doi.org/10.5194/egusphere-2024-3334, https://doi.org/10.5194/egusphere-2024-3334, 2024
Preprint under review for BG (discussion: final response, 5 comments)
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Our study explores how rising CO2 at the end of the last ice age impacted vegetation in the Iberian Peninsula. By analyzing pollen and ocean temperatures in marine sediments, we found that higher CO2 helped forests expand, even in cool or dry conditions. This shows that CO2 played a key role in shaping ecosystems during climate shifts. Understanding this past response helps us see how different factors interact and provides insights into how today’s ecosystems might adapt to rapidly rising CO2.
04 Nov 2024
Validating laboratory insights into the drivers of soil rewetting respiration pulses with field measurements
Xiankun Li, Marleen Pallandt, Dilip Naidu, Johannes Rousk, Gustaf Hugelius, and Stefano Manzoni
EGUsphere, https://doi.org/10.5194/egusphere-2024-3324, https://doi.org/10.5194/egusphere-2024-3324, 2024
Preprint under review for BG (discussion: final response, 8 comments)
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While laboratory studies have identified many drivers and their effects on the carbon emission pulse after rewetting of dry soils, a validation with field data is still missing. Here, we show that the carbon emission pulse in the laboratory and in the field increases with soil organic carbon and temperature, but their trends with pre-rewetting dryness and moisture increment at rewetting differ. We conclude that the laboratory findings can be partially validated.
04 Nov 2024
Relationships between phytoplankton pigments and DNA- or RNA-based abundances support ecological applications
Robert Lampe, Ariel Rabines, Steffaney Wood, Anne Schulberg, Ralf Goericke, Pratap Venepally, Hong Zheng, Michael Stukel, Michael Landry, Andrew Barton, and Andrew Allen
EGUsphere, https://doi.org/10.5194/egusphere-2024-3285, https://doi.org/10.5194/egusphere-2024-3285, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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With the likely emergence of satellite-based phytoplankton pigment data, it is increasingly important to examine relationships between phytoplankton pigments and other metrics of phytoplankton community composition. By using quantitative approaches, we show that phytoplankton pigments correlate with DNA- and RNA-based abundances, and examine how integration of these data addresses ecological questions relating to diversity patterns, harmful algal blooms, and inferring cellular activity.
04 Nov 2024
Fungi present distinguishable isotopic signals when grown on glycolytic versus tricarboxylic acid cycle intermediates
Stanislav Jabinski, Vítězslav Kučera, Marek Kopáček, Jan Jansa, and Travis B. Meador
EGUsphere, https://doi.org/10.5194/egusphere-2024-3153, https://doi.org/10.5194/egusphere-2024-3153, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Microbial production is a key parameter in estimations of organic matter cycling in environmental systems, and fungi play a major role as decomposers. In order to investigate fungal production and turnover times in soils, we incubated fungal pure cultures with isotopically labelled water and bicarbonate to investigate growth signals encoded into lipid biomarkers, which can be applied to improve flux estimates in environmental studies.
30 Oct 2024
Variability of CO2 and CH4 in a coastal peatland rewetted with brackish water from the Baltic Sea derived from autonomous high-resolution measurements
Daniel Pönisch, Henry C. Bittig, Martin Kolbe, Ingo Schuffenhauer, Stefan Otto, Peter Holtermann, Kusala Premaratne, and Gregor Rehder
EGUsphere, https://doi.org/10.5194/egusphere-2024-3246, https://doi.org/10.5194/egusphere-2024-3246, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Rewetted peatlands exhibit natural spatial and temporal biogeochemical heterogeneity, influenced by water level and vegetation. This study investigated the variability of the distribution of GHGs in a brackish-rewetted peatland. Two innovative sensor-equipped landers were used to measure a wide range of marine physicochemical variables at high temporal resolution. The measurements revealed strong fluctuations in CO2 and CH4, expressed as multi-day, diurnal and event-based variability.
30 Oct 2024
Winds with destructive potential across a topographic and seasonal gradient in a Central Amazon forest
Luciano Emmert, Susan Trumbore, Joaquim dos Santos, Adriano Lima, Niro Higuchi, Robinson Negrón-Juárez, Cléo Dias-Júnior, Tarek El-Madany, Olaf Kolle, Gabriel Ribeiro, and Daniel Marra
EGUsphere, https://doi.org/10.5194/egusphere-2024-3234, https://doi.org/10.5194/egusphere-2024-3234, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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For the first time, we documented wind gusts with the potential to damage trees in a forest in the Central Amazon. We used meteorological data collected at crown height over 24 months. We recorded 424 gusts, which occur more frequently and intensely in higher elevated areas and during the transition from the dry to the wet season. More intense rains showed the strongest relationship with extreme winds, highlighting the role of extreme events in tree mortality.
30 Oct 2024
From small scale variability to mesoscale stability in surface ocean pH: implications for air-sea CO2 equilibration
Louise Delaigue, Gert-Jan Reichart, Chris Galley, Yasmina Ourradi, and Matthew Paul Humphreys
EGUsphere, https://doi.org/10.5194/egusphere-2024-2853, https://doi.org/10.5194/egusphere-2024-2853, 2024
Preprint under review for BG (discussion: final response, 3 comments)
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Our study analyzed pH in ocean surface waters to understand how they fluctuate with changes in temperature, salinity, and biological activities. We found that temperature mainly controls daily pH variations, but biological processes also play a role, especially in affecting CO2 levels between the ocean and atmosphere. Our research shows how these factors together maintain the balance of ocean chemistry, which is crucial for predicting changes in marine environments.
29 Oct 2024
Saturating response of photosynthesis to increasing leaf area index allows selective harvest of trees without affecting forest productivity
Olivier Bouriaud, Ernst-Detlef Schulze, Konstantin Gregor, Issam Bourkhris, Peter Högberg, Roland Irslinger, Phillip Papastefanou, Julia Pongratz, Anja Rammig, Riccardo Valentini, and Christian Körner
EGUsphere, https://doi.org/10.5194/egusphere-2024-3092, https://doi.org/10.5194/egusphere-2024-3092, 2024
Preprint under review for BG (discussion: final response, 6 comments)
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The impact of harvesting on forests' carbon sink capacities is debated. One view is that their sink strength is resilient to harvesting, the other that it disrupts these capacities. Our work shows that leaf area index (LAI) has been overlooked in this discussion. We found that temperate forests' carbon uptake is largely insensitive to variations in LAI beyond about 4 m² m-², but that forests operate at higher levels.
29 Oct 2024
Temporal and Spatial Influences of Environmental Factors on the Distribution of Mesopelagic organism in the North Atlantic Ocean
Jie Yang, Jian Hui Li, and Ge Chen
EGUsphere, https://doi.org/10.5194/egusphere-2024-2991, https://doi.org/10.5194/egusphere-2024-2991, 2024
Preprint under review for BG (discussion: open, 2 comments)
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This study examines how environmental factors, particularly temperature, affect the seasonal and spatial distribution of mesopelagic organisms in the North Atlantic. Using data from 720 BGC-Argo floats, we identified distinct daily and seasonal migration patterns. Temperature was the key driver, followed by salinity and dissolved oxygen. These findings enhance our understanding of mesopelagic ecosystems, with potential implications for fisheries management.
24 Oct 2024
Perturbation increases source-dependent organic matter degradation rates in estuarine sediments
Guangnan Wu, Klaas G. J. Nierop, Bingjie Yang, Stefan Schouten, Gert-Jan Reichart, and Peter Kraal
EGUsphere, https://doi.org/10.5194/egusphere-2024-3192, https://doi.org/10.5194/egusphere-2024-3192, 2024
Preprint under review for BG (discussion: open, 1 comment)
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Estuaries store and process large amounts of carbon, making them vital to the global carbon cycle. In the Port of Rotterdam, we studied the source of organic matter (OM) in sediments and how it influences OM breakdown. We found that marine OM degrades faster than land OM, and human activities like dredging can accelerate this by exposing sediments to oxygen. Our findings highlight the impact of human activities on carbon storage in estuaries, which is key for managing estuarine carbon dynamics.
23 Oct 2024
Intertidal Regions Regulate Seasonal Coastal Carbonate System Dynamics in the East Frisian Wadden Sea
Julia Meyer, Yoana G. Voynova, Bryce Van Dam, Lara Luitjens, Dagmar Daehne, and Helmuth Thomas
EGUsphere, https://doi.org/10.5194/egusphere-2024-3048, https://doi.org/10.5194/egusphere-2024-3048, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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The study highlights the inter-seasonal variability of the carbonate dynamics of the East Frisian Wadden Sea, the world's largest intertidal area. During spring, increased biological activity leads to lower CO2 and nitrate levels, while total alkalinity (TA) rises slightly. In summer, TA increases, enhancing the ocean's ability to absorb CO2. Our research emphasizes the vital role of these intertidal regions in regulating carbon, contributing to a better understanding of carbon storage.
23 Oct 2024
Ideas and perspectives: How sediment archives can improve model projections of marine ecosystem change
Isabell Hochfeld, Ben A. Ward, Anke Kremp, Juliane Romahn, Alexandra Schmidt, Miklós Bálint, Lutz Becks, Jérôme Kaiser, Helge W. Arz, Sarah Bolius, Laura S. Epp, Markus Pfenninger, Christopher A. Klausmeier, Elena Litchman, and Jana Hinners
EGUsphere, https://doi.org/10.5194/egusphere-2024-3297, https://doi.org/10.5194/egusphere-2024-3297, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Marine ecosystem models (MEMs) are valuable for assessing the threats of global warming to biodiversity and ecosystem functioning, but their predictions vary widely. We argue that MEMs should consider evolutionary processes and undergo independent validation. Here, we present a novel framework for MEM development using validation data from sediment archives, which map long-term environmental and evolutionary change. Our approach is a crucial step towards improving the predictive power of MEMs.
23 Oct 2024
Extraordinary bloom of toxin-producing phytoplankton enhanced by strong retention in offshore continental shelf waters
Valeria Ana Guinder, Urban Tillmann, Martin Rivarossa, Carola Ferronato, Fernando Javier Ramirez, Bernd Krock, Haifeng Gu, and Martin Saraceno
EGUsphere, https://doi.org/10.5194/egusphere-2024-3157, https://doi.org/10.5194/egusphere-2024-3157, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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An unusual survey involving two vessels in the Argentine Sea over a ten-day period enabled synoptic observations of a significant bloom of toxic phytoplankton. Simultaneous species characterization of the bloom, along with measurements of surface currents and fronts, provided insights into its development and retention. Interdisciplinary approaches shed light on the biophysical coupling underlying the persistence and horizontal transport of harmful algal blooms in productive marine environments.
22 Oct 2024
Sea ice-associated algae and zooplankton fecal pellets fuel organic particle export in the seasonally ice-covered northwest Labrador Sea
Shao-Min Chen, Thibaud Dezutter, David Cote, Catherine Lalande, Evan Edinger, and Owen A. Sherwood
EGUsphere, https://doi.org/10.5194/egusphere-2024-3265, https://doi.org/10.5194/egusphere-2024-3265, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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The origins and composition of sinking organic matter are still understudied for the oceans, especially in ice-covered areas. We use amino acid stable isotopes combined with particle flux and plankton taxonomy to investigate the sources and composition of exported organic matter from a sediment trap derived time-series of sinking particles in the northwest Labrador Sea. We found that sea ice algae and fecal pellets may be important contributors to the sinking fluxes of carbon and nitrogen.
18 Oct 2024
Peltigera lichen thalli produce highly efficient ice nucleating agents
Rosemary J. Eufemio, Galit Renzer, Mariah Rojas, Jolanta Miadlikowska, Todd L. Sformo, François Lutzoni, Boris A. Vinatzer, and Konrad Meister
EGUsphere, https://doi.org/10.5194/egusphere-2024-2959, https://doi.org/10.5194/egusphere-2024-2959, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Co-editor-in-chief
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Peltigera lichens, one of the most abundant lichen genera, contain ice nucleators (INs) that enable freezing near 0 °C. Yet the frequency and efficiency of the INs is largely unknown. Our Pan-American screening of Peltigera reveals that the lichen thalli contain potent INs resistant to freeze-thaw cycles. Notably, a pure fungal culture from Peltigera britannica released the most efficient INs reported to date. Our findings emphasize the potential of Peltigera INs to impact atmospheric patterns.
Co-editor-in-chief
Peltigera clouds? This fascinating manuscript demonstrates the potential of Peltigera lichens from across a range of ecosystems to generate potent biological ice nucleators. These Peltigera lichen ice nucleators can be more potent than the bacteria Pseudomonas syringae, which is often viewed as the most efficient biological ice nucleators. Given the widespread occurrence of Peltigera across the globe, these lichen may be important contributors to biological ice nucleation.
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17 Oct 2024
Altered Seasonal Sensitivity of Net Ecosystem Exchange to Controls Driven by Nutrient Balances in a Semi-arid Savanna
Laura Dénise Nadolski, Tarek Sebastian El Madany, Jacob Allen Nelson, Arnaud Carrara, Gerardo Moreno, Richard K. F. Nair, Yunpeng Luo, Anke Hildebrandt, Victor Rolo, Markus Reichstein, and Sung-Ching Lee
EGUsphere, https://doi.org/10.5194/egusphere-2024-3190, https://doi.org/10.5194/egusphere-2024-3190, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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Semi-arid ecosystems are crucial for Earth's carbon balance and are sensitive to changes in nitrogen (N) and phosphorus (P) levels. Their carbon dynamics are complex and not fully understood. We studied how long-term nutrient changes affect carbon exchange. In summer, N+P changed plant composition and productivity. In transitional seasons, carbon exchange was less weather-dependent with N. Adding N and N+P are increasing carbon exchange variability, driven by grass greenness.
17 Oct 2024
Microbial communities inhabiting 600-year-old sediments in the Inka-Coya Lake located in the Atacama Desert
Coral Pardo-Esté, Juan Castro-Severyn, Francisco Remonsellez, Antonio Maldonado, Inger Heine Fuster, Hector Pizarro, and Adriana Aránguiz-Acuña
EGUsphere, https://doi.org/10.5194/egusphere-2024-3035, https://doi.org/10.5194/egusphere-2024-3035, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Inka-Coya Lake is located in the Atacama Desert, and this pioneer study characterized the gradient of microbial life along the deep lacustrine sediments that stratified for over 600 years, since the pre-mining period. Our results indicate there is great taxonomic novelty and strong relationships with geochemical composition especially in Cu, Fe, Ni, and V. We propose a clustering of taxa and function in three zones with characteristic taxonomic and functional potential.
16 Oct 2024
Duration of vegetation green-up response to snowmelt on the Tibetan Plateau
Jingwen Ni, Jin Chen, Yao Tang, Jingyi Xu, Jiahui Xu, Linxin Dong, Qingyu Gu, Bailang Yu, Jianping Wu, and Yan Huang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2885, https://doi.org/10.5194/egusphere-2024-2885, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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The average time differences (∆T) between green-up date and snowmelt onset date from 2001–2018 on the Tibetan Plateau were 36.7 days. With the increasing spring mean temperature, spring total precipitation and daily snowmelt, ∆T became shorter. Besides, in arid and low-vegetation areas, ∆T is primarily influenced by snowmelt, whereas in humid and high-vegetation areas, temperature plays a dominant role.
15 Oct 2024
Dynamic island mass effect from space. Part I: detecting the extent
Guillaume Bourdin, Lee Karp-Boss, Fabien Lombard, Gabriel Gorsky, and Emmanuel Boss
EGUsphere, https://doi.org/10.5194/egusphere-2024-2670, https://doi.org/10.5194/egusphere-2024-2670, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Remote islands and atolls create unique oceanic processes that affect the surrounding waters, known as the Island Mass Effect (IME). These processes bring nutrients to the ocean surface, leading to increasing phytoplankton concentration near islands. We combine data from various satellites and modeled currents to better track these changes. This reveals a larger IME impact than previously thought, suggesting that islands play a more significant role in ocean food chains in subtropical regions.
15 Oct 2024
Reconstructing Central African hydro-climate over the past century using freshwater bivalve shell geochemistry
Zita Kelemen, David P. Gillikin, and Steven Bouillon
EGUsphere, https://doi.org/10.5194/egusphere-2024-2714, https://doi.org/10.5194/egusphere-2024-2714, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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We analysed the C and O stable isotope composition (δ13C, δ18O) across the growth axis of museum-archived and recent Chambardia wissmanni shells from the Oubangui River (Congo Basin) covering sections of the past ~120 years. Recent shells showed a much wider range in δ18O values compared to historical specimens, consistent with the suggestion that dry periods in the upper Congo basin are becoming more extreme in recent times; highlighting their potential to reconstruct hydroclimatic conditions.
11 Oct 2024
Technical note: Investigating saline water uptake by roots using spectral induced polarization
Solomon Ehosioke, Sarah Garre, Johan Alexander Huisman, Egon Zimmermann, Mathieu Javaux, and Frederic Nguyen
EGUsphere, https://doi.org/10.5194/egusphere-2024-2628, https://doi.org/10.5194/egusphere-2024-2628, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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We investigated the electrical properties of the primary roots of Brachypodium and Maize plants during the uptake of fresh and saline water using SIP measurements in a frequency range from 1 Hz to 45 kHz. Our results indicate that salinity tolerance varies with the species, and that Maize is more tolerant to salinity than Brachypodium.
11 Oct 2024
Fate of dissolved organic matter across the permafrost–nearshore water continuum: role of the intertidal sediments
Aude Flamand, Jean-François Lapierre, and Gwénaëlle Chaillou
EGUsphere, https://doi.org/10.5194/egusphere-2024-2945, https://doi.org/10.5194/egusphere-2024-2945, 2024
Preprint under review for BG (discussion: open, 1 comment)
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In the context of climate change, increasing rates of coastal erosion and thawing of permafrost increase the fluxes of solutes to the Arctic Ocean. However, the fate of this newly mobilized material is still unclear and may alter ocean chemistry. We have explored the lateral inputs of carbon from coastal permafrost bluffs to the ocean via beaches in Kugmallit Bay. Our findings highlight that beaches may act as a permanent or transient terrestrial carbon sink, limiting its lateral export.
10 Oct 2024
Rising Arctic Seas and Thawing Permafrost: Uncovering the Carbon Cycle Impact in a Thermokarst Lagoon System in the outer Mackenzie Delta, Canada
Maren Jenrich, Juliane Wolter, Susanne Liebner, Christian Knoblauch, Guido Grosse, Fiona Giebeler, Dustin Whalen, and Jens Strauss
EGUsphere, https://doi.org/10.5194/egusphere-2024-2891, https://doi.org/10.5194/egusphere-2024-2891, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Climate warming in the Arctic is causing the erosion of permafrost coasts and the transformation of permafrost lakes into lagoons. To understand how this affects greenhouse gas (GHG) emissions, we studied carbon dioxide (CO₂) and methane (CH₄) production in lagoons with varying sea connections. Younger lagoons produce more CH₄, while CO₂ increases in more marine conditions. Flooding of permafrost lowlands due to rising sea levels may lead to higher GHG emissions from Arctic coasts in the future.
10 Oct 2024
On the added value of sequential deep learning for upscaling evapotranspiration
Basil Kraft, Jacob A. Nelson, Sophia Walther, Fabian Gans, Ulrich Weber, Gregory Duveiller, Markus Reichstein, Weijie Zhang, Marc Rußwurm, Devis Tuia, Marco Körner, Zayd Mahmoud Hamdi, and Martin Jung
EGUsphere, https://doi.org/10.5194/egusphere-2024-2896, https://doi.org/10.5194/egusphere-2024-2896, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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Global evapotranspiration (ET) can be estimated using machine learning (ML) models optimized on local data and applied to global data. This study explores whether sequential neural networks, which consider past data, perform better than models that do not. The findings show that sequential models struggle with global upscaling, likely due to their sensitivity to data shifts from local to global scales. To improve ML-based upscaling, additional data or integration of physical knowledge is needed.
09 Oct 2024
Evaluation of long-term carbon dynamics in afforested drained peatlands: Insights from using the ForSAFE-Peat Model
Daniel Escobar, Stefano Manzoni, Jeimar Tapasco, and Salim Belyazid
EGUsphere, https://doi.org/10.5194/egusphere-2024-2754, https://doi.org/10.5194/egusphere-2024-2754, 2024
Revised manuscript accepted for BG (discussion: final response, 8 comments)
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We studied carbon dynamics in afforested, drained peatlands using the ForSAFE-Peat model over two forest rotations. Our simulations showed that while trees store carbon, significant soil carbon losses occur, particularly early on, indicating that forest growth may not fully offset these losses once carbon time dynamics are considered. This emphasizes the need to consider both soil and harvested wood products when evaluating the climate impact of such systems.
09 Oct 2024
Effects of basalt, concrete fines, and steel slag on maize growth and heavy metal accumulation in an enhanced weathering experiment
Jet Rijnders, Arthur Vienne, and Sara Vicca
EGUsphere, https://doi.org/10.5194/egusphere-2024-3022, https://doi.org/10.5194/egusphere-2024-3022, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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A mesocosm experiment was set-up to investigate how maize responds to basalt, concrete fines and steel slags application, using a dose-response approach. Biomass increased with basalt application, but did not change with concrete fines or steel slags, except for increased tassel biomass. Mg, Ca and Si generally increased in the crops, while heavy metal concentrations remained unaffected or even decreased in the plants. Overall, crops were positively affected by application of silicate materials.
09 Oct 2024
Low sensitivity of a heavily-calcified coccolithophore under increasing CO2: the case study of Helicosphaera carteri
Stefania Bianco, Manuela Bordiga, Gerald Langer, Patrizia Ziveri, Federica Cerino, Andrea Stefano Di Giulio, and Claudia Lupi
EGUsphere, https://doi.org/10.5194/egusphere-2024-2681, https://doi.org/10.5194/egusphere-2024-2681, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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This work focuses on the response in culture experiments to increasing CO2 of the coccolithophore species Helicosphaera carteri, a unicellular marine calcifying microalgae. A slight increase in coccolith (calcite scales covering the cell) malformations without variation in size, shape or calcification-to-photosynthesis ratio is indicative of H. carteri low sensitivity to CO2 rise together with its ability to maintain a stable contribution to the marine rain ratio under future climate changes.
09 Oct 2024
Variation of the interspecific forest mass-density relationship along gradients of leaf area and global radiation
Jan J. M. van Roestel
EGUsphere, https://doi.org/10.5194/egusphere-2024-2753, https://doi.org/10.5194/egusphere-2024-2753, 2024
Preprint under review for BG (discussion: open, 1 comment)
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The self-thinning theory and the global energy balance theory are brought together in a model to show how the stand mass and tree density of relatively undisturbed forests vary globally along gradients of leaf area and the sum of global radiation over the growing season. The exponent of tree density converges to 1/2, which differs from the expected 1/3 value based on bivariate mass-density scaling. A thermodynamic interpretation is proposed that may be relevant for other plants and even animals.
07 Oct 2024
Sedimentary ancient DNA insights into foraminiferal diversity near the grounding line in the western Ross Sea, Antarctica
Ewa Demianiuk, Mateusz Baca, Danijela Popović, Inès Barrenechea Angeles, Ngoc-Loi Nguyen, Jan Pawlowski, John B. Anderson, and Wojciech Majewski
EGUsphere, https://doi.org/10.5194/egusphere-2024-2824, https://doi.org/10.5194/egusphere-2024-2824, 2024
Revised manuscript accepted for BG (discussion: final response, 5 comments)
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Co-editor-in-chief
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Ancient foraminifera DNA is studied in five Antarctic cores with sediments up to 25 kyr old. We use a standard and a new, more effective marker, which may become the next standard for paleoenvironmental studies. Much less diverse foraminifera occur on slopes of submarine moraines than in open-marine settings. Softly-walled foraminifera, not found in the fossil record, are especially abundant. There is no foraminiferal DNA in tills, suggesting its destruction during glacial redeposition.
Co-editor-in-chief
Based on the analysis of sedimentary ancient DNA, the authors show that Antarctic foraminiferal communities are diverse in open marine environments and significantly less diverse along slopes of submarine moraines. In both cases, DNA analysis reveals a high abundance of soft-walled monothalamids, which are not preserved in the fossil record. No foraminiferal DNA was found in tills, suggesting its destruction during glacial redeposition. A promising new foraminiferal mini-barcode marker is proposed, which merits further validation for application in future paleoecological investigations.
07 Oct 2024
Spatio-temporal variations in surface Marine Carbonate System properties across the Western Mediterranean Sea using Volunteer Observing Ship data
David Curbelo-Hernández, David González-Santana, Aridane González-González, J. Magdalena Santana-Casiano, and Melchor González-Dávila
EGUsphere, https://doi.org/10.5194/egusphere-2024-2709, https://doi.org/10.5194/egusphere-2024-2709, 2024
Preprint under review for BG (discussion: open, 2 comments)
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This study offers a unique high-resolution dataset (2019–2024) on surface physicochemical properties in the western Mediterranean Sea. It reveals accelerated surface warming, significantly altering CO2 levels and pH. Currently a net CO2 sink, the region may become a CO2 source by 2030 due to weakening ingassing. The research highlights the value of VOS lines for monitoring climate impacts and stresses the need for ongoing observation to enhance long-term trend accuracy and future projections.
07 Oct 2024
Effects of Submarine Groundwater on Nutrient Concentration and Primary Production in a Deep Bay of the Japan Sea
Menghong Dong, Xinyu Guo, Takuya Matsuura, Taichi Tebakari, and Jing Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2581, https://doi.org/10.5194/egusphere-2024-2581, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Submarine groundwater discharge (SGD), a common coastal hydrological process that involves submarine inflow of groundwater into the sea, is associated with a large nutrient load. To clarify the distribution of SGD-derived nutrients after release at the bottom of the sea and their contribution to phytoplankton growth in the marine ecosystem, we modeled the SGD process in Toyama Bay using a specialized computer code that can distinguish SGD-derived nutrients from nutrients from other sources.
02 Oct 2024
Assessing the lifetime of anthropogenic CO2 and its sensitivity to different carbon cycle processes
Christine Kaufhold, Matteo Willeit, Bo Liu, and Andrey Ganopolski
EGUsphere, https://doi.org/10.5194/egusphere-2024-2976, https://doi.org/10.5194/egusphere-2024-2976, 2024
Revised manuscript accepted for BG (discussion: final response, 8 comments)
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This study simulates long-term future climate scenarios to examine how long CO2 emissions will persist in the atmosphere. It shows that the effectiveness of carbon removal processes varies with the amount emitted. The removal of CO2 through silicate weathering is faster than previously thought, leading to a quicker reduction over time. The combined behaviour of different carbon cycle processes emphasizes the need to include all of them in models, as to better predict long-term atmospheric CO2.
02 Oct 2024
Hydrothermal inputs drive dynamic shifts in microbial communities in Lake Magadi, Kenya Rift Valley
Evan R. Collins, Troy M. Ferland, Isla S. Castañeda, R. Bernhart Owen, Tim K. Lowenstein, Andrew S. Cohen, Robin W. Renaut, Molly D. O'Beirne, and Josef P. Werne
EGUsphere, https://doi.org/10.5194/egusphere-2024-3006, https://doi.org/10.5194/egusphere-2024-3006, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Archaeal molecular fossils (tetraethers) have been used around the globe to track changes in climate. Little is known about archaeal response to environmental change in soda lakes, especially lakes influenced by hydrothermal inputs. For the first time in Lake Magadi, we show tetraethers tracking abrupt changes in methane and non-methane producers due to hydrothermal inputs to the lake. This study provides insight into the role of hydrothermal water sources and methane production in soda lakes.
02 Oct 2024
Cold-water coral mounds are effective carbon sinks in the western Mediterranean Sea
Luis Greiffenhagen, Jürgen Titschack, Claudia Wienberg, Haozhuang Wang, and Dierk Hebbeln
EGUsphere, https://doi.org/10.5194/egusphere-2024-2532, https://doi.org/10.5194/egusphere-2024-2532, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Co-editor-in-chief
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Cold-water coral mounds are large structures on the seabed that are built by corals over thousands of years. They are regarded as carbonate sinks, with a potentially important role in the marine carbon cycle, but more quantitative studies are needed. Using sediment cores, we calculate the amount of carbon that has been stored in two mounds over the last 400 thousand years. We provide the first numbers and show that up to 19 times more carbon is accumulated on mounds than on the common seafloor.
Co-editor-in-chief
This paper discusses the carbon capture by poorly studied cold-water corals. These coral mounds represent a lesser known part of the carbon cycle and the outcomes of the study highlight the importance of these structures for natural carbon capture and storage at the sea floor.
27 Sep 2024
Modelling decadal trends and the impact of extreme events on carbon fluxes in a deciduous temperate forest using the QUINCY model
Tea Thum, Tuuli Miinalainen, Outi Seppälä, Holly Croft, Cheryl Rogers, Ralf Staebler, Silvia Caldararu, and Sönke Zaehle
EGUsphere, https://doi.org/10.5194/egusphere-2024-2802, https://doi.org/10.5194/egusphere-2024-2802, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Climate change has potential to influence the carbon sequestration potential of terrestrial ecosystems and here also nitrogen cycle is important. We used a terrestrial biosphere model QUINCY at mixed deciduous forest in Canada. We investigated the usefulness of using leaf area index and leaf chlorophyll content to improve the parameterization of the model. This work paves way for using spaceborn observations in the model parameterization, also including information on the nitrogen cycle.
23 Sep 2024
Three-Compartment, Two Parameter, Concentration-Driven Model for Uptake of Excess Atmospheric CO2 by the Global Ocean
Stephen E. Schwartz
EGUsphere, https://doi.org/10.5194/egusphere-2024-2893, https://doi.org/10.5194/egusphere-2024-2893, 2024
Revised manuscript accepted for BG (discussion: final response, 12 comments)
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The net uptake coefficient of anthropogenic CO2 by the global ocean (net uptake flux divided by excess atmospheric CO2 stock above preindustrial) calculated with a simple, transparent, three-compartment concentration-driven model with two independent parameters is determined to be 0.010 ± 0.002 yr-1 (net uptake flux at year 2022 2.84 ± 0.6 Pg yr-1). This result compares well with observations and with much more complex carbon cycle models.
23 Sep 2024
Depth Effects of Long-term Organic Residue Application on Soil Organic Carbon Stocks in Central Kenya
Claude Raoul Müller, Johan Six, Daniel Mugendi Njiru, Bernard Vanlauwe, and Marijn Van de Broek
EGUsphere, https://doi.org/10.5194/egusphere-2024-2796, https://doi.org/10.5194/egusphere-2024-2796, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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We studied how different organic and inorganic nutrient inputs affect soil organic carbon (SOC) down to 70 cm in Kenya. After 19 years, all organic treatments increased SOC stocks as compared to the control, but mineral nitrogen had no significant effect. Manure was the organic treatment that significantly increased SOC the deepest as its effect could be observed down to 60 cm. Manure was the best strategy to limit SOC loss in croplands and maintain soil quality after deforestation.
20 Sep 2024
Soil and Biomass Carbon Storage is Much Higher in Central American than Andean Montane Forests
Cecilia M. Prada, Katherine D. Heineman, Maria J. Pardo, Camille Piponiot, and James W. Dalling
EGUsphere, https://doi.org/10.5194/egusphere-2024-2738, https://doi.org/10.5194/egusphere-2024-2738, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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The influence of elevation and soil nutrient availability on carbon stocks has not been evaluated for ectomycorrhizal forests in the tropics. In western Panama we calculated C pools in ten plots in an elevational gradient varying in relative abundance of EM-trees. We found exceptionally high aboveground soil C in high elevation EM-forest, in contrast to arbuscular mycorrhizal-dominated Andean forests.
20 Sep 2024
Occupancy history influences extinction risk of fossil marine microplankton groups
Isaiah E. Smith, Ádám T. Kocsis, and Wolfgang Kiessling
EGUsphere, https://doi.org/10.5194/egusphere-2024-2597, https://doi.org/10.5194/egusphere-2024-2597, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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We examine how change in a species' range size over time influences that species' extinction risk. We analyze the interaction of instantaneous range size, range size change, and fossil sampling, and how these terms relate to extinction risk in marine microplankton. We find that the change in geographic range is the most informative predictor of extinction among the three examined variables. Using predictive models, we also assess extinction probability in four extant groups.
19 Sep 2024
Foliar nutrient uptake from dust sustains plant nutrition
Anton Lokshin, Daniel Palchan, Elnatan Golan, Ran Erel, Daniele Andronico, and Avner Gross
EGUsphere, https://doi.org/10.5194/egusphere-2024-2531, https://doi.org/10.5194/egusphere-2024-2531, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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Our research explores how chickpea plants can absorb essential nutrients like phosphorus, iron, and nickel directly from dust deposited on their leaves, in addition to uptake through their roots. This process was particularly effective under higher levels of atmospheric CO2, leading to increased plant growth. By using Nd isotopic tools, we traced the nutrients from dust and found that certain leaf traits enhance this uptake. This discovery may become increasingly important as CO2 levels rise.
18 Sep 2024
Riverine dissolved organic matter responds to alterations differently in two distinct hydrological regimes from Northern Spain
Selin Kubilay, Edurne Estévez, José Barquín Ortiz, and Gabriel Singer
EGUsphere, https://doi.org/10.5194/egusphere-2024-2772, https://doi.org/10.5194/egusphere-2024-2772, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Here, we studied how dams change the natural flow of rivers and their organic matter dynamics in Northern Spain. We found that in Atlantic rivers, natural rivers showed a higher turnover of organic material quality, which we believe is due to the interference of dams with the natural seasonal flow patterns. This suggests that Mediterranean rivers might be more resilient to flow regime alterations while Atlantic rivers lose their natural variability in organic material.
18 Sep 2024
Anomalous Summertime CO2 sink in the subpolar Southern Ocean promoted by early 2021 sea ice retreat
Kirtana Naëck, Jacqueline Boutin, Sebastiaan Swart, Marcel Du Plessis, Liliane Merlivat, Laurence Beaumont, Antonio Lourenco, Francesco d'Ovidio, Louise Rousselet, Brian Ward, and Jean-Baptiste Sallée
EGUsphere, https://doi.org/10.5194/egusphere-2024-2668, https://doi.org/10.5194/egusphere-2024-2668, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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In Summer 2022, a "CARbon Interface OCean Atmosphere"(CARIOCA) drifting buoy observed an anomalously strong ocean carbon sink in the subpolar Southern Ocean associated with large plumes of chlorophyll-a. Lagrangian backward trajectories indicate that these waters originated from the sea ice edge, the previous Spring 2021. Our study highlights the northward migration of the CO2 sink associated with early sea ice retreat.
18 Sep 2024
Bio-climatic factors drive spectral vegetation changes in Greenland
Tiago Silva, Brandon Samuel Whitley, Elisabeth Machteld Biersma, Jakob Abermann, Katrine Raundrup, Natasha de Vere, Toke Thomas Høye, and Wolfgang Schöner
EGUsphere, https://doi.org/10.5194/egusphere-2024-2571, https://doi.org/10.5194/egusphere-2024-2571, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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Ecosystems in Greenland have experienced significant changes over recent decades. Here, we show the consistency of a high-resolution polar-adapted reanalysis product to represent bio-climatic factors influencing ecological processes. Our results describe the interaction between snowmelt and soil water availability before the growing season onset, infer how changes in the growing season relate to changes in spectral greenness and identify regions of ongoing changes in vegetation distribution.
12 Sep 2024
Study on the Biological Communities and Bioweathering of Marble Surfaces at Temple of Heaven Park, Beijing, China
Youping Tian
EGUsphere, https://doi.org/10.5194/egusphere-2024-2758, https://doi.org/10.5194/egusphere-2024-2758, 2024
Preprint under review for BG (discussion: open, 5 comments)
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As a World Heritage site, the deterioration and scientific conservation of the Temple of Heaven Park in Beijing, China, is a topic of widespread concern. This paper presents the first detailed study of biological weathering of marble relics in the Temple of Heaven Park, using a novel statistical method to quantitatively analyze the biological communities. This research will provide important scientific basis and effective measures for the protection of marble relics.
12 Sep 2024
Pathways for avoiding ocean biogeochemical damage: Mitigation limits, mitigation options, and projections
Timothée Bourgeois, Olivier Torres, Friederike Fröb, Aurich Jeltsch-Thömmes, Giang T. Tran, Jörg Schwinger, Thomas L. Frölicher, Jean Negrel, David Keller, Andreas Oschlies, Laurent Bopp, and Fortunat Joos
EGUsphere, https://doi.org/10.5194/egusphere-2024-2768, https://doi.org/10.5194/egusphere-2024-2768, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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Anthropogenic greenhouse gas emissions significantly impact ocean ecosystems through climate change and acidification, leading to either progressive or abrupt changes. This study maps the crossing of physical and ecological limits for various ocean impact metrics under three emission scenarios. Using Earth system models, we identify when these limits are exceeded, highlighting the urgent need for ambitious climate action to safeguard the world's oceans and ecosystems.
12 Sep 2024
Optimal set of leaf and whole-tree elements for predicting forest functioning
Ecio Souza Diniz, Eladio Rodríguez-Penedo, Roger Grau-Andrés, Jordi Vayreda, and Marcos Fernández-Martínez
EGUsphere, https://doi.org/10.5194/egusphere-2024-2572, https://doi.org/10.5194/egusphere-2024-2572, 2024
Revised manuscript accepted for BG (discussion: final response, 5 comments)
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In this study, we found that the accumulation of nutrients (e.g., carbon, nitrogen, phosphorus, calcium) in leaves is an important factor in explaining tree growth in forest ecosystems. This result provides evidence for forest growth studies aimed at forest conservation and restoration to better direct their resources to data collection and measurement. Collecting data on nutrient stocks in tree leaves can also provide valuable information to broaden our understanding of forest functioning.
10 Sep 2024
Distinct changes in carbon, nitrogen, and phosphorus cycling in the litter layer across two contrasting forest-tundra ecotones
Frank Hagedorn, Joesphine Imboden, Pavel Moiseev, Decai Gao, Emmanuel Frossard, Daniel Christen, Konstantin Gavazov, and Jasmin Fetzer
EGUsphere, https://doi.org/10.5194/egusphere-2024-2622, https://doi.org/10.5194/egusphere-2024-2622, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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At treeline, plant species change abruptly from low stature plants in tundra to trees in forests. Our study documents that from tundra towards forest, the litter layer gets strongly enriched in nutrients. We show that these litter quality changes alter nutrient processing by soil microbes and increase the nutrient release during decomposition in forest than in tundra. The associated improvement of nutrient availability in the forest potentially stimulates tree growth and treeline shifts.
09 Sep 2024
Impulse response functions as a framework for quantifying ocean-based carbon dioxide removal
Elizabeth Yankovsky, Mengyang Zhou, Michael Tyka, Scott Bachman, David Ho, Alicia Karspeck, and Matthew Long
EGUsphere, https://doi.org/10.5194/egusphere-2024-2697, https://doi.org/10.5194/egusphere-2024-2697, 2024
Revised manuscript under review for BG (discussion: final response, 9 comments)
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Ocean alkalinity enhancement (OAE) is a promising strategy for ocean-based carbon dioxide removal, as it attempts to accelerate a natural process operating on Earth and may have climatically significant scalability. However, our best strategy for assessing OAE effects involves running computationally expensive climate models. We develop a powerful statistical technique that is able to encapsulate the climatic response to OAE interventions, thus simplifying the OAE carbon accounting problem.
05 Sep 2024
Annual net CO2 fluxes from drained organic soils used for agriculture in the hemiboreal region of Europe
Arta Bārdule, Raija Laiho, Jyrki Jauhiainen, Kaido Soosaar, Andis Lazdiņš, Kęstutis Armolaitis, Aldis Butlers, Dovilė Čiuldienė, Andreas Haberl, Ain Kull, Milda Muraškienė, Ivika Ostonen, Gristin Rohula-Okunev, Muhammad Kamil-Sardar, Thomas Schindler, Hanna Vahter, Egidijus Vigricas, and Ieva Līcīte
EGUsphere, https://doi.org/10.5194/egusphere-2024-2523, https://doi.org/10.5194/egusphere-2024-2523, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Estimates of CO2 fluxes from drained nutrient-rich organic soils in cropland and grassland in the hemiboreal region of Europe revealed that annual net CO2 fluxes were lower than the latest (2014) IPCC emission factors provided for the whole temperate zone including hemiboreal region. Contribution of CO2 fluxes from shallow highly decomposed organic soils, former peatlands that no longer meet the IPCC criterion for organic soils, to total emissions can be high and should not be underestimated.
04 Sep 2024
Intercomparison of biogenic CO2 flux models in four urban parks in the city of Zurich
Stavros Stagakis, Dominik Brunner, Junwei Li, Leif Backman, Anni Karvonen, Lionel Constantin, Leena Järvi, Minttu Havu, Jia Chen, Sophie Emberger, and Liisa Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2024-2475, https://doi.org/10.5194/egusphere-2024-2475, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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The balance between CO2 uptake and emissions from urban green areas is still not well understood. This study evaluated for the first time the urban park CO2 exchange simulations by four different types of biosphere models by comparing them with observations. Even though some advantages and disadvantages of the different model types were identified, there was no strong evidence that more complex models performed better than simple ones.
29 Aug 2024
Spring-neap tidal cycles modulate the strength of the carbon source at the estuary-coast interface
Vlad A. Macovei, Louise C. V. Rewrie, Rüdiger Röttgers, and Yoana G. Voynova
EGUsphere, https://doi.org/10.5194/egusphere-2024-2643, https://doi.org/10.5194/egusphere-2024-2643, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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A commercial vessel equipped with scientific instruments regularly travelled between two large macro-tidal estuaries. We found that biogeochemical variability in the outer estuaries is driven by the 14-day spring-neap tidal cycle, with strong effects on dissolved inorganic and organic carbon concentrations and distribution. Since this land-sea interface effect increases the strength of the carbon source to the atmosphere by 74 % during spring tide, it should be accounted for in regional models.
22 Aug 2024
Surface CO2 Gradients Challenge Conventional CO2 Emission Quantification in Lentic Water Bodies under Calm Conditions
Patrick Aurich, Uwe Spank, and Matthias Koschorreck
EGUsphere, https://doi.org/10.5194/egusphere-2024-2550, https://doi.org/10.5194/egusphere-2024-2550, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Lakes can be sources and sinks for the greenhouse gas carbon dioxide. The gas exchange between the atmosphere and the water can be measured by taking gas samples in both. However, the depth of water samples is not well defined, which may cause errors. We hypothesized that gradients of CO2 concentrations develop under the surface when wind speeds are very low. Our measurements show that such a gradient can occur in calm nights, potentially shifting a lake from a CO2 sink to a source.
20 Aug 2024
An upper mesopelagic zone carbon budget for the subarctic North Pacific
Brandon Stephens, Montserrat Roca-Martí, Amy Maas, Vinícius Amaral, Samantha Clevenger, Shawnee Traylor, Claudia Benitez-Nelson, Philip Boyd, Ken Buesseler, Craig Carlson, Nicolas Cassar, Margaret Estapa, Andrea Fassbender, Yibin Huang, Phoebe Lam, Olivier Marchal, Susanne Menden-Deuer, Nicola Paul, Alyson Santoro, David Siegel, and David Nicholson
EGUsphere, https://doi.org/10.5194/egusphere-2024-2251, https://doi.org/10.5194/egusphere-2024-2251, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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The ocean’s mesopelagic zone (MZ) plays a crucial role in the global carbon cycle. This study combines new and previously published measurements of organic carbon supply and demand collected in August 2018 for the MZ in the subarctic North Pacific Ocean. Supply was insufficient to meet demand in August, but supply entering into the MZ in the spring of 2018 could have met the August demand. Results suggest observations over seasonal time scales may help to close MZ carbon budgets.
19 Aug 2024
Variations in vegetation evapotranspiration affect water yield in high-altitude areas
Yinying Jiao, Guofeng Zhu, Dongdong Qiu, Siyu Lu, Gaojia Meng, Rui Li, Qinqin Wang, Longhu Chen, and Wentong Li
EGUsphere, https://doi.org/10.5194/egusphere-2024-2246, https://doi.org/10.5194/egusphere-2024-2246, 2024
Preprint under review for BG (discussion: open, 1 comment)
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This study shows that transpiration is the key reason behind the high-altitude forest zone's limited runoff generation. Furthermore, within the altitude range of 2500–3200 meters, an increase in recirculated water vapor was observed alongside an increase in precipitation, suggesting a direct positive correlation between these two factors.
19 Aug 2024
The Impact of Scoria-Filled Aeration Trenches on the N-cycle and Greenhouse Gases Emissions from a Clayey Soil
Shahar Baram, Asher Bar-Tal, Anna Beriozkin, Roee Katzir, Alon Gal, and David Russo
EGUsphere, https://doi.org/10.5194/egusphere-2024-2140, https://doi.org/10.5194/egusphere-2024-2140, 2024
Preprint under review for BG (discussion: final response, 6 comments)
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We evaluate the impact of scoria-filled aeration trenches on N2O and CO2 emissions from a treated wastewater (TWW) irrigated orchard, using three years of field monitoring and 3-D numerical simulations. We show that trenches may increase the N2O fluxes year-round, and that filling them with hydraulically optimal soil may increase water uptake but concomitantly increase the N2O fluxes. Improved growth by the trees may balance the increased N2O emissions from the trenches.
16 Aug 2024
Inadequacies in the representation of sub-seasonal phytoplankton dynamics in Earth system models
Madhavan Girijakumari Keerthi, Olivier Aumont, Lester Kwiatkowski, and Marina Levy
EGUsphere, https://doi.org/10.5194/egusphere-2024-2294, https://doi.org/10.5194/egusphere-2024-2294, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Our study assesses the capability of CMIP6 models to reproduce satellite observations of sub-seasonal chlorophyll variability. Models struggle to reproduce the sub-seasonal variance and its contribution across timescales. Some models overestimate sub-seasonal variance and exaggerate its role in annual fluctuations, while others underestimate it. Underestimation is likely due to the coarse resolution of models, while overestimation may result from intrinsic oscillations in biogeochemical models.
15 Aug 2024
Reviews and syntheses: Current perspectives on biosphere research – 2024
Friedrich J. Bohn, Ana Bastos, Romina Martin, Anja Rammig, Niak Sian Koh, Giles B. Sioen, Bram Buscher, Louise Carver, Fabrice DeClerck, Moritz Drupp, Robert Fletcher, Matthew Forrest, Alexandros Gasparatos, Alex Godoy-Faúndez, Gregor Hagedorn, Martin Hänsel, Jessica Hetzer, Thomas Hickler, Cornelia B. Krug, Stasja Koot, Xiuzhen Li, Amy Luers, Shelby Matevich, H. Damon Matthews, Ina C. Meier, Awaz Mohamed, Sungmin O, David Obura, Ben Orlove, Rene Orth, Laura Pereira, Markus Reichstein, Lerato Thakholi, Peter Verburg, and Yuki Yoshida
EGUsphere, https://doi.org/10.5194/egusphere-2024-2551, https://doi.org/10.5194/egusphere-2024-2551, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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An interdisciplinary collaboration of 35 international researchers from 34 institutions highlighting nine recent findings in biosphere research. Within these themes, they discuss issues arising from climate change and other anthropogenic stressors, and highlight the co-benefits of nature-based solutions and ecosystem services. They discuss recent findings in the context of global trade and international policy frameworks, and highlight lessons for local implementation of nature-based solutions.
15 Aug 2024
Detection of Fast-Changing Intra-seasonal Vegetation Dynamics of Drylands Using Solar-Induced Chlorophyll Fluorescence (SIF)
Jiaming Wen, Giulia Tagliabue, Micol Rossini, Francesco Pietro Fava, Cinzia Panigada, Lutz Merbold, Sonja Leitner, and Ying Sun
EGUsphere, https://doi.org/10.5194/egusphere-2024-2529, https://doi.org/10.5194/egusphere-2024-2529, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Solar-induced chlorophyll fluorescence (SIF), a tiny optical signal emitted from the core photosynthetic machinery, has emerged as a promising tool to evaluate vegetation growth from satellites. We find satellite SIF can capture intra-seasonal (i.e., from days to weeks) vegetation dynamics of dryland ecosystems, while greenness-based vegetation indices cannot. This study generates novel insights for developing effective real-time vegetation monitoring systems to inform climate risk management.
14 Aug 2024
Spatiotemporal variability of CO2, N2O and CH4 fluxes from a semi-deciduous tropical forest soil in the Congo basin
Roxanne Daelman, Marijn Bauters, Matti Barthel, Emmanuel Bulonza, Lodewijk Lefevre, José Mbifo, Johan Six, Klaus Butterbach-Bahl, Benjamin Wolf, Ralf Kiese, and Pascal Boeckx
EGUsphere, https://doi.org/10.5194/egusphere-2024-2346, https://doi.org/10.5194/egusphere-2024-2346, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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The increase in atmospheric concentrations of several greenhouse gasses (GHG) since 1750 is attributed to human activity, however natural ecosystems, such as tropical forests, also contribute to GHG budgets. The Congo basin hosts the second largest tropical forest and is understudied. In this study, measurements of soil GHG exchange were carried out during 16 months in a tropical forest in the Congo Basin. Overall, the soil acted as a major source for CO2 and N2O and a minor sink for CH4.
13 Aug 2024
Snow thermal conductivity controls future winter carbon emissions in shrub-tundra
Johnny Rutherford, Nick Rutter, Leanne Wake, and Alex Cannon
EGUsphere, https://doi.org/10.5194/egusphere-2024-2445, https://doi.org/10.5194/egusphere-2024-2445, 2024
Preprint under review for BG (discussion: open, 1 comment)
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The Arctic winter is vulnerable to climate warming and ~1700 Gt of carbon stored in high latitude permafrost ecosystems is at risk of degradation in the future due to enhanced microbial activity. Poorly represented cold season processes, such as the simulation of snow thermal conductivity in Land Surface Models (LSMs), causes uncertainty in projected carbon emission simulations. Improved snow conductivity parameterization in CLM5.0 significantly increases predicted winter CO2 emissions to 2100.
12 Aug 2024
Magnesium (Mg/Ca, δ26Mg), boron (B/Ca, δ11B), and calcium ([Ca2+]) geochemistry of Arctica islandica and Crassostrea virginica extrapallial fluid and shell under ocean acidification
Blanca Alvarez Caraveo, Maxence Guillermic, Alan Downey-Wall, Louise P. Cameron, Jill N. Sutton, John A. Higgins, Justin B. Ries, Katie Lotterhos, and Robert A. Eagle
EGUsphere, https://doi.org/10.5194/egusphere-2024-1957, https://doi.org/10.5194/egusphere-2024-1957, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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We studied the geochemistry of two bivalves, Crassostrea virginica and Arctica islandica. We examined the effects of three ocean acidification conditions (ambient, moderate, and high) on the geochemistry of C. virginica. We show that bivalves have high physiological control over the internal calcifying fluid, presenting a challenge to using elemental proxies for reconstructing seawater parameters.
12 Aug 2024
Diatom shifts and limnological changes in a Siberian boreal lake: impacts of climate warming and anthropogenic pollution
Amelie Stieg, Boris K. Biskaborn, Ulrike Herzschuh, Andreas Marent, Jens Strauss, Dorothee Wilhelms–Dick, Luidmila A. Pestryakova, and Hanno Meyer
EGUsphere, https://doi.org/10.5194/egusphere-2024-2470, https://doi.org/10.5194/egusphere-2024-2470, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Globally, lake ecosystems have undergone significant shifts since the 1950s due to human activities. This study offers a unique 220-year sediment record from a remote Siberian boreal lake, revealing the impacts of climate warming and pollution. Multi-proxy analyses, including diatom taxonomy, silicon isotopes, carbon and nitrogen proxies, reveal complex biogeochemical interactions, highlighting the need for further research to mitigate anthropogenic effects on these vital water resources.
12 Aug 2024
Precipitation-fire-functional interactions control biomass stocks and carbon exchanges across the world’s largest savanna
Mathew Williams, David T. Milodowski, Thomas Luke Smallman, Kyle G. Dexter, Gabi C. Hegerl, Iain M. McNicol, Michael O'Sullivan, Carla M. Roesch, Casey M. Ryan, Stephen Sitch, and Aude Valade
EGUsphere, https://doi.org/10.5194/egusphere-2024-2497, https://doi.org/10.5194/egusphere-2024-2497, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Southern African woodlands are important in both regional and global carbon cycles. A new carbon analysis created by combining satellite data with ecosystem modelling shows that the region has a neutral C balance overall, but with important spatial variations. Patterns of biomass and C balance across the region are the outcome of climate controls on production, vegetation-fire interactions, which determine mortality of vegetation, and spatial variations in vegetation function.
06 Aug 2024
Covariation of redox potential profiles and water table level in peatland sites representing different drainage regimes: implications for ecological modelling
Markku Koskinen, Jani Anttila, Valerie Vranová, Ladislav Holik, Kevin Roche, Michel Vorenhout, Mari Pihlatie, and Raija Laiho
EGUsphere, https://doi.org/10.5194/egusphere-2024-2050, https://doi.org/10.5194/egusphere-2024-2050, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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Redox potential, indicative of the active pathways of organic matter decomposition, was monitored for two years in a boreal peatland with three drainage regimes. Contrary to expectations, water table level and redox potential were found to not correlate in a monotonic fashion and thus the relationship between water table level and redox conditions is not modellable by non-dynamic models.
05 Aug 2024
Technical Note: A modified formulation of dynamic energy budget theory for faster computation of biological growth
Jinyun Tang and William J. Riley
EGUsphere, https://doi.org/10.5194/egusphere-2024-2282, https://doi.org/10.5194/egusphere-2024-2282, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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A new mathematical formulation of the dynamic energy budget model is presented for the growth of biological organisms. The new theory combines mass conservation law and chemical kinetics theory, and is computationally faster than the standard formulation of dynamic energy budget model. In simulating the growth of Thalassiosira weissfloggi in a nitrogen-limiting chemostat, the new model is as good as the standard dynamic energy budget model using almost the same parameter values.
01 Aug 2024
Biogeochemical functioning of Lake Alaotra (Madagascar): a reset of aquatic carbon sources along the land-ocean gradient
Vao Fenotiana Razanamahandry, Alberto Borges, Liesa Brosens, Cedric Morana, Tantely Razafimbelo, Tovonarivo Rafolisy, Gerard Govers, and Steven Bouillon
EGUsphere, https://doi.org/10.5194/egusphere-2024-2213, https://doi.org/10.5194/egusphere-2024-2213, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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A comprehensive survey of the biogeochemistry of the lake Alaotra system showed that the lake and surrounding wetlands acted as a substantial source of new organic carbon (OC), which was exported downstream. Marsh vegetation is the main source of dissolved OC, while phytoplankton contributes to particulate OC pool. The biogeochemical functioning of Lake Alaotra differs from most East African lakes studied, likely due to its large surface area, shallow water depth, and surrounding wetlands.
01 Aug 2024
Sensitivity of tropical woodland savannas to El Niño droughts
Simone Matias Reis, Yadvinder Malhi, Ben Hur Marimon Junior, Beatriz S. Marimon, Huanyuan Zhang-Zheng, Renata Freitag, Cécile A. J. Girardin, Edmar Almeida de Oliveira, Karine da Silva Peixoto, Luciana Januário de Souza, Ediméia Laura Souza da Silva, Eduarda Bernardes Santos, Kamila Parreira da Silva, Maélly Dállet Alves Gonçalves, Cecilia A. L. Dahlsjö, Oliver L. Phillips, and Imma Oliveras Menor
EGUsphere, https://doi.org/10.5194/egusphere-2024-2118, https://doi.org/10.5194/egusphere-2024-2118, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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The 2015–2016 El Niño caused severe droughts in tropical forests, but its impact on the Cerrado, largest savanna, was unclear. Our study tracked the productivity of two key Cerrado vegetation types over five years. Before El Niño, productivity was higher in the transitional forest-savanna, but it dropped sharply during the event. Meanwhile, the savanna showed minor changes. These findings suggest that transitional ecosystems are particularly vulnerable to drought and climate change.
31 Jul 2024
Effects of photosymbiosis and related processes on planktic foraminifera-bound nitrogen isotopes in South Atlantic sediments
Alexandra Auderset, Sandi M. Smart, Yeongjun Ryu, Dario Marconi, Haojia Abby Ren, Lena Heins, Hubert Vonhof, Ralf Schiebel, Janne Repschläger, Daniel M. Sigman, Gerald H. Haug, and Alfredo Martínez-García
EGUsphere, https://doi.org/10.5194/egusphere-2024-2291, https://doi.org/10.5194/egusphere-2024-2291, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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This study investigates foraminifera-bound nitrogen isotopes (FB-δ15N) as a tool to study the history of photosymbiosis in planktic foraminifera. By analysing multiple species from the South Atlantic, we found that FB-δ15N differentiates between species with dinoflagellate symbionts and those without, probably due to internal ammonium recycling in the former. Overall, this study provides strong support for FB-δ15N as a tool for exploring the evolution of symbiosis in marine ecosystems.
31 Jul 2024
Modeling the contribution of micronekton diel vertical migrations to carbon export in the mesopelagic zone
Hélène Thibault, Frédéric Ménard, Jeanne Abitbol-Spangaro, Jean-Christophe Poggiale, and Séverine Martini
EGUsphere, https://doi.org/10.5194/egusphere-2024-2074, https://doi.org/10.5194/egusphere-2024-2074, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Micronekton significantly impacts oceanic carbon transport, yet often overlooked. Using a trait-based model, we simulated their diel vertical migrations and carbon production, revealing size, taxonomy, light and primary production as key factors. In temperate regions, micronekton influenced greatly the transport efficiency in summer. Future research must focus on micronekton metabolism and dynamics, considering global warming and their potential exploitation.
30 Jul 2024
Differential responses of soil microbiomes to ureolytic biostimulation across depths in Aridisols
Kesem Abramov, Svetlana Gelfer, Michael Tsesarsky, and Hadas Raveh-Amit
EGUsphere, https://doi.org/10.5194/egusphere-2024-1663, https://doi.org/10.5194/egusphere-2024-1663, 2024
Preprint under review for BG (discussion: open, 2 comments)
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Microbial-induced calcite precipitation (MICP) is considered an environmentally conscious technology for soil amelioration. We study the response of microbiomes to MICP stimulation in arid soils from different sites and depths. We show that different soil depths host distinct microbiomes, and that biostimulation selects for specific taxa while suppressing others. The study provides evidence for the effectiveness of biostimulation, yet shows that it comes with a cost for biodiversity.
26 Jul 2024
Ecosystem leaf area, gross primary production, and evapotranspiration responses to wildfire in the Columbia River Basin
Mingjie Shi, Nate McDowell, Huilin Huang, Faria Zahura, Lingcheng Li, and Xingyuan Chen
External preprint server, https://doi.org/10.22541/au.171053013.30286044/v2, https://doi.org/10.22541/au.171053013.30286044/v2, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Using Moderate Resolution Imaging Spectroradiometer data products, we quantitatively estimate the resistance and resilience of ecosystem functions to wildfires that occurred in the Columbia River Basin in 2015. Carbon state exhibits lower resistance and resilience than the ecosystem fluxes. The random forest feature importance analysis indicates that burn severity plays a minor role in the resilience of grassland, while it has a relatively major role in the resilience of forest and savanna.
26 Jul 2024
Potential of carbon uptake and local aerosol production in boreal and hemi-boreal ecosystems across Finland and in Estonia
Piaopiao Ke, Anna Lintunen, Pasi Kolari, Annalea Lohila, Santeri Tuovinen, Janne Lampilahti, Roseline Thakur, Maija Peltola, Otso Peräkylä, Tuomo Nieminen, Ekaterina Ezhova, Mari Pihlatie, Asta Laasonen, Markku Koskinen, Helena Rautakoski, Laura Heimsch, Tom Kokkonen, Aki Vähä, Ivan Mammarella, Steffen Noe, Jaana Bäck, Veli-Matti Kerminen, and Markku Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2024-1967, https://doi.org/10.5194/egusphere-2024-1967, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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Our research explores diverse ecosystems’ role in climate cooling via the concept of CarbonSink+ Potential. We measured CO2 uptake and loaal aerosol production in forests, farms, peatlands, urban gardens, and coastal areas across Finland and Estonia. The long-term data reveal that while forests are vital regarding CarbonSink+ Potential, farms and urban gardens also play significant roles. These insights can help optimize management policy of natural resource to mitigate global warming.
24 Jul 2024
Mire edge is not a marginal thing: Assessing the factors behind the formation, vegetation succession, and carbon balance of a subarctic fen margin
Teemu Juselius-Rajamäki, Sanna Piilo, Susanna Salminen-Paatero, Emilia Tuomaala, Tarmo Virtanen, Atte Korhola, Anna Autio, Hannu Marttila, Pertti Ala-Aho, Annalea Lohila, and Minna Väliranta
EGUsphere, https://doi.org/10.5194/egusphere-2024-2102, https://doi.org/10.5194/egusphere-2024-2102, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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The vegetation can be used to infer the potential climate feedback of peatlands. New studies have shown recent expansion of peatlands but their plant community succession of has not been studied. Although generally described as dry bog-types, our results show that peatland margins in a subarctic fen initiated as wet fen with high methane emissions and shifted to dryer peatland types only after dryer post Little Ice Age climate. Thus, they have acted as a carbon source for most of their history.
24 Jul 2024
Hybrid model estimate of the ocean carbon sink from 1959 to 2022
Jens Terhaar
EGUsphere, https://doi.org/10.5194/egusphere-2024-2171, https://doi.org/10.5194/egusphere-2024-2171, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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Co-editor-in-chief
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The ocean is a major natural carbon sink. Despite its importance, estimates of the ocean carbon sink remain uncertain. Here, I present a hybrid model estimate of the ocean carbon sink from 1959 to 2022. By combining ocean models in hindcast mode and Earth System Models, I keep the strength of each approach and remove the respective weaknesses. This hybrid model estimate is similar in magnitude than the best estimate of the Global Carbon Budget but 70 % less uncertain.
Co-editor-in-chief
The ocean plays a key role in the global carbon cycle and its carbon sink strength is critical for removing atmospheric carbon dioxide and stabilizing global climate. This oceanic carbon sink strength is difficult to measure and models provide estimates that differ from one another. Terhaar combines multiple modeling approaches using composite model-based averages and fully coupled Earth System Models to take advantages of the benefits of both, and in doing so derives a similar sink strength to existing estimates but with reduced uncertainty.
23 Jul 2024
Relationships between the concentration of particulate organic nitrogen and the inherent optical properties of seawater in oceanic surface waters
Alain Fumenia, Hubert Loisel, Rick Allen Reynolds, and Dariusz Stramski
EGUsphere, https://doi.org/10.5194/egusphere-2024-2218, https://doi.org/10.5194/egusphere-2024-2218, 2024
Revised manuscript accepted for BG (discussion: final response, 5 comments)
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Particulate organic nitrogen (PON) in the ocean refers to nitrogen contained in particles suspended such as phytoplankton, zooplankton, bacteria, viruses, and organic detritus. We used field measurements to determine relationships between PON and inherent optical properties of seawater across a broad range of marine environments. The presented relationships are expected to have application in the assessment of PON distribution and variations from in situ and satellite optical observations
22 Jul 2024
The bacteria-protist link as a main route of dissolved organic matter across contrasting productivity areas in the Patagonian Shelf
Celeste López-Abbate, John E. Garzón-Cardona, Ricardo Silva, Juan-Carlos Molinero, Laura A. Ruiz-Etcheverry, Ana M. Martínez, Azul S. Gilabert, and Rubén J. Lara
EGUsphere, https://doi.org/10.5194/egusphere-2024-1860, https://doi.org/10.5194/egusphere-2024-1860, 2024
Revised manuscript accepted for BG (discussion: final response, 7 comments)
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This study examines how microbial community structure, growth, and grazing impact the DOM pool in the Patagonian Shelf. Despite higher phytoplankton biomass, faster-growing bacteria were selectively grazed by protists leading to DOM accumulation, likely due to a reduction in DOM-consuming bacteria and the addition of egestion compounds. Experimental data showed that while bacteria remained as the primarily shapers of DOM quality, grazing pressure impacted on DOM accumulation.
18 Jul 2024
Technical note: New approach for the determination of N2 fixation rates by coupling a membrane equilibrator to a mass spectrometer on voluntary observing ships
Sören Iwe, Oliver Schmale, and Bernd Schneider
EGUsphere, https://doi.org/10.5194/egusphere-2024-2049, https://doi.org/10.5194/egusphere-2024-2049, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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We present a novel method to quantify N2 fixation by cyanobacteria, crucial in Baltic Sea eutrophication. Our Gas Equilibrium – Membrane-Inlet Mass Spectrometer (GE-MIMS), designed for operation on voluntary observing ships (VOS), enables large-scale monitoring of surface water N2 depletion caused by N2 fixation. Laboratory tests confirm the device’s accuracy and precision, ensuring it can complement current methods and contribute valuable data to better understand N2 fixation in the Baltic Sea.
18 Jul 2024
Ancient clays support contemporary biogeochemical activity in the Critical Zone
Vanessa M. Alfonso, Peter M. Groffman, Zhongqi Cheng, and David E. Seidemann
EGUsphere, https://doi.org/10.5194/egusphere-2024-1165, https://doi.org/10.5194/egusphere-2024-1165, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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This study sought to explore organic-mineral interactions by investigating the functional performance of exposed clays through measurements of biogeochemical processes occurring on these materials. Results indicate that ancient clays are contributing to contemporary biogeochemical processes at ecosystem and landscape scales by supporting an active microbial community and a wide range of nitrogen cycle processes encompassing mineralization, immobilization, nitrification, and denitrification.
17 Jul 2024
Stable iron isotope signals indicate a “pseudo-abiotic" process driving deep iron release in methanic sediments
Susann Henkel, Bo Liu, Michael Staubwasser, Simone A. Kasemann, Anette Meixner, David Aromokeye, Michael W. Friedrich, and Sabine Kasten
EGUsphere, https://doi.org/10.5194/egusphere-2024-1942, https://doi.org/10.5194/egusphere-2024-1942, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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We intend to unravel iron (Fe) reduction pathways in high depositional methanic sediments because pools of Fe minerals could stimulate methane oxidation, but also generation. Our data from the North Sea indicate that Fe release takes place mechanistically different to Fe reduction in shallow sediments that typically fractionates Fe isotopes. We conclude that fermentation of organic matter involving interspecies electron transfer, partly through conductive Fe oxides, could play an important role.
15 Jul 2024
The Effectiveness of Agricultural Carbon Dioxide Removal using the University of Victoria Earth System Climate Model
Rebecca Chloe Evans and H. Damon Matthews
EGUsphere, https://doi.org/10.5194/egusphere-2024-1810, https://doi.org/10.5194/egusphere-2024-1810, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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To mitigate our impact on the climate, research suggests that we will need to both drastically reduce emissions and perform carbon dioxide removal (CDR). We simulated future climates under three emissions scenarios, in which we removed some carbon from the air and put it into agricultural soil at varying rates. We found that agricultural CDR is much more effective at reducing global temperatures if done in a low emissions scenario and at a high rate, and it becomes less effective with time.
01 Jul 2024
CO2 flux characteristics of the grassland ecosystem and its response to environmental factors in the dry-hot valley of Jinsha River, China
Chaolei Yang, Yufeng Tian, Jingqi Cui, Guangxiong He, Jingyuan Li, Canfeng Li, Haichuang Duan, Zong Wei, Liu Yan, Xin Xia, Yong Huang, and Aihua Jiang
EGUsphere, https://doi.org/10.5194/egusphere-2024-1226, https://doi.org/10.5194/egusphere-2024-1226, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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The environmental factors and CO2 flux of the grassland ecosystem in the dry-hot valley of the Jinsha River exhibited highly seasonal characteristics. During the rainy season, the grassland showed a carbon sink feature, while during the dry season, it exhibited carbon emission status. Throughout the entire year, the grassland ecosystem acted as a weak carbon source, exhibiting a carbon-neutral. The CO2 flux was most influenced by vapor pressure deficit, relative humidity, and soil water content.
28 Jun 2024
Multispecies expression of coccolithophore vital effects with changing CO2 concentrations and pH in the laboratory with insights for reconstructing CO2 levels in geological history
Goulwen Le Guevel, Fabrice Minoletti, Carla Geisen, Gwendoline Duong, Virginia Rojas, and Michaël Hermoso
EGUsphere, https://doi.org/10.5194/egusphere-2024-1890, https://doi.org/10.5194/egusphere-2024-1890, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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This study explores the impact of environmental conditions on the chemistry of coccoliths, calcite minerals produced by marine algae, to better understand past climate changes. By cultivating different species of coccolithophores under various CO2 and pH levels, we have shown that the isotopic composition of certain species varies with CO2 concentration and quantified these variations.
28 Jun 2024
Depositional controls and budget of organic carbon burial in fine-grained sediments of the North Sea – the Helgoland Mud Area as a test field
Daniel Müller, Bo Liu, Walter Geibert, Moritz Holtappels, Lasse Sander, Elda Miramontes, Heidi Taubner, Susann Henkel, Kai-Uwe Hinrichs, Denise Bethke, Ingrid Dohrmann, and Sabine Kasten
EGUsphere, https://doi.org/10.5194/egusphere-2024-1632, https://doi.org/10.5194/egusphere-2024-1632, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Coastal and shelf sediments are the most important sinks for organic carbon (OC) on Earth. We produced a new high-resolution sediment and pore-water dataset from the Helgoland Mud Area (HMA), North Sea, to determine, which depositional factors control the preservation of OC. The burial efficiency is highest in an area of high sedimentation and terrigenous OC. The HMA covers 0.09 % of the North Sea, but accounts for 0.76 % of its OC accumulation, highlighting the importance of the depocentre.
27 Jun 2024
Exploring effects of variation in plant root traits on carbon emissions from estuarine marshes
Youssef Saadaoui, Christian Beer, Peter Mueller, Friederike Neiske, Joscha N. Becker, Annette Eschenbach, and Philipp Porada
EGUsphere, https://doi.org/10.5194/egusphere-2024-1756, https://doi.org/10.5194/egusphere-2024-1756, 2024
Preprint under review for BG (discussion: open, 4 comments)
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Estuarine marshes are vital for capturing carbon and benefiting the climate. Our research explored how plant-microbe interactions affect carbon cycling, focusing on traits like root oxygen loss. Using a model, we found that accounting for these trait variations significantly changes carbon balance estimates. This suggests that including plant diversity in ecosystem models improves predictions about carbon dynamics in estuarine marshes, highlighting their importance in climate regulation.
26 Jun 2024
Temporal dynamics and environmental controls of carbon dioxide and methane fluxes measured by the eddy covariance method over a boreal river
Aki Vähä, Timo Vesala, Sofya Guseva, Anders Lindroth, Andreas Lorke, Sally MacIntyre, and Ivan Mammarella
EGUsphere, https://doi.org/10.5194/egusphere-2024-1644, https://doi.org/10.5194/egusphere-2024-1644, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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Boreal rivers are significant sources of carbon dioxide (CO2) and methane (CH4) to the atmosphere but the controls of these emissions are uncertain. We measured four months of CO2 and CH4 exchange between a regulated boreal river and the atmosphere with eddy covariance. We found statistical relationships between the gas exchange and several environmental variables, the most important of which were dissolved CO2 partial pressure in water, wind speed, and water temperature.
20 Jun 2024
Evaluating state-of-the-art process-based and data-driven models in simulating CO2 fluxes and their relationship with climate in western European temperate forests
Gaïa Michel, Julien Crétat, Olivier Mathieu, Mathieu Thévenot, Andrey Dara, Robert Granat, Zhendong Wu, Clément Bonnefoy-Claudet, Julianne Capelle, Jean Cacot, and John S. Kimball
EGUsphere, https://doi.org/10.5194/egusphere-2024-1758, https://doi.org/10.5194/egusphere-2024-1758, 2024
Revised manuscript under review for BG (discussion: final response, 7 comments)
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This study questions the usefulness of state-ot-the-art models to characterize the temporal variability of atmosphere-ecosystem CO2 exchanges in western European forests. Their mean annual cycle and annual budget are better captured by statistical than physical models, while their interannual variability and long-term trend are better captured by models forced by climate variability. Accounting for both forest stands and climate variability is thus key for properly assessing CO2 fluxes.
19 Jun 2024
Improved understanding of eutrophication trends, indicators and problem areas using machine learning
Deep S. Banerjee and Jozef Skakala
External preprint server, https://doi.org/10.22541/essoar.171405637.76928549/v1, https://doi.org/10.22541/essoar.171405637.76928549/v1, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Nitrate is a crucial nutrient in oceans. Excess nutrients can trigger uncontrolled algae growth (eutrophication), damaging marine ecosystems. We used a machine learning tool to generate a skilled, gap-free, bi-decadal surface nitrate dataset from sparse observations. This dataset reveals areas on the North West European Shelf at risk of eutrophication, bi-decadal trends in coastal nitrate, and an impact of winter nitrate on spring phytoplankton blooms.
13 Jun 2024
Amplified bottom water acidification rates on the Bering Sea shelf from 1970–2022
Darren Pilcher, Jessica Cross, Natalie Monacci, Linquan Mu, Kelly Kearney, Albert Hermann, and Wei Cheng
EGUsphere, https://doi.org/10.5194/egusphere-2024-1096, https://doi.org/10.5194/egusphere-2024-1096, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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The Bering Sea shelf is a highly productive marine ecosystem that is vulnerable to ocean acidification. We use a computational model to simulate the carbon cycle and acidification rates from 1970–2022. The results suggest that bottom water acidification rates are more than twice as great as surface rates. Bottom waters are also naturally more acidic, thus these waters will pass key thresholds known to negatively impact marine organisms, such as red king crab, much sooner than surface waters.
12 Jun 2024
A time series analysis of transparent exopolymer particle distributions and C:N stoichiometry in the subtropical North Pacific: a key process in net community production and preformed nitrate anomalies?
Kieran Curran, Tracy Villareal, and Robert T. Letscher
EGUsphere, https://doi.org/10.5194/egusphere-2024-1416, https://doi.org/10.5194/egusphere-2024-1416, 2024
Preprint under review for BG (discussion: final response, 6 comments)
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This work provides a two year record of marine organic gel concentrations from an open ocean site in the subtropical North Pacific Ocean north of Hawaii. These microscopic gels are investigated to understand their importance as an understudied component of organic matter cycling by marine microbes. We find an important role for gel cycling during the summer months, helping explain previously contradictory estimates of nutrient supply and demand for the subtropical ocean.
12 Jun 2024
Dissolved organic matter fosters core mercury-methylating microbiome for methylmercury production in paddy soils
Qiang Pu, Bo Meng, Jen-How Huang, Kun Zhang, Jiang Liu, Yurong Liu, Mahmoud A. Abdelhafiz, and Xinbin Feng
EGUsphere, https://doi.org/10.5194/egusphere-2024-590, https://doi.org/10.5194/egusphere-2024-590, 2024
Revised manuscript accepted for BG (discussion: final response, 7 comments)
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This study examines the effect of dissolved organic matter (DOM) on microbial mercury (Hg) methylation in paddy soils. It uncovers that DOM regulates Hg methylation mainly through altering core Hg-methylating microbiome composition and boosting the growth of core Hg-methylating microorganisms. The study highlights that in the regulation of methylmercury formation in paddy soils, more attention should be paid to changes in DOM concentration and composition.
06 Jun 2024
Solubility characteristics of soil humic substances as a function of pH
Xuemei Yang, Jie Zhang, Khan M. G. Mostofa, Mohammad Mohinuzzaman, H. Henry Teng, Nicola Senesi, Giorgio S. Senesi, Jie Yuan, Yu Liu, Si-Liang Li, Xiaodong Li, Baoli Wang, and Cong-Qiang Liu
EGUsphere, https://doi.org/10.5194/egusphere-2023-2994, https://doi.org/10.5194/egusphere-2023-2994, 2024
Revised manuscript accepted for BG (discussion: final response, 7 comments)
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The solubility characteristics of soil humic acids (HA), fulvic acids (FA), and protein-like substances (PLS) at different pH values remain uncertain. The key findings includes: HA solubility increases with increasing pH and decreases with decreasing pH; HApH6 and HApH1 contribute to 39.1–49.2 % and 3.1–24.1 % of total DOM, respectively; and HApH2, FA, and PLS are highly soluble at acidic pH values and are transported by ambient water. These issues are vital for sustainable soil management.
05 Jun 2024
Evolution of biogeochemical Properties Inside Poleward Undercurrent Eddies in the Southeast Pacific Ocean
Lenna Oriana Ortiz-Castillo, Oscar Pizarro, Marcela Cornejo-D'Ottone, and Boris Dewitte
EGUsphere, https://doi.org/10.5194/egusphere-2024-1290, https://doi.org/10.5194/egusphere-2024-1290, 2024
Revised manuscript under review for BG (discussion: final response, 7 comments)
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Poleward undercurrent eddies (Puddies) transport a source water mass with low oxygen hundreds of kilometers away from the coast. A simulation based on a physical-biogeochemical model was used to characterize the biogeochemical average conditions inside the Puddies during their lifetime while modifying the conditions in the open sea. Our findings show that the biological activity extends the low oxygen core conditions counteracted by advection processes that tend to ventilate the core.
30 May 2024
Elephant megacarcasses increase local nutrient pools in African savanna soils and plants
Courtney G. Reed, Michelle L. Budny, Johan T. du Toit, Ryan Helcoski, Joshua P. Schimel, Izak P. J. Smit, Tercia Strydom, Aimee Tallian, Dave I. Thompson, Helga van Coller, Nathan P. Lemoine, and Deron E. Burkepile
EGUsphere, https://doi.org/10.5194/egusphere-2024-1514, https://doi.org/10.5194/egusphere-2024-1514, 2024
Revised manuscript accepted for BG (discussion: final response, 7 comments)
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We seek to understand the ecological legacies of elephants after they die. We sampled elephant carcasses in South Africa and found that they release nutrients into soil, which then enter plants and are available for consumption by other herbivores. This research reveals a key way that these elephants contribute to nutrient cycling on the savanna after death. It also highlights an important process that may be lost on savannas in areas where elephant populations are in decline.
29 May 2024
The energy-efficient reductive tricarboxylic acid cycle drives carbon uptake and transfer to higher trophic levels within the Kueishantao shallow-water hydrothermal system
Joely Marie Maak, Yu-Shih Lin, Enno Schefuß, Rebecca F. Aepfler, Li-Lian Liu, Marcus Elvert, and Solveig I. Bühring
EGUsphere, https://doi.org/10.5194/egusphere-2024-1356, https://doi.org/10.5194/egusphere-2024-1356, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Co-editor-in-chief
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In acidic hot springs off Kueishantao, Campylobacteria fix CO2 by using the reductive tricarboxylic acid cycle (rTCA), causing them to have an isotopically heavier biomass. Here, we showcase extremely low isotopic fractionation (of almost 0 ‰,) which has never been reported in environmental samples. Moreover, the crab Xenograpsus testudinatus relies up to 34 % on Campylobacterial biomass, showcasing the dependency of complex life on microscopic bacteria in harsh environments.
Co-editor-in-chief
This study presents new insights into autotrophic carbon fixation in shallow-water hydrothermal systems, emphasizing the dominance of reductive tricarboxylic acid (rTCA) cycle-utilizing Campylobacteria. Low isotopic fractionation values in vent fluids, possibly due to very acidic pH levels, extend the isotopic fractionation range of rTCA. The study also highlights the ecological significance of chemosynthetically fixed carbon, observed in higher trophic levels like the vent endemic crab Xenograpsus testudinatus, improving our understanding of carbon cycling in extreme environments and the interplay between microbial chemosynthesis and higher organisms.
27 May 2024
European forest cover during the Holocene reconstructed from pollen records
Luke Fionn Sweeney, Sandy P. Harrison, and Marc Vander Linden
EGUsphere, https://doi.org/10.5194/egusphere-2024-1523, https://doi.org/10.5194/egusphere-2024-1523, 2024
Preprint under review for BG (discussion: final response, 8 comments)
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Changes in tree cover across Europe during the Holocene are reconstructed from fossil pollen data using a model developed with modern observations of tree cover and modern pollen assemblages. There is a rapid increase in tree cover after the last glacial with maximum cover during the mid-Holocene and a decline thereafter; the timing of the maximum and the speed of the increase and subsequent decrease vary regionally likely reflecting differences in climate trajectories and human influence.
23 May 2024
Observations of methane net sinks in the Arctic tundra
Antonio Donateo, Daniela Famulari, Donato Giovannelli, Arturo Mariani, Mauro Mazzola, Stefano Decesari, and Gianluca Pappaccogli
EGUsphere, https://doi.org/10.5194/egusphere-2024-1440, https://doi.org/10.5194/egusphere-2024-1440, 2024
Revised manuscript under review for BG (discussion: final response, 4 comments)
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This study focuses on direct measurements of CO2 and CH4 turbulent eddy covariance fluxes in tundra ecosystems in the Svalbard Islands over a two-year period. Our results reveal dynamic interactions between climatic conditions and ecosystem activities such as photosynthesis and microbial activity. The observed net summertime methane uptake is correlated with the activation and aeration of soil microorganisms. High temperature anomalies increase CO2 and CH4 emissions.
14 May 2024
Methane, carbon dioxide and nitrous oxide emissions from two clear-water and two turbid-water urban ponds in Brussels (Belgium)
Thomas Bauduin, Nathalie Gypens, and Alberto V. Borges
EGUsphere, https://doi.org/10.5194/egusphere-2024-1315, https://doi.org/10.5194/egusphere-2024-1315, 2024
Preprint under review for BG (discussion: final response, 4 comments)
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Greenhouse gases (GHG) emissions from ponds can vary depending on the state of ponds (clear-water with macrophytes or turbid-water with phytoplankton). We studied CO2, CH4, and N2O emissions in clear and turbid urban ponds (June 2021 to December 2023) in Brussels. We observed seasonal differences in methanogenesis pathways, in CH4 emissions between clear and turbid ponds, and annual differences in total emissions of GHG, likely from intense El Niño event in 2023.
14 May 2024
Exploring micro-scale heterogeneity as a driver of biogeochemical transformations and gas transport in peat
Lukas Kohl, Petri Kiuru, Marjo Palviainen, Maarit Raivonen, Markku Koskinen, Mari Pihlatie, and Annamari Lauren
EGUsphere, https://doi.org/10.5194/egusphere-2024-1280, https://doi.org/10.5194/egusphere-2024-1280, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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We present an assay to illuminate heterogeneity of biogeochemical transformations within peat samples. For this, we injected isotope labelled acetate into peat cores and monitoring the release of label-derived gases, which we compared to microtomography images. The fraction of label converted to CO2 and the rapidness of this conversion was linked to injection depth as well as air-filled porosity. Pore network metric did not provide predictive power over compared to porosity alone.
13 May 2024
From the Top: Surface-derived Carbon Fuels Greenhouse Gas Production at Depth in a Neotropical Peatland
Alexandra L. Hedgpeth, Alison M. Hoyt, Kyle Cavanaugh, Karis J. McFarlane, and Daniela F. Cusack
EGUsphere, https://doi.org/10.5194/egusphere-2024-1279, https://doi.org/10.5194/egusphere-2024-1279, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Tropical peatlands store ancient carbon and have been identified as not only vulnerable to future climate change but take a long time to recover after disturbance. It is unknown if these gases are produced from decomposition of thousand-year-old peat. Radiocarbon dating shows emitted gases are young, indicating surface carbon, not old peat, drives emissions. Preserving these ecosystems can trap old carbon, mitigating climate change.
06 May 2024
Reviews and synthesis: increasing hypoxia in eastern boundary upwelling systems: a major stressor for zooplankton
Leissing Frederick, Mauricio A. Urbina, and Ruben Escribano
EGUsphere, https://doi.org/10.5194/egusphere-2024-836, https://doi.org/10.5194/egusphere-2024-836, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Evidence shows that due to global warming zooplankton inhabiting the coastal upwelling zone are exposed to increasing hypoxia affecting their physiology, metabolism, and population dynamics. The adaptive responses of zooplankton to cope with mild/severe hypoxia may depend on trade-offs with other metabolic/energy-demands, implying less energy for growth, feeding and reproduction with ecological consequences for the zooplankton populations and the marine food web.
02 May 2024
Technical note: Flow cytometry assays for the detection, counting and cell-sorting of polyphosphate-accumulating bacteria
Clémentin Bouquet, Hermine Billard, Cécile Bidaud, Jonathan Colombet, Young-Tae Chang, Karim Benzerara, Fériel Skouri-Panet, Elodie Duprat, and Anne-Catherine Lehours
EGUsphere, https://doi.org/10.5194/egusphere-2024-1085, https://doi.org/10.5194/egusphere-2024-1085, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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In the context of the ecological sustainability of phosphorus (P), the ubiquitous presence of polyphosphate-accumulating bacteria (PAB) in natural environments invites efforts to reveal their unknown roles in the biogeochemical cycle of P. In this study, we provide a generic protocol for the detection, quantification, and cell sorting of PAB by combining efficient staining of intracellular polyphosphate (polyP) granules in PAB and their subsequent detection by flow cytometry.
26 Apr 2024
The distribution and abundance of planktonic foraminifera under summer sea-ice in the Arctic Ocean
Flor Vermassen, Clare Bird, Tirza M. Weitkamp, Kate F. Darling, Hanna Farnelid, Céline Heuzé, Allison Y. Hsiang, Salar Karam, Christian Stranne, Marcus Sundbom, and Helen K. Coxall
EGUsphere, https://doi.org/10.5194/egusphere-2024-1091, https://doi.org/10.5194/egusphere-2024-1091, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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We provide the first systematic survey of planktonic foraminifera in the high Arctic Ocean. Our results describe the abundance and species composition under summer sea-ice. They indicate that the polar specialist N. pachyderma is the only species present, with subpolar species absent. The dataset will be a valuable reference for continued monitoring of the state of planktonic foraminifera communities as they respond to the ongoing sea-ice decline and the ‘Atlantification’ of the Arctic Ocean.
26 Apr 2024
Disentangling future effects of climate change and forest disturbance on vegetation composition and land-surface properties of the boreal forest
Lucia S. Layritz, Konstantin Gregor, Andreas Krause, Stefan Kruse, Ben F. Meyer, Tom A. M. Pugh, and Anja Rammig
EGUsphere, https://doi.org/10.5194/egusphere-2024-1028, https://doi.org/10.5194/egusphere-2024-1028, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Disturbances (e.g. fire) can change which species grow in a forest, affecting water, carbon, energy flows, and the climate. They are expected to increase with climate change, but it is uncertain by how much. We studied how future climate and disturbances might impact vegetation with a simulation model. Our findings highlight the importance of considering both factors, with future disturbance patterns posing significant uncertainty. More research is needed to understand their future development.
24 Apr 2024
Constraining 2010–2020 Amazonian carbon flux estimates with satellite solar-induced fluorescence (SIF)
Archana Dayalu, Marikate Mountain, Bharat Rastogi, John B. Miller, and Luciana Gatti
EGUsphere, https://doi.org/10.5194/egusphere-2024-1082, https://doi.org/10.5194/egusphere-2024-1082, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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The Amazon is facing unprecedented disturbance. Determining trends in Amazonia’s carbon balance and its sensitivity to disturbance requires reliable vegetation models that adequately capture how its ecosystems exchange carbon with the atmosphere. Our work presents novel estimates of vegetation carbon exchange with the atmosphere across the Amazon, estimated using ground- and satellite-based ecosystem measurements. Our model agrees with independent aircraft observations from discrete locations.
15 Apr 2024
Synchrony of African rainforest solar induced chlorophyll fluorescence and environmental factors
Russell Doughty, Michael C. Wimberly, Dan Wanyama, Helene Peiro, Nicholas Parazoo, Sean Crowell, and Moses Azong Cho
EGUsphere, https://doi.org/10.5194/egusphere-2023-3022, https://doi.org/10.5194/egusphere-2023-3022, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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We find West African SIF to increase during the dry season and peak prior to precipitation, similar to the Amazon. In Central Africa, we find a continental-scale bimodal seasonality in SIF, the minimum of which is synchronous with precipitation, but its maximum is likely less related to environmental drivers. We also find important differences in the seasonality of SIF and VIs, which indicates that VI-based estimates of photosynthesis could be inaccurate as they have been shown to be the Amazon.
04 Apr 2024
Afforestation induced shift in the microbial community explains enhanced decomposition of subsoil organic matter
Tatjana Carina Speckert, Arnaud Huguet, and Guido Lars Bruno Wiesenberg
EGUsphere, https://doi.org/10.5194/egusphere-2024-870, https://doi.org/10.5194/egusphere-2024-870, 2024
Revised manuscript under review for BG (discussion: final response, 7 comments)
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Afforestation on former pasture and its potential implication on the soil microbial community structure remains still an open question, particularly in mountainous regions. We investigate the effect of afforestation on a subalpine pasture on the soil microbial community structure by combining the analysis of PLFA and GDGTs. We found differences in the microbial community structure with evidence of increasing decomposition of soil organic matter due to the alteration in substrate quality.
04 Apr 2024
Biological response of eelgrass epifauna, Taylor’s sea hare (Phyllaplysia taylori) and eelgrass isopod (Idotea resecata), to elevated ocean alkalinity
Kristin Jones, Lenaïg Hemery, Nicholas Ward, Peter Regier, Mallory Ringham, and Matthew Eisaman
EGUsphere, https://doi.org/10.5194/egusphere-2024-972, https://doi.org/10.5194/egusphere-2024-972, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Ocean alkalinity enhancement is a marine carbon dioxide removal method that aims to mitigate the effects of climate change. This method causes localized increases in ocean pH, but the biological impacts of such changes are not well known. Our study investigated the response of two nearshore invertebrate species to increased pH and found the sea hare to be sensitive to pH changes, while the isopod was more resilient. Understanding interactions with biology is important as this field expands.
02 Apr 2024
Ocean Alkalinity Enhancement (OAE) does not cause cellular stress in a phytoplankton community of the sub-tropical Atlantic Ocean
Librada Ramírez, Leonardo J. Pozzo-Pirotta, Aja Trebec, Víctor Manzanares-Vázquez, José L. Díez, Javier Arístegui, Ulf Riebesell, Stephen D. Archer, and María Segovia
EGUsphere, https://doi.org/10.5194/egusphere-2024-847, https://doi.org/10.5194/egusphere-2024-847, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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We studied the potential effects of increasing ocean alkalinity on a natural plankton community in subtropical waters of the Atlantic near Gran Canaria, Spain. Alkalinity is the capacity of water to resist acidification and plankton are usually microscopic plants (phytoplankton) and animals (zooplankton), often less than 2,5 cm in length. This study suggests that increasing ocean alkalinity did not have a significant negative impact on the studied plankton community.
25 Mar 2024
Uncertainty in Amazon vegetation productivity in CMIP6 projections driven by surface energy fluxes
Matteo Mastropierro, Daniele Peano, and Davide Zanchettin
EGUsphere, https://doi.org/10.5194/egusphere-2024-823, https://doi.org/10.5194/egusphere-2024-823, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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We address how different ESMs represent vegetation productivity, in terms of carbon fluxes, within the Amazon basin. By statistically assessing the role of climatological and model specific factors that influence vegetation, we showed that surface energy fluxes and the implementation of Phosphorous limitation resulted to be the main drivers of model uncertainties in a future scenario. Reducing these uncertainties allows to increase the reliability of tropical land carbon and climate projections
07 Mar 2024
The 16S rDNA microbiome of the Arctic foraminifera Neogloboquadrina pachyderma is comprised of hydrocarbon-degrading bacteria and a diatom chloroplast store
Clare Bird, Kate F. Darling, Rabecca Thiessen, and Anna J. Pieńkowski
EGUsphere, https://doi.org/10.5194/egusphere-2024-497, https://doi.org/10.5194/egusphere-2024-497, 2024
Revised manuscript under review for BG (discussion: final response, 6 comments)
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The polar planktonic foraminifer N. pachyderma eats bacteria and diatoms. Unlike other planktonic species, it also keeps the diatom chloroplasts (photosynthesising organelles) inside its cell. In benthic foraminifera this is known as kleptoplasty, and the roles of these stolen chloroplasts are diverse. Their role in N. pachyderma needs to be investigated to find out if stored chloroplasts enable N. pachyderma to live in polar waters and under the ice where no other planktonic species survive.
04 Mar 2024
Ocean alkalinity enhancement in an open ocean ecosystem: Biogeochemical responses and carbon storage durability
Allanah Joy Paul, Mathias Haunost, Silvan Urs Goldenberg, Jens Hartmann, Nicolás Sánchez, Julieta Schneider, Niels Suitner, and Ulf Riebesell
EGUsphere, https://doi.org/10.5194/egusphere-2024-417, https://doi.org/10.5194/egusphere-2024-417, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Ocean alkalinity enhancement (OAE) is being assessed for its potential to absorb atmospheric CO2 and store it for a long time. OAE still needs comprehensive assessment of its safety and effectiveness. We studied an idealised OAE application in a natural low nutrient ecosystem over one month. Our results showed that biogeochemical functioning remained mostly stable, but that the long-term capability for storing carbon may be limited at high alkalinity concentration.
29 Jan 2024
Drought counteracts soil warming more strongly in the subsoil than in the topsoil according to a vertical microbial SOC model
Marleen Pallandt, Marion Schrumpf, Holger Lange, Markus Reichstein, Lin Yu, and Bernhard Ahrens
EGUsphere, https://doi.org/10.5194/egusphere-2024-186, https://doi.org/10.5194/egusphere-2024-186, 2024
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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As soils get warmer due to climate change, SOC decomposes faster because of higher microbial activity, but only with sufficient soil moisture. We modelled how microbes decompose plant litter and microbial residues at different soil depths. We found that deep soil layers are more sensitive than topsoils. SOC is lost from the soil with warming, but this can be mitigated or worsened depending on the type of litter and its sensitivity to temperature. Droughts can reduce warming-induced SOC losses.
25 Jan 2024
Predicting dominant terrestrial biomes at a global scale using machine learning algorithms, climate variable indices, and extreme climate indices
Hisashi Sato
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-106, https://doi.org/10.5194/bg-2023-106, 2024
Preprint withdrawn (discussion: closed, 6 comments)
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Modelling potential natural biome distribution is one of the most classical issues in biogeoscience. This study shows how accurate models can be constructed without simplifying climate data by employing machine-learning techniques. While extreme climate data enhance predictions, their inclusion can significantly reduce model reliability. With the convolutional neural network algorithm emerging as the preferred choice, this research paves the way for more robust global-scale biome predictions.
03 Jan 2024
Cenozoic pelagic accumulation rates and biased sampling of the deep sea record
Johan Renaudie and David B. Lazarus
EGUsphere, https://doi.org/10.5194/egusphere-2023-3087, https://doi.org/10.5194/egusphere-2023-3087, 2024
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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Co-editor-in-chief
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We provide a new compilation of rates at which sediments deposited in the deep sea over the last 70 million years. We highlight a bias, linked to the drilling process, that makes it more likely for high rates to be recovered for younger sediments than for older ones. Correcting for this bias, the record show, contrary to previous estimates, a more stable history, thus providing some insights on the past mismatch between physico-chemical model estimates and observations.
Co-editor-in-chief
This paper reveals a previously unrecognized bias in the marine sediment record, challenging conventional interpretations of long-term carbon sequestration and weathering trends. While biases in the fossil and geological records are well-studied, this study demonstrates that deep-sea sedimentation data are also systematically skewed, necessitating a critical reevaluation of widely used paleoceanographic proxies. As a comprehensive meta-analysis of marine core data, these findings have far-reaching implications, highlighting the need to account for age-dependent biases in sedimentation-related proxies to refine our understanding of Earth's past climate and carbon cycle dynamics.
20 Dec 2023
Pacific Southern Ocean coccolithophore-derived particulate inorganic carbon (PIC): A novel comparative analysis of in-situ and satellite-derived measurements
Mariem Saavedra-Pellitero, Karl-Heinz Baumann, Nuria Bachiller-Jareno, Harold Lovell, Nele Manon Vollmar, and Elisa Malinverno
EGUsphere, https://doi.org/10.5194/egusphere-2023-2801, https://doi.org/10.5194/egusphere-2023-2801, 2023
Revised manuscript accepted for BG (discussion: final response, 6 comments)
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In this manuscript we combine micropalaeontology and remote-sensing. We compare the calcium carbonate produced by tiny marine algae called coccolithophores to satellite-derived particulate organic carbon in the Southern Ocean. They show good agreement north of the polar front, but hugely differ south of it. We argue that those highly reflective values could be due to small opal particles and we highlight the need to improve satellite algorithms in this unexplored part of the ocean.
18 Dec 2023
Similar importance of inter-tree and intra-tree variations in wood density observations in Central Europe
Hui Yang, Krzysztof Stereńczak, Zbigniew Karaszewski, and Nuno Carvalhais
EGUsphere, https://doi.org/10.5194/egusphere-2023-2691, https://doi.org/10.5194/egusphere-2023-2691, 2023
Preprint under review for BG (discussion: final response, 6 comments)
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Wood density is crucial for ecological and carbon stock assessment, yet its labor-intensive analysis limits studies across species and spaces. Our study, based on 48,000 samples from Central Europe, reveals that, even without species information, 91% of inter-tree variations can be predicted by vegetation indexes, topography, and soil texture. Importantly, we highlight neglected intra-tree variation, showing substantial variations vertically along the height and radially from the center to bark.
23 Oct 2023
Determination of appropriate land use/cover pattern based on the hydroclimatic regime to support regional ecological management in the agro-pastoral ecotone of northwest China
Yuzuo Zhu and Xuefeng Xu
EGUsphere, https://doi.org/10.5194/egusphere-2023-2287, https://doi.org/10.5194/egusphere-2023-2287, 2023
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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Studies have found excessive re-vegetation causes negative environmental effects in the agro-pastoral ecotone of northwest China, while the latest national ecological project plans to expand grasslands to 60 %. Therefore incorporating an appropriate mixture of land use/cover into decision-making is urgently required. Thus, this paper identified the proper land use/cover pattern within the local hydrological and climatic metrics, for the first time, among scenarios simulated by CLM 5.0.
11 Oct 2023
Disentangling the effects of vegetation and water on the satellite observations of soil organic carbon stocks in western European topsoils
Lixin Lin, Xixi Liu, and Yuan Sun
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-170, https://doi.org/10.5194/bg-2023-170, 2023
Revised manuscript not accepted (discussion: closed, 5 comments)
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We attempted to disentangle the covers of vegetation and water on soil organic carbon model using fuzzy disentangling. We used the model to simulate the soil organic carbon stocks in western European topsoil. The results show that the per-unit and total SOC stocks in western European topsoil as 99.742 t C ha−1 and 9.373 Pg, respectively. The gap of the results is narrower compared with previous study. The stable simulated values are the result of disentangling of the vegetation and water cover.
10 Oct 2023
Reviews and syntheses: Abrupt ocean biogeochemical change under human-made climatic forcing – warming, acidification, and deoxygenation
Christoph Heinze, Thorsten Blenckner, Peter Brown, Friederike Fröb, Anne Morée, Adrian L. New, Cara Nissen, Stefanie Rynders, Isabel Seguro, Yevgeny Aksenov, Yuri Artioli, Timothée Bourgeois, Friedrich Burger, Jonathan Buzan, B. B. Cael, Veli Çağlar Yumruktepe, Melissa Chierici, Christopher Danek, Ulf Dieckmann, Agneta Fransson, Thomas Frölicher, Giovanni Galli, Marion Gehlen, Aridane G. González, Melchor Gonzalez-Davila, Nicolas Gruber, Örjan Gustafsson, Judith Hauck, Mikko Heino, Stephanie Henson, Jenny Hieronymus, I. Emma Huertas, Fatma Jebri, Aurich Jeltsch-Thömmes, Fortunat Joos, Jaideep Joshi, Stephen Kelly, Nandini Menon, Precious Mongwe, Laurent Oziel, Sólveig Ólafsdottir, Julien Palmieri, Fiz F. Pérez, Rajamohanan Pillai Ranith, Juliano Ramanantsoa, Tilla Roy, Dagmara Rusiecka, J. Magdalena Santana Casiano, Yeray Santana-Falcón, Jörg Schwinger, Roland Séférian, Miriam Seifert, Anna Shchiptsova, Bablu Sinha, Christopher Somes, Reiner Steinfeldt, Dandan Tao, Jerry Tjiputra, Adam Ulfsbo, Christoph Völker, Tsuyoshi Wakamatsu, and Ying Ye
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-182, https://doi.org/10.5194/bg-2023-182, 2023
Revised manuscript under review for BG (discussion: final response, 6 comments)
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For assessing the consequences of human-induced climate change for the marine realm, it is necessary to not only look at gradual changes but also at abrupt changes of environmental conditions. We summarise abrupt changes in ocean warming, acidification, and oxygen concentration as the key environmental factors for ecosystems. Taking these abrupt changes into account requires greenhouse gas emissions to be reduced to a larger extent than previously thought to limit respective damage.
05 Oct 2023
Impacts of passive experimental warming on daytime and night-time respiration in a semi-natural grassland
Deepali Bansal, Pankaj Tiwari, Gautam Talukdar, and Gopal Singh Rawat
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-168, https://doi.org/10.5194/bg-2023-168, 2023
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Ecosystem respiration is influenced by daytime (DT) and night-time (NT) phenomenon. We studied the potential impacts of experimental warming on DT and NT respiration rates. Warming increased both DT and NT respiration rates. Q10 analyses revealed that NT respiration rates are more sensitive to warming than DT. This is the first study addressing the gap of monitoring night-time respiration along with daytime to estimate the respiration rates under experimental warming.
29 Sep 2023
Crystalline Iron Oxides Stimulate Methanogenesis Under Sulfate Reducing Conditions in the Terrestrial Subsurface
Brandon C. Enalls, Mon Oo Yee, Amrita Bhattacharya, Kristine Cabugao Grace, Sara Gushgari-Doyle, Terry C. Hazen, and Romy Chakraborty
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-174, https://doi.org/10.5194/bg-2023-174, 2023
Revised manuscript not accepted (discussion: closed, 7 comments)
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Methanogenic and sulfate-reducing microbes compete for resources in sediments. At our field site, methanogens and sulfate reducers co-exist along with conductive iron oxides, which can transfer electrons between microbes, reducing resource limitation. We incubated microbes with iron oxides of varying crystallinities to test whether they stimulate simultaneous methane production and sulfate reduction. Our results highlight the direct influences mineralogy has on microbial biogeochemistry.
26 Sep 2023
Carbon footprint and greenhouse gas emissions from rice based agricultural systems calculated with a co-designed carbon footprint calculation tool
Mohammad Mofizur Rahman Jahangir, Eduardo Aguilera, Jannatul Ferdous, Farah Mahjabin, Abdullah Al Asif, Hassan Ahmad, Maximilian Bauer, Alberto Sanz Cobeña, Christoph Müller, and Mohammad Zaman
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-165, https://doi.org/10.5194/bg-2023-165, 2023
Publication in BG not foreseen (discussion: closed, 2 comments)
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Greenhouse gas from major agricultural systems from the Indo Gangetic Plane has been estimated and compared with the measured data which will help develop regional GHG inventories and the global GHG budget. These data will reduce the uncertainty in global GHG budget which had a large uncertainty due to lack of regional data.
22 Sep 2023
The marine methane cycle in the Canadian Arctic Archipelago during summer
Alessandra D'Angelo, Cynthia Garcia-Eidell, Zak Kerrigan, Jacob Strock, Frances Crable, Nikolas VanKeersbilck, Humair Raziuddin, Theressa Ewa, Samira Umar, Andrew L. King, Miquel Gonzelez-Meler, and Brice Loose
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-157, https://doi.org/10.5194/bg-2023-157, 2023
Manuscript not accepted for further review (discussion: closed, 4 comments)
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In summer 2019, the Northwest Passage Project explored the Canadian Arctic Archipelago (CAA). Our study revealed methane oversaturation in upper CAA waters, driven by meltwater, turbidity, and specific microbial activity. It highlights the need to distinguish active methane zones. Western CAA showed higher methane activity, while the east had lower levels due to Atlantic Water influence. These findings contribute to understanding Arctic methane dynamics and its climate change implications.
21 Sep 2023
Ocean models as shallow sea oxygen deficiency assessment tools: from research to practical application
Sarah Piehl, René Friedland, Thomas Neumann, and Gerald Schernewski
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-152, https://doi.org/10.5194/bg-2023-152, 2023
Revised manuscript not accepted (discussion: closed, 6 comments)
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We integrated observations essential for policy decisions with high-resolution 3D model results to improve the reliability of oxygen assessments. Based on our findings, we suggest merging only high temporal and/or vertical resolution station data with model data to increase confidence in oxygen assessments. While showing the strengths and limitations of our approach we show that model simulations are an useful tool for policy-relevant oxygen assessments.
13 Sep 2023
Representing socio-economic factors in the INFERNO global fire model using the Human Development Index
Joao Carlos Martins Teixeira, Chantelle Burton, Douglas I. Kelly, Gerd A. Folberth, Fiona M. O'Connor, Richard A. Betts, and Apostolos Voulgarakis
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-136, https://doi.org/10.5194/bg-2023-136, 2023
Revised manuscript not accepted (discussion: closed, 7 comments)
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Representing socio-economic impacts on fires is crucial to underpin the confidence in global fire models. Introducing these into INFERNO, reduces biases and improves the modelled burnt area (BA) trends when compared to observations. Including socio-economic factors in the representation of fires in Earth System Models is important for realistically simulating BA, quantifying trends in the recent past, and for understanding the main drivers of those at regional scales.
04 Sep 2023
Environmental and vegetation control on active layer and soil temperature in an Arctic tundra ecosystem in Alaska
Kevin J. Gonzalez Martinez, Donatella Zona, Trent Biggs, Kristine Bernabe, Danielle Sirivat, Francia Tenorio, and Walter Oechel
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-117, https://doi.org/10.5194/bg-2023-117, 2023
Revised manuscript not accepted (discussion: closed, 5 comments)
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Permafrost soils contain twice the amount of carbon than the atmosphere, and its release could majorly affect global temperatures. This study found that a thicker moss layer resulted in cooler temperatures deeper in the soil, despite warmer surface temperatures. The top green living moss layer was the most important in regulating the soil temperatures and should be considered when predicting the response of permafrost thaw to climate change.
17 Aug 2023
Quantification of allochthonous and autochthonous organic carbon in large and shallow Lake Wuliangsu based on distribution patterns and δ13C signatures of n-alkanes
Qingfeng Zhao, Aifeng Zhou, and Yuxin He
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-134, https://doi.org/10.5194/bg-2023-134, 2023
Manuscript not accepted for further review (discussion: closed, 6 comments)
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We presented a quantitative method to calculate the contributions of different OC sources to a shallow lake by combining distribution pattern and δ13C values of n-alkanes. This method could be more accurate than the one from bulk organic proxies, and effectively reduce the potential impacts from OC degradation. The results indicate that submerged macrophytes mainly situated in open water zone could play a more important role inducing stronger both OC accumulation and CH4 production.
15 Aug 2023
Long-term reduction in CO2 emissions from the Elbe River due to water quality improvement
Mingyang Tian, Jens Hartmann, Gibran Romero-Mujalli, Thorben Amann, Lishan Ran, and Ji-Hyung Park
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-131, https://doi.org/10.5194/bg-2023-131, 2023
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Effective water quality management in the Elbe River from 1984 to 2018 significantly reduced CO2 emissions, particularly after Germany's reunification. Key factors in the reduction include organic carbon removal and nutrient management, with nitrogen control being more critical than phosphorus for the restoration of ecosystem capacity. Unpredictable influxes of organic carbon and the relocation of emissions from wastewater treatment can cause uncertainties for CO2 removals.
19 Jul 2023
Water usage of old growth oak at elevated CO2 in the FACE of climate change
Susan Elizabeth Quick, Giulio Curioni, Nicholas J. Harper, Stefan Krause, and Angus Rob MacKenzie
EGUsphere, https://doi.org/10.5194/egusphere-2023-1522, https://doi.org/10.5194/egusphere-2023-1522, 2023
Revised manuscript accepted for BG (discussion: final response, 4 comments)
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To study the effects of rising carbon dioxide levels on water usage of old growth temperate oak forest, we monitored trees in an open-air elevated CO2 experiment for five years. We found no significant changes in water usage for ~34 % increase in atmospheric CO2. Stresses under this experiment may take longer to show their effect. Tree water usage depends on tree size, i.e. stem size and the canopy area, across all treatments. Experimental infrastructure changed the water demand of the trees.
13 Apr 2023
Down in the dungeons: microbial redox reactions and geochemical transformations define the biogeochemistry of an estuarine sediment column
Thibault Duteil, Raphaël Bourillot, Olivier Braissant, Adrien Henry, Michel Franceschi, Marie-Joelle Olivier, Nathalie Le Roy, Benjamin Brigaud, Eric Portier, and Pieter T. Visscher
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-62, https://doi.org/10.5194/bg-2023-62, 2023
Revised manuscript not accepted (discussion: closed, 4 comments)
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Water chemistry was measured in an estuarine sediment core at a depth of 6 m. These measurements indirectly identify microbial metabolisms that disrupt water chemistry. In addition, microbial activity in sediments was measured for direct evidence of the presence of microorganisms. Impacts of these disturbances, studied by modelling show that new mineral phases can precipitate in depth.
06 Mar 2023
Nitrogen limitation information retrieved from data assimilation
Song Wang, Carlos Sierra, Yiqi Luo, Jinsong Wang, Weinan Chen, Yahai Zhang, Aizhong Ye, and Shuli Niu
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-33, https://doi.org/10.5194/bg-2023-33, 2023
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Nitrogen is important for plant growth and carbon uptake, which is uaually limited in nature and can constrain carbon storage and impact efforts to combat climate change. We developed a new method of combining data and models to determine if and how much an ecosystem is nitrogen limited. This new method can help determine if and to what extent an ecosystem is nitrogen-limited, providing insight into nutrient limitations on a global scale and guiding ecosystem management decisions.
27 Feb 2023
What is eating my rocks? A possible novel biological niche in limestone
Trudy M. Wassenaar, Cees W. Passchier, Nora Groschopf, Anna Jantschke, Regina Mertz-Kraus, and Janos L. Urai
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-32, https://doi.org/10.5194/bg-2023-32, 2023
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Marbles in the desert areas of Namibia and Oman were found to be consumed from inside the rock mass by microbiological activity of a thus far unknown nature that created bands of parallel tubules. These bands formed along fractures in the rock and only surfaced after erosion made them visible. We consider this a new niche for life that has so far not been described. These life forms may have an unknown impact on the global carbon cycle.
06 Feb 2023
Human activities determine vegetation water use in the middle and lower reaches of arid areas
Siyu Lu, Guofeng Zhu, Rui Li, Yinying Jiao, Gaojia Meng, Dongdong Qiu, Yuwei Liu, Lei Wang, Xinrui Lin, Yuanxiao Xu, Qinqin Wang, and Longhu Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-1, https://doi.org/10.5194/bg-2023-1, 2023
Manuscript not accepted for further review (discussion: closed, 4 comments)
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The study shows that precipitation and soil water are the most important sources for forest trees in the mountainous areas, and that agricultural vegetation in the middle and lower oasis areas mainly absorbs soil water recharged by irrigation. The desert area forms vegetation in the ecological water transfer area, and the vegetation mainly absorbs soil water, lake water and groundwater formed by ecological water transfer.
02 Feb 2023
Evidence of deep subsurface sulfur cycle in a sediment core from eastern Arabian Sea
Aninda Mazumdar, Aditya Peketi, Namrata Khadke, Subhashree Mishra, Ankita Ghosh, Sai Pavan Pillutla, Mohd Sadique, Kalyani Sivan, and Anjali Zatale
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-3, https://doi.org/10.5194/bg-2023-3, 2023
Preprint withdrawn (discussion: closed, 3 comments)
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Deep biospheric processes deal with microbial activities and its influence on chemical-mineralogical changes in the sediments below the surface. These microbial and inorganic processes extend from few meters to several kms below the surface. These processes have been reported from deep mines to ocean sediments. In the present study we have unraveled the evidence of deep biospheric activities in 300 m long sediment core underlined 2500 m of water column from temperature eastern Arabian sea.
23 Jan 2023
Biogeochemistry of climate driven shifts in Southern Ocean primary producers
Ben J. Fisher, Alex J. Poulton, Michael P. Meredith, Kimberlee Baldry, Oscar Schofield, and Sian F. Henley
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-10, https://doi.org/10.5194/bg-2023-10, 2023
Revised manuscript not accepted (discussion: closed, 4 comments)
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The Southern Ocean is warming faster than the global average. As a globally important carbon sink and nutrient source, climate driven changes in ecosystems can be expected to cause widespread changes to biogeochemical cycles. We analysed earth system models and showed that productivity is expected to increase across the Southern Ocean, driven by different phytoplankton groups at different latitudes. These predictions carry large uncertainties, we propose targeted studies to reduce this error.
12 Jan 2023
Ideas and perspectives: Errors associated with the gross nitrification rates in forested catchments calculated from the triple oxygen isotopic composition (Δ17O) of stream nitrate
Weitian Ding, Urumu Tsunogai, and Fumiko Nakagawa
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-236, https://doi.org/10.5194/bg-2022-236, 2023
Revised manuscript not accepted (discussion: closed, 4 comments)
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Past studies used the Δ17O of stream nitrate to estimate GNR in each forested catchment. However, the GNR estimated from the Δ17O of stream nitrate using the equations was more than six times the actual GNR in our simulated calculation for a forested catchment. As a result, it must be essential to clarify/verify the distribution of the Δ17O values of NO3− in forested soils before applying the Δ17O values of stream NO3− to estimate GNR.
05 Jan 2023
Ideas and perspectives: soil cracking should be given great attention in the collapse of Kobresia ecosystems on the Tibetan Plateau
Yujie Niu, Victor Squires, and Limin Hua
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-222, https://doi.org/10.5194/bg-2022-222, 2023
Preprint withdrawn (discussion: closed, 0 comments)
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Soil cracks act as preferential flow channels, greatly affecting the dynamics of hydrological process in Kobresia meadows, and may further threaten the drinking water security. Soil cracks expose the Kobresia ecosystems under overgrazing to chronic drought stress, and accelerate the erosion of Kobresia turfs. Gradual alpine ecosystem degradation is more difficult to detect, soil cracking can be used as a visual indicator of early alpine grassland degradation.
03 Jan 2023
Modelling the interactive effects of viral presence and global warming on Baltic Sea ecosystem dynamics
Shubham Krishna, Victoria Peterson, Luisa Listmann, and Jana Hinners
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-249, https://doi.org/10.5194/bg-2022-249, 2023
Revised manuscript not accepted (discussion: closed, 5 comments)
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Marine viruses have been identified as key players in biogeochemical cycles and in the termination of phytoplankton bloom. In this study, we apply a coupled model system to investigate the role viruses in Baltic Sea ecosystem and how it will change with the climate change. According to our results, presence of viruses increased nutrient retention in the upper water column and reduced the transfer of organic matter to higher trophic levels. Future warming is expected to elevate these effects.
03 Jan 2023
Ideas and perspectives: The benthic iron flux from sandy advective bioturbated sediments
Laura M. Wehrmann, Darci A. Swenson Perger, Ian P. Dwyer, Nils Volkenborn, Christina Heilbrun, and Robert C. Aller
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-247, https://doi.org/10.5194/bg-2022-247, 2023
Revised manuscript not accepted (discussion: closed, 6 comments)
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We discuss the mechanisms allowing for the rapid biogeochemical cycling and enhanced benthic flux of dissolved Fe in sandy permeable sediments. We use a case study to highlight that bioirrigation by benthic macrofauna plays a key role in controlling the extent of the benthic Fe flux. We suggest that permeable sediments, which make up 50 % of continental shelf deposits globally, constitute a significant and underestimated source of sediment-derived Fe to the ocean along continental margins.
20 Dec 2022
Multi-site evaluation of modelled methane emissions over northern wetlands by the JULES land surface model coupled with the HIMMELI peatland methane emission model
Yao Gao, Eleanor J. Burke, Sarah E. Chadburn, Maarit Raivonen, Mika Aurela, Lawrence B. Flanagan, Krzysztof Fortuniak, Elyn Humphreys, Annalea Lohila, Tingting Li, Tiina Markkanen, Olli Nevalainen, Mats B. Nilsson, Włodzimierz Pawlak, Aki Tsuruta, Huiyi Yang, and Tuula Aalto
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-229, https://doi.org/10.5194/bg-2022-229, 2022
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We coupled a process-based peatland CH4 emission model HIMMELI with a state-of-art land surface model JULES. The performance of the coupled model was evaluated at six northern wetland sites. The coupled model is considered to be more appropriate in simulating wetland CH4 emission. In order to improve the simulated CH4 emission, the model requires better representation of the peat soil carbon and hydrologic processes in JULES and the methane production and transportation processes in HIMMELI.
28 Nov 2022
Dissolved organic matter composition regulates microbial degradation and carbon dioxide production in pristine subarctic rivers
Taija Saarela, Xudan Zhu, Helena Jäntti, Mizue Ohashi, Jun'ichiro Ide, Henri Siljanen, Aake Pesonen, Heidi Aaltonen, Anne Ojala, Hiroshi Nishimura, Timo Kekäläinen, Janne Jänis, Frank Berninger, and Jukka Pumpanen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-225, https://doi.org/10.5194/bg-2022-225, 2022
Manuscript not accepted for further review (discussion: closed, 4 comments)
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This study investigated the molecular composition and carbon dioxide production of water samples collected from two subarctic rivers that represent contrasting types of catchment characteristics. The results highlight the role of clearwater environments in microbial degradation and greenhouse gas dynamics of subarctic catchments.
17 Nov 2022
Process Rate Estimator: A novel model to predict total denitrification using natural abundance stable isotopes of N2O
Charlotte Decock, Juhwan Lee, Matti Barthel, Elizabeth Verhoeven, Franz Conen, and Johan Six
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-221, https://doi.org/10.5194/bg-2022-221, 2022
Preprint withdrawn (discussion: closed, 6 comments)
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One of the least well understood processes in the nitrogen (N) cycle is the loss of nitrogen gas (N2), referred to as total denitrification. This is mainly due to the difficulty of quantifying total denitrification in situ. In this study, we developed and tested a novel modeling approach to estimate total denitrification over the depth profile, based on concentrations and isotope values of N2O. Our method will help close N budgets and identify management strategies that reduce N pollution.
14 Oct 2022
Reviews and Syntheses: Carbon biogeochemistry of Indian estuaries
Manab Kumar Dutta, Krishnan Sreelash, Damodaran Padmalal, Nicholas D. Ward, and Thomas S. Bianchi
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-200, https://doi.org/10.5194/bg-2022-200, 2022
Revised manuscript not accepted (discussion: closed, 4 comments)
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Indian estuaries contribute to 2.62 % and 1.09 % of global riverine DIC and DOC export to the ocean, respectively. Major Indian estuaries emit ~9718 Gg yr-1 and 3.27 Gg yr-1 of CO2 and CH4 to the atmosphere, respectively, which contributes ~0.67 % and ~0.12 % to global CO2 and CH4 outgassing from estuaries.
11 Oct 2022
Spatio-temporal changes in cryoconite community, isotopic, and elemental composition over the ablation season of an alpine glacier
Tereza Novotná Jaroměřská, Roberto Ambrosini, Dorota Richter, Miroslawa Pietryka, Przemyslaw Niedzielski, Juliana Souza-Kasprzyk, Piotr Klimaszyk, Andrea Franzetti, Francesca Pittino, Lenka Vondrovicová, Tyler Kohler, and Krzysztof Zawierucha
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-198, https://doi.org/10.5194/bg-2022-198, 2022
Preprint withdrawn (discussion: closed, 10 comments)
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Changes in the composition and biomass of photoautotrophs and consumers on glacier indicated phenological or ecological controls over their communities. We demonstrated that the recognition of the community structure of cryoconite holes requires a broad-scale and seasonal approach since biological communities vary in time and space on the glacier surface.
02 Sep 2022
Technical note: Photosynthetic capacity estimation is dependent on model assumptions
Yujie Wang and Christian Frankenberg
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-172, https://doi.org/10.5194/bg-2022-172, 2022
Revised manuscript not accepted (discussion: closed, 5 comments)
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Leaf light absorption coefficient is often not measured along with leaf gas exchange, but assumed to be constant. This potentially causes biases in estimated photosynthetic capacity and modeled photosynthetic rates. We explored how leaf light absorption features and light source may impact the photosynthesis modeling, and found that the biases are dependent of model assumptions. Researchers need to be more cautious with these inaccurate assumptions in photosynthesis models.
19 Aug 2022
Variations of carbon flux at different time scales in a semi-fixed sandy land ecosystem in Horqin Sandy Land, China
Yayi Niu, Yuqiang Li, Wei Liu, Xuyang Wang, and Yun Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-171, https://doi.org/10.5194/bg-2022-171, 2022
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Seasonal Reco was regulated by both shallow and deep soil water content (SWC80 and SWC10). PPFD and the soil water content at 80 cm regulated seasonal NEE and GPP variation. Rainfall (PPT), soil temperature, and SWC regulated monthly carbon-flux variation. Inter-annual variation of NEE was modulated by the total annual PPT. Annual variation of GPP was regulated by PPFD and SWC80. At all time scales, water availability controlled ecosystem carbon fluxes.
12 Aug 2022
Diel variations in planktonic ciliate community structure in the northern South China Sea and tropical Western Pacific
Chaofeng Wang, Yi Dong, Michel Denis, Li Zhao, Haibo Li, Shan Zheng, Wuchang Zhang, and Tian Xiao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-151, https://doi.org/10.5194/bg-2022-151, 2022
Revised manuscript not accepted (discussion: closed, 6 comments)
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The present study reported on diel variations of planktonic ciliate community structure in the nSCS and tWP, and ciliate do preformed diel vertical migrations. In both the nSCS and tWP, abundance proportions of large size-fraction aloricate ciliates in night were higher than in day. While for tintinnids, abundance proportion of large lorica oral diameter in night were lower than in day.
27 Jul 2022
Physical parameters beneficial for grouping of western barbastelle bats into clusters during hibernation
Grzegorz Kłys, Zbigniew Ziembik, and Joanna Makuchowska-Fryc
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-159, https://doi.org/10.5194/bg-2022-159, 2022
Revised manuscript not accepted (discussion: closed, 8 comments)
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Social hibernation of animals is one of the most important physiological and ecological behaviours. The purpose of the study was the investigation of the influence of the roostsite climate parameters: temperature (T), humidity (Rh) and air flow velocity (v) on the clustering of the Barbastella barbastellus (western barbastelle) during hibernation. The quantile linear regression method was used for the statistical analysis of the results.
25 Jul 2022
Impact of sky conditions on net ecosystem productivity of a “floating blanket” wetland in southwest China
Yamei Shao, Huizhi Liu, Qun Du, Yang Liu, Jihua Sun, and Yaohui Li
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-131, https://doi.org/10.5194/bg-2022-131, 2022
Manuscript not accepted for further review (discussion: closed, 4 comments)
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The effects of sky conditions on ecosystem productivity over wetlands received little attention. Based on eddy covariance measurements during 2016–2020, we explored the impact of sky conditions on net ecosystem productivity (NEP) over an alpine marsh wetland in southwest China. We found diffuse radiation played a critical role in the variations of NEP, and gloomier sky condition was conducive to increasing apparent quantum yield and NEP.
15 Jun 2022
Variations in land types detected using methane retrieved from space-borne sensor
Saheba Bhatnagar, Mahesh Kumar Sha, Laurence Gill, Bavo Langerock, and Bidisha Ghosh
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-88, https://doi.org/10.5194/bg-2022-88, 2022
Revised manuscript not accepted (discussion: closed, 4 comments)
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Different land types emit a different quantity of methane, with wetlands being one of the largest sources of methane emissions, contributing to climate change. This study finds variations in land types using the methane total column data from Sentinel 5-precursor satellite with a machine learning algorithm. The variations in land types were identified with high confidence, demonstrating that the methane emissions from the wetland and other land types substantially affect the total column.
04 May 2022
Effects of seasonal and diel variations in thermal stratification on phytoplankton in a regulated river
Eunsong Jung, Gea-Jae Joo, Hyo Gyeom Kim, Dong-Kyun Kim, and Hyun-Woo Kim
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-42, https://doi.org/10.5194/bg-2022-42, 2022
Preprint withdrawn (discussion: closed, 4 comments)
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Thermal stratification in rivers has increased, often with negative ecological effects. We implemented vertical water sampling both seasonally and diurnally and then calculated three stratification indices in the Nakdong River after intensive river channel modification. The results suggest that the river has summer stratification, which is involved in amplifying cyanobacterial bloom intensity.
12 Apr 2022
Modelling the impact of wood density dependent tree mortality on the spatial distribution of Amazonian vegetation carbon
Mathilda Hancock, Stephen Sitch, Fabian Jörg Fischer, Jérôme Chave, Michael O'Sullivan, Dominic Fawcett, and Lina María Mercado
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-87, https://doi.org/10.5194/bg-2022-87, 2022
Publication in BG not foreseen (discussion: closed, 2 comments)
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Global vegetation models often underestimate the spatial variability of carbon stored in the Amazon forest. This paper demonstrates that including spatially varying tree mortality rates, as opposed to a homogeneous rate, in one model, significantly improves its simulations of the forest carbon store. To overcome the limited resolution of tree mortality data, this research presents a simple method of calculating mortality rates across Amazonia using a dependence on wood density.
10 Mar 2022
Large-diameter trees control forest structure and function in successional temperate forests
Chang-Bae Lee, Arshad Ali, Zuoqiang Yuan, James A. Lutz, Jens-Christian Svenning, and Min-Ki Lee
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-60, https://doi.org/10.5194/bg-2022-60, 2022
Publication in BG not foreseen (discussion: closed, 3 comments)
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Large-diameter trees have an overwhelming effect on aboveground biomass (AGB) in successional temperate forests. Moreover, they mediate the effects of abiotic drivers on AGBs in overstory and whole community and play an important role in both controlling the diversity and structure of remaining trees. In addition, our study highlights the mechanisms of biomass dominance of large-diameter trees associated with self-thinning process and resource availability in successional forests.
07 Mar 2022
Roots induce hydraulic redistribution to promote nutrient uptake and nutrient cycling in nutrient-rich but dry near-surface layers
Jing Yan and Teamrat Ghezzehei
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-52, https://doi.org/10.5194/bg-2022-52, 2022
Publication in BG not foreseen (discussion: closed, 4 comments)
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Although hydraulic redistribution (HR) is a well-documented phenomenon, whether it is a passive happy accident or actively controlled by roots is not well understood. Our modeling study suggests HR is long-range feedback between roots that inhabit heterogeneously resourced soil regions. When nutrients and organic matter are concentrated in shallow layers that experience frequent drying, root-exudation facilitated HR allows plants to mineralize and extract the otherwise inaccessible nutrients.
02 Mar 2022
The importance of spatial resolution in the modelling of methane emissions from natural wetlands
Yousef Albuhaisi, Ype van der Velde, and Sander Houweling
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-55, https://doi.org/10.5194/bg-2022-55, 2022
Manuscript not accepted for further review (discussion: closed, 5 comments)
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An important uncertainty in the modelling of methane emissions from natural wetlands is the wetland area. It is important to get the spatiotemporal covariance between the variables that drive methane emissions right for accurate quantification. Using high-resolution wetland and soil carbon maps, in combination with a simplified methane emission model that is coarsened in six steps from 0.005° to 1°, we find a strong relation between wetland emissions and the model resolution.
21 Feb 2022
Recent significant decline of strong carbon peat accumulation rates in tropical Andes related to climate change and glacier retreat
Romina Llanos, Patricia Moreira-Turcq, Bruno Turcq, Raúl Espinoza Villar, Yizet Huaman, Thomas Condom, and Bram Willems
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-47, https://doi.org/10.5194/bg-2022-47, 2022
Manuscript not accepted for further review (discussion: closed, 8 comments)
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Our results highlight a marked decrease of high carbon accumulation rates in Andean peatlands over the last decades due to the diminution in melt water inflow generated by the retreat of glaciers as a consequence of regional warming. These marked changes stress the high ecological sensitivity of these peatlands, endangering their outstanding role in the regional (and even global) C cycle as large C sinks that contribute to the mitigation of global climate change.
10 Feb 2022
High-resolution modelling of long-term trends in the oxygen and carbon cycles of the Benguela upwelling system
Katharina Dorothea Six and Uwe Mikolajewicz
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-27, https://doi.org/10.5194/bg-2022-27, 2022
Preprint withdrawn (discussion: closed, 4 comments)
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We developed a global ocean biogeochemical model with a zoom on the Benguela upwelling system. We show that the high spatial resolution is necessary to capture long-term trends of oxygen of the recent past. The regional anthropogenic carbon uptake over the last century is lower than compared to a coarser resolution ocean model as used in Earth system models. This suggests that, at least for some regions, the changes projected by these Earth system models are associated with high uncertainty.
07 Feb 2022
Assessing the effects of no-till on SOC dynamics throughout the soil profile after grassland renovation and conversion to silage maize
Josue De Los Rios, Arne Poyda, Thorsten Reinsch, Christof Kluß, Ralf Loges, and Friedhelm Taube
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-6, https://doi.org/10.5194/bg-2022-6, 2022
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Land use change (LUC) and conventional tillage (CT) are resulting in the reduction of the high soil organic carbon (SOC) stocks stored in grassland ecosystems during their conversion and renovation, contributing thus to global warming. Using no-tillage (NT) is seen as an avenue to minimize or even conserve SOC stocks during these events. Our results show that SOC losses are greatly reduced after grassland conversion to arable land, whereas during renovation it contributes to conserve them.
24 Jan 2022
Reviews and syntheses: Assessment of Biogeochemical Models in the Marine Environment
Kaltham Ismail and Maryam Rashed Al-Shehhi
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-351, https://doi.org/10.5194/bg-2021-351, 2022
Manuscript not accepted for further review (discussion: closed, 4 comments)
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This review illustrates the types of common biogeochemical models categorized based on the complexity levels and the governing equations. A comprehensive assessment of their performances in reproducing biogeochemical parameters such as chlorophyll-a, nutrients, carbon and oxygen are presented herein based on reviewing more than 100 research papers.
17 Jan 2022
Pronounced seasonal and spatial variability in determinants of phytoplankton biomass dynamics along a near–offshore gradient in the southern North Sea
Viviana Otero, Steven Pint, Klaas Deneudt, Maarten De Rijcke, Jonas Mortelmans, Lennert Schepers, Patricia Cabrera, Koen Sabbe, Wim Vyverman, Michiel Vandegehuchte, and Gert Everaert
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-11, https://doi.org/10.5194/bg-2022-11, 2022
Revised manuscript not accepted (discussion: closed, 7 comments)
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A mechanistic ecological model analysed which factors drive marine phytoplankton biomass dynamics in the southern part of the North Sea and how their relationship to primary production varies on a spatiotemporal scale. We found a spatiotemporal dependence, meaning that the effects of changing abiotic conditions on phytoplankton biomass dynamics are difficult to generalise. The tailor-made ecological model will enables to predict phytoplankton biomass dynamics under future climate scenarios.
13 Jan 2022
Observing intermittent biological productivity and vertical carbon transports during the spring transition with BGC Argo floats in the western North Pacific
Chiho Sukigara, Ryuichiro Inoue, Kanako Sato, Yoshihisa Mino, Takeyoshi Nagai, Andrea J. Fassbender, Yuichiro Takeshita, Stuart Bishop, and Eitarou Oka
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-9, https://doi.org/10.5194/bg-2022-9, 2022
Manuscript not accepted for further review (discussion: closed, 4 comments)
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To investigate the physical changes in the ocean from winter to spring and the corresponding biological activities, two automated floats were used to conduct observations in the western North Pacific from January to April 2018. During the observation, repeated storms passed and mixed the ocean surface layer. Afterwards, active biological activity was observed. Using data from the float, we observed the formation, decomposition, and settling of particulate organic matter.
12 Jan 2022
Genetic functional potential displays minor importance in explaining spatial variability of methane fluxes within a Eriophorum vaginatum dominated Swedish peatland
Joel Dawson White, Lena Ström, Veiko Lehsten, Janne Rinne, and Dag Ahrén
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-353, https://doi.org/10.5194/bg-2021-353, 2022
Revised manuscript not accepted (discussion: closed, 4 comments)
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Microbes that produce CH4 play an important role to climate. Microbes which emit CH4 from wetlands is poorly understood. We observed that microbial community was of importance in explaining CH4 emission. We found, that microbes that produce CH4 hold the ability to produce and consume CH4 in multiple ways. This is important in terms of future climate scenarios, where wetlands are expected to shift. Therefore, we expect the community to be highly adaptive to future climate scenarios.
03 Jan 2022
Significant methane undersaturation during austral summer in the Ross Sea (Southern Ocean)
Wangwang Ye, Hermann W. Bange, Damian L. Arévalo-Martínez, Hailun He, Yuhong Li, Jianwen Wen, Jiexia Zhang, Jian Liu, Man Wu, and Liyang Zhan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-334, https://doi.org/10.5194/bg-2021-334, 2022
Manuscript not accepted for further review (discussion: closed, 4 comments)
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CH4 is the second important greenhouse gas after CO2. We show that CH4 consumption and sea-ice melting influence the CH4 distribution in the Ross Sea (Southern Ocean), causing undersaturation and net uptake of CH4 during summertime. This study confirms the capability of surface water in the high-latitude Southern Ocean regions to take up atmospheric CH4 which, in turn, will help to improve predictions of how CH4 release/uptake from the ocean will develop when sea-ice retreats in the future.
16 Dec 2021
Biological response to hydrodynamic factors in estuarine-coastal systems: a numerical analysis in a micro-tidal bay
Marta F.-Pedrera Balsells, Manel Grifoll, Margarita Fernández-Tejedor, Manuel Espino, Marc Mestres, and Agustín Sánchez-Arcilla
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-322, https://doi.org/10.5194/bg-2021-322, 2021
Revised manuscript not accepted (discussion: closed, 5 comments)
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Phytoplankton in coastal bays is influenced by physical variables (wind or freshwater inputs) that can influence the composition of phytoplankton. A numerical model has been applied to understand this variability. The simulations show that during weak wind events there is physical separation between surface and deep layers, penalising phytoplankton growth. During intense wind, mixing of the water column occurs, increasing the phytoplankton biomass in the lower layers.
08 Dec 2021
Effects of tropical rainforest conversion to rubber plantation on soil quality in Hainan Island, China
Rui Sun, Guoyu Lan, Chuan Yang, Zhixiang Wu, Banqian Chen, and Klaus Fraedrich
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-303, https://doi.org/10.5194/bg-2021-303, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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A soil quality index (SQI) based on 21 soil properties was employed to assess soil quality changes from tropical rainforest (TR) to rubber plantations (RP) . The results showed that the SQI of RP decreased by 26.48 % compared to TR, while four investigated soil properties increased. The SQI of both the TR and RP showed significant spatial differences, which, under TR, was more sensitive to seasonal changes than those under RP.
03 Dec 2021
Improving the stomatal resistance, photosynthesis and two big leaf algorithms for grass in the regional climate model COSMO-CLM
Evgenii Churiulin, Vladimir Kopeikin, Markus Übel, Jürgen Helmert, Jean-Maria Bettems, and Merja Helena Tölle
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-294, https://doi.org/10.5194/bg-2021-294, 2021
Revised manuscript not accepted (discussion: closed, 8 comments)
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Our research is an important step towards a more realistic representation of vegetation in regional climate models. We have implemented in COSMO-CLM the new algorithms for stomatal resistance, leaf photosynthesis and two-big leaf. We applied the modern phenology algorithms of CLM model and fully adapted them for COSMO-CLM. The personal software was created for validation COSMO-CLM results. The research also brought out many tensions, which we are going to update in our next developments.
29 Nov 2021
Linking sediment biodegradability with its origin in shallow coastal environments
Justine Louis, Anniet M. Laverman, Emilie Jardé, Alexandrine Pannard, Marine Liotaud, Françoise Andrieux-Loyer, Gérard Gruau, Florian Caradec, Emilie Rabiller, Nathalie Lebris, and Laurent Jeanneau
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-318, https://doi.org/10.5194/bg-2021-318, 2021
Preprint withdrawn (discussion: closed, 6 comments)
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This work has described the variability in sedimentary organic matter composition through a broad sampling campaign of marine mudflats at the regional scale (Brittany Region), and made the link with sediment potential biodegradability and nutrient release. In these coastal ecosystems affected by the eutrophication, the potential impact of human activities on the nutrient dynamics at the sediment-water interface was highlighted.
11 Nov 2021
Variations in and environmental controls of primary productivity in the Amundsen Sea
Jianlong Feng, Delei Li, Jing Zhang, and Liang Zhao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-296, https://doi.org/10.5194/bg-2021-296, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
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Although some studies have been conducted on primary productivity in the Amundsen Sea, the spatial differences and mechanisms that drive differences in phenology, decadal and long-term changes in primary productivity are still not clear. We first obtained a bioregional map of the Amundsen Sea. Using the bioregionalization outputs, the limiting factors that affect spatial differences, the phenology, decadal and long-term changes of primary productivity was analyzed.
03 Nov 2021
Sensitivity of plankton assemblages to hydroclimate variability in the Barents Sea
Elliott L. Price, Rowena F. Stern, Claire Mahaffey, Claudia Castellani, and Rachel M. Jeffreys
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-279, https://doi.org/10.5194/bg-2021-279, 2021
Preprint withdrawn (discussion: closed, 7 comments)
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Plankton are a vital group of organisms in the arctic as they are prey for animals such as fish, seals and whales. Communities of plankton consist of many different species that need different environmental conditions in order to thrive. Using data from the past decade, we show how changes to environmental conditions on an interannual time scale results in changes to the plankton community. The changes we found could have wider impacts on fisheries, and other species that feed upon plankton.
29 Oct 2021
Pameterization of the responses of subarctic European vegetation to key environmental variables for ozone risk assessment
Stefanie Falk, Ane V. Vollsnes, Aud B. Eriksen, Lisa Emberson, Connie O'Neill, Frode Stordal, and Terje Koren Berntsen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-260, https://doi.org/10.5194/bg-2021-260, 2021
Revised manuscript not accepted (discussion: closed, 6 comments)
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Subarctic vegetation is threatened by climate change and ozone. We assess essential climate variables in 2018/19. 2018 was warmer and brighter than usual in Spring with forest fires and elevated ozone in summer. Visible damage was observed on plant species in 2018. We find that generic parameterizations used in modeling ozone dose do not suffice. We propose a method to acclimate these parameterizations and find an ozone-induced biomass loss of 2.5 to 17.4 % (up to 6 % larger than default).
18 Oct 2021
Modeling of the large-scale nutrient biogeochemical cycles in Lake Onego
Oleg P. Savchuk, Alexey V. Isaev, and Nikolay N. Filatov
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-249, https://doi.org/10.5194/bg-2021-249, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Empirical information on the nutrient cycles in the second largest European Lake Onego is almost lacking. We covered the deficit by realistic simulation of the lake’s ecosystem dynamics during 1985–2015 with the 3D ecohydrodynamic model. Important results include: a) 3D dynamics of major nutrient variables and fluxes; b) quantification of the spring phytoplankton bloom, previously overlooked; c) coherent nutrient budgets. The model is a useful tool for forecasting with different scenarios.
29 Sep 2021
Methane accumulation affected by particulate organic carbon in upper Yangtze deep valley dammed cascade reservoirs, China
Yuanyuan Zhang, Youheng Su, Zhe Li, Shuhui Guo, Lunhui Lu, Bin Zhang, and Yu Qin
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-234, https://doi.org/10.5194/bg-2021-234, 2021
Preprint withdrawn (discussion: closed, 6 comments)
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POC in the XLD and XJB reservoirs mainly originates from terrestrial POC (56 %). CH4 oxidation potentially influences the variations in CH4 concentrations and δ13C-CH4 in cascade reservoirs. Water level variations and flow regulation caused by reservoir operation are primary factors for the input of terrestrial POC. The cumulative effect of POC at a bimonthly scale was not significant in the XLD and XJB reservoirs. Terrestrial POC displays more persistent impacts on CH4 accumulation.
10 Sep 2021
Large Herbivores Affecting Permafrost – Impacts of Grazing on Permafrost Soil Carbon Storage in Northeastern Siberia
Torben Windirsch, Guido Grosse, Mathias Ulrich, Bruce C. Forbes, Mathias Göckede, Juliane Wolter, Marc Macias-Fauria, Johan Olofsson, Nikita Zimov, and Jens Strauss
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-227, https://doi.org/10.5194/bg-2021-227, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
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With global warming, permafrost thaw and associated carbon release are of increasing importance. We examined how large herbivorous animals affect Arctic landscapes and how they might contribute to reduction of these emissions. We show that over a short timespan of roughly 25 years, these animals have already changed the vegetation and landscape. On pastures in a permafrost area in Siberia we found smaller thaw depth and higher carbon content than in surrounding non-pasture areas.
08 Sep 2021
Effect of vegetation distribution driven by hydrological fluctuation on sedimental stoichiometry regulating N2O emissions in freshwater wetland
Huazu Liu, Qiu Jin, Ruijie Shi, Chengxu Lv, Junxiao Luo, Yan He, Wei Yang, Xiaoguang Xu, Shenhua Qian, and Wei Li
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-208, https://doi.org/10.5194/bg-2021-208, 2021
Preprint withdrawn (discussion: closed, 4 comments)
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Hydrodynamics drive the distribution of plant communities in wetlands to form vegetation zones where the emission of N2O varies with plant species. The N2O emission decreased with the increase in carbon to nitrogen ratio of sediments, approximating a threshold. The distribution of plants under hydrodynamics modified the sedimental chemistry, resulting in the variations of bacteria. Hydraulic regulation rather than direct planting would be an effective strategy to reduce N2O in wetlands.
17 Aug 2021
Dissolved organic carbon vertical movement and carbon accumulation in West Siberian peatlands
Evgeny A. Zarov, Elena D. Lapshina, Iris Kuhlmann, and Ernst-Detlef Schulze
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-211, https://doi.org/10.5194/bg-2021-211, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
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The waterlogging process started ~11 000 years ago at the Mukhrino peatland (Russia, western Siberia). Since that time the peat accumulation has been started with the average rate 0.67 mm per year. The highest carbon accumulation rate found for bottom layers formed by shrubs and tress (63.0–76.0 gC m−2 year−1) and the lowest rate found for the upper layers formed by mosses (34.0 gC m−2 year−1). Dissolved carbon may move downward through the peatland with the average rate 0.047 cm year−1.
13 Jul 2021
The impacts of model structure, parameter uncertainty and experimental design on Earth system model simulations of litter bag decomposition experiments
Daniel M. Ricciuto, Xiaojuan Yang, Dali Wang, and Peter E. Thornton
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-163, https://doi.org/10.5194/bg-2021-163, 2021
Publication in BG not foreseen (discussion: closed, 4 comments)
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This paper uses a novel approach to quantify the impacts of the choice of decomposition model on carbon and nitrogen cycling. We compare the models to experimental data that examined litter decomposition over five different biomes. Despite widely differing assumptions, the models produce similar patterns of decomposition when nutrients are limiting. This differs from past analyses that did not consider the impacts of changing environmental conditions or nutrients.
12 Jul 2021
Biomarker characterization of the North Water Polynya, Baffin Bay: Implications for local sea ice and temperature proxies
David J. Harning, Brooke Holman, Lineke Woelders, Anne E. Jennings, and Julio Sepúlveda
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-177, https://doi.org/10.5194/bg-2021-177, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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In order to better reconstruct the geologic history of the North Water Polynya, we provide modern validations and calibrations of lipid biomarker proxies in Baffin Bay. We find that sterols, rather than HBIs, most accurately capture the current extent of the North Water Polynya and will be a valuable tool to reconstruct its past presence/absence. Our local temperature calibrations for alkenones, GDGTs and OH-GDGTs reduce the uncertainty present in global temperature calibrations.
08 Jul 2021
Manifestations and environmental implications of microbially-induced calcium carbonate precipitation (MICP) by the cyanobacterium Dolichospermum flosaquae
Refat Abdel-Basset, Elhagag Ahmed Hasssan, and Hans-Peter Grossart
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-146, https://doi.org/10.5194/bg-2021-146, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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The aim of this work is to explore the ability of the cyanobacterium Dolichospermum flosaquae in microbially-induced calcium carbonate precipitation (MICP). Environmentally, MICP controls the availability of calcium, carbon and phosphorus in freshwater lakes and carbon exchange with the atmosphere. Citrate, at 4 mg/L, induced the highest carbonate alkalinity, the highest calcium consumption, the highest urease activity along with the lowest photosynthetic and respiratory oxygen exchange.
24 Jun 2021
Biological response to wind and terrestrial nitrate in the western and southern continental shelves of the Gulf of Mexico
Javier González-Ramírez, Alejandro Parés-Sierra, and Jushiro Cepeda-Morales
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-142, https://doi.org/10.5194/bg-2021-142, 2021
Publication in BG not foreseen (discussion: closed, 2 comments)
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We evaluated the impact of river nutrients on primary production over the southern and western shelves of the Gulf of Mexico. For this, new flow and nutrient data were integrated into a coupled model. The model reproduced the biological response in the gulf based on the concentration and distribution of chlorophyll. In the deep region, this response was dominated by vertical mixing and mesoscale structures, over the shelves was dominated by coastal upwelling and fluvial nutrient contributions.
19 May 2021
Geophysical and biogeochemical observations using BGC Argo floats in the western North Pacific during late winter and early spring, Part 2: Biological processes during restratification periods in the euphotic and twilight layers
Chiho Sukigara, Ryuichiro Inoue, Kanako Sato, Yoshihisa Mino, Takeyoshi Nagai, Andrea J. Fassbender, Yuichiro Takeshita, and Eitarou Oka
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-116, https://doi.org/10.5194/bg-2021-116, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We combined ship-borne water sampling with the use of two Argo floats equipped with biogeochemical sensors to determine the changes in primary productivity associated with the passage of storms and resultant disturbance in the subtropical western North Pacific. We found that the episodic influx of carbon to the surface facilitated by storms played a key role in promoting primary production. Particulate carbon transported to the twilight layer were not the major substrate for the respiration.
18 May 2021
Ozone-induced gross primary productivity reductions over European forests inferred from satellite observations
Jasdeep Singh Anand, Alessandro Anav, Marcello Vitale, Daniele Peano, Nadine Unger, Xu Yue, Robert J. Parker, and Hartmut Boesch
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-125, https://doi.org/10.5194/bg-2021-125, 2021
Publication in BG not foreseen (discussion: closed, 4 comments)
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Ozone damages plants, which prevents them from absorbing CO2 from the atmosphere. This poses a potential threat to preventing dangerous climate change. In this work, satellite observations of forest cover, ozone, climate, and growing season are combined with an empirical model to estimate the carbon lost due to ozone exposure over Europe. The estimated carbon losses agree well with prior modelled estimates, showing for the first time that satellites can be used to better understand this effect.
05 May 2021
Fluorescent double labelling of F-actin in Foraminifera: evaluation of granular pattern F-actin organisation in reticulopodia
Jan Goleń, Jarosław Tyszka, and Karolina Godos
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-76, https://doi.org/10.5194/bg-2021-76, 2021
Manuscript not accepted for further review (discussion: closed, 6 comments)
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We present images of foraminiferal pseudopodia stained with two different actin-labelling fluorescent probes (SiR-actin and Phalloidin Atto 488) showing very similar staining patterns. The highest intensity of fluorescence in both channels is observed in micrometre-sized granules. These observations allow for rejection the staining artefacts hypotheses and support the possibility that these granules contain physiologically functional form of actin cytoskeleton in foraminifera.
23 Apr 2021
Insights into nitrogen fixation below the euphotic zone: trials in an oligotrophic marginal sea and global compilation
Siqi Wu, Moge Du, Xianhui Sean Wan, Corday Selden, Mar Benavides, Sophie Bonnet, Robert Hamersley, Carolin R. Löscher, Margaret R. Mulholland, Xiuli Yan, and Shuh-Ji Kao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-104, https://doi.org/10.5194/bg-2021-104, 2021
Preprint withdrawn (discussion: closed, 3 comments)
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Nitrogen (N2) fixation is one of the most important nutrient sources to the ocean. Here, we report N2 fixation in the deep, dark ocean in the South China Sea via a highly sensitive new method and elaborate controls, showing the overlooked importance of N2 fixation in the deep ocean. By global data compilation, we also provide an easy measured basic parameter to estimate deep N2 fixation. Our study may help to expand the area limit of N2 fixation studies and better constrain global N2 fixation.
23 Apr 2021
Unravelling Light and Microbial Activity as Drivers of Organic Matter Transformations in Tropical Headwater Rivers
James F. Spray, Thomas Wagner, Juliane Bischoff, Sara Trojahn, Sevda Norouzi, Walter Hill, Julian Brasche, Leroy James, and Ryan Pereira
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-92, https://doi.org/10.5194/bg-2021-92, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Sunlight and microbial activity break down river dissolved organic matter (DOM), releasing greenhouse gases, but are poorly understood in tropical headwaters. We incubated water in light and darkness, using novel methods to quantify changes in DOM concentration and character. Light removed up to 9 % of DOM, but microbial activity had a varied response. Importantly, light affected DOM compounds considered photo-resistant; likewise microbial activity degraded compounds thought to be bio-resistant.
22 Apr 2021
Reviews and syntheses: Enhancing research and monitoring of land-to-atmosphere greenhouse gases exchange in developing countries
Dong-Gill Kim, Ben Bond-Lamberty, Youngryel Ryu, Bumsuk Seo, and Dario Papale
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-85, https://doi.org/10.5194/bg-2021-85, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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While greenhouse gas (GHG) research has adopted highly advanced technology some have adopted appropriate technology and approach (AT&A) such as low-cost instrument, open source software and participatory research and their results were well accepted by scientific communities. In terms of cost, feasibility and performance, integration of low-cost and low-technology, participatory and networking based research approaches can be AT&A for enhancing GHG research in developing countries.
15 Apr 2021
Cells of matter and life – towards understanding the internal structure and spatial patchiness of particles and plankton distribution in the Arctic fjords
Emilia Trudnowska, Katarzyna Dragańska-Deja, Sławomir Sagan, and Katarzyna Błachowiak-Samołyk
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-98, https://doi.org/10.5194/bg-2021-98, 2021
Revised manuscript not accepted (discussion: closed, 4 comments)
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Patches (concentration hotspots) of particles and plankton are fundamental “cells” for trophic interactions and organic carbon cycling. But the patterns of their heterogeneous distribution and structuring are still hardly understood. We mapped the spatio-temporal distribution patterns and analysed the internal structure of 94 patches of various size fractions, classified them into several types and discussed the potential mechanisms governing their formation and existence.
31 Mar 2021
Evolution of the long-term and estuary-scale phytoplankton patterns in the Scheldt estuary: the disappearance of net growth in the brackish region
Dante M. L. Horemans, Yoeri M. Dijkstra, Michèle Tackx, Patrick Meire, and Tom J. S. Cox
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-59, https://doi.org/10.5194/bg-2021-59, 2021
Manuscript not accepted for further review (discussion: closed, 8 comments)
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We study the appearance in 2008–2014 and disappearance after 2015 of a phytoplankton spring-bloom in the brackish region in the Scheldt estuary. To this end, we analyze long-term in situ observations covering the full estuary and apply a model approach to determine which of the changed conditions may explain the observed change in phytoplankton. Our results suggest that insight into the zooplankton dynamics is essential to understand the phytoplankton dynamics in the Scheldt estuary.
09 Mar 2021
Sulfate reduction and anaerobic oxidation of methane in sediments of
the South-Western Barents Sea
Claudio Argentino, Kate Alyse Waghorn, Stefan Bünz, and Giuliana Panieri
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-58, https://doi.org/10.5194/bg-2021-58, 2021
Preprint withdrawn (discussion: closed, 5 comments)
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We investigated sulfate and methane cycling in sediments of the SW Barents Sea associated with a shallow gas accumulation. The depth of the sulfate-methane transition zone ranges between 3.5 m and 29.2 m, and all methane is consumed within the sediment. Results from this study are important to better understand the dynamic of the sulfate-methane transition and to predict its response to future scenarios of increasing methane fluxes in Arctic continental shelves affected by ocean warming.
03 Mar 2021
High greenhouse gas fluxes from peatlands under various
disturbances in the Peruvian Amazon
Jaan Pärn, Kaido Soosaar, Thomas Schindler, Katerina Machacova, Waldemar Alegría Muñoz, Lizardo Fachín, José Luis Jibaja Aspajo, Robinson I. Negron-Juarez, Martin Maddison, Jhon Rengifo, Danika Journeth Garay Dinis, Adriana Gabriela Arista Oversluijs, Manuel Calixto Ávila Fucos, Rafael Chávez Vásquez, Ronal Huaje Wampuch, Edgar Peas García, Kristina Sohar, Segundo Cordova Horna, Tedi Pacheco Gómez, Jose David Urquiza Muñoz, Rodil Tello Espinoza, and Ülo Mander
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-46, https://doi.org/10.5194/bg-2021-46, 2021
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Despite alarming forecasts for the Amazonian peat swamp forests, greenhouse gas emissions from the different peat environments have rarely been compared. We measured CO2, CH4 and N2O emissions from the soil in 3 sites around Iquitos, Peru: a pristine swamp forest, a young forest and a slash-and-burn manioc field. We saw a devastating effect on global climate from a slight water-table drawdown in the peat swamp forests, while the manioc field emitted moderate amounts of the greenhouse gases.
23 Feb 2021
Tritium activity concentration and behaviour in coastal
regions of Fukushima in 2014
Michio Aoyama, Sabine Charmasson, Yasunori Hamajima, Celine Duffa, Daisuke Tsumune, and Yutaka Tateda
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-10, https://doi.org/10.5194/bg-2021-10, 2021
Manuscript not accepted for further review (discussion: closed, 5 comments)
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Results of observations of the 3H activity concentrations at Fukushima coast showed the large effect of 3H flux through the rivers to coastal waters. The 3H activity concentration close to Fukushima accident site was significantly high compared to the 3H activity concentration in surrounding waters both north and south of the FNPP1 site and in river waters. The 3H/137Cs activity ratios in coastal waters were 1.2–2.2, which is significantly high compared to that observed just after the accident.
23 Feb 2021
Influence of land use and occupation on the water quality of a
microbasin in the southwestern Amazon
Alan Gomes Mendonça, Josilena de Jesus Laureano, Daíse da Silva Lopes, Lindolaine Machado de Sousa, Tiago de Oliveira Lima, Ana Lúcia Denardin da Rosa, Beatriz Machado Gomes, Igor David da Costa, and Elisabete Lourdes do Nascimento
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-485, https://doi.org/10.5194/bg-2020-485, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Aimed at improving the management of water resources in the Brazilian Amazon, studies providing relevant data and proposals are needed. This study through tools such as GIS and laboratory studies have provided data relevant to the framework of a watershed in southwestern Amazon. Different water quality parameters were analyzed relating them directly with the use of analysis and occupation of the basin, getting relevant results to improve the quality of water resources in the region.
15 Feb 2021
Weekly reconstruction of pH and total alkalinity in an upwelling-dominated coastal ecosystem through neural networks (ATpH-NN): The case of Ría de Vigo (NW Spain)
between 1992 and 2019
Daniel Broullón, Fiz F. Pérez, and María Dolores Doval
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-33, https://doi.org/10.5194/bg-2021-33, 2021
Publication in BG not foreseen (discussion: closed, 2 comments)
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We created a weekly database of pH and total alkalinity in a coastal upwelling system between 1992 and 2019. This product is very relevant to analyze the natural variability and the anthropogenic influence in the CO2 system in order to gain knowledge about the drivers of the variability and the possible future conditions of the Ría de Vigo. Biological ocean acidification experiments can also take advantage of this product to better restrict its parameters.
08 Feb 2021
Impact of typhoons on particulate and dissolved 137Cs activities in seawater off the Fukushima Prefecture: results from the SOSO 5 Rivers cruise (October 2014)
Michio Aoyama, Sabine Charmasson, Yasunori Hamajima, and Celine Duffa
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-491, https://doi.org/10.5194/bg-2020-491, 2021
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Our results showed that the dissolved radiocaesium activities were generally higher at coastal sites and decreased with distance from shore. The portion of particulate 137Cs to the total 137Cs ranged from 0.13 to 0.96.
The ratio of 137Cs to 134Cs activity in organic particles did not change with distance from shore and generally remained around 1.
The 137Cs / 134Cs activity ratio in seawater was estimated to be 1.074 ± 0.015 which was in good agreement with the ratio of 1.06 in core unit 1.
14 Jan 2021
Radiative transfer modeling with BGC-Argo float data in the
Mediterranean Sea
Elena Terzić, Arnau Miró, Paolo Lazzari, Emanuele Organelli, and Fabrizio D'Ortenzio
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-473, https://doi.org/10.5194/bg-2020-473, 2021
Preprint withdrawn (discussion: closed, 6 comments)
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This study integrates numerical simulations (using a multi-spectral optical model) with in-situ measurements of floats and remotely sensed observations from satellites. It aims at improving our current understanding of the impact that different constituents (such as pure water, colored dissolved organic matter, detritus and phytoplankton) have on the in-water light propagation.
04 Dec 2020
Air–sea carbon flux from high-temporal-resolution data of in situ CO2 measurements in the southern North Sea
Steven Pint, Gert Everaert, Hannelore Theetaert, Michiel B. Vandegehuchte, and Thanos Gkritzalis
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-442, https://doi.org/10.5194/bg-2020-442, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
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We calculated the air–sea CO2 flux in the southern North Sea for 2018 using high frequency data from the ICOS Station BE-FOS-Thornton Buoy. The area acted as a CO2 sink for this year but we also identified a seasonal variability of the CO2 flux during this period, both in terms of amplitude but also direction (source–sink). The data set and our analysis showcase the importance of high quality and high frequency data in order to constrain the air–sea CO2 flux in coastal dynamic environments.
02 Dec 2020
Multi-year CO2 budgets in South African semi-arid Karoo ecosystems
under different grazing intensities
Oksana Rybchak, Justin du Toit, Jean-Pierre Delorme, Jens-Kristian Jüdt, Kanisios Mukwashi, Christian Thau, Gregor Feig, Mari Bieri, and Christian Brümmer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-420, https://doi.org/10.5194/bg-2020-420, 2020
Revised manuscript not accepted (discussion: closed, 6 comments)
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We studied the impacts of livestock grazing on carbon budgets in the semi-arid South African Karoo by comparing two sites under different grazing intensities. The previously overgrazed site, characterised by unpalatable grasses and thus poorly suited as pasture, sequestered more carbon over the four-year measurement period, compared to the lenient-grazed site. The studied ecosystems act as either carbon sinks or sources depending on precipitation.
24 Nov 2020
Do marine benthos breathe what they eat?
Xiaoguang Ouyang, Cheuk Yan Lee, and Shing Yip Lee
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-424, https://doi.org/10.5194/bg-2020-424, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We used the gas isotope of marine macrobenthos respired carbon dioxide to track their immediate and integrated food. This is a new paradigm called
You breathe what you eat, which adds to the existing paradigm of
You are what you eatin food web studies. The new paradigm reflects macrobenthos' feeding habit and taxa. Our data also show carbon dioxide fluxes respired by marine macrobenthos are related to their sizes. This will help to better constrain carbon fluxes contributed by macrobenthos.
23 Nov 2020
Contribution of the nongrowing season to annual N2O emissions from the
continuous permafrost region in Northeast China
Weifeng Gao, Dawen Gao, Liquan Song, Houcai Sheng, Tijiu Cai, and Hong Liang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-305, https://doi.org/10.5194/bg-2020-305, 2020
Preprint withdrawn (discussion: closed, 7 comments)
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The N2O emissions ranged from −35.75 to 74.16 μg·m−2·h−1 during the nongrowing season in the permafrost region. The nongrowing season N2O emissions ranged from 0.89 to 1.44 kg ha−1, which contributed to 41.96–53.73 % of the annual budget, accounting for almost half of the annual emissions in the permafrost region. Nongrowing season N2O emissions is an important component of annual emissions and cannot be ignored in the permafrost region.
21 Nov 2020
Cambial-age related correlations of stable isotopes and tree-ring
widths in wood samples of tree-line conifers
Tito Arosio, Malin M. Ziehmer-Wenz, Kurt Nicolussi, Christian Schlüchter, and Markus Leuenberger
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-406, https://doi.org/10.5194/bg-2020-406, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
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A recent analysis of stable isotopes of samples from larch and cembran trees, revealed that δD and δ18O exhibit no trends in adult trees, but trends in the juvenile period. In this work we applied a correlation analysis on different cambial age to verify if these changes were correlated with tree-ring width values. The results prove a significant correlation between tree-ring-width and both hydrogen and oxygen stable isotopes before 100 year of cambial age, but not afterwards, in both species.
17 Nov 2020
Drivers of the variability of the isotopic composition of water vapor
in the surface boundary layer
Jelka Braden-Behrens, Lukas Siebicke, and Alexander Knohl
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-398, https://doi.org/10.5194/bg-2020-398, 2020
Preprint withdrawn (discussion: closed, 6 comments)
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We use directly measured isotopic compositions and isoforcing values in combination with meteorological data and PBL height information to gain a better understanding of the variability of the isotopic composition of H2Ov. We directly compare the measured changes in isotopic composition with isoforcing-related changes (driven by local evapotranspiration ET). We conclude that it is important to account for PBL height when interpreting isoforcing data.
13 Nov 2020
Manifestations and environmental implications of microbially-induced calcium
carbonate precipitation (MICP) by the cyanobacterium Dolichospermum
flosaquae
Refat Abdel-Basset, Elhagag Ahmed Hassan, and Hans-Peter Grossart
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-378, https://doi.org/10.5194/bg-2020-378, 2020
Revised manuscript not accepted (discussion: closed, 9 comments)
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This work was planned and implemented to evaluate the capacity of the Cyanobacterium Dolichospermum flosaquae in microbially induced calcium carbonate precipitation (MICP), which in turn exerts numerous impacts in biogeochemistry of freshwater lakes. MICP is also a determinant of atmospheric carbon emission and eutrophication. Calcium citrate was the most inductive for MICP powered by photosynthesis. The results can be modeled for the implications of MICP in biogeochemical cycles of Ca, C & P.
19 Oct 2020
Latitudinal patterns in the concentrations of biologically utilised
elements in the surface ocean
Daisy Pickup and Toby Tyrrell
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-371, https://doi.org/10.5194/bg-2020-371, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
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Concentrations of chemical elements dissolved in seawater differ from place to place in the surface ocean. Understanding how they change, and why, is important, for instance to understand ocean carbon storage or to understand nutrient supply for life in the ocean. We used a new global dataset to study spatial changes of numerous elements, many not studied before. We find a common pattern: an increase from low to high latitudes, because deep water rises to the surface at high latitudes.
15 Oct 2020
Warmer winters causes an increase of chlorophyll-a concentration in
deeper layers: the opposite role of convection and self-shading on the
example of the Black Sea
Elena A. Kubryakova and Arseny A. Kubryakov
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-366, https://doi.org/10.5194/bg-2020-366, 2020
Revised manuscript not accepted (discussion: closed, 8 comments)
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In this article, we use Bio-Argo data to demonstrate the opposite impact of winter convection and self-shading on chlorophyll's vertical distribution in the Black Sea. During cold winter, a larger amount of nutrients is entrained in the upper layer. The chlorophyll concentration (Chl) in upper layers increases, which shades the deeper layers, where Chl decreases. The opposite is observed in warm years, when light penetrates to the nitrocline and Chl increase in deeper layers.
08 Oct 2020
Intersecting Methane Production and Oxidation Zones in Freshwater Sediments
Xueping Chen, Juan Yu, Lihua Liu, Jing Sun, Fayan Bai, Ming Yang, Zheng Chen, Chiquan He, Xiaoyan Liu, Shuang Bai, and Fushun Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-330, https://doi.org/10.5194/bg-2020-330, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Multiple lines of geochemical, microbiological, and molecular analyses evidenced the crossing zones of methane production and oxidation in the sediments of a freshwater reservoir. Hydrogenotrophic and aceticlastic methanogens were active in the upper and deeper layers, respectively. Two hotspots of AOM were determined there with a higher potential of consumption than the production, sulfate and iron AOM dominated in the subsurface layer and synchronously coupled nitrite-AOM in the middle layer.
14 Sep 2020
The effect of organic matter (OM) quality on the redox stability of OM-Fe association in freshwater sediments
Nana O.-A. Osafo, Jiří Jan, Petr Porcal, Daniel A. Petrash, and Jakub Borovec
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-296, https://doi.org/10.5194/bg-2020-296, 2020
Manuscript not accepted for further review (discussion: closed, 6 comments)
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We investigated the role that OM quality plays in the stability of the OM-Fe association in freshwater sediments. It was found that non-humic components enhance OM-Fe stability, while humic components enhance the reductive dissolution of OM-Fe. This information is useful for predicting the fate of OM-Fe in freshwater systems with discrete sources of OM. Stable OM-Fe complexes improve aqueous environments by reducing the release of greenhouse gases, heavy metals and excess nutrients, such as P.
11 Sep 2020
Extraterrestrial dust as a source of bioavailable Fe for the ocean productivity
Rudraswami N. Gowda, Mayank Pandey, Matthew J. Genge, and Dafilgo Fernandes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-283, https://doi.org/10.5194/bg-2020-283, 2020
Preprint withdrawn (discussion: closed, 6 comments)
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Bioavailable Fe is necessary component for phytoplankton to survive and will play a crucial role in reducing the carbon dioxide in the atmosphere. The Fe increase the primary productivity of ocean which is rare in the isolated region of the ocean. Here, the role of extraterrestrial dust become significant as smoke from the ablation and etching also contribute Fe to this organism which in turn reduces the adverse effect on the climate by acting as sink of carbon dioxide.
31 Aug 2020
Rapid abiotic transformation of marine dissolved organic material to particulate organic material in surface and deep waters
Paola Valdes Villaverde, Cesar Almeda Jauregui, and Helmut Maske
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-291, https://doi.org/10.5194/bg-2020-291, 2020
Preprint withdrawn (discussion: closed, 6 comments)
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The oceans sequester more than 1/4 of the anthropogenic CO2, mainly through the sinking of organic particles (POM) to the seafloor. POM samples are collected on filter; the filtrate is expected to contain only dissolved organic material, but we found unexpectedly high POM when the filtrate was refiltered. We interpret this POM as gels that were formed in the filtrate by hydraulic stress during the filtration. In deep water samples the POM collected can be less than the POM in the filtrate.
19 Aug 2020
Effects of land use and water quality on greenhouse gas emissions from an urban river system
Long Ho, Ruben Jerves-Cobo, Matti Barthel, Johan Six, Samuel Bode, Pascal Boeckx, and Peter Goethals
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-311, https://doi.org/10.5194/bg-2020-311, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
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Rivers are being polluted by human activities, especially in urban areas. We studied the greenhouse gas (GHG) emissions from an urban river system. The results showed a clear trend between water quality and GHG emissions in which the more polluted the sites were, the higher were their emissions. When river water quality worsened, its contribution to global warming can go up by 10 times. Urban rivers emitted 4-times more than of the amount of GHGs compared to rivers in natural sites.
13 Aug 2020
Importance of succession in estimating biomass loss: Combining remote sensing and individual-based forest models
Ulrike Hiltner, Andreas Huth, and Rico Fischer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-264, https://doi.org/10.5194/bg-2020-264, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
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The aim of our study is to to analyze the consequences of elevated tree mortality on tropical forest dynamics and to provide a methodology that can reduce uncertainties in estimating biomass loss due to tree mortality at local and country levels.
07 Aug 2020
Human-induced influence on eggs and larval fish transport in a subtropical estuary
Maria Helena P. António, José H. Muelbert, and Elisa H. L. Fernandes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-281, https://doi.org/10.5194/bg-2020-281, 2020
Revised manuscript not accepted (discussion: closed, 5 comments)
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The Barra Jetties at the mouth of the Lagoa dos Patos estuary were recently changed. The hydrodynamic model TELEMAC-3D coupled to passive particles was used to simulate the transport of eggs and larvae of croaker, in controlled simulations. Hydrodynamic changes occurred reflected on the transport of eggs and larvae, with a reduction in the abundance and extension of the incursion into the estuary in the new jetties configuration. The results can help the management and circumvent of fish stocks.
31 Jul 2020
Influence of microorganisms on initial soil formation along a
glacier forefield on King George Island, maritime Antarctica
Patryk Krauze, Dirk Wagner, Diogo Noses Spinola, and Peter Kühn
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-203, https://doi.org/10.5194/bg-2020-203, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Soils from the recently deglaciated foreland of the Ecology Glacier, King George Island, were analyzed using soil chemical and microbiological methods to gain insight into the state of soil formation and its interplay with microbial activity. In the foreland of the Ecology Glacier, acidification, soil carbon/nitrogen accumulation, and changes in microbial communities and vegetation were observable on a decadal timescale, whereas weathering processes occur centuries/millenia after deglaciation.
08 Jul 2020
Temporal and spatial mediated changes in subsurface microbial
community assemblages and functions
Madison C. Davis
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-238, https://doi.org/10.5194/bg-2020-238, 2020
Manuscript not accepted for further review (discussion: closed, 8 comments)
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Different patterns of bacterial communities may occur in different groundwater types. Hurricanes and seasons may not always induce perturbations in bacterial communities. Changes in chemistry and local hydrology within the different regions of groundwater appear to have caused the apparent changes in the bacterial communities. Understanding how the microbes in different groundwater regions react to changes is important for groundwater management and conservation.
03 Jul 2020
Photodegradation and biodegradation of dissolved organic
matter on the surface of the Greenland Ice Sheet
Miranda J. Nicholes, Christopher Williamson, Martyn Tranter, Alexandra Holland, Marian Yallop, and Alexandre Anesio
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-227, https://doi.org/10.5194/bg-2020-227, 2020
Publication in BG not foreseen (discussion: closed, 3 comments)
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This incubation experiment assessed the role of solar radiation and heterotrophic bacteria in the degradation of organic carbon in surface ice of the Greenland Ice Sheet. Although ultraviolet radiation was found to alter carbon composition, heterotrophic degradation caused the greatest changes to both carbon composition and quantity. Both processes are likely interlinked within the surface ice and are fundamental to controlling the composition of carbon exported to downstream environments.
01 Jul 2020
Diel and seasonal variability of methane emissions from a shallow and eutrophic pond
Wenli Zhang, Shangbin Xiao, Heng Xie, Jia Liu, Dan Lei, and Andreas Lorke
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-178, https://doi.org/10.5194/bg-2020-178, 2020
Manuscript not accepted for further review (discussion: closed, 5 comments)
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We analyzed CH4 emissions from a shallow and small eutrophic pond and found that 88.6 % of CH4 emissions was directly released by bubbling. The higher the temperature, the higher the eutrophication level and the greater the amount of methane released. Our study highlights that increasing eutrophication by anthropogenic impacts and climate warming will increase CH4 emissions from ponds, thus representing a positive feedback mechanism to global warming.
29 Jun 2020
Seed traits and phylogeny explain plant distribution at large
geographic scale
Kai Chen, Kevin S. Burgess, Fangliang He, Xiang-Yun Yang, Lian-Ming Gao, and De-Zhu Li
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-186, https://doi.org/10.5194/bg-2020-186, 2020
Revised manuscript not accepted (discussion: closed, 6 comments)
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Understanding the mechanisms that shape the geographic distribution of plant species is a central theme of biogeography. In the study, we quantify the joint effects of key seed traits and phylogeny on species' distribution across 1,616 species of seed plants on the basis of a ten-year seed conservation initiative in China. Our findings show that, seed mass, seed mass variability, seed dispersal mode and phylogeny, together explained 40.44 % of the variance in species range size.
25 Jun 2020
Thermocline depth and euphotic zone thickness regulate the abundance of diazotrophic cyanobacteria in Lake Tanganyika
Benedikt Ehrenfels, Maciej Bartosiewicz, Athanasio S. Mbonde, Kathrin B. L. Baumann, Christian Dinkel, Julian Junker, Tumaini Kamulali, Ismael A. Kimirei, Daniel Odermatt, Francesco Pomati, Emmanuel A. Sweke, and Bernhard Wehrli
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-214, https://doi.org/10.5194/bg-2020-214, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
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Cyanobacterial blooms are a widespread phenomenon, but their formation is poorly understood in nutrient-poor water bodies. During two cruises we collected physical, nutrient, pigment and phytoplankton data to study nitrogen fixing cyanobacteria (diazotrophs) in Lake Tanganyika, Africa. We found that, due to their capability of fixing gaseous nitrogen, diazotrophs thrive when the supply of dissolved inorganic nitrogen to the sun-lit surface waters is low, but phosphorous is still available.
16 Jun 2020
Warmer winter causes deepening and intensification of summer
subsurface bloom in the Black Sea: the role of convection and self-shading
mechanism
Elena A. Kubryakova and Arseny A. Kubryakov
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-210, https://doi.org/10.5194/bg-2020-210, 2020
Manuscript not accepted for further review (discussion: closed, 5 comments)
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In a year with cold winter, a larger amount of nutrients is convectively entrained in the upper layer, which increases the growth of phytoplankton in the upper layer and causes self-shading of deeper layers. In years with warm winter convective nutrient fluxes are low, the amount of phytoplankton and light attenuation decreases and light penetrates to the layer of nitrate maximum which causes intense summer deep bloom. The yearly-averaged concentration of chlorophyll in both years is comparable.
11 Jun 2020
Cereal-legume mixtures increase net CO2 uptake in a forage system of the Eastern Pyrenees
Mercedes Ibañez, Núria Altimir, Àngela Ribas, Werner Eugster, and Maria-Teresa Sebastià
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-173, https://doi.org/10.5194/bg-2020-173, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Our study unravels the influence of forage species on ecosystem scale CO2 fluxes, and is the first long term dataset of a forage system in the Pyrenees. We found strong evidence that cereal legume mixtures enhanced system's CO2 sink capacity compared to cereal monocultures, by enhancing photosynthesis and voluntary regrowth, decisive for the net CO2 budget. This knowledge is crucial to develop climate change mitigation strategies, while ensuring productivity of forage systems.
08 Jun 2020
An interrupting mechanism to prevent the formation of coastal hypoxiaby winds
Juan Yao, Juying Wang, Hongbin Liu, and Kedong Yin
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-188, https://doi.org/10.5194/bg-2020-188, 2020
Preprint withdrawn (discussion: closed, 4 comments)
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Our study finds that winds appear to be a dominant regulating force on the formation of hypoxia in the Pearl River estuarine waters. The wind speed > 6 m/s appears to a threshold above which the water column stratification is destroyed and the formation of bottom hypoxia is interrupted. The frequency of such the above-threshold wind events decreases significantly, implying that climate change induced variability in wind speeds can exasperate the coastal formation of bottom hypoxia in the region.
04 Jun 2020
Climate data induced uncertainties in simulated carbon fluxes under corn and soybean systems
Varaprasad Bandaru
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-129, https://doi.org/10.5194/bg-2020-129, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Agroecosystem models often rely on climate datasets to assess carbon balance on croplands. However errors in climate datasets may lead to inaccurate assessment of carbon fluxes affecting management and policy decisions targeting carbon friendly agriculture. We studied biases in climate datasets and impacts on simulated carbon fluxes under corn and soybeans. Results suggest that climate datasets display a significant margin of error leading to uncertainty in simulated net carbon balance upto 66 %.
04 Jun 2020
Sample preservation and pre-treatment in stable isotope analysis: Implications for the study of aquatic food webs
Marc Jürgen Silberberger, Katarzyna Koziorowska-Makuch, Karol Kuliński, and Monika Kędra
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-199, https://doi.org/10.5194/bg-2020-199, 2020
Revised manuscript not accepted (discussion: closed, 6 comments)
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The use of stable isotope ratios to study food webs, requires multiple decisions about sample preservation and pre-treatments. In this study we demonstrate how different preservation and pre-treatment methods affect the interpretation of stable isotope data and highlight that today's guidelines are not applicable when data are used in Bayesian mixing models. Particularly the identified effects of freezing demonstrate that our understanding of the utilization of organic matter might be biased.
20 May 2020
New insights into mechanisms of sunlight-mediated high-temperature accelerated diurnal production-degradation of fluorescent DOM in lake waters
Yijun Liu, Jie Yuan, Fu-Jun Yue, Si-Liang Li, Baoli Wang, Mohammad Mohinuzzaman, Xuemei Yang, Nicola Senesi, Xinyu Lao, Longlong Li, Cong-Qiang Liu, Rob M. Ellam, and Khan M. G. Mostofa
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-145, https://doi.org/10.5194/bg-2020-145, 2020
Manuscript not accepted for further review (discussion: closed, 5 comments)
14 May 2020
A comparison of bacterial communities from OMZ sediments in the Arabian Sea and the Bay of Bengal reveals major differences in nitrogen turnover and carbon recycling potential
Jovitha Lincy and Cathrine Sumathi Manohar
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-162, https://doi.org/10.5194/bg-2020-162, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We report on sediment microbial communities from the two basins of the northern Indian Ocean, namely the Arabian Sea and the Bay of Bengal. We used a comparative amplicon sequencing, biogeochemical analysis and metagenomic modeling to explore the microbial communities and predict their metabolic potential. This revealed the potential for different pathways of respiration and organic matter turnover, which may add to understanding why the two basins are different in their oxygen concentrations.
22 Apr 2020
Differential effects of redox conditions on the decomposition of litter and soil organic matter
Yang Lin, Ashley N. Campbell, Amrita Bhattacharyya, Nicole DiDonato, Allison M. Thompson, Malak M. Tfaily, Peter S. Nico, Whendee L. Silver, and Jennifer Pett-Ridge
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-59, https://doi.org/10.5194/bg-2020-59, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Soils in tropical forests play an important role of breaking down dead plant tissue and returning carbon to the atmosphere. This process is previously thought to be regulated soil oxygen level. However, we found that the break-down of new plant carbon by soils did not depend on oxygen. Even without oxygen, some soil microbes can use plant carbons in the forms like sugar and protein. Once these compounds were exhausted, oxygen limitation became to influence organic matter break-down.
03 Apr 2020
Alternation of heterotrophic bacterial and archaeal production along nitrogen and salinity gradients in coastal wetlands
Gema L. Batanero, Andy J. Green, Juan A. Amat, Marion Vittecoq, Curtis A. Suttle, and Isabel Reche
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-60, https://doi.org/10.5194/bg-2020-60, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Coastal wetlands provide ecosystem services such as a reduction in nitrogen inputs into coastal waters and storage organic carbon. The rise of sea level will salinize many coastal wetlands. Here, we analyzed the abundance of prokaryotes and the heterotrophic production of bacteria and archaea in wetlands from the Mediterranean coast. We observed a switch from bacterial-dominated production to archaeal-dominated production with increases of anthropogenic nitrogen inputs and salinity.
01 Apr 2020
Effects of environmental and management factors on worldwide maize and soybean yields over the 20th and 21st centuries
Tzu-Shun Lin, Yang Song, Atul K. Jain, Peter Lawrence, and Haroon S. Kheshgi
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-68, https://doi.org/10.5194/bg-2020-68, 2020
Preprint withdrawn (discussion: closed, 7 comments)
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ISAM model was used to estimate soybean and maize crop yields over 1901–2100 driven by changes in environmental factors and management factors. Over the 20th century, each of these factors contributes to the increase in global crop yield with increasing nitrogen fertilizer application the strongest of these drivers for maize and increasing [CO2] the strongest for soybean. Over the 21st century, changing climate drives yield lower, while rising [CO2] drives yield higher for both crops.
27 Mar 2020
Improved parameterization of the weathering kinetics module in the PROFILE and ForSAFE models
Harald Ulrik Sverdrup, Eric H. Oelkers, Martin Erlandsson Lampa, Salim Belyazid, Daniel Kurz, and Cecilia Akselsson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-464, https://doi.org/10.5194/bg-2019-464, 2020
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Equations, parameters and constants describing mineral dissolution kinetics have now been obtained for 113 minerals from 12 major structural groups, comprising all types of minerals encountered in most soils. The PROFILE and ForSAFE weathering sub-model was extended to cover two-dimensional catchments, both in the vertical and the horizontal direction, including the hydrology.
25 Mar 2020
Contrasting juxtaposition of two paradigms for diazotrophy in an Earth System Model of intermediate complexity
Ulrike Löptien and Heiner Dietze
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-96, https://doi.org/10.5194/bg-2020-96, 2020
Manuscript not accepted for further review (discussion: closed, 5 comments)
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Nitrogen fixation, conducted by specific microorganisms, makes molecular nitrogen available for marine biota. By this means this process exerts major control on the growth of algae in the ocean. This study compares two contemporary paradigms, anticipating the ecological niche of N-fixing organisms in an Earth System Model. We illustrate respective uncertainties in climate projections and suggest specific observations to advance the reliable representation of nitrogen fixation in numerical models.
20 Mar 2020
Interpretation of kinetic isotope fractionation between aqueous Fe(II)
and ferrihydrite under a high degree of microbial reduction
Lei Jiang, Chuanjun Wu, Mingqing Li, Xuegong Li, and Jiwei Li
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-85, https://doi.org/10.5194/bg-2020-85, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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We use ferrihydrite as a terminal electron acceptor to conduct microbial dissimilatory iron reduction experiments. The results show that Fe isotope equilibrium fractionation occurs due to rapid electron transfer and atom exchange (ETAE) between aqueous Fe(II) and Fe(III) on the surface of minerals at a low degree of reduction. At a high degree of reduction, the kinetic isotope fractionation occurs as the amount of absorbed Fe(II) increases and the driving force of ETAE decreases.
10 Mar 2020
Spring distribution of shelled pteropods across the Mediterranean Sea
Roberta Johnson, Clara Manno, and Patrizia Ziveri
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-53, https://doi.org/10.5194/bg-2020-53, 2020
Revised manuscript not accepted (discussion: closed, 6 comments)
03 Mar 2020
Modelled potential forest area in the forest-steppe of central Mongolia is about three times of actual forest area
Michael Klinge, Choimaa Dulamsuren, Florian Schneider, Stefan Erasmi, Markus Hauck, Uudus Bayarsaikhan, and Daniela Sauer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-13, https://doi.org/10.5194/bg-2020-13, 2020
Manuscript not accepted for further review (discussion: closed, 6 comments)
Short summary
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The Mongolian forest-steppe suffers from fire and woodcutting. The forest distribution was analysed by tree biomass, remote sensing and climate data. Tree biomass was reduced at forest edges and in small forest, and high in alluvial forests. The actual tree biomass represented 57 % of that in 1986, prior to extensive fires. Relationships between forests and topographic and climatic parameters enable modelling of potential forest, which is about three times the actual forest area.
28 Feb 2020
On evapotranspiration and eddy covariance measurements corrections
Bartosz M. Zawilski
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-43, https://doi.org/10.5194/bg-2020-43, 2020
Preprint withdrawn (discussion: closed, 0 comments)
Short summary
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One of the most used techniques in order to assess the greenhouse gases flux is the Eddy Covariance (EC) technique that supposes the mean air vertical speed nullity. While working extensively with another technique used for soil effluxes measurements: dynamically closed chambers, it became obvious that there is a mass flow from the soil, it means that the vertical air speed can only be positive and caused by water evaporation. Based on vapor evaporation rate, EC corrections are very important.
25 Feb 2020
Improving maps of forest aboveground biomass: A combined approach using machine learning with a spatial statistical model
Shaoqing Dai, Xiaoman Zheng, Lei Gao, Chengdong Xu, Shudi Zuo, Qi Chen, Xiaohua Wei, and Yin Ren
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-36, https://doi.org/10.5194/bg-2020-36, 2020
Preprint withdrawn (discussion: closed, 9 comments)
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This paper proposes a method to integrate the advantages of machine learning and spatial statistics, different datasets, and multiple environmental covariates to improve the accuracy of aboveground biomass estimation models, which provides a useful reference for climate change mitigation. This combined method can make full use of data from different sources, and realize the complementary advantages of machine learning and spatial statistics, which has important implications for other fields.
19 Feb 2020
A zooplankton diel vertical migration parameterization for coastal marine ecosystem modeling
Ariadna Celina Nocera, Dany Dumont, and Irene R. Schloss
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-10, https://doi.org/10.5194/bg-2020-10, 2020
Manuscript not accepted for further review (discussion: closed, 6 comments)
Short summary
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Zooplankton, which means drifting animals, represents a large class of animals that graze the phytoplankton that grows near the surface of oceans, lakes and estuaries and feed many other organisms of aquatic food webs. It is known that zooplankton migrate vertically every day in the water column to avoid visual predation, a process that is not often represented in ecosystem models. This paper presents a model that simulate this behavior and study its impacts on a coastal ocean environment.
14 Feb 2020
Comment on Ideas and perspectives: is shale gas a major driver of recent increase in global atmospheric methane?by Robert W. Howarth (2019)
Michael D. Lewan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-419, https://doi.org/10.5194/bg-2019-419, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
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A plethora of publicly available data show that the δ13C1 values of shale gas are typically heavier than those of conventional gas. This contradiction renders Howarth's ideas, perspectives,and calculations on methane emissions from shale gas invalid. The plethora of publicly available shale-gas data, also indicates that shale gas and conventional gas on a global basis cannot be readily distinguished based solely on δ13C1 values.
10 Feb 2020
Combining hyperspectral remote sensing and eddy covariance data streams for estimation of vegetation functional traits
Javier Pacheco-Labrador, Tarek S. El-Madany, M. Pilar Martin, Rosario Gonzalez-Cascon, Arnaud Carrara, Gerardo Moreno, Oscar Perez-Priego, Tiana Hammer, Heiko Moossen, Kathrin Henkel, Olaf Kolle, David Martini, Vicente Burchard, Christiaan van der Tol, Karl Segl, Markus Reichstein, and Mirco Migliavacca
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-501, https://doi.org/10.5194/bg-2019-501, 2020
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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The new generation of sensors on-board satellites have the potential to provide richer information about the function of vegetation than before. This information, nowadays missing, is fundamental to improve our understanding and prediction of carbon and water cycles, and therefore to anticipate effects and responses to Climate Change. In this manuscript we propose a method to exploit the data provided by these satellites to successfully obtain this information key to face Climate Change.
05 Feb 2020
Emissions of monoterpenes from new Scots pine foliage: dependency on season, stand age and location and importance for models
Ditte Taipale, Juho Aalto, Pauliina Schiestl-Aalto, Markku Kulmala, and Jaana Bäck
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-502, https://doi.org/10.5194/bg-2019-502, 2020
Preprint withdrawn (discussion: closed, 8 comments)
31 Jan 2020
Oxygen and light determine the pathways of nitrate reduction in a highly saline lake
Nicolás Valiente, Franz Jirsa, Thomas Hein, Wolfgang Wanek, Patricia Bonin, and Juan José Gómez-Alday
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-20, https://doi.org/10.5194/bg-2020-20, 2020
Preprint withdrawn (discussion: closed, 6 comments)
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Saline lakes are prone to the accumulation of anthropogenic contaminants, making them highly vulnerable environments to nitrate pollution. We used the revised 15N-isotope pairing technique with sediments from a eutrophic hypersaline lake to unravel the nitrate removal pathways carrying on. Our work shows for the first time the coexistence of denitrification, DNRA and anammox in a highly saline/hypersaline lake, with extraordinarily high rates of coupled DNRA-anammox.
30 Jan 2020
Climate reconstructions based on GDGTs and pollen surface datasets from Mongolia and Siberia: Calibrations and applicability to extremely dry and cold environments
Lucas Dugerdil, Sébastien Joannin, Odile Peyron, Isabelle Jouffroy-Bapicot, Boris Vannière, Bazartseren Boldgiv, and Guillemette Ménot
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-475, https://doi.org/10.5194/bg-2019-475, 2020
Preprint withdrawn (discussion: closed, 5 comments)
02 Jan 2020
Estimation of biogenic volatile organic compound (BVOC) emissions in China using WRF–CLM–MEGAN coupled model
Lifei Yin, Zhenying Xu, Mingxu Liu, Tingting Xu, Tiantian Wang, Wenling Liao, Mengmeng Li, Xuhui Cai, Ling Kang, Hongsheng Zhang, and Yu Song
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-458, https://doi.org/10.5194/bg-2019-458, 2020
Manuscript not accepted for further review (discussion: closed, 6 comments)
Short summary
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Biogenic Volatile Organic Compounds (BVOCs) emission of terrestrial vegetation is an important part of biogeochemical cycle. Compared with previous studies which calculate regional BVOC emissions independently, the coupled model WRF-CLM-MEGAN achieves an integrated parameterization of BVOC emissions and other land surface processes, and therefore provides a more reasonable estimate. The model could be further coupled with chemistry module to fully investigate the land-atmosphere interactions.
16 Dec 2019
Calcite and vaterite biosynthesis by nitrate dissimilating bacteria in carbonatogenesis process under aerobic and anaerobic conditions
Marwa Eltarahony, Sahar Zaki, Ayman Kamal, and Desouky Abd-El-Haleem
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-444, https://doi.org/10.5194/bg-2019-444, 2019
Preprint withdrawn (discussion: closed, 6 comments)
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This study utilized the bacterial strains in carbonatogenesis process through nitrate reduction under aerobic and anaerobic conditions. The precipitated CaCO3 were characterized, it was either calcite or vaterite. Overall, carbonatogenesis process via nitrate reduction is totally biological, ecofriendly, inexpensive, and promotes CaCO3 precipitations without accumulation of toxic by-product. The produced biosafe CaCO3 would be employed for subsequent environmental and medical applications.
16 Dec 2019
Acidification-vulnerable carbonate system of the East Sea (Japan Sea)
Taehee Na, Jeomshik Hwang, Soyun Kim, Seonghee Jeong, TaeKeun Rho, and Tongsup Lee
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-474, https://doi.org/10.5194/bg-2019-474, 2019
Preprint withdrawn (discussion: closed, 6 comments)
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Acidification of the East Sea (ES) deep waters was occurring at fast rates. A small supply of alkalinity by CaCO3 compared to a large supply of DIC by OM decomposition makes the deep waters of the ES vulnerable to acidification by CO2 input. The water age of the ES deep waters is similar to that in the S. Atlantic. However, DIC / TA ratio is much higher in the ES than that in the S. Atlantic. Recent re-initiation of deep-water formation appears to change the carbonate chemistry of deep waters of ES.
10 Dec 2019
Distinct microbial composition and functions in an underground high-temperature hot spring at different depths
Shijie Bai and Xiaotong Peng
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-406, https://doi.org/10.5194/bg-2019-406, 2019
Preprint withdrawn (discussion: closed, 4 comments)
09 Dec 2019
Reviews and syntheses: Anthropogenically breaking macro-ecospatial chains? – case review of HU Line
Yi Lin and Martin Herold
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-418, https://doi.org/10.5194/bg-2019-418, 2019
Manuscript not accepted for further review (discussion: closed, 6 comments)
Short summary
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This review analyzed the possibility of anthropogenically breaking the macro-ecospatial transition zones, in the case of Hu Line in China. The contribution of this work is of fundamental implication for pointing out a scientific way of further examining the macro-ecological debates such as
China's tree-planting drive could falter in a warming world(Nature, 2019).
25 Nov 2019
A hydroclimatic model for the distribution of fire on Earth
Matthias M. Boer, Víctor Resco De Dios, Elisa Z. Stefaniak, and Ross A. Bradstock
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-441, https://doi.org/10.5194/bg-2019-441, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
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Existing global fire models struggle to reproduce the geographical distribution of fire from interactions of climate, vegetation, terrain and land use. We present a new model for global fire potential based on fundamental biophysical constraints controlling fire activity in all biomes. Our global model predicts the potential mean annual fractional burned area as a function of hydroclimatic constraints on the production and (seasonal) desiccation of fuels.
22 Nov 2019
On surface fluxes at night – the virtual chamber approach
Bruce B. Hicks, Nebila Lichiheb, Deb L. O'Dell, Joel Oetting, Neal S. Eash, Mark Heuer, and Latoya Myles
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-393, https://doi.org/10.5194/bg-2019-393, 2019
Manuscript not accepted for further review (discussion: closed, 5 comments)
11 Nov 2019
Changes in Particulate and Mineral Associated Organic Carbon with Land Use in Contrasting Soils
Sabina Yeasmin, Balwant Singh, Cliff T. Johnston, Donald L. Sparks, and Quan Hua
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-416, https://doi.org/10.5194/bg-2019-416, 2019
Preprint withdrawn (discussion: closed, 4 comments)
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This study demonstrated impact of land use change on organic carbon (OC) pools in four soils with contrasting mineralogy for both surface and sub-surface depths. Bulk soils were isolated into particulate and mineral associated OC by density fractionation, and analysed for mineralogy, OC, nitrogen and isotopic signatures. Results reveal that quantity and quality of OC after land use change was influenced by nature of C input in surface soils and by mineral-organic association in sub-surface soils.
05 Nov 2019
Measuring frequently during peak soil N2O emissions is more important than choosing the time of day to sample
Jordi T. Francis Clar and Robert P. Anex
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-396, https://doi.org/10.5194/bg-2019-396, 2019
Preprint withdrawn (discussion: closed, 4 comments)
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The daily pattern of soil nitrous oxide (N2O) emissions has guided the choice of a sampling time meant to maximize the accuracy of N2O flux estimates. We analyzed several years of soil N2O emissions from a highly fertilized system including several difficult-to-measure peak emissions events. In this system, accurate estimation of N2O fluxes requires continuous and frequent sampling, especially during peak events; scheduled sampling based on the daily pattern of emissions provides little benefit.
04 Nov 2019
Validation of a coupled δ2Hn-alkane-δ18Osugar paleohygrometer approach based on a climate chamber experiment
Johannes Hepp, Bruno Glaser, Dieter Juchelka, Christoph Mayr, Kazimierz Rozanski, Imke Kathrin Schäfer, Willibald Stichler, Mario Tuthorn, Roland Zech, and Michael Zech
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-427, https://doi.org/10.5194/bg-2019-427, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
28 Oct 2019
Relationships between leaf δ15N and leaf metallic nutrients
Chongjuan Chen, Yingjie Wu, Shuhan Wang, Zhaotong Liu, and Guoan Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-328, https://doi.org/10.5194/bg-2019-328, 2019
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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Relationships between leaf δ15N and concentrations of leaf metallic nutrients have not been examined as yet though they could enhance our understanding of N cycling. By analyzing 624 non-N2-fixing plant samples, we first found that leaf δ15N was positively correlated with leaf K, Ca, Mg and Zn, negatively correlated with leaf Fe, and not related to leaf Mn. All of them together explained 55.7 % of variations in leaf δ15N. This study emphasized the significance of metallic nutrients in N cycling.
18 Oct 2019
Phosphorus attenuation in streams by water-column geochemistry and benthic sediment reactive iron
Zachary P. Simpson, Richard W. McDowell, and Leo M. Condron
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-400, https://doi.org/10.5194/bg-2019-400, 2019
Revised manuscript not accepted (discussion: closed, 5 comments)
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Streams buffer phosphorus (P), making it difficult to know how mitigation measures work. We examined this P buffer across 31 diverse streams in Canterbury, New Zealand. We found catchment geology to be a major control for precipitation reactions in the water and the forms of P and iron (Fe) in sediments. Poorly crystalline Fe oxides in sediments predicted chemical sorption of P. These reactions may determine the P available for biota, and further, that Fe cycling is closely related to that of P.
15 Oct 2019
Reshaped acclimation traits of dominant tree species under manipulated rainfall would alter their coexisting relation in a low-subtropical secondary evergreen forest
Lei Ouyang, Jianguo Gao, Ping Zhao, Weijun Shen, Xingquan Rao, Liwei Zhu, and Guangyan Ni
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-392, https://doi.org/10.5194/bg-2019-392, 2019
Preprint withdrawn (discussion: closed, 4 comments)
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The different spatial and temporal patterns of water use, together with the contrasting water use strategies, could partly explain the current coexistence of two dominant tree species in South China. Their varying performance under different water conditions implies possible shifts in species dominance within the forest community that were potentially stimulated under future precipitation change scenarios from a long-term perspective.
07 Oct 2019
Simulating oceanic radiocarbon with the FAMOUS GCM: implications for its use as a proxy for ventilation and carbon uptake
Jennifer E. Dentith, Ruza F. Ivanovic, Lauren J. Gregoire, Julia C. Tindall, Laura F. Robinson, and Paul J. Valdes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-365, https://doi.org/10.5194/bg-2019-365, 2019
Publication in BG not foreseen (discussion: closed, 4 comments)
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We have added three new tracers (a dye tracer and two representations of radiocarbon, 14C) into the ocean of the FAMOUS climate model to study large-scale circulation and the marine carbon cycle. The model performs well compared to modern 14C observations, both spatially and temporally. Proxy 14C records are interpreted in terms of water age, but comparing our dye tracer to our 14C tracer, we find that this is only valid in certain areas; elsewhere, the carbon cycle complicates the signal.
02 Oct 2019
Low CO2 evasion rate from the mangrove surrounding waters of Sundarban
Anirban Akhand, Abhra Chanda, Kenta Watanabe, Sourav Das, Tatsuki Tokoro, Kunal Chakraborty, Sugata Hazra, and Tomohiro Kuwae
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-388, https://doi.org/10.5194/bg-2019-388, 2019
Preprint withdrawn (discussion: closed, 4 comments)
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Globally, mangrove surrounding waters are considered net sources of atmospheric CO2. We estimated the air–water CO2 flux with high temporal resolution in mangrove surrounding waters in the Indian Sundarbans and found that the water can act as a sink or weak source of CO2. We suggest that the CO2 efflux from the mangroves surrounding waters of Sundarbans are much lower than the recently estimated world average, and that such low-efflux areas should be included in global mangrove carbon budgeting.
30 Sep 2019
Trace elements in mussel shells from the Brazos River, Texas: environmental and biological control
Alexander A. VanPlantinga and Ethan L. Grossman
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-323, https://doi.org/10.5194/bg-2019-323, 2019
Revised manuscript not accepted (discussion: closed, 11 comments)
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Modern freshwater mussel shells from the Brazos River, Texas were analyzed for trace element composition in order to build upon previous stable isotope data from the shells and evaluate them as environmental archives. Shell Mn / Ca varied inversely with river discharge and shell manganese is probably ingested in the form of particulate organic matter. The shell Mn / Ca data was used to reconstruct river discharge patterns.
25 Sep 2019
Anoxic monimolimnia: Nutrients devious feeders
Areti Gianni and Ierotheos Zacharias
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-349, https://doi.org/10.5194/bg-2019-349, 2019
Revised manuscript not accepted (discussion: closed, 5 comments)
23 Sep 2019
A New Characterization of the Upper Waters of the central Gulf of México based on Water Mass Hydrographic and Biogeochemical Characteristics
Gabriela Yareli Cervantes-Diaz, Jose Martín Hernández-Ayón, Alberto Zirino, Sharon Zinah Herzka, Victor Camacho-Ibar, Ivonne Montes, Joël Sudre, and Juan Antonio Delgado
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-340, https://doi.org/10.5194/bg-2019-340, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
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In this work we presents a new classification of water masses in the GoM, based on thermohaline properties and dissolved oxygen (DO) concentration using data from a total of five summer and winter cruises carried out primarily in the central GoM. The importance of this redefinition of the water masses contributes to a better understanding of their role in the dynamics of nutrients (and carbon).
04 Sep 2019
Formation and origin of Fe-Si oxyhydroxide deposits at the ultra-slow spreading Southwest Indian Ridge
Kaiwen Ta, Zijun Wu, Xiaotong Peng, and Zhaofu Luan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-315, https://doi.org/10.5194/bg-2019-315, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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Fe-Si oxyhydroxide deposits are ubiquitously found in hydrothermal environments. Formation process and mechanism on modern hydrothermal Fe-Si oxyhydroxides at ultra-slow spreading centers remain poorly understood. This study suggests that microbial activity plays a significant role in the formation of Fe-Si oxyhydroxides at the at ultra-slow spreading SWIR. Biogenic Fe-Si oxyhydroxides potentially provide insights into the origin and evolution of life in the geologic record.
29 Aug 2019
High-throughput screening of sediment bacterial communities from Oxygen Minimum Zones of the northern Indian Ocean
Jovitha Lincy and Cathrine Manohar
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-330, https://doi.org/10.5194/bg-2019-330, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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The study compares the sediment bacterial community structure within the oxygen minimum zone (OMZ) of the Arabian Sea and the Bay of Bengal. Bacterial diversity analysis reveals that the off Paradip site of Bay of Bengal OMZ is highly diverse and unexplored in comparison to the off Goa site of the Arabian Sea OMZ. It is also interesting to note that even though the phylogenetic diversity was different, the relative contribution of functional genes was almost the same.
27 Aug 2019
Insights on nitrogen and phosphorus co-limitation in global croplands from theoretical and modelling fertilization experiments
Bruno Ringeval, Marko Kvakić, Laurent Augusto, Philippe Ciais, Daniel Goll, Nathaniel D. Mueller, Christoph Müller, Thomas Nesme, Nicolas Vuichard, Xuhui Wang, and Sylvain Pellerin
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-298, https://doi.org/10.5194/bg-2019-298, 2019
Preprint withdrawn (discussion: closed, 5 comments)
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Crossed fertilization additions lead to the definition of nutrient interaction categories. However, the implications of such categories in terms of nutrient interaction modeling are not clear. We developed a theoretical analysis of nitrogen and phosphorus fertilization experiments, then applied it to current estimates of nutrient limitation in cropland. We found that a true co-limitation could affect up to 42 % of the global maize area when using a given formalism of nutrient interaction.
12 Aug 2019
A new approach for assessing climate change impacts in ecotron experiments
Inne Vanderkelen, Jakob Zschleischler, Lukas Gudmundsson, Klaus Keuler, Francois Rineau, Natalie Beenaerts, Jaco Vangronsveld, and Wim Thiery
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-267, https://doi.org/10.5194/bg-2019-267, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
08 Aug 2019
Ideas and perspectives: Emerging contours of a dynamic exogenous kerogen cycle
Thomas M. Blattmann
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-273, https://doi.org/10.5194/bg-2019-273, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
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Growing evidence points to the dynamic role that kerogen is playing on the Earth's surface in controlling atmospheric chemistry over geologic time. Although quantitative constraints on weathering of kerogen remain loose, its changing weathering behavior modulated by the activity of glaciers, suggest that this largest pool of reduced carbon on Earth may have played a key part in atmospheric CO2 variability across recent glacial-interglacial times and beyond.
31 Jul 2019
On modeling the Southern Ocean Phytoplankton Functional Types
Svetlana N. Losa, Stephanie Dutkiewicz, Martin Losch, Julia Oelker, Mariana A. Soppa, Scarlett Trimborn, Hongyan Xi, and Astrid Bracher
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-289, https://doi.org/10.5194/bg-2019-289, 2019
Manuscript not accepted for further review (discussion: closed, 7 comments)
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This study highlights recent advances and challenges of applying coupled physical-biogeochemical modeling for investigating the distribution of the key phytoplankton groups in the Southern Ocean. By leveraging satellite and in situ observations we define numerical ecological model requirements in the phytoplankton trait specification and level of physiological and morphological differentiation for capturing and explaining the observed biogeography of diatoms, coccolithophores and Phaeocystis.
10 Jul 2019
Nitrogen cycling in the Elbe estuary from a joint 3D-modelling and observational perspective
Johannes Pein, Annika Eisele, Richard Hofmeister, Tina Sanders, Ute Daewel, Emil V. Stanev, Justus van Beusekom, Joanna Staneva, and Corinna Schrum
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-265, https://doi.org/10.5194/bg-2019-265, 2019
Revised manuscript not accepted (discussion: closed, 6 comments)
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The Elbe estuary is subject to vigorous tidal forcing from the sea side and considerable biological inputs from the land side. Our 3D numerical coupled physical-biogeochemical integrates these forcing signals and provides highly realistic hindcasts of the associated dynamics. Model simulations show that the freshwater part of Elbe estuary is inhabited by plankton. According to simulations these organism play a key role in converting organic inputs into nitrate, the major inorganic nutrient.
05 Jul 2019
A social-ecological approach to identify and quantify biodiversity
tipping points in South America's seasonal dry ecosystems
Kirsten Thonicke, Fanny Langerwisch, Matthias Baumann, Pedro J. Leitão, Tomáš Václavík, Ane Alencar, Margareth Simões, Simon Scheiter, Liam Langan, Mercedes Bustamante, Ignacio Gasparri, Marina Hirota, Jan Börner, Raoni Rajao, Britaldo Soares-Filho, Alberto Yanosky, José-Manuel Ochoa-Quinteiro, Lucas Seghezzo, Georgina Conti, and Anne Cristina de la Vega-Leinert
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-221, https://doi.org/10.5194/bg-2019-221, 2019
Publication in BG not foreseen (discussion: closed, 2 comments)
Short summary
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Tropical dry forests and savannas harbor unique biodiversity and provide critical ecosystem services (ES), yet they are under severe pressure globally. We need to improve our understanding of how and when this pressure provokes tipping points in biodiversity and the associated social-ecological systems. We propose an approach to investigate how drivers leading to natural vegetation decline trigger biodiversity tipping and illustrate it using the example of the Dry Diagonal in South America.
04 Jul 2019
Cryptic role of tetrathionate in the sulfur cycle: A study from Arabian Sea oxygen minimum zone sediments
Subhrangshu Mandal, Sabyasachi Bhattacharya, Chayan Roy, Moidu Jameela Rameez, Jagannath Sarkar, Svetlana Fernandes, Tarunendu Mapder, Aditya Peketi, Aninda Mazumdar, and Wriddhiman Ghosh
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-248, https://doi.org/10.5194/bg-2019-248, 2019
Manuscript not accepted for further review (discussion: closed, 13 comments)
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Sulfur cycling is a crucial component of sediment biogeochemistry within the marine realm. Microbial processes of sulfur cycle work in conjunction with the carbon cycle to remineralize organic matters sequestered in the sea-bed, influenceing metal deposition. Whereas thiosulfate has long been appreciated as a key junction in the sulfur cycle of global marine sediment, the present geomicrobial study brings to the fore hitherto-unappreciated roles of tetrathionate.
01 Jul 2019
C3 plants converge on a universal relationship between leaf maximum carboxylation rate and chlorophyll content
Xiaojin Qian, Liangyun Liu, Holly Croft, and Jingming Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-228, https://doi.org/10.5194/bg-2019-228, 2019
Preprint withdrawn (discussion: closed, 6 comments)
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The leaf maximum carboxylation rate (Vcmax) is a key photosynthesis parameter. We attempt to investigate whether a universal and stable relationship exists between leaf Vcmax25 and chlorophyll content across different C3 plant types from a plant physiological perspective and verify it using field experiments. The results confirm that leaf chlorophyll can be a reliable proxy for estimating Vcmax25, providing an operational approach for the global mapping of Vcmax25 across different plant types.
01 Jul 2019
Global database and model on dissolved carbon in soil solution
Joep Langeveld, Alexander F. Bouwman, Wim Joost van Hoek, Lauriane Vilmin, Arthur H. W. Beusen, José M. Mogollón, and Jack J. Middelburg
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-238, https://doi.org/10.5194/bg-2019-238, 2019
Preprint withdrawn (discussion: closed, 6 comments)
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We compiled a global database on annual average dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in soil solutions. We use this database to construct the first global models and maps on DOC in soil pore water. Highest concentrations in shallow soils occur in forests of cooler, humid zones. Highest concentrations in deeper soils are calculated for Histosols. Our research enables a spatially explicit first estimation of dissolved carbon in soil solution on the global scale.
18 Jun 2019
Behaviour of Dissolved Phosphorus with the associated nutrients in relation to phytoplankton biomass of the Rajang River-South China Sea continuum
Edwin Sien Aun Sia, Jing Zhang, Shan Jiang, Zhuoyi Zhu, Gonzalo Carrasco, Faddrine Holt Jang, Aazani Mujahid, and Moritz Müller
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-219, https://doi.org/10.5194/bg-2019-219, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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Nutrient loads carried by large rivers and discharged into the continental shelf and coastal waters are vital to support primary production. Our knowledge of tropical river systems is fragmented with very few seasonal studies available for Southeast Asia (SEA). We present data from three sampling campaigns on the longest river in Malaysia, the Rajang river. Our results show the generalization of SEA as a nutrient hotspot might not hold true for all regions and requires further investigation.
17 Jun 2019
Abiotic CO2 sources confound interpretation of temperature responses of in situ respiration in geothermally warmed forest soils of Iceland
Marja Maljanen, Heli Yli-Moijala, Bjarni Didrik Sigurdsson, and Christina Biasi
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-213, https://doi.org/10.5194/bg-2019-213, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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We studied the proportion of biotic and abiotic CO2 fluxes from soil using static chamber method and stable isotope approach from a geothermally warmed area in southern Iceland. These sites can be used cost efficiently to study the effects of soil warming on the ecosystem. However, our study showed that a significant amount of CO2 emitted from the higher warming levels can have non-biotic origin and this has to be taken into account when measuring respiration fluxes on such volcanic sites.
11 Jun 2019
Improving non-representative-sample prediction of forest
aboveground biomass maps: A combined machine
learning and spatial statistical approach
Shaoqing Dai, Xiaoman Zheng, Lei Gao, Shudi Zuo, Qi Chen, Xiaohua Wei, and Yin Ren
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-202, https://doi.org/10.5194/bg-2019-202, 2019
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
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We propose a low-cost approach that combines machine learning with spatial statistics to construct a regional forest C sequestration map from non-representative sample units. The experimental results demonstrate that the combined methods can improve the accuracy of the C sequestration map. This work provides a useful reference for climate change mitigation and other cases that used non-representative sample units.
06 Jun 2019
The influence of tropical Indian Ocean warming and Indian Ocean Dipole on the surface chlorophyll concentration in the eastern Arabian Sea
Syam Sankar, Anoop Thondithala Ramachandran, Kemgang Ghomsi Franck Eitel, Dmitry Kondrik, Radharani Sen, Ramesh Madipally, and Lasse H. Pettersson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-169, https://doi.org/10.5194/bg-2019-169, 2019
Manuscript not accepted for further review (discussion: closed, 5 comments)
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We analyzed the role of Indian Ocean warming and positive Indian Ocean Dipole (IOD) events on the chlorophyll concentrations in the Eastern Arabian Sea (EAS). Positive IOD years were found to be less favorable for inducing coastal upwelling in the region. Significant negative correlation between positive IODs and chlorophyll concentrations show that in the event of occurrence of frequent positive IOD events under a warming regime, the chlorophyll concentration is likely to decrease during fall.
20 May 2019
Using Remote Sensing to Monitor the Spring Phenology of Acadia National Park across Elevational Gradients
Yan Liu, Caitlin McDonough MacKenzie, Richard B. Primack, Michael J. Hill, Xiaoyang Zhang, Zhuosen Wang, and Crystal B. Schaaf
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-126, https://doi.org/10.5194/bg-2019-126, 2019
Preprint withdrawn (discussion: closed, 6 comments)
20 May 2019
The Holocene Evolution of a Sedimentary Carbon Store in a Mid Latitude Fjord
Craig Smeaton, Xingqian Cui, Thomas S. Bianchi, Alix G. Cage, John A. Howe, and William E. N. Austin
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-163, https://doi.org/10.5194/bg-2019-163, 2019
Publication in BG not foreseen (discussion: closed, 2 comments)
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The sediments in fjords are known to be important sites for locking carbon away for long periods of time (thousands of years) but the processes by which climate and human activity influence the development of these coastal carbon stores is poorly understood. A record of long-term sediment burial from a Scottish fjord allows us to investigate the role that humans and climate has played. The results indicate that both climate and humans have an impact on terrestrial ecosystems.
14 May 2019
CO2 and CH4 fluxes are decoupled from organic carbon loss in drying reservoir sediments
Tricia Light, Núria Catalán, Santiago Giralt, and Rafael Marcé
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-128, https://doi.org/10.5194/bg-2019-128, 2019
Revised manuscript not accepted (discussion: closed, 6 comments)
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Water reservoir sediments can store large amounts of organic. However, it is unclear what happens to this organic carbon when water reservoirs go dry due to drought, water diversion, etc. Here, we conducted laboratory incubations of reservoir sediment to determine the effect of drying on this stored organic carbon. We found that while some of the organic carbon in water reservoir sediments is released to the atmosphere as reservoirs go dry, other sediment processes can offset these emissions.
07 May 2019
Ventilation dynamics of the Oxygen Minimum Zone in the Arabian Sea
Henrike Schmidt, Rena Czeschel, and Martin Visbeck
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-168, https://doi.org/10.5194/bg-2019-168, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Our investigations give a detailed insight on the changing current system at intermediate depth in the Arabian Sea and allow to draw conclusions on ventilation pathways of the oxygen minimum zone and its seasonal variability. In response to the monsoon system the boundary currents change direction and feature a regionally varying ventilation pattern.
02 May 2019
ENSO-driven fluctuations in oxygen supply and vertical extent of oxygen-poor waters in the oxygen minimum zone of the Eastern Tropical South Pacific
Yonss Saranga José, Lothar Stramma, Sunke Schmidtko, and Andreas Oschlies
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-155, https://doi.org/10.5194/bg-2019-155, 2019
Revised manuscript accepted for BG (discussion: closed, 8 comments)
Short summary
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In situ observations along the Peruvian and Chilean coasts have exhibited variability in the water column oxygen concentration. This variability, which is attributed to the El Niño Southern Oscillation (ENSO), might have implication on the vertical extension of the Eastern Tropical South Pacific (ETSP) oxygen minimum zone. Here using a coupled physical-biogeochemical model, we provide new insights into how ENSO variability affects the vertical extension of the oxygen-poor waters of the ETSP.
29 Apr 2019
Tree size and age induced stem carbon content variations cause an uncertainty in forest carbon stock estimation
Suhui Ma, Anwar Eziz, Di Tian, Zhengbing Yan, Qiong Cai, Mingwei Jiang, Chengjun Ji, and Jingyun Fang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-87, https://doi.org/10.5194/bg-2019-87, 2019
Preprint withdrawn (discussion: closed, 4 comments)
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Stem carbon (C) content is one of the important tree traits and widely used to present tree C content to estimate forest C stocks. Based on a 576 age-specific tree organ C content dataset, our results showed that C content of tree varied significantly among organs. Stem C content increased with the increasing tree size and age. Using stem C content as tree C content could produce an error of −2.49 %–5.87 %. This suggests considering tree organ C content of stand in estimating forest C stock.
29 Apr 2019
Impact of metabolic pathways and salinity on the hydrogen isotope ratios of haptophyte lipids
Gabriella M. Weiss, David Chivall, Sebastian Kasper, Hideto Nakamura, Fiz da Costa, Philippe Soudant, Jaap S. Sinninghe Damsté, Stefan Schouten, and Marcel T. J. van der Meer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-147, https://doi.org/10.5194/bg-2019-147, 2019
Preprint withdrawn (discussion: closed, 6 comments)
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In this study, we used four different haptophyte species and six different organic compounds to investigate the relationship between organic matter synthesis and salinity. We showed that creation in different parts of the cell (chloroplast versus cytosol) determined which compounds retain a correlation between their hydrogen isotopes and salinity. This is important for using hydrogen isotopes to reconstruct salinity in the geologic record.
12 Apr 2019
Effect of crustose lichen (Ochrolecia frigida) on soil CO2 efflux in a sphagnum moss community over western Alaska tundra
Yongwon Kim, Sang-Jong Park, and Bang-Yong Lee
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-121, https://doi.org/10.5194/bg-2019-121, 2019
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Sphagnum moss habitats store large amounts of carbon, which helps reduce thermal insulative capacity and the preservation of permafrost in Subarctic and Arctic. However, airborne infected crustose lichen (Ochrolecia frigida) causes the withering to death of sphagnum in permafrost regions. Soil CO2 efflux in crustose lichen was higher than in healthy sphagnum. This demonstrates that higher soil temperature and lower moisture in crustose lichen patches are attributed to enhanced soil CO2 emission.
01 Apr 2019
Methane oxidation potential of the arctic wetland soils of a taiga-tundra ecotone in northeastern Siberia
Jun Murase, Atsuko Sugimoto, Ryo Shingubara, Tomoki Morozumi, Shinya Takano, and Trofim C. Maximov
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-98, https://doi.org/10.5194/bg-2019-98, 2019
Manuscript not accepted for further review (discussion: closed, 6 comments)
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We determined the potential methane oxidation rate of the wetland soils in northeastern Siberia in situ or immediately after sampling to avoid the possible influence of sample storage. The soils had a high methane oxidation potential even under anoxic and frozen conditions, while the plant-associated methane oxidation is negligible. The results show the high tolerance and resilience of methane oxidation to the unfavorable conditions, contributing to understanding the methane cycle in the Arctic.
29 Mar 2019
Prioritization of the vector factors controlling Emiliania huxleyi blooms in subarctic and arctic seas: A multidimensional statistical approach
Dmitry Kondrik, Eduard Kazakov, Svetlana Chepikova, and Dmitry Pozdnyakov
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-104, https://doi.org/10.5194/bg-2019-104, 2019
Revised manuscript not accepted (discussion: closed, 5 comments)
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Emiliania huxleyi species forms in the world's oceans generally huge blooms that affect both the content in the atmosphere of CO2, the major greenhouse gas, and marine ecology. The natural factors conditioning the dynamics of such blooms are many. To unravel the complexity of their conjoint action, and comprehend these blooms spatio-temporal variations, and open the way to predict their further development, sophisticated statistical techniques were employed to confidently rank the factors.
15 Mar 2019
Technical Note: Low Cost Mesocosms Design for Studies of Tropical Marine Environments
Ruben R. Raygosa-Barahona, Sebastien Putzeys, Jorge Herrera, and Daniel Pech
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-56, https://doi.org/10.5194/bg-2019-56, 2019
Manuscript not accepted for further review (discussion: closed, 4 comments)
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The effects of tropical climatic conditions on a mesocosm enclosure were studied. An electric marine thruster is used to avoid stratification in the water. Also the mesocosms is submerged in water to maintain the temperature variations within reasonable ranges. With high variations of ambient temperature (> 20 ºC, during the day), the variations in the mesocosm temperature were only 3 ºC. The range of temperature variations were similar to those that occur in certain tropical environments.
13 Mar 2019
Quantifying climatic influences on tree-ring width
Guangqi Li, Sandy P. Harrison, and I. Colin Prentice
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-63, https://doi.org/10.5194/bg-2019-63, 2019
Publication in BG not foreseen (discussion: closed, 4 comments)
Short summary
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Current methods of removing age effect from tree-ring are influenced by sampling biases – older trees are more abundantly sampled for recent decades, when the strongest environmental change happens. New technique of extracting environment-driven signals from tree ring is specifically designed to overcome this bias, drawing on theoretical tree growth. It removes sampling-bias effectively and shows consistent relationships between growth and climates through time and across two conifer species.
13 Mar 2019
Transparent exopolymer particle binding of organic and inorganic particles in the Red Sea: Implications for downward transport of biogenic materials
Abdullah H. A. Dehwah, Donald M. Anderson, Sheng Li, Francis L. Mallon, Zenon Batang, Abdullah H. Alshahri, Michael Hegy, and Thomas M. Missimer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-59, https://doi.org/10.5194/bg-2019-59, 2019
Preprint withdrawn (discussion: closed, 6 comments)
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Marine gels are an important component of the biochemical composition of seawater. Transparent exopolymer particles (TEP) are gels composed of acidic polysaccharides and other organic compounds that bind with suspended sediments and allow them to travel from the surface to the bottom of the sea. TEP becomes a food supply for the deep ocean and allows bacteria to grow and ultimately become food for growth of higher life forms.
12 Mar 2019
Constraining the soil carbon source to cave-air CO2: evidence from the high-time resolution monitoring soil CO2, cave-air CO2 and its δ13C in Xueyudong, Southwest China
Min Cao, Yongjun Jiang, Jiaqi Lei, Qiufang He, Jiaxin Fan, and Ze Zeng
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-66, https://doi.org/10.5194/bg-2019-66, 2019
Preprint withdrawn (discussion: closed, 10 comments)
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We monitored with high-resolution equipment for two years the CO2 concentration in the overlying soil and the Xueyu cave where a subterranean stream going through to explore their seasonal variational patterns and distinguish the contribution from the soil and stream. Our results show that there are abrupt variations of CO2 in the cave in April and November every year which should be due to the variations in precipitation and temperature. It's better to visit a subtropical karst cave in winter.
11 Mar 2019
Seasonal Sinking rates of Transparent Exopolymer Particles (TEP) concentrations with associated Carbon flux in adjacent Bohai Seaand Yellow Sea
M. Shahanul Islam, Jun Sun, Xiaoqian Li, and Xiaoyun Leng
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-58, https://doi.org/10.5194/bg-2019-58, 2019
Manuscript not accepted for further review (discussion: closed, 8 comments)
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This manuscript expressed several seasonal datasets on TEP and its sinking rates through descriptive comparison with previous work. This paper will provide a clear scenario for further research to the interested scientist about oceanic carbon pool associated with TEP. The manuscript were designed after discussing of TEP assemblage and its sinking variations through different depths with seasonal (autumn, summer & winter) fluctuations in two dynamic seas of China (Bohai Sea & Yellow Sea).
21 Feb 2019
Water limitation may restrict the positive effect of higher temperatures on weathering rates in forest soils
Salim Belyazid, Cecilia Akselsson, and Giuliana Zanchi
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-44, https://doi.org/10.5194/bg-2019-44, 2019
Revised manuscript not accepted (discussion: closed, 8 comments)
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The release of base cations from mineral weathering is expected to increase in response to higher temperatures associated with climate change. By considering the effect of changes in moisture, this study shows that climate change will lead to an increase in weathering rates, but to lower extent than expected due to water limitation. The study uses an integrated forest ecosystem model that simultaneously simulates changes in soil and vegetation and the feedbacks between them.
19 Feb 2019
Effects of nitrogen deposition on growing-season soil methane sink
across global forest biomes
Enzai Du, Nan Xia, and Wim de Vries
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-29, https://doi.org/10.5194/bg-2019-29, 2019
Preprint withdrawn (discussion: closed, 9 comments)
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Based on an analysis of the results from existing N addition experiments, the effect of N deposition on growing-season soil CH4 flux was assessed across global forest biomes. The results showed that growing-season soil CH4 flux was significantly affected by N additions, the effect being dependent on the N addition level and forest biome. This work improves our understanding of biome-specific effect of N deposition on soil CH4 uptake, which should be considered by process-based models.
18 Feb 2019
Reviews and syntheses: Weathering of silicate minerals in soils and watersheds: Parameterization of the weathering kinetics module in the PROFILE and ForSAFE models
Harald Ulrik Sverdrup, Eric Oelkers, Martin Erlandsson Lampa, Salim Belyazid, Daniel Kurz, and Cecilia Akselsson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-38, https://doi.org/10.5194/bg-2019-38, 2019
Revised manuscript not accepted (discussion: closed, 7 comments)
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The present publication documents the kinetic parameterisation of the related PROFILE (steady state) and ForSAFE (integrated dynamics) models. It gives the full coefficient database for about 100 minerals occurring in most soils. The text outlines the principles and methods used in setting the coefficient values. It outlines how the models with the parameterisation based on laboratory kinetics, is successful in estimating field weathering rates similar to what is being observed.
18 Feb 2019
Is the content and potential preservation of soil organic carbon reflected by cation exchange capacity? A case study in Swiss forest soils
Emily F. Solly, Valentino Weber, Stephan Zimmermann, Lorenz Walthert, Frank Hagedorn, and Michael W. I. Schmidt
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-33, https://doi.org/10.5194/bg-2019-33, 2019
Revised manuscript not accepted (discussion: closed, 11 comments)
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Soils are the largest reservoir of carbon on land. In the context of global change, it is important to assess which environmental variables are needed to describe changes in the content of soil organic carbon. We assessed how climatic, vegetation and edaphic variables explain the variance of soil organic carbon content in Swiss forests. Our results provide a first indication that considering the effective cation exchange capacity of soils in future biogeochemical simulations could be beneficial.
15 Feb 2019
Hyposalinity tolerance inthecoccolithophorid Emiliania huxleyi under the influence of ocean acidification involves enhanced photosynthetic performance
Jiekai Xu, John Beardall, and Kunshan Gao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-4, https://doi.org/10.5194/bg-2019-4, 2019
Revised manuscript not accepted (discussion: closed, 5 comments)
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A lot of papers studying Ocean acidification (OA) have been published while no related reports can be found on the combined effects of OA with decreased salinity on coccolithophores yet.Thus, we investigated the physiological responses of an Emiliania huxleyi strain grown at 2CO2 concentrations and 3 levels of salinity and found cells could tolerate reduced salinity under OA as its increased light capturing capability, which suggests a potential niche extension of coccolithophores in the future.
15 Feb 2019
Role of Microbial Communities in the Weathering and Stalactite Formation in Karst Topography
Tung-Yi Huang, Bing-Mu Hsu, Cheng-Wei Fan, Hsin-Chi Tsai, Chien-Yi Tung, and Jung-Sheng Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-12, https://doi.org/10.5194/bg-2019-12, 2019
Preprint withdrawn (discussion: closed, 4 comments)
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This study surveyed the bacterial genetic material from environment around a limestone gulch, namely scrapes on speleothem surface, dripping water through speleothem, earth under a plan limestone wall, and scrapes from the plan wall. By the estimation of bioinformatics prediction, the relative abundance of bacteria inducing calcium precipitation in scrapes of speleothems and the water were about 100 times higher than the plan wall, while weathering related bacteria were plenty on the plan wall.
15 Feb 2019
Environment Gradient related Dissimilatory Nitrate Reduction to Ammonium in Huangmao Sea Estuary: Rates and Community Diversity
Ran Jiang, Shu-Xin Zhang, Gou Wei, Rui He, Li-Ling Yang, and Xin-Sheng Chai
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-31, https://doi.org/10.5194/bg-2019-31, 2019
Preprint withdrawn (discussion: closed, 7 comments)
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Since the nitrogen related eutrophication has become a severe problem in the Pearl River Delta complex area(PRE) in South China, it is important to have further understanding of nitrogen cycles in this area. The significant geographic and climatic differences in PRE and other estuaries, up to date there is lack of studies about the microbial mediated the dissimilatory nitrate reduction to ammonium(DNRA) pathways. This study provide a better understanding of DNRA in South China estuaries.
14 Feb 2019
Mapping trends in woody cover throughout Namibian savanna with MODIS seasonal phenological metrics and field inventory data
Vladimir R. Wingate, Nikolaus J. Kuhn, Stuart R. Phinn, and Cornelis van der Waal
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-28, https://doi.org/10.5194/bg-2019-28, 2019
Manuscript not accepted for further review (discussion: closed, 5 comments)
14 Feb 2019
Global variability of carbon use efficiency in terrestrial ecosystems
Xiaolu Tang, Nuno Carvalhais, Catarina Moura, Bernhard Ahrens, Sujan Koirala, Shaohui Fan, Fengying Guan, Wenjie Zhang, Sicong Gao, Vincenzo Magliulo, Pauline Buysse, Shibin Liu, Guo Chen, Wunian Yang, Zhen Yu, Jingjing Liang, Leilei Shi, Shenyan Pu, and Markus Reichstein
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-37, https://doi.org/10.5194/bg-2019-37, 2019
Preprint withdrawn (discussion: closed, 4 comments)
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Vegetation CUE is a key measure of carbon transfer from the atmosphere to terrestrial biomass. This study modelled global CUE with published observations using random forest. CUE varied with ecosystem types and spatially decreased with latitude, challenging the previous conclusion that CUE was independent of environmental controls. Our results emphasize a better understanding of environmental controls on CUE to reduce uncertainties in prognostic land-process model simulations.
12 Feb 2019
Diversity, distribution and nitrogen use strategies of bacteria in the South China Sea basin
Yuan-Yuan Li, Xiao-Huang Chen, Peng-Fei Wu, Dong-Xu Li, Lin Lin, and Da-Zhi Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-529, https://doi.org/10.5194/bg-2018-529, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
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Systematic studies on diversities and nitrogen use strategies of bacterial communities in the South China Sea basin are still scarce. Here, we applied high-throughput sequencing, bioinformatic analysis and qPCR assays, and found that the depth was a significant explanatory variable for the bacterial populations from different water masses. Amino acids and ammonium were the major nitrogen sources for bacteria while urea, ammonia and nitrite played vital roles in different regions of the basin.
23 Jan 2019
Drivers of 21st Century carbon cycle variability in the North
Atlantic Ocean
Matthew P. Couldrey, Kevin I. C. Oliver, Andrew Yool, Paul R. Halloran, and Eric P. Achterberg
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-16, https://doi.org/10.5194/bg-2019-16, 2019
Revised manuscript not accepted (discussion: closed, 4 comments)
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Determining how much carbon dioxide (CO2) the oceans absorb is key to predicting human-caused climate change. A computer model of the ocean shows how the North Atlantic will change up to the end of the century. Year-to-year variations are mostly caused by changes in ocean temperature and seawater chemistry, altering CO2 solubility. By 2100, human emissions cause the biggest changes. The near term changes are physically driven, which may be more predictable than biological changes.
14 Jan 2019
Response of soil respiration and soil microbial biomass carbon and nitrogen to grazing management in the Loess Plateau, China
Zhen Wang, Xiuli Wan, Mei Tian, Xiaoyan Wang, Junbo Chen, Xianjiang Chen, Shenghua Chang, and Fujiang Hou
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-531, https://doi.org/10.5194/bg-2018-531, 2019
Manuscript not accepted for further review (discussion: closed, 10 comments)
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A two-year soil respiration were measured in a long-term rotational grazing experiment plots with precise grazing intensity in warm and cold season grazing grassland on the Loess Plateau, China. We found grazing season and grazing patterns significantly affected the rate of soil respiration. Grazing intensities tended to increase soil microbial biomass carbon and soil microbial biomass nitrogen, while grazing season had little effect on soil microbial biomass nitrogen.
10 Dec 2018
The role of hydrodynamic and biogeochemistry on CO2 flux and
pCO2 at the Amazon River mouth
Diani F. S. Less, Alan C. Cunha, Henrique O. Sawakuchi, Vania Neu, Aline M. Valério, Nicholas D. Ward, Daimio C. Brito, Joel E. M. Diniz, William Gagne-Maynard, Carlos M. Abreu, Milton Kampel, Alex V. Krusche, and Jeffrey E. Richey
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-465, https://doi.org/10.5194/bg-2018-465, 2018
Preprint withdrawn (discussion: closed, 3 comments)
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Biogeochemistry studies focused in carbon cycle in the Amazon River mouth are scarce. Our study provided a long-term quantification of CO2 fluxes and pCO2 and evaluation of the most important hydrodynamic, biogeochemical and meteorological parameters related to them. The highest FCO2 and pCO2 was obtained at high discharge season, water and air temperatures, dissolved oxygen, dissolved organic carbon, nitrate, dissolved inorganic nitrogen and pH could be considered predictors for pCO2 and FCO2.
05 Dec 2018
Effects of dry and wet Saharan dust deposition in the tropical North Atlantic Ocean
Laura F. Korte, Franziska Pausch, Scarlett Trimborn, Corina P. D. Brussaard, Geert-Jan A. Brummer, Michèlle van der Does, Catarina V. Guerreiro, Laura T. Schreuder, Chris I. Munday, and Jan-Berend W. Stuut
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-484, https://doi.org/10.5194/bg-2018-484, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
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This paper shows the differences of nutrient release after dry and wet Saharan dust deposition in the tropical North Atlantic Ocean at 12° N. Incubation experiments were conducted along an east-west transect. Large differences were observed between both deposition types with wet deposition being the dominant source of phosphate, silicate, and iron. Both deposition types suggest that Saharan dust particles might be incorporated into marine snow aggregates and act as ballast mineral.
22 Nov 2018
Silicon cycled by tropical forest trees: effects of species, elevation and bedrock on Mount Kinabalu, Malaysia
Ryosuke Nakamura, Hidehiro Ishizawa, Rota Wagai, Shizuo Suzuki, Kanehiro Kitayama, and Kaoru Kitajima
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-447, https://doi.org/10.5194/bg-2018-447, 2018
Preprint withdrawn (discussion: closed, 4 comments)
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Silicon (Si) accumulation by plants should affect biogeochemical cycling of Si, but its geographical patterns are unknown for tropical forests. Comparing forests from 700–3100 m a.s.l. on Mt. Kinabalu, we demonstrate for the first time that lowland forests include more trees with high Si concentrations and have greater annual Si flux via leaf litter, regardless of the bedrock types. Our data of 71 tree species strongly suggest the importance of plant traits in modulating ecosystem Si cycling.
15 Nov 2018
Variation of key elements in soils and plant tissues in subalpine forests of the northern Rocky Mountains, USA
David P. Pompeani, Kendra K. McLauchlan, Barrie V. Chileen, Kyra D. Wolf, and Philip E. Higuera
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-443, https://doi.org/10.5194/bg-2018-443, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
09 Nov 2018
Different sensitivities of litter decomposition and nutrient release to ultraviolet radiation
Weiming Yan, Zhouping Shangguan, and Yangquanwei Zhong
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-445, https://doi.org/10.5194/bg-2018-445, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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Ultraviolet (UV) radiation is an important driver of litter decomposition in ecosystems. In this study, we determined the response of litter decomposition and nutrient release to UV changes using the meta-analysis based on global data. We found that UV plays an important role in litter decomposition in areas of relatively low precipitation and the effect on litter decomposition depends on many factors. Our results suggested changes in UV radiation altered C and N cycling during decomposition.
08 Nov 2018
The Mediterranean subsurface phytoplankton dynamics and their impact on Mediterranean bioregions
Julien Palmiéri, Jean-Claude Dutay, Fabrizio D'Ortenzio, Loïc Houpert, Nicolas Mayot, and Laurent Bopp
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-423, https://doi.org/10.5194/bg-2018-423, 2018
Manuscript not accepted for further review (discussion: closed, 8 comments)
Short summary
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In this model study, we highlight the importance of the subsurface phytoplankton dynamic in the Mediterranean sea. Comparing surface chlorophyll annual cycle to vertically integrated one, we show how important the subsurface phytoplankton community is, throughout the Mediterranean. It shows that surface chlorophyll is incomplete and cannot alone be considered a good proxy of the total phytoplankton biomass. Then, we decrypt some deep chlorophyll maximum mechanisms in the low production area.
06 Nov 2018
Alkalinity and nitrate concentrations in calcareous watersheds: Are they linked,
and is there an upper limit to alkalinity?
Beat Müller, Joseph S. Meyer, and René Gächter
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-461, https://doi.org/10.5194/bg-2018-461, 2018
Preprint withdrawn (discussion: closed, 5 comments)
Short summary
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Data from aquifers, rivers and lakes in calcareous watersheds in Switzerland display a distinct correlation between alkalinity and nitrate concentrations. Analysis of long-term datasets suggests that this close positive relationship is a result of three processes: (i) mineralization of organic fertilizer, (ii) exchange of acid or base ions during the uptake of ammonium or nitrate by crop plants, and (iii) carbon dioxide release by roots as a result of fertilizer-stimulated plant growth.
02 Nov 2018
Evaluation of atmospheric nitrogen inputs into marine ecosystems of the North Sea and Baltic Sea – part B: contribution by shipping and agricultural emissions
Daniel Neumann, Hagen Radtke, Matthias Karl, and Thomas Neumann
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-365, https://doi.org/10.5194/bg-2018-365, 2018
Publication in BG not foreseen (discussion: closed, 8 comments)
Short summary
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The contribution of atmospheric nitrogen deposition to the marine dissolved inorganic nitrogen (DIN) pool of the North and Baltic Sea was assessed for the year 2012. Atmospheric deposition accounted for approximately 10 % to 15 % of the DIN but its residence time differed between both water bodies. The nitrogen contributions of atmospheric shipping and agricultural imissions also were assessed. Particularly the latter source had a large impact in coastal regions.
29 Oct 2018
Microbial Community Function in Electroactive Biofilm-based Constructed Wetlands
Carlos A. Ramírez-Vargas, Carlos A. Arias, Liang Zhang, and Hans Brix
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-428, https://doi.org/10.5194/bg-2018-428, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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This study focuses on the microbial characterization of Microbial Electrochemical-based Constructed Wetland (METland), with a method that evaluates the diversity of microbial communities based on carbon consumption. Two electro-conductive materials were tested. The systems showed differences in carbon consumption. Also, were established correlations between carbon use and removal of pollutants. The obtained results provide useful insight into the spatial dynamics of METland systems.
19 Oct 2018
The role of light as vital effect on coral skeleton oxygen isotopic ratio
Anne Juillet-Leclerc
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-433, https://doi.org/10.5194/bg-2018-433, 2018
Preprint withdrawn (discussion: closed, 3 comments)
Short summary
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My manuscript is the result of a reflexion process about the meaning of coral skeleton tracers. I realized that in contrast to biologists, geochemists always neglect the light role on proxies. Light influence is difficult to separate from temperature. Thus, I used coral culture in controlled conditions. Once the process identified, I read differently the literature dedicated to the coral skeleton δ18 and found several evidences demonstrating that light could explain the vital effect.
16 Oct 2018
Surface transport of DOC acts as a trophic link among Mediterranean sub-basins
Chiara Santinelli, Roberto Iacono, Ernesto Napolitano, and Maurizio Ribera d'Alcalá
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-418, https://doi.org/10.5194/bg-2018-418, 2018
Revised manuscript not accepted (discussion: closed, 5 comments)
Short summary
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Part of the energy in the ocean is stored as dissolved organic carbon. Water moves around, bringing this energy from one place to another, down to the deep layers and up again. Here, we show that horizontal currents can have a strong impact on the carbon cycle, because they can transport chemical energy far away, establishing links between distant areas of the ocean and feeding regions in which the local accumulation of chemical energy is low.
15 Oct 2018
Assessment of paleo-ocean pH records from boron isotope ratio in the Pacific
and Atlantic ocean corals: Role of anthropogenic CO2 forcing and oceanographic factors to pH variability
Mohd Tarique and Waliur Rahaman
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-438, https://doi.org/10.5194/bg-2018-438, 2018
Preprint withdrawn (discussion: closed, 3 comments)
12 Oct 2018
Seasonal Net Ecosystem Metabolism of the Near-Shore Reef System in La Parguera, Puerto Rico
Melissa Meléndez, Joseph Salisbury, Dwight Gledhill, Chris Langdon, Julio M. Morell, Derek Manzello, Sylvia Musielewicz, and Adrienne Sutton
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-408, https://doi.org/10.5194/bg-2018-408, 2018
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
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Using observations from the NOAA CO2 buoy in La Parguera, Puerto Rico along with modeling approaches yield useful indices of biological processes affecting the water column over the reef. This study provided the first long-term monitoring of coral reef biological processes. Results show that processes that produce CO2 dominated over most of the year leading to high dissolution rates. This can have implications on the reef system's ability to recover to other climate-scale stressors (warming).
12 Oct 2018
Evaluation of atmospheric nitrogen inputs into marine ecosystems of the North Sea and Baltic Sea – part A: validation and time scales of nutrient accumulation
Daniel Neumann, Matthias Karl, Hagen Radtke, and Thomas Neumann
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-364, https://doi.org/10.5194/bg-2018-364, 2018
Manuscript not accepted for further review (discussion: closed, 9 comments)
Short summary
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Atmospheric nitrogen deposition contributes 20 % to 40 % to bioavailable nitrogen inputs into the North Sea and Baltic Sea. Excessive bioavailable nitrogen may lead to intensified algal blooms in these water bodies resulting in several negative consequences for the marine ecosystem. We traced atmospheric nitrogen in the marine ecosystem via an ecosystem model and estimated the contribution of atmospheric nitrogen to plankton biomass in different regions of the North and Baltic Sea over five years.
21 Sep 2018
Phosphorus and carbon in soil particle size fractions – A global synthesis
Marie Spohn
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-404, https://doi.org/10.5194/bg-2018-404, 2018
Manuscript not accepted for further review (discussion: closed, 5 comments)
Short summary
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Phosphorus (P) supply for agriculture will likely decrease in the future. Therefore, it is important to understand the behavior of phosphorus in soils. The study shows that soil organic phosphorus concentrations depend on climate, and that organic P is more strongly enriched in the clay size fraction than organic carbon (C) and inorganic P. The strong sorption of organic P in soil, especially in the clay size fraction, makes organic P less vulnerable to land-use change than soil organic C.
13 Sep 2018
Methane emissions from a sediment-deposited island in a Lancang-Mekong reservoir
Wenqing Shi, Qiuwen Chen, Jianyun Zhang, Cheng Chen, Yuchen Chen, Yuyu Ji, Juhua Yu, and Bryce R. Van Dam
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-380, https://doi.org/10.5194/bg-2018-380, 2018
Preprint withdrawn (discussion: closed, 7 comments)
Short summary
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As the second most important greenhouse gas, the production of methane undermines the green credentials of hydropower. We investigated methane emissions from a reservoir island and discovered self-mitigation of methane emissions in a ring-like zone around the island edge. Understanding the self-mitigation of methane emissions in dammed rivers will help to screen effective strategies for lessening the global warming effects of hydropower systems.
04 Sep 2018
The Coupling of Carbon, Nitrogen and Sulphur Transformational Processes in River Sediments Based on Correlationship among the Functional Genes
Mingzhu Zhang, Yang Li, Qingye Sun, Piaoxue Chen, and Xuhao Wei
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-369, https://doi.org/10.5194/bg-2018-369, 2018
Preprint withdrawn (discussion: closed, 2 comments)
Short summary
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(1) Correlation among functional genes could speculate the coupled systems of C-N-S.
(2) The amoA-AOA and dsrB played a secondary role in the systems.
(3) Functional genes (aprA, mcrA and hzo) counted for much in the systems.
(4) C and N showed combined effects in the coupling transformation.
(2) The amoA-AOA and dsrB played a secondary role in the systems.
(3) Functional genes (aprA, mcrA and hzo) counted for much in the systems.
(4) C and N showed combined effects in the coupling transformation.
27 Aug 2018
Spatial pattern of Kd(PAR) and its relationship with light absorption of optically active components in inland waters across China
Zhidan Wen, Kaishan Song, Chong Fang, Qian Yang, Ge Liu, Yingxin Shang, and Xiaodi Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-348, https://doi.org/10.5194/bg-2018-348, 2018
Preprint withdrawn (discussion: closed, 8 comments)
Short summary
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The spatial distribution of the attenuation of photosynthetic active radiation (Kd(PAR)) was routinely estimated in China lakes and reservoirs. The light absorption coefficient of OACs could explain 70 %–87 % of Kd(PAR) variations. Kd(PAR) could be predicted from aOACs values in the inland waters. Besides, results of this study are suggesting that new studies on the variability of Kd(PAR) in inland waters must consider the hydrodynamic conditions, trophic status and OACs within the water column.
24 Aug 2018
Investigation of scale interaction between rainfall and ecosystem carbon exchange ofWestern Himalayan Pine dominated vegetation
Sandipan Mukherjee, K Chandra Sekar, Priyanka Lohani, Kireet Kumar, Prabir Patra, and Kentaro Ishijima
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-299, https://doi.org/10.5194/bg-2018-299, 2018
Preprint withdrawn (discussion: closed, 6 comments)
21 Aug 2018
Characterization of chromophoric dissolved organic matter in lakes on the Tibet Plateau, China, using spectroscopic analysis
Kaishan Song, Sijia Li, Zhidan Wen, Lili Lyu, and Yingxin Shang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-259, https://doi.org/10.5194/bg-2018-259, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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Inland lakes are a direct link among the land, atmospheric and oceans (via rivers). Little is currently known about colored dissolved organic matter and its relationship with water quality in lakes across the Tibet Plateau. For these brackish and saline lakes, a high salt content with accumulation of carbon and low organic colored dissolved matter in brackish lakes, indicating the influence of strong evapoconcentration, intense ultraviolet irradiance and landscapes.
20 Aug 2018
High Riverine CO2 Outgassing affected by Land Cover Types in the Yellow River Source Region
Mingyang Tian, Xiankun Yang, Lishan Ran, Yuanrong Su, Lingyu Li, Ruihong Yu, Haizhu Hu, and Xi Xi Lu
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-292, https://doi.org/10.5194/bg-2018-292, 2018
Preprint withdrawn (discussion: closed, 8 comments)
Short summary
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We investigated the spatial and temporal variability of riverine CO2 outgassing characteristics of the Yellow River source region. Riverine CO2 emission were in situ monitored under different land cover types (i.e., glacier, permafrost, wetland, and grassland) in the research area.This study will lead to a better understanding of riverine carbon export, especially for alpine rivers, which will help refine the global estimation of global GHG gas emission.
02 Aug 2018
Unveiling the Perth Canyon and its deep-water faunas
Julie A. Trotter, Charitha Pattiaratchi, Paolo Montagna, Marco Taviani, James Falter, Ron Thresher, Andrew Hosie, David Haig, Federica Foglini, Quan Hua, and Malcolm T. McCulloch
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-319, https://doi.org/10.5194/bg-2018-319, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
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The first ROV exploration of the Perth Canyon offshore southwest Australia discovered diverse
hot spotsof deep-sea biota to depths of ~ 2000 m. Some corals were living below the carbonate saturation horizon. Extensive coral graveyards found at ~ 700 and ~ 1700 m are between ~ 18 000 and ~ 30 000 years old, indicating these corals flourished during the last ice age. Anthropogenic carbon detected within the upper ~ 800 m highlights the increasing threat of climate change to deep-sea ecosystems.
02 Aug 2018
Potential effects of deep seawater discharge by an Ocean Thermal Energy Conversion plant on the marine microorganisms in oligotrophic waters
Mélanie Giraud, Véronique Garçon, Denis De La Broise, Stéphane L'Helguen, Joël Sudre, and Marie Boye
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-306, https://doi.org/10.5194/bg-2018-306, 2018
Manuscript not accepted for further review (discussion: closed, 5 comments)
Short summary
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Associated to transitional
blueenergies, first investigation of the environmental impact on the marine microorganisms of an Ocean Thermal Energy Conversion (OTEC) pilot plant before its installation, using numerical simulation and in situ experimentations. No environmental standards are available yet. Microbiodiversity can be impacted in one scenario of the OTEC functioning. Give the basis for anticipating the long-term effects of renewable marine thermal energies on the environment.
23 Jul 2018
Spatiotemporal variability of light attenuation and net ecosystem metabolism in a back-barrier estuary
Neil K. Ganju, Jeremy M. Testa, Steven E. Suttles, and Alfredo L. Aretxabaleta
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-335, https://doi.org/10.5194/bg-2018-335, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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Estuaries are productive ecosystems that provide habitat for flora and fauna. We measured changes in light and oxygen, along with variables such as tides and waves, to understand how productivity in the estuary changed over daily and seasonal time periods. We found large differences in productivity between channels and seagrass beds, as well as a link between light climate and productivity. This study will help us understand how estuaries will respond to future changes in conditions.
18 Jul 2018
The importance of tree demography and root water uptake for modelling the carbon and water cycles of Amazonia
Emilie Joetzjer, Fabienne Maignan, Jérôme Chave, Daniel Goll, Ben Poulter, Jonathan Barichivich, Isabelle Maréchaux, Sebastiaan Luyssaert, Matthieu Guimberteau, Kim Naudts, Damien Bonal, and Philippe Ciais
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-308, https://doi.org/10.5194/bg-2018-308, 2018
Revised manuscript not accepted (discussion: closed, 8 comments)
Short summary
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This study explores the relative contributions of tree demographic, canopy structure and hydraulic processes on the Amazonian carbon and water cycles using large-scale process-based model. Our results imply that explicit coupling of the water and carbon cycles improves the representation of biogeochemical cycles and their spatial variability. Representing the variation in the ecological functioning of Amazonia should be the next step to improve the performance and predictive ability of models.
12 Jul 2018
Influence of concurrence of extreme drought and heat events on carbon and energy fluxes in dominant ecosystems in the Pacific Northwest region
Hyojung Kwon, Whitney Creason, Beverly E. Law, Christopher J. Still, and Chad Hanson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-297, https://doi.org/10.5194/bg-2018-297, 2018
Preprint retracted (discussion: closed, 1 comment)
Short summary
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Ecosystem responses to short-term extreme climate were diverse and non-linear due to the interactive effects of physiological and environmental factors even within the same plant functional types and species in the Pacific Northwest. A negative (reducing) effect of the short-term extreme climate on seasonal carbon uptake was observed. Douglas-fir is likely to experience more constraints on carbon uptake than ponderosa pine if hot/dry season intensifies in the Pacific Northwest.
06 Jul 2018
Spring phenology and phenology-climate links inferred from two remotely sensed vegetation indices across regions and biomes
Xiyan Xu, William J. Riley, Charles D. Koven, and Gensuo Jia
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-257, https://doi.org/10.5194/bg-2018-257, 2018
Preprint withdrawn (discussion: closed, 7 comments)
05 Jul 2018
A mechanistic model for electrical conduction in soil–root continuum: a virtual rhizotron study
Sathyanarayan Rao, Félicien Meunier, Solomon Ehosioke, Nolwenn Lesparre, Andreas Kemna, Frédéric Nguyen, Sarah Garré, and Mathieu Javaux
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-280, https://doi.org/10.5194/bg-2018-280, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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This paper illustrates the impact of electrical property of maize root segments on the Electrical Resistivity Tomography (ERT) inversion results with the help of numerical model. The model includes explicit root representation in the finite element mesh with root growth, transpiration and root water uptake. We show that, ignoring root segments could lead to wrong estimation of water content using ERT method.
21 Jun 2018
Estimating global gross primary productivity using chlorophyll
fluorescence and a data assimilation system with the
BETHY-SCOPE model
Alexander J. Norton, Peter J. Rayner, Ernest N. Koffi, Marko Scholze, Jeremy D. Silver, and Ying-Ping Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-270, https://doi.org/10.5194/bg-2018-270, 2018
Revised manuscript has not been submitted (discussion: closed, 2 comments)
Short summary
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This study presents a global estimate of land carbon uptake through photosynthesis. We make use satellite chlorophyll fluorescence measurements, a visible indicator of photosynthesis, to optimize model parameters and then use the optimized model to estimate photosynthetic carbon uptake. This provides a new tool that can combine measurements and observations in a systematic way and maximise the use of chlorophyll fluorescence to improve our understanding of the land carbon cycle.
18 Jun 2018
Impact of the 2011 off the Pacific coast of Tohoku earthquake on a deep-sea
benthic ecosystem: evidence from living and dead benthic foraminifera on the landward slope of the Japan Trench
Akira Tsujimoto, Ritsuo Nomura, Hidetaka Nomaki, Kazuno Arai, Mutsuo Inoue, and Katsunori Fujikura
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-237, https://doi.org/10.5194/bg-2018-237, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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We examined the impact of the earthquake and tsunami following the 2011 off the Pacific coast of Tohoku earthquake on the deep-sea benthic ecosystems. The episodic deposition of sediments resulting from the earthquake caused a drastic decrease in the original benthic foraminifera and colonization of opportunistic species with a low diversity within 17 months.
14 Jun 2018
Reviews and syntheses:
Processes and functional genes involved in
nitrogen cycling in marine environments
Ramiro Ramos and Silvia Pajares
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-279, https://doi.org/10.5194/bg-2018-279, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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The nitrogen cycle maintains the functioning of marine ecosystems and will be a crucial component in how the ocean responds to global environmental change. In this review, we summarize the current understanding of the marine microbial nitrogen cycle, its underlying biochemical and enzymatic reactions, the ecology and distribution of participating microorganisms in different marine ecosystems, and the main impacts of anthropogenic activities on the marine N cycle.
07 Jun 2018
Changes in carbon stocks of Fagus forest ecosystems along an altitudinal gradient on Mt. Fanjingshan in Southwest China
Qiong Cai, Chengjun Ji, Xuli Zhou, Wenjing Fang, Tianli Zheng, Jiangling Zhu, Lei Shi, Haibo Li, Jianxiao Zhu, and Jingyun Fang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-242, https://doi.org/10.5194/bg-2018-242, 2018
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
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Quantifying different carbon (C) pools in forest ecosystems is important in understanding C cycling in forests. However, the C pools of Chinese beech (Fagus) forests have seldom been studied. Here, the altitudinal patterns of four C pools in beech forests in Southwest China were investigated, and the stand age was proved to be a key factor shaping such patterns. Thus, this study provides data for understanding Chinese beech forests and stresses the importance of stand age in C accumulation.
28 May 2018
Dynamic interactions between iron and sulfur cycles from Arctic methane seeps
Pauline Latour, Wei-Li Hong, Simone Sauer, Arunima Sen, William P. Gilhooly III, Aivo Lepland, and Fotios Fouskas
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-223, https://doi.org/10.5194/bg-2018-223, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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Dissolved iron is one of the most important nutrients for the marine life. The production and consumption of dissolved iron are therefore closely associated with the carbon cycling in the ocean. We present geochemical data and numerical modeling results to discuss how the supply of dissolved iron, from marine sediments to the ocean, is connected to carbon and sulfur cycles and influence the distribution of animals in environments with high methane supply.
07 May 2018
Ammonia impacts methane oxidation and methanotrophic community in freshwater sediment
Yuyin Yang, Jianfei Chen, Shuguang Xie, and Yong Liu
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-193, https://doi.org/10.5194/bg-2018-193, 2018
Preprint withdrawn (discussion: closed, 5 comments)
03 May 2018
Seasonal and spatial variability of methane emissions from a subtropical reservoir in Eastern China
Le Yang, Hepeng Li, Chunlei Yue, and Jun Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-195, https://doi.org/10.5194/bg-2018-195, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
27 Apr 2018
Ecosystem respiration in coastal tidal flats can be modelled from air temperature, plant biomass and inundation regime
Xueyang Yu, Siyuan Ye, Linda Olsson, Mengjie Wei, Ken W. Krauss, and Hans Brix
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-186, https://doi.org/10.5194/bg-2018-186, 2018
Preprint retracted (discussion: closed, 4 comments)
Short summary
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Partition ecosystem respiration of a Suaeda salsa wetland into plant and soil derived efflux according to in-situ observations.
Quantify the interactive influence of air temperatre, biomass and water regime.
Develop a rapid assessment method which could be potentially used to project regional gaseous carbon loss from coastal Suaeda salsa wetlands.
27 Apr 2018
The response of seagrass (Posidonia oceanica) meadow metabolism to CO2 levels and hydrodynamic exchange determined with aquatic eddy covariance
Dirk Koopmans, Moritz Holtappels, Arjun Chennu, Miriam Weber, and Dirk de Beer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-199, https://doi.org/10.5194/bg-2018-199, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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Over the next century the dissolved carbon dioxide gas and hydrogen ion concentrations in seawater will triple. We used a new technique that incorporates the net productivity of all organisms in a ten square meter area to examine what the future of seagrass might look like. We compared seagrass at a CO2 vent to seagrass at a conventional shore. Seagrass meadow productivity was reduced at the vent, but it is likely that contaminants in vent fluids may have been the cause.
26 Apr 2018
Carbon Stocks and Accumulation Rates in Salt Marshes of
the Pacific Coast of Canada
Stephen G. Chastain, Karen Kohfeld, and Marlow G. Pellatt
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-166, https://doi.org/10.5194/bg-2018-166, 2018
Revised manuscript not accepted (discussion: closed, 5 comments)
Short summary
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We generated estimates of carbon stocks and accumulation rates in soils of salt marshes from Clayoquot Sound on the west coast of Canada. Following established methodologies, we sampled seven sites to generate a regional average estimate and compared it with global marsh carbon data. Our results show the marshes as highly efficient carbon accumulation
hotspots, comparable with those from elsewhere on the NE Pacific coast or similar latitude ranges.
26 Apr 2018
Phylogeny of the Stipa and implications for grassland evolution in China: based on biogeographic evidence
Qing Zhang, Junjun Chen, and Yong Ding
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-140, https://doi.org/10.5194/bg-2018-140, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
20 Apr 2018
Calibrating a process-based forest model with a rich observational dataset at 22 European forest sites
David Cameron, Christophe Flechard, and Marcel Van Oijen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-156, https://doi.org/10.5194/bg-2018-156, 2018
Revised manuscript not accepted (discussion: closed, 7 comments)
06 Apr 2018
Minimum temperature and precipitation determine fish richness pattern in China's nature reserves
Wende Chen, Shengbin Chen, Mengwei Shen, Lingfeng Mao, Peihao Peng, Juan Wang, Dan Zhao, and Yuelin Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-389, https://doi.org/10.5194/bg-2017-389, 2018
Revised manuscript has not been submitted (discussion: closed, 3 comments)
03 Apr 2018
Higher response of terrestrial plant growth to ammonium than nitrate addition
Liming Yan, Xiaoni Xu, and Jianyang Xia
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-124, https://doi.org/10.5194/bg-2018-124, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
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The patterns of the ratio of atmospheric deposited ammonium- to nitrate-N shows an increasing trend with the total N load since the industrial revolution. As a key role of N in plant growth, it is important to know the general response patterns of plant growth to N forms. By the synthesized dataset and meta-analysis, we found a higher response of plant growth to NH4+-N than NO3−-N addition across all species. Our results suggest plant could more positively respond to N deposition in the future.
28 Mar 2018
Impacts of Nitrogen Addition on Nitrous Oxide Emission: Model-Data Comparison
Yujin Zhang, Minna Ma, Huajun Fang, Dahe Qin, Shulan Cheng, and Wenping Yuan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-126, https://doi.org/10.5194/bg-2018-126, 2018
Revised manuscript has not been submitted (discussion: closed, 3 comments)
Short summary
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The study aims to examine the performance of six widely–used N2O models under different levels of atmospheric N deposition in a subtropical forest receiving the highest N deposition. The performances are determined by the model structures and algorithms. The study highlights the need to improve representation of N2O production and diffusion processes, and the key control of soil water-filled pore. The results have significant implications for the improvement and future development of N2O model.
19 Mar 2018
Lability of natural organic matter in freshwater: a simple
method for detection using hydrogen peroxide as an indicator
Isabela Carreira Constantino, Amanda Maria Tadini, Marcelo Freitas Lima, Lídia Maria de Almeida Plicas, Altair Benedito Moreira, and Márcia Cristina Bisinoti
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-122, https://doi.org/10.5194/bg-2018-122, 2018
Preprint withdrawn (discussion: closed, 4 comments)
Short summary
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The lability or recalcitrance of natural organic matter is key characteristic in dynamic of others entities present in aquatic systems, but there was not yet a direct method to quantification of labile (LOM) and recalcitrant (ROM) organic matter. The method proposed to quantify and ROM concentrations was developed using the hydrogen peroxide kinetic in freshwater samples. This method was employed in freshwater samples for one year and the results were related with seasonality.
16 Mar 2018
Global patterns of leaf nutrient resorption in herbaceous plants
Zhiqiang Wang, Zhexuan Fan, Qi Zhao, Jinzhi Ran, and Karl J. Niklas
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-112, https://doi.org/10.5194/bg-2018-112, 2018
Manuscript not accepted for further review (discussion: closed, 6 comments)
13 Mar 2018
Inferring particle dynamics in the Mediterranean Sea from in-situ
pump POC and chloropigment data using Bayesian statistics
Weilei Wang, Cindy Lee, and Francois Primeau
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-6, https://doi.org/10.5194/bg-2018-6, 2018
Revised manuscript not accepted (discussion: closed, 5 comments)
Short summary
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We introduce a new model that can infer particle dynamics rate constants using large volume pump chloropigment data. We compare the inferred rate constants to those estimated using the same tracers but collected using sinking velocity (SV) sediment traps, and to those estimated using SV trap thorium data. We conclude that the two different sampling methods have less influence on particle aggregation and disaggregation rate constant estimations than do the two different tracers themselves.
27 Feb 2018
Comparative analysis of trade-offs and synergies in ecosystem services
between Guanzhong Basin and Hanzhong Basin in China
Bo-Yan Li, Wei Wang, and Yun-Chen Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-33, https://doi.org/10.5194/bg-2018-33, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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1.Comparative analysis was used to study the ES interactions in two basins at a fine spatio-temporal scale.
2.The trade-off relationships between FP and NPP were the most significant in both basins.
3.The synergistic relationships between WR and NPP, as well as between WR and SC weakened in the two basins over 20 years.
4.The synergies and trade-offs between the ES were widespread in the two basins, rather than pure trade-offs or synergies.
2.The trade-off relationships between FP and NPP were the most significant in both basins.
3.The synergistic relationships between WR and NPP, as well as between WR and SC weakened in the two basins over 20 years.
4.The synergies and trade-offs between the ES were widespread in the two basins, rather than pure trade-offs or synergies.
15 Feb 2018
Quantification of the fine-scale distribution of Mn-nodules: insights from AUV multi-beam and optical imagery data fusion
Evangelos Alevizos, Timm Schoening, Kevin Koeser, Mirjam Snellen, and Jens Greinert
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-60, https://doi.org/10.5194/bg-2018-60, 2018
Revised manuscript has not been submitted (discussion: closed, 4 comments)
Short summary
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AUV hydro-acoustic and optical data enhance high resolution quantitative mapping of deep sea hard substrates such Mn-nodules. Machine learning algorithms predict with good accuracy the Mn-nodules abundances over large scale areas utilizing one third of ground truth optical data. Accurate maps of Mn-nodule abundances raise new questions about the role of fine scale geomorphology in nodule formation, provide new insights in deep sea ecological studies, and improve mineral assessment estimations.
13 Feb 2018
Microbial Community Structure and Activity Changes in Response
to the Development of Hypoxia in a Shallow Estuary
Yunjung Park, Sujin Kim, Soonja Cho, Jaeho Cha, and Soonmo An
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-64, https://doi.org/10.5194/bg-2018-64, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Our work addresses the influences of hypoxia on microbes in three independent aspects (activity, abundance and community structure). The activity and community structure in water column were less affected compared to the sediment (an interesting
SRB (sulphate reducing bacteria) successionhappened in sediment). Our results also illustrated that the intriguing N dynamics recently discovered in the OMZ (such as AOA dynamics) might also be important in the hypoxic zone.
05 Feb 2018
Regulation of N2O emissions from acid organic soil drained for agriculture: Effects of land use and season
Arezoo Taghizadeh-Toosi, Lars Elsgaard, Tim Clough, Rodrigo Labouriau, and Søren Ole Petersen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-9, https://doi.org/10.5194/bg-2018-9, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
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Organic soils are extensively under agricultural management which lead to high emissions of N2O. We searched for relationships between seasonal variation in N2O emissions and potential driving variables such as temperature, precipitation, water table depth, N availability, and possible decomposibility of peat. Reducing surplus N in the soil, for example by use of a plant cover, and stabilisation of water table depth during the year, appear to be keys to controlling N2O emissions.
05 Feb 2018
Alaskan Stream flow in the eastern subarctic Pacific and the eastern
Bering Sea and its impact on biological productivity
Sergey Prants, Andrey Andreev, Michael Uleysky, and Maxim Budyansky
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-477, https://doi.org/10.5194/bg-2017-477, 2018
Manuscript not accepted for further review (discussion: closed, 3 comments)
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We demonstrate the transport pathways of Alaskan Stream water in the eastern subarctic Pacific and the eastern Bering Sea from October 1, 1994 to September 12, 2016 with the help of altimetry-based Lagrangian maps. A mesoscale eddy activity in the Alaskan Stream region and the eastern Bering Sea is shown to be relatedwith the wind stress curl in winter. The mesoscale dynamics may determine not only lower-trophic-level organism biomass but also salmon abundance/catch in the study area.
01 Feb 2018
Boreal forest soil is a significant and diverse source of volatile organic
compounds
Mari Mäki, Hermanni Aaltonen, Jussi Heinonsalo, Heidi Hellén, Jukka Pumpanen, and Jaana Bäck
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-22, https://doi.org/10.5194/bg-2018-22, 2018
Preprint withdrawn (discussion: closed, 6 comments)
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Vegetation emissions of volatile organic compounds (VOCs) are intensively studied world-wide, but remains largely unknown how effectively belowground VOCs are produced and released into the atmosphere. We demonstrate that boreal forest soil is a diverse source and storage of VOCs, because more than 50 VOCs were detected in the soil air. Our results give evidence that VOC production processes and storages partly differ from those VOCs that are simultaneously emitted from the soil surface.
30 Jan 2018
Carbonyl sulfide (OCS) exchange between soils and the atmosphere affected by soil moisture and compensation points
Rüdiger Bunk, Zhigang Yi, Thomas Behrendt, Dianming Wu, Meinrat Otto Andreae, and Jürgen Kesselmeier
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-20, https://doi.org/10.5194/bg-2018-20, 2018
Manuscript not accepted for further review (discussion: closed, 6 comments)
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We examined the OCS exchange of four soils with the atmosphere. The laboratory setup used allowed to monitor this exchange while simultaneously monitor soil moisture. The OCS exchange of those soils was measured over full range from very wet to very dry.
We found that uptake of OCS is highly dependent on soil moisture, that probably heterotroph and autotrophs drive the uptake at different soil moistures and that the role of soils as net consumer or producers of OCS may vary with soil moisture.
23 Jan 2018
Excess nitrogen as a marker of intense dinitrogen fixation in the Western Tropical South Pacific Ocean: impact on the thermocline waters of the South Pacific
Alain Fumenia, Thierry Moutin, Sophie Bonnet, Mar Benavides, Anne Petrenko, Sandra Helias Nunige, and Christophe Maes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-557, https://doi.org/10.5194/bg-2017-557, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
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The Melanesian archipelago waters between 160° E and 170° W are characterized by a significant N2 fixation rates and an excess of particulate organic nitrogen compared to the canonical ratio of Redfield and a positive N*. We hypothesize that the southern branch of the subtropical gyre is probably the main vector of excess nitrogen transport in the thermocline waters showing an influence of nitrogen fixation occurring in the western tropical in a large part of the South Pacific.
23 Jan 2018
Modeling transient soil moisture limitations on microbial
carbon respiration
Yuchen Liu, Matthew J. Winnick, Hsiao-Tieh Hsu, Corey R. Lawrence, Kate Maher, and Jennifer L. Druhan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-10, https://doi.org/10.5194/bg-2018-10, 2018
Preprint withdrawn (discussion: closed, 6 comments)
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Microbes naturally occur in soils and respire CO2, thus constituting a significant source of atmospheric greenhouse gases. We seek to improve predictions for the amount of CO2 emitted from soil by contrasting two models compared against lab measured respiration rates using natural soil samples at a range of soil moistures. Results show that a simplified model is more suitable for interpreting soil respiration rates below 100 cm, while a more complex approach is necessary for shallower depths.
22 Jan 2018
Functional spatial contextualisation of the effects of multiple stressors in marine bivalves
Antonio Giacoletti and Gianluca Sarà
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-13, https://doi.org/10.5194/bg-2018-13, 2018
Preprint retracted (discussion: closed, 5 comments)
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The manuscript integrates experimental investigation of multiple stressors effects' on bivalves with model simulations aimed to predict future potential effects on Life-History traits. Our model species has been projected into a future climate change scenario, crossed with a lower pH and hypoxia events. This study mechanistically quantify the major threat represented by hypercapnia and hypoxia phenomena for the growth, reproduction and fitness of mussels under current climate change context.
22 Jan 2018
Role of Calanus sinicus (Copepoda, Calanoida) on dimethylsulfide production in Jiaozhou Bay
Juan Yu, Jiyuan Tian, Zhengyu Zhang, Guipeng Yang, and Hongju Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-568, https://doi.org/10.5194/bg-2017-568, 2018
Preprint retracted (discussion: closed, 5 comments)
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Data from the field experiment showed that Calanus sinicus was the predominant copepod in Jiaozhou Bay and has no apparent effect on DMS/DMSP production. The results in the laboratory experiment showed that the effects of C. sinicus grazing on DMS/DMSP production differed depending on the food type, food concentration and salinity. The data presented in this study are helpful to evaluate the copepod role on the biogeochemical cycle of DMSP in Jiaozhou Bay.
16 Jan 2018
Interactive effects of seawater carbonate chemistry, light intensity and nutrient availability on physiology and calcification of the coccolithophore Emiliania huxleyi
Yong Zhang, Feixue Fu, David A. Hutchins, and Kunshan Gao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-11, https://doi.org/10.5194/bg-2018-11, 2018
Revised manuscript not accepted (discussion: closed, 6 comments)
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To investigate responses of the calcifying E. huxleyi to multiple environmental factors, we investigated its growth, POC and PIC quotas and photosynthesis parameter at different levels of CO2, light, dissolved inorganic nitrogen and phosphate concentrations. High CO2 (HC) and low nitrogen (LN) synergistically decreased growth rates, high light compensated for inhibition of low phosphate (LP) on growth rates at LC, but exacerbated inhibition of LP at HC. LN or LP increased PIC quotas and ETRmax.
16 Jan 2018
Spatial estimation of soil carbon, nitrogen and phosphorus stoichiometry in complex terrains: a case study of Schrenk's spruce forest in the Tianshan Mountains
Zhonglin Xu, Yapeng Chang, Lu Li, Qinghui Luo, Zeyuan Xu, Xiaofei Li, Xuewei Qiao, Xinyi Xu, Xinni Song, and Yao Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-536, https://doi.org/10.5194/bg-2017-536, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Spatial distribution of ecological stochiometry is useful for studies corresponding to nutrient limitations, community dynamics, nutrient use efficiency and biogeochemical cycles. We syctematically sampled the soils in Schrenk's spruce forest and modeled the spatial distribution of C : N : P ratios in the forest. we found that multipel linear regression models could be reliably used to model the spatial patterns of soil elemental concentrations and stoichiometric ratios in mountainous terrain.
12 Jan 2018
Winter mixing, mesoscale eddies and eastern boundary current: Engines for biogeochemical variability of the central Red Sea during winter/early spring period
Nikolaos D. Zarokanellos and Burton H. Jones
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-544, https://doi.org/10.5194/bg-2017-544, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
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This is the first in-situ study that describes the temporal-spatial variability in the Red Sea during the winter/spring transition. In situ oceanographic glider data and remotely sensed chlorophyll are used to demonstrate how physical processes control biogeochemical variability in the central Red Sea. We believe that continuing to study these processes in the globally extreme Red Sea will help us to better understand the climate effects.
11 Jan 2018
Plants in movement – Floristic and climatic characterization of the
New Jersey hinterland during the Palaeogene–Neogene transition in
relation to major glaciation events
Sabine Prader, Ulrich Kotthoff, Francine M.G. McCarthy, Gerhard Schmiedl, Timme H. Donders, and David R. Greenwood
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-511, https://doi.org/10.5194/bg-2017-511, 2018
Manuscript not accepted for further review (discussion: closed, 4 comments)
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The observed palaeovegetation movement signals probably correspond to several glacial phases of the middle Oligocene and Early Miocene and might be best reflected within peaks of the conifer forests. Glacial phases exposed shallow shelf areas and allowed the spreading of substrate-depending forest formations. Temperature estimates revealing relative stable humid warm temperate conditions. A Sporadic occurred extinct taxon widens the understanding of its distribution pattern during the Cenozoic.
10 Jan 2018
Seasonal dynamics and disturbance of phytoplankton biomass in the wake of Tahiti as observed by Biogeochemical-Argo floats
Raphaëlle Sauzède, Elodie Martinez, Orens Pasqueron de Fommervault, Antoine Poteau, Alexandre Mignot, Christophe Maes, Hervé Claustre, Julia Uitz, Keitapu Maamaatuaiahutapu, Martine Rodier, Catherine Schmechtig, and Victoire Laurent
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-541, https://doi.org/10.5194/bg-2017-541, 2018
Revised manuscript not accepted (discussion: closed, 4 comments)
02 Jan 2018
Deriving Photosynthetically Active Radiation at ground level in cloud-free conditions from Copernicus Atmospheric Monitoring Service (CAMS) products
William Wandji Nyamsi, Phillipe Blanc, John A. Augustine, Antti Arola, and Lucien Wald
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-512, https://doi.org/10.5194/bg-2017-512, 2018
Manuscript not accepted for further review (discussion: closed, 6 comments)
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This paper proposes a new, fast and accurate method for estimating photosynthetically active radiation at ground level in cloud-free conditions at any place and time. The method performs very well with the Copernicus Atmosphere Monitoring Service products as inputs describing the state of the atmosphere. An accuracy that is close to the uncertainty of the measurements themselves is reached. We believe that our research will be widely used in the near future.
18 Dec 2017
Physical and chemical evolution of dissolved organic matter across the ablation season on a glacier in the central Tibetan Plateau
Lin Feng, Yanqing An, Jianzhong Xu, Shichang Kang, Xiaofei Li, Yongqiang Zhou, Yunlin Zhang, Bin Jiang, and Yuhong Liao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-507, https://doi.org/10.5194/bg-2017-507, 2017
Revised manuscript not accepted (discussion: closed, 6 comments)
14 Dec 2017
A new procedure for processing eddy-covariance data to better quantify atmosphere-aquatic ecosystem CO2 exchanges
Tatsuki Tokoro and Tomohiro Kuwae
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-499, https://doi.org/10.5194/bg-2017-499, 2017
Manuscript not accepted for further review (discussion: closed, 6 comments)
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The eddy covariance (EC) method is the most promising approach for the measurement of atmospheric CO2 flux. However, the methods are currently in the development stage, and have large uncertainties. In this study, we improved the post-processing procedure for the EC method to reduce the uncertainty. The new processing method is expected to be useful in studies related to ecosystem-atmospheric CO2 interactions.
30 Nov 2017
Atmospheric nitrogen deposition to terrestrial ecosystems across Germany
Martijn Schaap, Sabine Banzhaf, Thomas Scheuschner, Markus Geupel, Carlijn Hendriks, Richard Kranenburg, Hans-Dieter Nagel, Arjo J. Segers, Angela von Schlutow, Roy Wichink Kruit, and Peter J. H. Builtjes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-491, https://doi.org/10.5194/bg-2017-491, 2017
Revised manuscript has not been submitted (discussion: closed, 3 comments)
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Deposition of nitrogen and sulfur from the atmosphere on ecosystems causes a loss of biodiversity. We used a combination of atmospheric modelling and deposition observations to estimate the deposition to ecosystems across Germany. We estimate that 70 % of the ecosystems in Germany receive too much nitrogen from deposition. The results are used to determine whether economic activities causing nitrogen emissions are allowed in sensitive areas.
30 Nov 2017
CO2 and CH4 budgets and global warming potential modifications in Sphagnum-dominated peat mesocosms invaded by Molinia caerulea
Fabien Leroy, Sébastien Gogo, Christophe Guimbaud, Léonard Bernard-Jannin, Xiaole Yin, Guillaume Belot, Wang Shuguang, and Fatima Laggoun-Défarge
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-423, https://doi.org/10.5194/bg-2017-423, 2017
Revised manuscript has not been submitted (discussion: closed, 2 comments)
27 Nov 2017
The importance of nitrogen fixation to a temperate, intertidal embayment determined using a stable isotope mass balance approach
Douglas G. Russell, Adam J. Kessler, Wei Wen Wong, and Perran L. M. Cook
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-418, https://doi.org/10.5194/bg-2017-418, 2017
Preprint withdrawn (discussion: closed, 4 comments)
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Using discrete measurements to investigate nitrogen cycling in marine environments can be problematic as such extrapolations mightn't accurately describe how nitrogen is processed over large spatial and temporal scales. The ability of a stable isotope and mass balance to overcome these issues was investigated, with results being compared to actual sedimentary nitrogen measurements. The closeness of the results suggested that the model developed accurately described the cycling of nitrogen.
16 Nov 2017
Aerobiology and passive restoration of biological soil crusts
Steven D. Warren, Larry L. St. Clair, and Steven D. Leavitt
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-430, https://doi.org/10.5194/bg-2017-430, 2017
Revised manuscript has not been submitted (discussion: closed, 4 comments)
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Biological soil crusts (BSCs), common features of arid soils, are consortia of cyanobacteria, algae, fungi, lichens, and mosses. They control soil hydrology and stability, concentrate essential nutrients, and influence vascular plant survival.
BSCs are easily disturbed and slow to recover. Mechanisms of recovery are poorly understood. From the field of aerobiology, we find that BSC organisms are carried airborne between areas, continents, and even hemispheres.
13 Nov 2017
Lifestyle dependent occurrence of airborne fungi
Daniel A. Pickersgill, Jörn Wehking, Hauke Paulsen, Eckhard Thines, Ulrich Pöschl, Janine Fröhlich-Nowoisky, and Viviane R. Després
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-452, https://doi.org/10.5194/bg-2017-452, 2017
Manuscript not accepted for further review (discussion: closed, 6 comments)
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To investigate lifestyle dependent sporulation strategies of wind-dispersed fungi, species and genera identified in environmental air samples were grouped according to their lifestyles or ecological niches. Findings revealed unrecognized characteristic patterns in the seasonal occurrence and size distribution of fungal spores for different types of pathogenic and saprophytic fungi growing on herbaceous and woody plants.
08 Nov 2017
Controls on spatial and temporal patterns of soil nitrogen availability in a High Arctic wetland
Jacqueline K. Y. Hung, David M. Atkinson, and Neal A. Scott
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-440, https://doi.org/10.5194/bg-2017-440, 2017
Preprint withdrawn (discussion: closed, 4 comments)
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This paper presents findings that highlight the intricate relationships that exist between plant-available nutrients and carbon exchange in a High Arctic environment. The findings here suggest that finer scale processes altering nitrogen availability have influence on the overall carbon balance of wet sedge meadows in the High Arctic. Seasonal changes in nutrient availability is one key factor that regulates the magnitude and direction of responses to climate change.
07 Nov 2017
Biogeochemical contrast between different latitudes and the effect of human activity on spatio-temporal carbon cycle change in Asian river systems
Tadanobu Nakayama
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-447, https://doi.org/10.5194/bg-2017-447, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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This paper intends to investigate the ability of an advanced eco-hydrologic and biogeochemical coupling model NICE-BGC to estimate diurnal and seasonal variations of carbon flux budgets between different latitudes from various watersheds. Result implies shift of importance of aquatic metabolism and terrestrially derived carbon between daytime and nighttime. The result also helps to contribute on the further improvement in biogeochemical cycle along terrestrial-aquatic continuum.
02 Nov 2017
Effects of the interaction of ocean acidification, solar radiation, and warming on biogenic dimethylated sulfur compounds cycling in the Changjiang River Estuary
Shan Jian, Jing Zhang, Hong-Hai Zhang, and Gui-Peng Yang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-453, https://doi.org/10.5194/bg-2017-453, 2017
Manuscript not accepted for further review (discussion: closed, 6 comments)
01 Nov 2017
Historical record of the effects of anthropogenic pollution on benthic foraminifera over the last 110 years in Gamak Bay, South Korea
Da Un Jeong, Yeon Gyu Lee, Yong Wan Kim, Jung Jun Park, and Jung Sick Lee
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-383, https://doi.org/10.5194/bg-2017-383, 2017
Manuscript not accepted for further review (discussion: closed, 3 comments)
26 Oct 2017
CO2 Flux and its Relationship with Water Parameters and Biological Activity in the Ji-Paraná River (Rondônia State – Western Amazon)
Thandy Junio da Silva Pinto and Beatriz Machado Gomes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-407, https://doi.org/10.5194/bg-2017-407, 2017
Revised manuscript has not been submitted (discussion: closed, 2 comments)
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This study investigates the regulating mechanism for the CO2 exchange between air and water, and evidences that the biologic activity is an important regulating mechanism for the CO2 emission rate and the seasonal variation controls it. Most studies have considered the physical-chemical water parameters and atmospheric variation as a regulating mechanism in the gas exchange, however, we have concluded the biologic activity can be a driver for the regulation of carbon evasion in tropical rivers.
23 Oct 2017
Variations in soil carbon, nitrogen, phosphorus and stoichiometry along forest succession in southern China
Shuai Ouyang, Wenhua Xiang, Mengmeng Gou, Pifeng Lei, Liang Chen, Xiangwen Deng, and Zhonghui Zhao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-408, https://doi.org/10.5194/bg-2017-408, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
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Our results showed that forest succession affected SOC, TN, and TP concentrations, storage and stoichiometry. SOC and TN exhibited a significant increasing tendency, while those of TP decreased significantly, indicating an increasing P limitation for plant growth as succession proceeded.
23 Oct 2017
Dissolved organic matter release by phytoplankton in the context of the Dynamic Energy Budget theory
Eleni Livanou, Anna Lagaria, Stella Psarra, and Konstadia Lika
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-426, https://doi.org/10.5194/bg-2017-426, 2017
Manuscript not accepted for further review (discussion: closed, 5 comments)
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A model quantifying the two conceptual mechanisms of dissolved organic matter (DOM) release by phytoplankton, namely passive diffusion and active exudation, under different nutrient availability scenarios is proposed. The model resolves the relationship between primary production and DOM release, which depends on nutrient availability and predicts the production of DOM with different molecular and elemental ratio signatures, with potential implications for phytoplankton–bacteria relationships.
12 Oct 2017
Causes of uncertainty in observed and projected heterotrophic respiration from Earth System Models
Cary Lynch, Corinne Hartin, Min Chen, and Ben Bond-Lamberty
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-405, https://doi.org/10.5194/bg-2017-405, 2017
Revised manuscript has not been submitted (discussion: closed, 8 comments)
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Heterotrophic respiration (RH) is a large part of the carbon cycle, but it is poorly simulated by climate models. We examine the relationships between RH and key climate variables to understand this uncertainty in observations and from climate models. Compared to observations, models overestimate both the RH trend and climatological relationships. In the future, the relationship between RH and temperature is strong and can be used to explore a wide range of future scenarios.
29 Sep 2017
Diurnal, seasonal and long-term behaviour of high arctic tundra-heath ecosystem dynamics inferred from model ensembles constrained by time-integrated CO2 fluxes
Wenxin Zhang, Per-Erik Jansson, and Bo Elberling
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-382, https://doi.org/10.5194/bg-2017-382, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
25 Sep 2017
Disturbances of Biological Soil Crust by fossorial birds increase plant diversity in a Peruvian desert
María Cristina Rengifo and Cesar Arana
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-376, https://doi.org/10.5194/bg-2017-376, 2017
Revised manuscript not accepted (discussion: closed, 6 comments)
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This article is one of the first involving biological soil crust (BSC) in Peru. Our study was located in a unique ecosystem in the Peruvian desert. Here we asked if the effects of birds disturbing the BSC had an effect on the vegetation. We analyze differences in soil moisture, nutrients, seed germination and seedling emergence. Our results revealed that soil moisture content and plant diversity was increased by disturbing the BSC, and remarks the importance of ecological interactions.
22 Sep 2017
Ideas and perspectives: Can we use the soil carbon saturation deficit to quantitatively assess the soil carbon storage potential, or should we explore other strategies?
Pierre Barré, Denis A. Angers, Isabelle Basile-Doelsch, Antonio Bispo, Lauric Cécillon, Claire Chenu, Tiphaine Chevallier, Delphine Derrien, Thomas K. Eglin, and Sylvain Pellerin
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-395, https://doi.org/10.5194/bg-2017-395, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Soil C storage is currently discussed at a high political level. This paper discusses whether the concept of soil C saturation deficit can be appropriate to determine quantitatively the soil C storage potential and contribute to answer operational questions raised by policy makers. After a review of the literature, we conclude that for practical and conceptual reasons, the C saturation deficit is not appropriate for assessing quantitatively the soil total OC storage potential.
20 Sep 2017
On the potential causes of the recent Pelagic Sargassum blooms events in the tropical North Atlantic Ocean
Sandrine Djakouré, Moacyr Araujo, Aubains Hounsou-Gbo, Carlos Noriega, and Bernard Bourlès
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-346, https://doi.org/10.5194/bg-2017-346, 2017
Revised manuscript has not been submitted (discussion: closed, 4 comments)
18 Sep 2017
Influence of Tidal Inundation on CO2 Exchange between Salt Marshes and the Atmosphere
Hafsah Nahrawi, Monique Y. Leclerc, Gengsheng Zhang, and Roshani Pahari
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-356, https://doi.org/10.5194/bg-2017-356, 2017
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Salt marsh is one of the most productive system on Earth. To understand the salt marsh-atmosphere CO2 exchange, it is important to consider the effect of tidal inundation in this ecosystem. Eddy-covariance systems were used to capture CO2. Results showed that, CO2 exchange was reduced by 40 % during high tide events in August 2014, despite only 10 % of the events occurred in that month. The inclusion of such results has implications to quantify the carbon budget and its changes as sea level rises.
14 Sep 2017
A mathematical representation of microalgae distribution in aridisol and water scarcity
Abdolmajid Lababpour
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-359, https://doi.org/10.5194/bg-2017-359, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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A mathematical model was developed to support aridisol restoration processes. In the model, interaction of microalgae and soil water was formulated. Then, the model coupled partial differential equations were solved numerically. The model outputs reveal biomass distribution and water consumption in the horizontal surface. In addition, the model has ability to include effective factors such as light irradiation and weather temperature.
13 Sep 2017
Intense pCO2 and [O2] Oscillations in a Mussel-Seagrass Habitat: Implications for Calcification
Vincent Saderne, Peer Fietzek, Jens Daniel Müller, Arne Körtzinger, and Claas Hiebenthal
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-351, https://doi.org/10.5194/bg-2017-351, 2017
Preprint withdrawn (discussion: closed, 2 comments)
28 Aug 2017
Organic and inorganic carbon and their stable isotopes in surface sediments of the Yellow River Estuary
Zhitong Yu, Xiujun Wang, Guangxuan Han, Xingqi Liu, and Enlou Zhang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-353, https://doi.org/10.5194/bg-2017-353, 2017
Manuscript not accepted for further review (discussion: closed, 7 comments)
25 Aug 2017
The Ballast Effect in the Indian Ocean
Tim Rixen, Birgit Gaye, Kay-Christian Emeis, and Venkitasubramani Ramaswamy
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-317, https://doi.org/10.5194/bg-2017-317, 2017
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Sediment trap experiments showed that in the river-influenced regions of the Indian Ocean lithogenic matter supplied from land controls the organic carbon export into the deep sea via its ballast effect in sinking particles. Carbonate produced by plankton is the main ballast material in the open ocean. The ballast effect increases the CO2 uptake of the organic carbon pump by enhancing the amount of nutrients used to bind CO2 and by favouring the sedimentation of organic matter.
25 Aug 2017
Comment on Growth responses of trees and understory plants to nitrogen fertilization in a subtropical forest in Chinaby Tian et al. (2017)
Taiki Mori
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-358, https://doi.org/10.5194/bg-2017-358, 2017
Preprint withdrawn (discussion: closed, 3 comments)
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Negative effects of over-fertilization have been long reported in agricultural field. A recent paper by Tian et al. (2017) reported that application of NH4NO3 solution significantly reduced understory vegetation. In this note, I suggest the possibility that the negative effects were caused by the monthly application of NH4NO3 solution with high concentration (as high as 0.4 M and 0.8 M).
21 Aug 2017
A temperature threshold to identify the driving climate forces of the respiratory process in terrestrial ecosystems
Zhiyuan Zhang, Renduo Zhang, Yang Zhou, Alessandro Cescatti, Georg Wohlfahrt, Minmin Sun, Juan Zhu, Vincenzo Magliulo, Feng Tao, and Guanhong Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-345, https://doi.org/10.5194/bg-2017-345, 2017
Manuscript not accepted for further review (discussion: closed, 6 comments)
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This study highlight the key role of temperature as main controlling factor of the maximum respiration rates in most terrestrial ecosystems, while other driving forces reduce the maximum respiration rates and temperature sensitivity of the respiratory process. These findings are particularly relevant under the current scenario of rapid global warming, given that the potential climate-induced changes in ecosystem respiration may lead to substantial anomalies in terrestrial carbon budget.
08 Aug 2017
Impact of land use and soil properties on soil methane flux response to biochar addition
Weiwei Cong, Jun Meng, and Samantha C. Ying
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-281, https://doi.org/10.5194/bg-2017-281, 2017
Revised manuscript has not been submitted (discussion: closed, 8 comments)
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This paper examines the role of soil properties, biochar properties, and management factors in methane emission/uptake of biochar amended paddy and upland soils through the use of quantitative meta-analysis. Our findings show that variations in soil characteristics including SOC, C/N, and pH significantly influences the methane flux from biochar treated soils, while biochar characteristics and management practices have less to no effect as determined by the magnitude of the Hedge's d metric.
20 Jul 2017
Ideas and perspectives: New research examples of autumnal climate change ecology
Ulf Büntgen and Paul J. Krusic
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-265, https://doi.org/10.5194/bg-2017-265, 2017
Revised manuscript not accepted (discussion: closed, 3 comments)
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Changes in autumnal climate affecting the diversity and productivity of the ecosphere are arguably as important as vernal climatic changes. Here we present three examples of innovative, recent research in wildlife biology (big-game hunting), wood anatomy (tree-ring formation) and mycology (mushroom inventory), which refine our ability to better understand how varying environmental and climatic conditions impact the phenology, productiviy and diversity of different organisms in autumn.
17 Jul 2017
226Ra and 228Ra in the stratified estuary of the Krka River (Adriatic Sea, Croatia): implications for submarine groundwater discharge and its derived nutrients
Jianan Liu, Jinzhou Du, Blaženka Gašparović, Milan Čanković, Enis Hrustić, Neven Cukrov, Zhuoyi Zhu, and Ruifeng Zhang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-254, https://doi.org/10.5194/bg-2017-254, 2017
Preprint retracted (discussion: closed, 4 comments)
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In this manuscript, we evaluated the submarine groundwater discharge (SGD) by three approaches and its derived nutrients in the highly stratified Krka River Estuary (KRE), Croatia based on radium isotopes. By establishing the water and nutrient budgets in the KRE surface layer, even if SGD accounted for a small portion of the total water input, nutrient fluxes through SGD were significant, especially the high N : P ratios in SGD have the notable potential to impact the ecosystem of the KRE.
12 Jul 2017
Field-obtained carbon and nitrogen uptake rates of phytoplankton in the Laptev and East Siberian seas
Sang Heon Lee, Jang Han Lee, Howon Lee, Jae Joong Kang, Jae Hyung Lee, Dabin Lee, SoHyun An, Dean A. Stockwell, and Terry E. Whitledge
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-234, https://doi.org/10.5194/bg-2017-234, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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The Laptev and East Siberian seas are highly dynamic in terms of active processing of organic matters impacting the transport to the deep Arctic Ocean. However, they have been the least biologically studied region in the Arctic Ocean. As a part of the NABOS program, our field-measured data, which are very scarce in this region, such as major inorganic nutrient and chl-a concentrations and carbon and nitrogen uptake rates of phytoplankton in this study will be very valuable for basic ground.
10 Jul 2017
Potential Impact of Carbonate Chemistry Change (pCO2) on Krill and
Krill-based Food chain in the Southern Ocean with emphasis on
Embryogenesis of Antarctic krill
Robert Y. George
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-207, https://doi.org/10.5194/bg-2017-207, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Our knowledge on the physiological responses of Antarctic krill Euphausia superba to increased pCO2 is meager. However, Saba et al. (2012) reported from experimental studies on E. superba that sufficiently elevated CO2 concentrations could alter internal acid base balance, compromising homeostatic regulation and disrupting internal systems ranging from oxygen transport to ion balance. Perturbation experiments with E. superba under elevated CO2 (672 ppm) ingestion rates of krill averaged.
07 Jul 2017
The contribution of land-use change versus climate variability to the
1940s CO2 plateau: Former Soviet Union as a test case
Ana Bastos, Anna Peregon, Érico A. Gani, Sergey Khudyaev, Chao Yue, Wei Li, Célia Gouveia, and Philippe Ciais
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-267, https://doi.org/10.5194/bg-2017-267, 2017
Revised manuscript not accepted (discussion: closed, 13 comments)
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The ice-core record indicates a stabilization of atmospheric CO2 in the 1940s, which is not captured by the state-of-the-art reconstructions of CO2 sources and sinks.
The 1940s where marked by major socio-economic disruptions due to war. At the same time, very strong warming was registered in the high-latitudes. Here we evaluate the contributions of these two factors to a possible increase in the terrestrial sink not captured in other datasets, using the Former Soviet Union as a case study.
04 Jul 2017
13C labelling study of constitutive and stress-induced terpenoide
missions from Norway spruce and Scots pine
Cheng Wu, Iida Pullinen, Stefanie Andres, Astrid Kiendler-Scharr, Einhard Kleist, Andreas Wahner, Jürgen Wildt, and Thomas F. Mentel
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-260, https://doi.org/10.5194/bg-2017-260, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Biogenic volatile organic compounds are important for atmospheric chemistry. We showed by 13CO2 labelling experiments that biosynthesis is not restricted to the presence of light. In particular sesquiterpenes exhibit substantial de novo emissions in darkness with the carbon being delivered from alternative carbon sources. Our findings are of importance for future emissions under conditions of climate change as the response of de novo emissions to stresses differs from that of pool emissions.
03 Jul 2017
Winter phytoplankton blooms in the offshore south Adriatic waters (1995–2012) regulated by hydroclimatic events: Special emphasis on the exceptional bloom of 1995
Mirna Batistić, Damir Viličić, Vedrana Kovačević, Nenad Jasprica, Héloise Lavigne, Marina Carić, Rade Garić, and Ana Car
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-205, https://doi.org/10.5194/bg-2017-205, 2017
Preprint retracted (discussion: closed, 8 comments)
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Contrary to earlier statements winter bloom is typical of the open South Adriatic.
Its intensity depends on different water masses that enter the Adriatic, synergy of regional meteorology and mixing processes that affect these water masses. More intense blooms have occurred under certain hydroclimatic conditions: the East Mediterranean Transient (EMT), extreme winters, and reversal years that switch between anticyclonic and ciclonic circulation in the Ionian Sea.
12 Jun 2017
Evidence for microbial mediated nitrate cycling within floodplain sediments during groundwater fluctuations
Nicholas J. Bouskill, Mark E. Conrad, Markus Bill, Eoin L. Brodie, Yiwei Cheng, Chad Hobson, Matthew Forbes, Karen L. Casciotti, and Kenneth H. Williams
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-212, https://doi.org/10.5194/bg-2017-212, 2017
Preprint retracted (discussion: closed, 4 comments)
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This work couples isotope geochemical techniques with mechanistic microbial modeling in an attempt to further unravel the major factors responsible for an observed reduction in nitrate concomitant with a rising water table within floodplain sediments. We focus on 3 depths below ground surface with different periods of saturation and varying degrees of microbial nitrate loss. Using a microbial model we identify the controlling factors on denitrification responsible for these differences.
09 Jun 2017
An Orphan Problem Looking for Adoption: Responding to Ocean Acidification Utilising Existing International Institutions
Ellycia R. Harrould-Kolieb
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-230, https://doi.org/10.5194/bg-2017-230, 2017
Revised manuscript not accepted (discussion: closed, 4 comments)
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This research finds that there is a dearth of policy making pertaining to ocean acidification at the international level. Indeed, only three institutions are found to have initiated rue-making or implementation activities with the goal of either preventing worsening acidification or responding to its impacts. In light of this, this paper proposes that there are a variety of institutions that could be utilized to enhance the international response to ocean acidification.
01 Jun 2017
Estimating total alkalinity for coastal ocean acidification monitoring at regional to continental scales in Australian coastal waters
Kimberlee Baldry, Nick Hardman-Mountford, and Jim Greenwood
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-221, https://doi.org/10.5194/bg-2017-221, 2017
Revised manuscript not accepted (discussion: closed, 6 comments)
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Total alkalinity (TA) is a measure of the oceans ability to resist changes in pH. In the face of ocean acidification, having the ability to predict the distribution of TA in coastal waters may provide insight into which regions might be prone to larger pH changes. Here we test a number of commonly used models for reconstructing TA. We find that within Australian coastal waters, using salinity alone is not the best choice in this region and that models are regionally dependent.
19 May 2017
Organic exudates promote Fe(II) oxidation in Fe limited cultures of Trichodesmium erythraeum
Hanieh T. Farid, Kai G. Schulz, and Andrew L. Rose
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-129, https://doi.org/10.5194/bg-2017-129, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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This study provides new insights into: (a) how organic exudates from a marine cyanobacterium may influence iron speciation and bioavailability in the extracellular milieu; and (b) approaches for evaluating rate constants for Fe(II) oxidation in the presence of unknown organic ligands. Given that microorganisms play critical roles in biochemical cycling of trace metals in water systems, the findings are expected to improve nutrient uptake models and be of interest to broad range of readers.
16 May 2017
Living coccolithophores from the eastern equatorial Indian Ocean during the spring intermonsoon: Indicators of hydrography
Jun Sun, Haijiao Liu, Xiaodong Zhang, Cuixia Zhang, and Shuqun Song
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-112, https://doi.org/10.5194/bg-2017-112, 2017
Manuscript not accepted for further review (discussion: closed, 5 comments)
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The coccolithophore abundance in this study was relatively low, resulting from the weak winds and minimal nutrient upwelling compared to previous studies that were conducted during the monsoon seasons. During the spring intermonsoon period, no significant oceanic circulation occurred in the EEIO except for WJs. We inferred that, in the study area, different coccolithophore species had specific environmental preferences. Thus, coccolithophore species are good indicators of oceanographic changes.
12 May 2017
Accounting for multiple forcing factors and product substitution enforces the cooling effect of boreal forests
Eero Nikinmaa, Tuomo Kalliokoski, Kari Minkkinen, Jaana Bäck, Michael Boy, Yao Gao, Nina Janasik-Honkela, Janne I. Hukkinen, Maarit Kallio, Markku Kulmala, Nea Kuusinen, Annikki Mäkelä, Brent D. Matthies, Mikko Peltoniemi, Risto Sievänen, Ditte Taipale, Lauri Valsta, Anni Vanhatalo, Martin Welp, Luxi Zhou, Putian Zhou, and Frank Berninger
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-141, https://doi.org/10.5194/bg-2017-141, 2017
Manuscript not accepted for further review (discussion: closed, 3 comments)
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We estimated the impact of boreal forest management on climate, considering the effects of carbon, albedo, aerosols, and effects of industrial wood use. We made analyses both in current and warmer climate of 2050. The aerosol effect was comparable to that of carbon sequestration. Deciduous trees may have a large potential for mitigation due to their high albedo and aerosol effects. If the forests will be used more intensively and mainly for pulp and energy, the warming influence is clear.
08 May 2017
Seasonal effects of photophysiology and chlorophyll a abundance on phytoplankton group-specific primary production in the Kuroshio region as revealed by SeaStar/SeaWiFS
Takafumi Hirata and Koji Suzuki
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-164, https://doi.org/10.5194/bg-2017-164, 2017
Preprint withdrawn (discussion: closed, 4 comments)
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This work delivers a regional estimates of primary production due to diatoms, haptophytes and cyanobacteria around the Kuroshio current. Using a novel methodology, photosynthetic efficiency and abundance of marine phytoplankton are now viewed from a satellite in space. Our see that variability in primary production by diatoms is mainly regulated by their abundance rather than their efficiency, whereas the variability by cyanobacteria is more regulated by their efficiency than their abundance.
03 May 2017
Vulnerability of soil organic matter of anthropogenically disturbed organic soils
Annelie Säurich, Bärbel Tiemeyer, Axel Don, Michel Bechtold, Wulf Amelung, and Annette Freibauer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-127, https://doi.org/10.5194/bg-2017-127, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Drained organic soils are hotspots of CO2 emissions. Due to mineralisation and mixing with mineral soil, the soil organic carbon (SOC) content of large areas of former peatlands decreased drastically. We evaluated potential CO2 emissions from such soils and true peat by aerobic incubation. Surprisingly, CO2 emissions increased in magnitude and variability with stronger disturbance and lower SOC content. This indicates that mixing peat with mineral soil is not a promising mitigation option.
02 May 2017
Ocean acidification dampens warming and contamination effects on the physiological stress response of a commercially important fish
Eduardo Sampaio, Ana R. Lopes, Sofia Francisco, Jose R. Paula, Marta Pimentel, Ana L. Maulvault, Tiago Repolho, Tiago F. Grilo, Pedro Pousão-Ferreira, António Marques, and Rui Rosa
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-147, https://doi.org/10.5194/bg-2017-147, 2017
Manuscript not accepted for further review (discussion: closed, 5 comments)
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Through controlled experimental approach, we found that ocean acidification offsets physiological stress prompted by ocean warming and methylmercury contamination. These intertwined mechanisms have great implications in the future fitness of, not only Argyrosomus regius, but also of other teleost fish of commercial and ecological importance, in future ocean scenarios. Our research highlights the need of multi-stressor studies in order to accurately predict future individual and stock conditions.
21 Apr 2017
Biogeochemical diversity and hot moments of GHG emissions from shallow alkaline lakes in the Pantanal of Nhecolândia, Brazil
Laurent Barbiero, Marcos Siqueira Neto, Rosangela Rodrigues Braz, Janaina Braga de Carmo, Ary Tavares Rezende Filho, Edmar Mazzi, Fernando Antonio Fernandes, Sandra Regina Damatto, and Plinio Barbosa de Camargo
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-108, https://doi.org/10.5194/bg-2017-108, 2017
Manuscript not accepted for further review (discussion: closed, 10 comments)
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Large tropical alkaline wetlands are likely to contribute significantly to the global GHG emissions budget, but little data are available. The study shows the diversity of situations that depend on local biogeochemical processes and their stage of development during the season. Hot moments are identified and must be taken into account for calculating the regional emission budget.
10 Apr 2017
Atmospheric dry and wet nitrogen deposition in agro-pastoral catchments of the China and Mongolia Altay
Jin Ling Lv, Andreas Buerkert, Guo Jun Liu, Chao Yan Lv, Xi Ming Zhang, Kai Hui Li, and Xue Jun Liu
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-55, https://doi.org/10.5194/bg-2017-55, 2017
Manuscript not accepted for further review (discussion: closed, 5 comments)
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Very little research has been conducted to quantify atmospheric N deposition in agro-pastoral transition zones. Based on this, we chose a typical agro-pastoral transition zone in the border area of China and Mongolia and used scientific method to compare the dynamics and amounts of wet and dry N deposition in this area. This will hopefully supply the scientific evidence required to introduce more rational N application and manure management strategies for similar areas throughout central Asia.
05 Apr 2017
The dynamics and export of dissolved organic carbon from subtropical
small mountainous rivers during typhoon and non-typhoon periods
Tsung-Yu Lee, Li-Chin Lee, Jr-Chuan Huang, Shih-Hao Jien, Thomas Hein, Franz Zehetner, Shuh-Ji Kao, and Fuh-Kwo Shiah
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-105, https://doi.org/10.5194/bg-2017-105, 2017
Revised manuscript not accepted (discussion: closed, 4 comments)
03 Apr 2017
Carbon cycling on the East Siberian Arctic Shelf – a change in air-sea
CO2 flux induced by mineralization of terrestrial organic carbon
Erik Gustafsson, Christoph Humborg, Göran Björk, Christian Stranne, Leif G. Anderson, Marc C. Geibel, Carl-Magnus Mörth, Marcus Sundbom, Igor P. Semiletov, Brett F. Thornton, and Bo G. Gustafsson
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-115, https://doi.org/10.5194/bg-2017-115, 2017
Preprint withdrawn (discussion: closed, 2 comments)
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In this study we quantify key carbon cycling processes on the East Siberian Arctic Shelf. A specific aim is to determine the pathways of terrestrial organic carbon (OC) supplied by rivers and coastline erosion – and particularly to what extent degradation of terrestrial OC contributes to air-sea CO2 exchange. We estimate that the shelf is a weak CO2 sink, although this sink is considerably reduced mainly by degradation of eroded OC and to a lesser extent by degradation of riverine OC.
22 Mar 2017
Optical and molecular-level characterization of fluvial organic matter biodegradation in a highly urbanized river system
Most Shirina Begum, Hyojin Jin, Inae Jang, Jung-Min Lee, Han Bin Oh, and Ji-Hyung Park
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-93, https://doi.org/10.5194/bg-2017-93, 2017
Manuscript not accepted for further review (discussion: closed, 6 comments)
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A basin-scale field survey was combined with two laboratory incubation experiments to explore human impacts on organic matter biodegradation and CO2 emission in a highly urbanized river system in South Korea. The results suggest that river impoundment and pollution can alter the optical properties and biodegradability of both dissolved and particulate organic matter in the modified river system to such a degree that can induce a priming effect on biodegradation and CO2 emission.
21 Mar 2017
Changing mineralogical properties of shells may help minimize the impact of hypoxia-induced metabolic depression on calcification
Jonathan Y. S. Leung and Napo K. M. Cheung
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-85, https://doi.org/10.5194/bg-2017-85, 2017
Preprint retracted (discussion: closed, 12 comments)
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Hypoxia has become more prevalent and probably affects the shell growth of calcifying organisms via metabolic depression. Yet, inconsistent results have been found. We examined the potential compensatory mechanism to hypoxia and found that a calcifying polychaete can maintain shell growth and mechanical strength under hypoxia possibly by changing mineralogical properties of shells. This compensatory mechanism may enable calcifying organisms to persist under metabolically stressful environment.
13 Mar 2017
Nitrous oxide variability at sub-kilometre resolution in the Atlantic sector of the Southern Ocean
Imke Grefe, Sophie Fielding, Karen J. Heywood, and Jan Kaiser
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-73, https://doi.org/10.5194/bg-2017-73, 2017
Revised manuscript not accepted (discussion: closed, 3 comments)
13 Mar 2017
Rainfall pattern greatly affects water use by Mongolian Scots pine on a sandy soil, in a semi-arid climate
Hongzhong Dang, Lizhen Zhang, Wenbin Yang, Jinchao Feng, Hui Han, and Wei Li
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-69, https://doi.org/10.5194/bg-2017-69, 2017
Manuscript not accepted for further review (discussion: closed, 10 comments)
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The large intra- and inter-annual rainfall variances were insufficient to maintain soil moisture levels in the upper soil layers (where the majority of roots lie) at a level sufficient to avoid frequent drought. Daily stand transpiration was sensitive to drought, decreasing by 5–46 % under moderate drought, by 48–62 % under severe drought and by 65 % under extreme drought. This study will enable a much better understanding of the reasons for the observed serious degradation of Mongolian Scots pine.
10 Feb 2017
Seasonal and inter-annual variations in carbon fluxes in a tropical
river system (Tana River, Kenya)
Naomi Geeraert, Fred O. Omengo, Fredrick Tamooh, Trent R. Marwick, Alberto V. Borges, Gerard Govers, and Steven Bouillon
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-31, https://doi.org/10.5194/bg-2017-31, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We observed that the relationship between the concentrations and the water discharge in the Tana River changed in wet seasons with and without flooding. Detailed sampling in those seasons is required in order to construct several rating curves and to obtain reliable flux estimates. The sediment and carbon fluxes in function of discharge will help us to asses the flux changes that can be expected when the hydrology changes due to climate change or human impact.
06 Feb 2017
The Relationship between Tropical Cyclone Activity, Nutrient Loading, and Algal Blooms over the Great Barrier Reef
Chelsea L. Parker, Amanda H. Lynch, Stephanie A. Spera, and Keith R. Spangler
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-23, https://doi.org/10.5194/bg-2017-23, 2017
Manuscript not accepted for further review (discussion: closed, 3 comments)
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We use satellite imaging to explore the relationships between tropical cyclones and water quality that is harmful to the Great Barrier Reef. Tropical cyclones reduce water quality 8- and 16-days post-storm where cyclone size is more significant than duration or intensity. Water quality declines first through sediments re-suspended by strong winds, then through rainfall runoff and nutrient loading. Leaching and erosion from coastal land must be reduced, especially with future climate change.
30 Jan 2017
Changes in the Si / P weathering ratio and their effect on the selection of coccolithophores and diatoms
Virginia García-Bernal, Óscar Paz, and Pedro Cermeño
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-4, https://doi.org/10.5194/bg-2017-4, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Marine diatoms are responsible for roughly 40 % of modern ocean primary production and contribute disproportionately to the drawdown of atmospheric carbon dioxide through the export of organic carbon into the deep sea and sediments. Over the past 40 Myr their rise to ecological prominence and consequential decline of coccolithophores is linked to the silicon to phosphorus weathering ratio, which controls the oceanic nutrient inventories and hence the competitive ability of diatoms.
26 Jan 2017
Holistic monitoring of increased pollutant loading and its impact on the environmental condition of a coastal lagoon with Ammonia as a proxy for impact on biodiversity
Areen Sen and Punyasloke Bhadury
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-13, https://doi.org/10.5194/bg-2017-13, 2017
Revised manuscript not accepted (discussion: closed, 4 comments)
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Eutrophication poses a serious threat to the ecological functioning of lagoons in the era of Anthropocene. In this study, using water chemistry and biological (foraminifera) proxies, eutrophication was tracked in Asia's largest coastal lagoon, Chilika for 12 months. The investigation revealed that concentration of dissolved nitrate was extremely high along with sedimentary organic carbon deposit and benthic foraminifera abundance, both of which are characteristics of coastal eutrophication.
18 Jan 2017
R-Package BIOdry: DendroClimatic Modeling from Multilevel
Ecological Data Series
Wilson Lara, Stella Bogino, and Felipe Bravo
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-550, https://doi.org/10.5194/bg-2016-550, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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BIOdry package was developed for dendroclimatic modeling. The package integrates one-level modeling, multilevel analysis, and multivariate comparison of Multilevel Ecological Data Series. We tested the package by studying dendroclimatic relationships of pine forests (P. pinaster Ait.) of north and east-central Spain. Dendroclimatic inferences were affected by within-sample variabilities. BIOdry package proved to be a valuable tool to study complex dendroclimatic time-space relationships.
12 Jan 2017
Improvement of Soil Respiration Parameterization in a Dynamic Global Vegetation Model and Its Impact on the Simulation of Terrestrial Carbon Fluxes
Dongmin Kim, Myong-In Lee, and Eunkyo Seo
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-549, https://doi.org/10.5194/bg-2016-549, 2017
Preprint retracted (discussion: closed, 8 comments)
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This study investigates the impacts of temperature sensitivity of soil respiration (Q10) on the terrestrial carbon cycle using CLM4 off-line simulation. This study develops a new parameterization for determining Q10 by considering the soil respiration dependence on soil temperature and moisture obtained by multiple regression. The results show that distribution of heterogenous Q10 induces to overcome the soil respiration and GPP distribution comparing with original Q10 parameterization.
09 Jan 2017
High growth potential and activity of 0.2 µm filterable bacteria habitually present in coastal seawater
Yumiko Obayashi and Satoru Suzuki
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-560, https://doi.org/10.5194/bg-2016-560, 2017
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We report habitual presence of 0.2 µm filterable forms of typical marine bacteria having high growth potential in temperate coastal seawater. The results imply that starvation forms of marine bacteria should be ubiquitous not only in very oligotrophic open oceans but also in temperate coastal environments, and that these bacteria are always ready for growing in changeable aquatic ecosystems. They are expected to have high activity for organic matter processing in biogeochemical carbon cycle.
02 Jan 2017
No significant changes in topsoil carbon in the grasslands of northern China between the 1980s and 2000s
Shangshi Liu, Yuanhe Yang, Haihua Shen, Huifeng Hu, Xia Zhao, He Li, Taoyu Liu, and Jingyun Fang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-473, https://doi.org/10.5194/bg-2016-473, 2017
Preprint retracted (discussion: closed, 4 comments)
20 Dec 2016
Uncertainties in global crop model frameworks: effects of cultivar distribution, crop management and soil handling on crop yield estimates
Christian Folberth, Joshua Elliott, Christoph Müller, Juraj Balkovic, James Chryssanthacopoulos, Roberto C. Izaurralde, Curtis D. Jones, Nikolay Khabarov, Wenfeng Liu, Ashwan Reddy, Erwin Schmid, Rastislav Skalský, Hong Yang, Almut Arneth, Philippe Ciais, Delphine Deryng, Peter J. Lawrence, Stefan Olin, Thomas A. M. Pugh, Alex C. Ruane, and Xuhui Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-527, https://doi.org/10.5194/bg-2016-527, 2016
Manuscript not accepted for further review (discussion: closed, 3 comments)
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Global crop models differ in numerous aspects such as algorithms, parameterization, input data, and management assumptions. This study compares five global crop model frameworks, all based on the same field-scale model, to identify differences induced by the latter three. Results indicate that foremost nutrient supply, soil handling, and crop management induce substantial differences in crop yield estimates whereas crop cultivars primarily result in scaling of yield levels.
19 Dec 2016
Glycerol dialkyl glycerol tetraether variations in the northern Chukchi Sea, Arctic Ocean, during the Holocene
Yu-Hyeon Park, Masanobu Yamamoto, Leonid Polyak, and Seung-Il Nam
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-529, https://doi.org/10.5194/bg-2016-529, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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The analysis of microbial lipid (GDGTs) in three sediment cores from the northern Chukchi Sea margin provides insights into GDGTs production, sources and SST in this region of the Arctic during the Holocene. Different patterns in GDGTs distribution between cores may indicate spatial differences in the pathways of Pacific waters and sea-ice extent. TEX86 and TEX86L indices potentially useful for SST reconstruction show millennial-scale variability, but the controls are not well understood.
16 Dec 2016
Intercomparison of Terrestrial Carbon Fluxes and Carbon Use Efficiency Simulated by CMIP5 Earth System Models
Dongmin Kim, Myong-In Lee, Su-Jong Jeong, Jungho Im, Dong Hyun Cha, and Sanggyun Lee
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-536, https://doi.org/10.5194/bg-2016-536, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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This study compares historical simulations of the terrestrial carbon cycle produced by 10 ESMs that participated in the CMIP5. The models show noticeable deficiencies compared to the MODIS data and large differences among the simulations, although the MME mean provides a realistic global mean value and spatial distributions. MME is reflected by the systematic biases of simulated biogeochemical processes which depends on temperature conditions strongly in every plant functional types.
12 Dec 2016
Phytoplankton communities determine the spatio-temporal heterogeneity of alkaline phosphatase activity: evidence from a tributary of the Three Gorges Reservoir
Yijun Yuan, Yonghong Bi, and Zhengyu Hu
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-455, https://doi.org/10.5194/bg-2016-455, 2016
Revised manuscript not accepted (discussion: closed, 7 comments)
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Alkaline phosphatase plays an important role in phosphorus cycling. In order to screen the alkaline phosphatase activity in the tributaries of the Three Gorges reservoir, annual investigation was conducted in the Xiaojiang River. It was proved that APA in the tributaries of TGR contributed mainly by phytoplankton, and the spatio-temporal heterogeneity of APA was determined by phytoplankton communities. Besides, WL, WT and SRP regulated the spatio-temporal heterogeneity of APA.
07 Dec 2016
Carbon budget assessment of an irrigated wheat and maize rotation cropland with high groundwater table in the North China Plain
Quan Zhang, Hui-Min Lei, Da-Wen Yang, Lihua Xiong, and Beijing Fang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-484, https://doi.org/10.5194/bg-2016-484, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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With the increasing concern about global warming, investigating carbon cycle becomes imperative to predict future climate trend. As cropland has great potentials in mitigating carbon emissions, therefore we designed a comprehensive carbon budget assessment in a typical cropland in North China Plain, the results indicate the high groundwater table contributes to carbon sink of this cropland. The conclusion confirms that field management has profound effect on cropland carbon cycle.
29 Nov 2016
Influence of climate variability, fire and phosphorus limitation on the vegetation structure and dynamics in the Amazon-Cerrado border
Emily Ane Dionizio da Silva, Marcos Heil Costa, Andrea Almeida Castanho, Gabrielle Ferreira Pires, Beatriz Schwantes Marimon, Ben Hur Marimon-Junior, Eddie Lenza, and Fernando Martins Pimenta
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-510, https://doi.org/10.5194/bg-2016-510, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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This study uses a dynamic vegetation model to evaluate the role of interannual climate variability, fire occurrence and phosphorus limitation on the vegetation dynamics and structure in the Amazon-Cerrado transition. We show that the inclusion of these factors gradually improve the simulation of vegetation types and, although the model typically simulates more than 80% of the variability of biomass in the transition zone, model improvements are still needed.
22 Nov 2016
Shell dissolution observed in Limacina helicina antarctica from the
Ross Sea, Antarctica: paired shell characteristics and in situ seawater
chemistry
Kevin M. Johnson, Umihiko Hoshijima, Cailan S. Sugano, Alice T. Nguyen, and Gretchen E. Hofmann
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-467, https://doi.org/10.5194/bg-2016-467, 2016
Revised manuscript not accepted (discussion: closed, 5 comments)
22 Nov 2016
Passive adsorption of neighbouring plant volatiles linked to associational susceptibility in a subarctic ecosystem
Adedayo Mofikoya, Kazumi Miura, Toini Holopainen, and Jarmo K. Holopainen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-464, https://doi.org/10.5194/bg-2016-464, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We show in the paper, volatile chemical based plant interaction in a subarctic ecosystem. We provide evidence of passive adsorption of neighbouring plant volatiles and its potential effect on focal plant fitness. Our results show that neighbouring plants might play an important role in the fitness and chemical composition of a plant. This study was done in a nature reserve forest site in the subarctic to minimize the effects of ozone and other environmental pollutants that may degrade volatiles.
15 Nov 2016
Impact of annual and seasonal precipitation and air temperature on gross primary production in Mediterranean ecosystems in Europe
Svenja Bartsch, Bertrand Guenet, Christophe Boissard, Juliette Lathière, Jean-Yves Peterschmitt, Annemiek Stegehuis, Ilja-M. Reiter, Thierry Gauquelin, Virginie Baldy, and Catherine Fernandez
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-491, https://doi.org/10.5194/bg-2016-491, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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Mediterranean ecosystems are significant carbon sinks but the carbon dynamic in such ecosystem is still not fully understood. An improved understanding of the drivers of the carbon fixation by plants is needed to better predict how such ecosystems will respond to climate change. We showed that annual precipitation was not a significant driver of annual carbon fixation by plants.
03 Nov 2016
Quantification of basal ice microbial cell delivery to the glacier margin
Mario Toubes-Rodrigo, Simon J. Cook, David Elliott, and Robin Sen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-471, https://doi.org/10.5194/bg-2016-471, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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For the first time, we have quantified the amount of cells exported from sediment-rich glacier basal ice to the glacier margin. Approximately 1017 cells per year are being released to the forefront of Svínafellsökull (SE Iceland), and in laboratory conditions between 101 and 106 cells per gram of sediment were able to proliferate. These cells may trigger the process of soil formation that will end up with the establishment of vegetation in the bare sediment the glacier leave after its retreat
24 Oct 2016
Acidification counteracts negative effects of warming on diatom silicification
Alexandra Coello-Camba and Susana Agustí
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-424, https://doi.org/10.5194/bg-2016-424, 2016
Revised manuscript not accepted (discussion: closed, 6 comments)
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We demonstrated that the effects of increased temperature and pCO2
on the silicification process in diatoms are interactive, showing a temperature dependent capacity of increased pCO2 to buffer the negative effects of warming. Therefore, as long as the increase in temperature does not surpass the buffering capacity of pCO2, the increase of this latter stressor will help diatoms to retain their sinking properties, preserving their role in the biogeochemical
cycles of silica and carbon.
13 Oct 2016
Functional classification of bioturbating macrofauna in marine
sediments using time-resolved imaging of particle displacement
and multivariate analysis
Stina Lindqvist, Johan Engelbrektsson, Susanne P. Eriksson, and Stefan Hulth
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-411, https://doi.org/10.5194/bg-2016-411, 2016
Preprint withdrawn (discussion: closed, 4 comments)
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This contribution describes a general procedure for functional classification of benthic macrofauna based on a suite of variables for particle reworking. Despite the challenge to generalize species functionality, time-resolved high-resolution imaging of particle displacement combined with multivariate analysis, provides a general tool for functional classification of macrofauna. Species were grouped in accordance to quantity and time, as well as vertical distance of particle transport.
04 Oct 2016
Climate-driven change in a Baltic Sea summer microplanktonic community – desalination play a more important role than ocean acidification
Angela Wulff, Maria Karlberg, Malin Olofsson, Anders Torstensson, Lasse Riemann, Franciska Steinhoff, Malin Mohlin, Nina Ekstrand, and Melissa Chierici
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-383, https://doi.org/10.5194/bg-2016-383, 2016
Manuscript not accepted for further review (discussion: closed, 3 comments)
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The Baltic Sea could expect increased precipitation (lower salinity) and increased concentration of atmospheric CO2 over the next 100 years. In a 12-day outdoor experiment, we tested the combined effects of lower salinity and increased CO2 concentrations on a natural summer microplanktonic community. Lower salinity seemed more important than increased pCO2. Thus, we do not expect any dramatic effects of increased pCO2 in combination with decreased salinity on the Baltic microplanktonic food web.
29 Sep 2016
Combined effects of elevated pCO2 and temperature on biomass and carbon fixation of phytoplankton assemblages in the northern South China Sea
Guang Gao, Peng Jin, Nana Liu, Futian Li, Shanying Tong, David A. Hutchins, and Kunshan Gao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-403, https://doi.org/10.5194/bg-2016-403, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Our shipboard experiments showed high temperature and CO2 (HTHC) did not affect phytoplankton biomass at nearshore station but decreased it at offshore station. HT did not change dark respiration at nearshore station but enhanced it at offshore station. Our findings indicate that responses of coastal and offshore phytoplankton assemblages to ocean warming and acidification may be contrasting, with the pelagic phytoplankton communities being more sensitive to these two global change factors.
16 Sep 2016
Relating historical vegetation cover to aridity index patterns in the
greater desert region of northern China: Implications to planned and
existing restoration projects
Yanying Shao, Yuqing Zhang, Xiuqin Wu, Charles P.-A. Bourque, Jutao Zhang, Shugao Qin, and Bin Wu
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-376, https://doi.org/10.5194/bg-2016-376, 2016
Preprint retracted (discussion: closed, 10 comments)
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Methods of aridity index, Mann–Kendall test and Convergent cross mapping were combined to quantify the spatiotemporal variations in precipitation, air temperature, aridity, and vegetation, and to assess plant growth with respect to climatic changes in dryland. Our results show a practically relevant in ecological restoration and implicate that future planning of new restoration projects should ideally take into account drying/wetting trends currently being observed in northern China.
06 Sep 2016
Responses of the diatom Asterionellopsis glacialis to increasing sea water CO2 concentrations and the effect of turbulence
Francesca Gallo, Kai G. Schulz, Eduardo B. Azevedo, João Madruga, and Joana Barcelos e Ramos
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-352, https://doi.org/10.5194/bg-2016-352, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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Global change driven by humans activities may affect phytoplankton, which are important primary producers. Assessing the combined effect of turbulence and ocean acidification on the species Asterionellopsis glacialis, we found that turbulence magnifies the acidification stress, with negative effects on their growth. In the natural environment, this might have consequences to phytoplankton community composition and production with feedbacks to climate.
31 Aug 2016
Hydrothermal activity lowers trophic diversity in Antarctic sedimented hydrothermal vents
James B. Bell, William D. K. Reid, David A. Pearce, Adrian G. Glover, Christopher J. Sweeting, Jason Newton, and Clare Woulds
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-318, https://doi.org/10.5194/bg-2016-318, 2016
Revised manuscript not accepted (discussion: closed, 5 comments)
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Areas of the deep-seafloor where hydrothermal fluid flows through sediment are amongst the least studied environments on the planet. We studied the faunal and microbial food webs at one such system in the Southern Ocean and found evidence of a wide range of organic matter fixation pathways, both at vent sites and non-vent sites. Although faunal uptake of in situ food production was low, it was much wider spread than previously realised, raising important questions about seafloor food webs.
24 Aug 2016
Rooting and plant density strongly determine greenhouse gas budget
of water hyacinth (Eichhornia crassipes) mats
Ernandes Sobreira Oliveira Junior, Yingying Tang, Sanne J. P. van den Berg, Leon P. M. Lamers, and Sarian Kosten
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-297, https://doi.org/10.5194/bg-2016-297, 2016
Manuscript not accepted for further review (discussion: closed, 12 comments)
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The differential effects of the aquatic plants on greenhouse gas fluxes may be due to plant density and whether or not the plant roots can access the sediment. We therefore looked into the effect of these two variables on water hyacinth greenhouse gas balance using a laboratory experiment. We found that greenhouse gas dynamics were strongly influenced by plant density and rooting. Our findings pinpoint management options that can optimize carbon sequestration and minimize CH4 emissions.
21 Jul 2016
Anaerobic methane oxidation in an East African great lake (Lake Kivu)
Fleur A. E. Roland, François Darchambeau, Cédric Morana, Sean A. Crowe, Bo Thamdrup, and Alberto V. Borges
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-300, https://doi.org/10.5194/bg-2016-300, 2016
Manuscript not accepted for further review (discussion: closed, 6 comments)
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We studied methane consumption in a tropical Great Lake (Lake Kivu, East Africa). Lake Kivu has huge methane concentrations in its deep anoxic waters, but is a very poor emitter of methane to the atmosphere, which suppose a strong methane consumption in the water column. During this study, we put in evidence high aerobic and anaerobic consumption rates, whose relative importance varied with the season (higher aerobic rates in dry season, when the oxic compartment is wider).
30 Jun 2016
Seasonal variability of dissolved organic matter in the Columbia
River: In situ sensors elucidate biogeochemical and molecular
analyses
Urban Johannes Wünsch, Boris Peter Koch, Matthias Witt, and Joseph Andrew Needoba
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-263, https://doi.org/10.5194/bg-2016-263, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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We used a combination of continuously measuring water chemistry sensors and periodic sampling efforts to assess the seasonal variability of dissolved organic matter (DOM) in the Columbia River in spring and summer 2013.
We found that our sensors can provide detailed data on carbon export that far exceed usual monitoring efforts. The detailed data help to understand the impact of short-lived events, such as rainstorms, on the overall terrestrial carbon flux in the Columbia River.
30 Jun 2016
Continuous measurements of nitrous oxide isotopomers during
incubation experiments
Malte Winther, David Balslev-Harder, Søren Christensen, Anders Priemé, Bo Elberling, Eric Crosson, and Thomas Blunier
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-258, https://doi.org/10.5194/bg-2016-258, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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Nitrous oxide (N2O) is an important and strong greenhouse gas in the atmosphere and part of climate. N2O is produced by microbes in terrestrial and aquatic ecosystems. The properties of each specific molecule can be used to determine the source. We implemented continuous measurements of N2O during incubation of denitrifying bacteria and believe that similar experiments will lead to a better understanding of N2O turnover and on the biotic mechanisms behind greenhouse gas exchange of the Globe.
20 Jun 2016
Feasibility for detection of ecosystem response to disturbance by atmospheric carbon dioxide
Bjorn-Gustaf J. Brooks, Ankur R. Desai, Britton B. Stephens, Anna M. Michalak, and Jakob Zscheischler
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-223, https://doi.org/10.5194/bg-2016-223, 2016
Manuscript not accepted for further review (discussion: closed, 3 comments)
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CO2 is the primary greenhouse gas, and its abundance in the atmosphere tends to increase during disturbances like drought. This paper demonstrates how CO2 measurements are combined with models to determine not only how strongly different locations influence CO2 measurement stations, but also the capacity of those measurement stations to detect drought effects. Understanding detection sensitivity will help assess what kinds of changes and turnings points can be monitored using atmospheric CO2.
16 Jun 2016
Agricultural uses reshape soil C, N, and P stoichiometry in subtropical ecosystems
H. Y. Liu, J. G. Zhou, J. Shen, Y. Y. Li, Y. Li, T. D. Ge, G. Guggenberger, and J. Wu
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-211, https://doi.org/10.5194/bg-2016-211, 2016
Revised manuscript not accepted (discussion: closed, 8 comments)
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We studied the spatial distribution of soil C, N, and P (carbon, nitrogen, and phosphorus) stoichiometry of the ecosystems in a subtropical catchment, and found that the stoichiometry was shaped in relatively narrow ranges in agricultural uses, and its spatial variations with topography were remarkably reduced. Thus, our findings demonstrate that intensive agriculture can change the spatial distributions of soil C, N, and P and the associated stoichiometry in a hilly subtropical catchment.
14 Jun 2016
Using coupled hydrodynamic biogeochemical models to predict the effects of tidal turbine arrays on phytoplankton dynamics
Pia Schuchert, Louise Kregting, Daniel Pritchard, Graham Savidge, and Björn Elsäßer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-232, https://doi.org/10.5194/bg-2016-232, 2016
Manuscript not accepted for further review (discussion: closed, 6 comments)
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There are environmental concerns associated with the installation of tidal energy devices (TEDs) along coastal environments. One concern relates to the likely change in the hydrodynamics where changes in hydrodynamics may potentially modify key predictors of phytoplankton derived primary production. Using a coupled 2-dimensional biogeochemical and hydrodynamic model, results showed that light had a larger effect on phytoplankton dynamics than an array of TEDs.
06 Jun 2016
Large uncertainty in ecosystem carbon dynamics resulting from ambiguous numerical coupling of carbon and nitrogen biogeochemistry: A demonstration with the ACME land model
Jinyun Tang and William J. Riley
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-233, https://doi.org/10.5194/bg-2016-233, 2016
Preprint retracted (discussion: closed, 4 comments)
01 Jun 2016
Under a new light: validation of eddy covariance flux with light response functions of assimilation and estimates of heterotrophic soil respiration
Georgia R. Koerber, Wayne S. Meyer, Qiaoqi SUN, Peter Cale, and Cacilia M. Ewenz
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-182, https://doi.org/10.5194/bg-2016-182, 2016
Revised manuscript not accepted (discussion: closed, 6 comments)
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A severe bushfire in January 2014 at the Calperum flux tower, operational since August 2010, provided variation in ecosystem respiration and leaf area index to estimate the heterotrophic soil respiration from the y-intercept and was 44 % of net ecosystem exchange of carbon dioxide in the year after the bushfire. Light response functions with a calculated assimilation from equalizing the soil temperature and water content in the night and day allowed incorporation of light suppressed autotrophic respiration.
30 May 2016
Microtopography matters for CH4 formation in a peat soil: a combined inhibitor and 13C study
Johannes Krohn, Ivana Lozanovska, Yakov Kuzyakov, and Maxim Dorodnikov
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-162, https://doi.org/10.5194/bg-2016-162, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
19 May 2016
Monodeuterated methane: an isotopic probe to measure biological methane metabolism rates and track catabolic exchange reactions
Jeffrey J. Marlow, Joshua A. Steele, Wiebke Ziebis, Silvan Scheller, David Case, and Victoria J. Orphan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-202, https://doi.org/10.5194/bg-2016-202, 2016
Revised manuscript not accepted (discussion: closed, 7 comments)
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Methane is a powerful greenhouse gas that plays a major role in the planet's biogeochemical cycles and climate system. Measuring rates of microbial methane consumption is an important capability that allows scientists to better quantify fluxes between reservoirs and assess potential impacts. This study presents a new method for measuring these rates using monodeuterated methane; the approach is logistically streamlined and offers a distinct isotopic dimension for methane metabolism analysis.
17 May 2016
Seasonal and vertical variations in soil CO2 production in a beech forest: an isotopic flux-gradient approach
Emilie Delogu, Bernard Longdoz, Caroline Plain, and Daniel Epron
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-194, https://doi.org/10.5194/bg-2016-194, 2016
Preprint withdrawn (discussion: closed, 3 comments)
17 May 2016
Response of soil respiration to nitrogen addition along a degradation gradient in a temperate steppe of northern China
Jinbin Chen, Xiaotian Xu, Hongyan Liu, and Wei Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-119, https://doi.org/10.5194/bg-2016-119, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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Our research main results were that the response of soli respiration differed with the severity of degradation after nitrogen addition. And the difference of magnitude of soil respiration were decreased along with nitrogen fertilizer. In additon, we found that the dominat factor controlling soil respiration changed across different degradation grasslands. Those results showed that degradation affected soil respiration and nitrogen addition might alter degraded grasslands soil carbon emissions.
10 May 2016
Sediment characteristics as an important factor for revealing carbon storage in Zostera marina meadows: a comparison of four European areas
Martin Dahl, Diana Deyanova, Silvia Gütschow, Maria E. Asplund, Liberatus D. Lyimo, Ventzislav Karamfilov, Rui Santos, Mats Björk, and Martin Gullström
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-137, https://doi.org/10.5194/bg-2016-137, 2016
Manuscript not accepted for further review (discussion: closed, 3 comments)
03 May 2016
Distinctly different bacterial communities in surface and oxygen minimum layers in the Arabian Sea
Mandar Bandekar, Nagappa Ramaiah, Anand Jain, and Ram Murti Meena
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-147, https://doi.org/10.5194/bg-2016-147, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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Oxygen minimum zones occur mostly in nutrient rich upwelling regions. They are sprawling intensifying due to anthropogenic impacts. In denitrification depths of 200–1000 m in Arabian Sea (AS) DO is < 20 M making it the largest anoxic region. We aimed to delineate phylogenetic diversity of bacterial community and find it to be diverse yet distinctively different communities predominate surface and OMZ layers. Prokaryote types adapted to low DO likely play vital roles in C, N & S cycling in AS OMZ.
29 Apr 2016
Improving vegetation phenological parameterization of a land surface model
Baozhang Chen and Mingliang Che
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-165, https://doi.org/10.5194/bg-2016-165, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Most studies of phenological estimates focusing on the phenology (RSP) retrieval algorithms based on remote sensing data, however, published studies that comparing process-based phenology models are limited. In this study, we evaluated two common used phenological algorithms in a land surface model (LSM) with selected eddy covariance flux tower measurements. We concluded the growing season index algorithm has good performance and can reasonably capture vegetation phenological changes in LSMs.
25 Apr 2016
Evaluation of modeled global carbon dynamics: analysis based on global carbon flux and above-ground biomass data
Bao-Lin Xue, Qinghua Guo, Tianyu Hu, Yongcai Wang, Shengli Tao, Yanjun Sun, Jin Liu, and Xiaoqian Zhao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-142, https://doi.org/10.5194/bg-2016-142, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Validation of dynamic global vegetation models are usually hampered by the poor availability of global biomass data over global scales. We evaluated model simulated gross primary production (GPP) and potential above-ground biomass (AGB) by literature-collected values. Independent validation showed that model could reproduce spatial patterns of GPP and evapotranspiration; but not for AGB. Results also showed that different meteorological inputs can also introduce substantial difference in AGB.
11 Apr 2016
Integrating aquatic and terrestrial biogeochemical model to predict effects of reservoir creation on CO2 emissions
Weifeng Wang, Nigel T. Roulet, Youngil Kim, Ian B. Strachan, Paul del Giorgio, Yves T. Prairie, and Alain Tremblay
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-100, https://doi.org/10.5194/bg-2016-100, 2016
Revised manuscript not accepted (discussion: closed, 7 comments)
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Water reservoirs emit greenhouse gases. We developed a 1-dimensional biogeochemical model to predict CO2 emissions from boreal reservoirs. We found that the CO2 emissions are initially high, steeply decline in the first three years, and then steadily decrease with increasing reservoir age, suggesting that flooded terrestrial organic matter has long-term (> 100 years) effects on CO2 emissions. Our model could be used to evaluate the role of boreal reservoirs as sources of greenhouse gas emissions.
06 Apr 2016
Ecosystem feedbacks from subarctic wetlands: vegetative and atmospheric CO2 controls on greenhouse gas emissions
Matthew J. Bridgman, Barry H. Lomax, and Sofie Sjogersten
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-105, https://doi.org/10.5194/bg-2016-105, 2016
Preprint withdrawn (discussion: closed, 4 comments)
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This study investigate if elevated atmospheric carbon dioxide enhance methane emissions from wetlands and if responses vary among different sedge species. Half of the species increased in biomass under elevated carbon dioxide compared to controls, resulting in greater soil methane emissions. In contrast, biomass and methane emissions of the other species was reduced under elevated carbon dioxide. This shows that species specific responses to elevated carbon dioxide impacted methane emissions.
04 Apr 2016
Spatial Patterns of Phosphorus Fractions in Soils of Temperate Forest Ecosystems with Silicate Parent Material
Florian Werner, Tilman René de la Haye, Sandra Spielvogel, and Jörg Prietzel
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-98, https://doi.org/10.5194/bg-2016-98, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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We assessed spatial patterns of phosporus (P) in soils of a geosequence and major P binding partners to describe spatial and pedogenetic changes of P distribution and to identify mechanisms for these changes. We found, that the distribution of total P was generally best matched by the distribution pattern of organic P. Soil organic matter-sesquioxide-complexes, as well as Al and Fe oxyhydroxides were identified as main binding partners of organic P at all stages of pedogenesis.
04 Apr 2016
Permafrost thaw and release of inorganic nitrogen from polygonal tundra soils in eastern Siberia
Fabian Beermann, Moritz Langer, Sebastian Wetterich, Jens Strauss, Julia Boike, Claudia Fiencke, Lutz Schirrmeister, Eva-Maria Pfeiffer, and Lars Kutzbach
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-117, https://doi.org/10.5194/bg-2016-117, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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This paper aims to quantify pools of inorganic nitrogen in permafrost soils of arctic Siberia and to estimate annual release rates of this nitrogen due to permafrost thaw. We report for the first time stores of inorganic nitrogen in Siberian permafrost soils. These nitrogen stores are important as permafrost thaw can mobilize substantial amounts of nitrogen, potentially changing the nutrient balance of these soils and representing a significant non-carbon permafrost climate feedback.
04 Apr 2016
Wildfire effects on ecosystem nitrogen cycling in a Chinese boreal larch forest, revealed by 15N natural abundance
Weili Liu, Lin Qi, Yunting Fang, and Jian Yang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-91, https://doi.org/10.5194/bg-2016-91, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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Wildfire is a major disturbance in boreal forest ecosystem and strongly affects ecosystem N cycling. We find that even 5 years after a wildfire, isotopic signatures of soil and plant N pools are still different from those in unburned areas in a Chinese boreal forest. Our results show persistent legacy effects in the form of increased N losses following wildfires. The fire-induced increases in NH3 volatilization may greatly contribute to the increased δ15N values in plant and soil.
04 Apr 2016
Icelandic grasslands as long-term C sinks under elevated N inputs
Niki I. W. Leblans, Bjarni D. Sigurdsson, Rien Aerts, Sara Vicca, Borgthór Magnússon, and Ivan A. Janssens
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-111, https://doi.org/10.5194/bg-2016-111, 2016
Revised manuscript not accepted (discussion: closed, 5 comments)
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Increasing nitrogen (N) deposition has enhanced productivity in many ecosystems and thereby the terrestrial sink for anthropogenic CO2 emissions. However, little is known about how long this N-induced carbon (C) sink can continue. We studied the effect of elevated N inputs on short- (decadal) and long-term (millennial) C storage in Icelandic grasslands and found that chronically elevated N inputs led to a strengthening of this sink for at least 1600 years, in absence of large-scale disturbances.
23 Mar 2016
Tracking the direct impact of rainfall on groundwater at Mt. Fuji by multiple analyses including microbial DNA
Ayumi Sugiyama, Suguru Masuda, Kazuyo Nagaosa, Maki Tsujimura, and Kenji Kato
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-78, https://doi.org/10.5194/bg-2016-78, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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Direct impact of rainfall on groundwater at Mt. Fuji, the largest volcanic mountain in Japan, was elucidated by multiple analyses including microbial DNA. Bacterial abundance and DNA not only supported the findings on the movement of groundwater obtained from chemical analyses, but elucidated chemically unseen flow. An evidence of piston flow in deep groundwater was first shown through changes in Archaeal density and diversity. Microbial analysis extends our understanding of groundwater.
21 Mar 2016
Mechanisms of methane transport through Populus trichocarpa
Ellynne Kutschera, Aslam Khalil, Andrew Rice, and Todd Rosenstiel
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-60, https://doi.org/10.5194/bg-2016-60, 2016
Revised manuscript has not been submitted (discussion: closed, 6 comments)
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The paper presents new research on how this important greenhouse gas is transported from the soil to the atmosphere through trees. A relationship between methane flux and temperature is found. Isotopic fractionation of methane is measured: warmer temperatures result in higher flux and smaller fractionation. Multiple transport processes are likely at work, where different mechanisms dominate at low and high temperatures. This has implications for methane flux from trees in a warmer world.
17 Mar 2016
Lagrangian characterization of nitrate supply and episodes of extreme phytoplankton blooms in the Great Australian Bight
Paulina Cetina-Heredia, Erik van Sebille, Richard Matear, and Moninya Roughan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-53, https://doi.org/10.5194/bg-2016-53, 2016
Revised manuscript not accepted (discussion: closed, 3 comments)
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Characterizing phytoplankton growth influences fisheries and climate. We use a lagrangian approach to identify phytoplankton blooms in the Great Australian Bight (GAB), and associate them with nitrate sources. We find that 88 % of the nitrate utilized in blooms is originated between the GAB and the SubAntarctic Front. Large nitrate concentrations are supplied at depth but do not reach the euphotic zone often. As a result, 55 % of blooms utilize nitrate supplied in the top 100 m.
15 Mar 2016
Dryland vegetation functional response to altered rainfall amounts and variability derived from satellite time series data
Gregor Ratzmann, Ute Gangkofner, Britta Tietjen, and Rasmus Fensholt
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-48, https://doi.org/10.5194/bg-2016-48, 2016
Revised manuscript not accepted (discussion: closed, 6 comments)
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Anticipating impacts of changes in rainfall regimes on dryland ecosystems requires the understanding of the functional response to rainfall of those water limited environments. Here we show for two arid/semi-arid African regions based on satellite data that higher rainfall variability leads to a more dynamic vegetation response to rainfall. This applies irrespective of vegetation type. It moreover indicates that regions experiencing a higher rainfall variability may be more resilient to drought.
25 Feb 2016
Reviews and syntheses: Methane biogeochemistry in Sundarbans mangrove ecosystem, NE coast of India; a box modeling approach
Manab Kumar Dutta and Sandip Kumar Mukhopadhyay
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-58, https://doi.org/10.5194/bg-2016-58, 2016
Revised manuscript not accepted (discussion: closed, 3 comments)
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This study made an detailed understanding on production, consumption and fluxes of methane from different sub-ecosystems of Sundarbans mangrove forest. The mangrove environment was found to be rich in organic carbon content as well as methane concentration. A most of the produced methane transported to the atmosphere where 85 % of total supply undergoes photo-oxidation. Like sediment estuaries are also methane supersatuarated and about 70 % of methane within estuary undergoes microbial oxidation.
This article is included in the Encyclopedia of Geosciences
22 Feb 2016
Rates and pathways of CH4 oxidation in ferruginous Lake Matano, Indonesia
A. Sturm, D. A. Fowle, C. Jones, K. Leslie, S. Nomosatryo, C. Henny, D. E. Canfield, and S. A. Crowe
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-533, https://doi.org/10.5194/bg-2015-533, 2016
Revised manuscript has not been submitted (discussion: closed, 3 comments)
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Methane is a very potent greenhouse gas whose release into the atmosphere has become a growing concern for global climate change. In nearly every aquatic environment there are microbes which either produce methane as a by-product of their metabolism or consume it for energy. Our work examined the rates of methane consumption through experimentation in a deep tropical lake to help quantify global emissions of this greenhouse gas from these environments and provide context for paleo-carbon cycles.
19 Feb 2016
The pelagic microbial food web structure in Sanggou Bay, Yellow Sea: Spatial variation over four successive seasons
Xue Chen, Wuchang Zhang, Michel Denis, Yuan Zhao, Lingfeng Huang, Zengjie Jiang, and Tian Xiao
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-665, https://doi.org/10.5194/bg-2015-665, 2016
Manuscript not accepted for further review (discussion: closed, 6 comments)
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We documented the distributions of environmental variables and abundances and biomasses of MFW components. Cluster analysis leaded to distinguish Inner Bay and Outer Bay clusters at each season. We confirmed the existence of a strong relationship among all MFW components and established upper and lower empirical linear boundaries for all the MFW component relationships with HP. Our study showed that the normalisation method could be used in marine area to study the microbial food web structure.
12 Feb 2016
The silica-carbon biogeochemical cycle in the Bohai Sea and its responses to the changing terrestrial loadings
Jun Liu, Lex Bouwman, Jiaye Zang, Chenying Zhao, Xiaochen Liu, and Xiangbin Ran
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-42, https://doi.org/10.5194/bg-2016-42, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
11 Feb 2016
The asynchronous response of carbon gain and water loss generate spatio-temporal pattern of WUE along elevation gradient in southwest China
Xiangyang Sun, Mei Huang, and Genxu Wang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-652, https://doi.org/10.5194/bg-2015-652, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
11 Feb 2016
Which are important soil parameters influencing the spatial heterogeneity of 14C in soil organic matter?
Stephan John, Gerrit Angst, Kristina Kirfel, Sebastian Preusser, Carsten W. Mueller, Christoph Leuschner, Ellen Kandeler, and Janet Rethemeyer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-11, https://doi.org/10.5194/bg-2016-11, 2016
Manuscript not accepted for further review (discussion: closed, 4 comments)
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In this manuscript we investigate chemical, biological and physical soil parameters and their influence on 14C contents and distribution in three nearby soil profiles under beech forest. We found a large heterogeneity in 14C contents in the profiles, mainly caused by the abundance of roots. Our results indicate that 14C analysis of individual soil profiles – as it is done in most studies – may lead to misleading assumptions of SOM turnover in soils when extrapolated on larger areas.
10 Feb 2016
Soil greenhouse gases emissions reduce the benefit of mangrove plant to mitigating atmospheric warming effect
Guangcheng Chen, Bin Chen, Dan Yu, Yong Ye, Nora F. Y. Tam, and Shunyang Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-662, https://doi.org/10.5194/bg-2015-662, 2016
Revised manuscript not accepted (discussion: closed, 10 comments)
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Up to now, the adverse warming effect of soil greenhouse gas (GHG) emissions has scarcely been considered with respect to the role of mangrove wetlands in mitigating global warming. Our study showed that the warming effect of soil GHG emission would largely offset the benefit of plant CO2 sequestration, and we propose the assessment of the direct mitigation of atmospheric warming by mangrove ecosystem that should take into account both soil greenhouse gas emissions and plant CO2 sequestration.
02 Feb 2016
Are fire mediated feedbacks burning out of control?
J. Lloyd and E. M. Veenendaal
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-660, https://doi.org/10.5194/bg-2015-660, 2016
Revised manuscript not accepted (discussion: closed, 3 comments)
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Fire has been proposed as the key driver of tropical forest and savanna biome distributions with many tropical ecologists believing that these biomes constitute alternate stable states (ASS). Contributing to an ongoing debate as evidence supporting the existence of ASS in the terrestrial tropics, we find all current arguments presented as supporting the existence of ASS to be flawed, with five specific fallacious argumentation types identified.
29 Jan 2016
Deep-sea ecosystem: a world of positive biodiversity – ecosystem functioning relationships?
Elisa Baldrighi, Donato Giovannelli, Giuseppe d’Errico, Marc Lavaleye, and Elena Manini
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-26, https://doi.org/10.5194/bg-2016-26, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
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The manuscript provides new interesting insights into the investigation of the relationship between biodiversity and ecosystem functioning (BEF) in the deep-sea ecosystems. We show the effect of macrobenthic fauna structural and functional diversity on the ecosystem functioning and efficiency. The effect of the “rare” species on the BEF relations has been discussed. Understanding BEF relationships an the processes underneath is pivotal in preserving the deep-sea ecosystem and its functioning.
18 Jan 2016
CO2 emissions from German drinking water reservoirs estimated from routine monitoring data
H. Saidi and M. Koschorreck
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-648, https://doi.org/10.5194/bg-2015-648, 2016
Manuscript not accepted for further review (discussion: closed, 6 comments)
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Reservoirs are a significant source of greenhouse gases. We determined the emission of CO2 from a large number of German drinking water reservoirs from routine monitoring data. German reservoirs were only a small source of CO2. Differences between reservoirs were caused by the CO2 concentration in the water and could be approximated from the pH of the water. Weather fluctuations had a minor impact on annual emissions. In total, German drinking water reservoirs emitt 44000 t of CO2 anually.
18 Jan 2016
Technical Note: Rapid Normal-phase Separation of Phytoplankton Lipids by Ultra-High Performance Supercritical Fluid Chromatography (UHPSFC)
J. Brandsma, T. R. Sutton, J. M. Herniman, J. E. Hunter, T. E. G. Biggs, C. Evans, C. P. D. Brussaard, A. D. Postle, T. J. Jenkins, and G. J. Langley
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-13, https://doi.org/10.5194/bg-2016-13, 2016
Manuscript not accepted for further review (discussion: closed, 3 comments)
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Marine phytoplankton fix around 1 billion tonnes of carbon as lipid biomass each year. We present a new method for analysing complex lipid mixtures from phytoplankton biomass using supercritical fluid technology which has better resolution and is several times faster than existing methods. Thus, it enables larger-scale and more in-depth studies of phytoplankton lipid metabolism, the way it is controlled by ecological and environmental processes, and its impact on global biogeochemistry.
18 Jan 2016
Controls of longitudinal variation in δ13C-DIC in rivers: A global meta-analysis
K. A. Roach, M. A. Rodríguez, Y. Paradis, and G. Cabana
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-558, https://doi.org/10.5194/bg-2015-558, 2016
Revised manuscript not accepted (discussion: closed, 4 comments)
18 Jan 2016
Community change of microorganisms in the Muztagata and Dunde glacier and climatic and environmental implications
Yong Chen, Xiang-Kai Li, Jing Si, Guang-Jian WU, Li-De Tian, and Shu-Rong Xiang
Biogeosciences Discuss., https://doi.org/10.5194/bg-2015-637, https://doi.org/10.5194/bg-2015-637, 2016
Revised manuscript not accepted (discussion: closed, 3 comments)
15 Dec 2015
Differences in spatial and temporal root lifespan of temperate steppes across Inner Mongolia grasslands
W.-M. Bai, M. Zhou, Y. Fang, and W.-H. Zhang
Biogeosciences Discuss., 12, 19999–20023, https://doi.org/10.5194/bgd-12-19999-2015, https://doi.org/10.5194/bgd-12-19999-2015, 2015
Manuscript not accepted for further review (discussion: closed, 9 comments)
09 Dec 2015
High-resolution ocean pH dynamics in four subtropical Atlantic benthic habitats
C. A. Hernández, S. Clemente, C. Sangil, and J. C. Hernández
Biogeosciences Discuss., 12, 19481–19498, https://doi.org/10.5194/bgd-12-19481-2015, https://doi.org/10.5194/bgd-12-19481-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Anthropogenic CO2 emissions cause ocean acidification. Here we present in situ high-resolution coastal pH dynamics data gathered at subtropical Atlantic benthic habitats. These bottoms are characterized by different macroalgae stands, which generate contrasting pH patterns naturally experienced by all organisms within that ecosystem. Ocean acidification exposure experiments or predictive models identifying species at particular risk must incorporate these patterns to be ecologically relevant.
25 Nov 2015
The interaction between nitrogen and phosphorous is a strong predictor of intra-plant variation in nitrogen isotope composition in a desert species
J. Zhang, L. Gu, J. Zhang, R. Wu, F. Wang, G. Lin, B. Wu, Q. Lu, and P. Meng
Biogeosciences Discuss., 12, 18769–18794, https://doi.org/10.5194/bgd-12-18769-2015, https://doi.org/10.5194/bgd-12-18769-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
16 Nov 2015
Concentrations and ratios of Sr, Ba and Ca along an estuarine river to the Gulf of Mexico – implication for sea level rise effects on trace metal distribution
S. He and Y. J. Xu
Biogeosciences Discuss., 12, 18425–18461, https://doi.org/10.5194/bgd-12-18425-2015, https://doi.org/10.5194/bgd-12-18425-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
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The study found that salinity strongly affects spatiotemporal distributions of Sr and Ca concentrations and their ratios, but has no effect on Ba concentration, which appears mainly geochemically controlled. These results indicate that concentrations of Sr and Ca in the world’s estuaries will very likely increase in the future as sea level rise continues, which could affect aquatic environments and biological communities.
11 Nov 2015
Estimation of nutrient contributions from the ocean across a river basin using stable isotope analysis
K. Nakayama, Y. Maruya, K. Matsumoto, M. Komata, K. Komai, and T. Kuwae
Biogeosciences Discuss., 12, 18185–18211, https://doi.org/10.5194/bgd-12-18185-2015, https://doi.org/10.5194/bgd-12-18185-2015, 2015
Revised manuscript not accepted (discussion: closed, 6 comments)
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We conducted field experiments to understand the recycling of total nitrogen from the ocean across an entire river basin using stable isotope analysis. To our best knowledge, for the world's first we estimated the marine derived nutrients recycling rate. This study also demonstrates that TN may be recycled from the ocean to the river basin not only directly due to runs of salmon, but also indirectly due to subsequent transportation processes, such as sea eagles feeding and defecation.
09 Nov 2015
Prescribed-burning vs. wildfire: management implications for annual carbon emissions along a latitudinal gradient of Calluna vulgaris-dominated vegetation
V. M. Santana, J. G. Alday, H. Lee, K. A. Allen, and R. H. Marrs
Biogeosciences Discuss., 12, 17817–17849, https://doi.org/10.5194/bgd-12-17817-2015, https://doi.org/10.5194/bgd-12-17817-2015, 2015
Manuscript not accepted for further review (discussion: closed, 7 comments)
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We modelled carbon emissions after prescribed burning in heathlands and showed they are linked to biomass production patterns determined by climate. Burning rotations that minimize C losses in one specific place can maximize losses in others. It is a challenge to design management plans for reducing carbon losses, especially when we superimposed wildfires on burning rotations. Predicted increases in wildfire frequencies interact and modify these optimum burning rotation intervals for C loss.
16 Oct 2015
Interactive effects of and light on growth rates and RUBISCO content of small and large centric diatoms
G. Li and D. A. Campbell
Biogeosciences Discuss., 12, 16645–16672, https://doi.org/10.5194/bgd-12-16645-2015, https://doi.org/10.5194/bgd-12-16645-2015, 2015
Revised manuscript not accepted (discussion: closed, 6 comments)
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Marine photosynthetic diatoms span a range of cellular sizes, with important implications for carbon cycling. Nitrogen is increasing rapidly in coastal areas. We grew small and large marine centric diatoms and found that under low nitrogen media both strains conserved their cellular allocation of nitrogen to their photosynthetic system. The large diatom grew faster under low nitrogen, while the small diatom could exploit high levels of nitrogen to grow faster.
28 Sep 2015
Comparing solubility algorithms of greenhouse gases in Earth-System modelling
V. M. N. C. S. Vieira, E. Sahlée, P. Jurus, E. Clementi, H. Pettersson, and M. Mateus
Biogeosciences Discuss., 12, 15925–15945, https://doi.org/10.5194/bgd-12-15925-2015, https://doi.org/10.5194/bgd-12-15925-2015, 2015
Manuscript not accepted for further review (discussion: closed, 8 comments)
28 Sep 2015
Improving estimations of greenhouse gas transfer velocities by atmosphere–ocean couplers in Earth-System and regional models
V. M. N. C. S. Vieira, E. Sahlée, P. Jurus, E. Clementi, H. Pettersson, and M. Mateus
Biogeosciences Discuss., 12, 15901–15924, https://doi.org/10.5194/bgd-12-15901-2015, https://doi.org/10.5194/bgd-12-15901-2015, 2015
Manuscript not accepted for further review (discussion: closed, 5 comments)
24 Sep 2015
Ocean acidification modulates expression of genes and physiological performance of a marine diatom
Y. Li, S. Zhuang, Y. Wu, H. Ren, F. Cheng, X. Lin, K. Wang, J. Beardall, and K. Gao
Biogeosciences Discuss., 12, 15809–15833, https://doi.org/10.5194/bgd-12-15809-2015, https://doi.org/10.5194/bgd-12-15809-2015, 2015
Revised manuscript not accepted (discussion: closed, 3 comments)
23 Sep 2015
Carbon dynamics and changing winter conditions: a review of current understanding and future research directions
M. Haei and H. Laudon
Biogeosciences Discuss., 12, 15763–15808, https://doi.org/10.5194/bgd-12-15763-2015, https://doi.org/10.5194/bgd-12-15763-2015, 2015
Revised manuscript not accepted (discussion: closed, 3 comments)
14 Sep 2015
Environmental controls on leaf wax δD ratios in surface peats across the monsoonal region of China
X. Huang, J. Xue, X. Wang, and P. A. Meyers
Biogeosciences Discuss., 12, 15157–15184, https://doi.org/10.5194/bgd-12-15157-2015, https://doi.org/10.5194/bgd-12-15157-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
01 Sep 2015
Influence of measurement uncertainties on soluble aerosol iron over the oceans
N. Meskhidze, M. S. Johnson, D. Hurley, and K. Dawson
Biogeosciences Discuss., 12, 14377–14400, https://doi.org/10.5194/bgd-12-14377-2015, https://doi.org/10.5194/bgd-12-14377-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
20 Aug 2015
Protist communities in a marine oxygen minimum zone off Costa Rica by 454 pyrosequencing
H. Jing, E. Rocke, L. Kong, X. Xia, H. Liu, and M. R. Landry
Biogeosciences Discuss., 12, 13483–13509, https://doi.org/10.5194/bgd-12-13483-2015, https://doi.org/10.5194/bgd-12-13483-2015, 2015
Manuscript not accepted for further review (discussion: closed, 3 comments)
Short summary
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Photosynthetic Dinoflagellates predominated in the surface, while potential parasitic Dinoflagellates and Ciliates dominated in the OMZ and deeper water in Costa Rica Dome. Total and active protists in the anoxic core were distinct from those in others depths. Reduced community diversity and presence of parasitic/symbiotic trophic lifestyles in the suboxic/anoxic OMZ suggests that oxygen deficiency could cause a change of protist community and the associated microbial food web as well.
19 Aug 2015
Seasonal, sub-seasonal and spatial fluctuations in oxygen-depleted bottom waters in an embayment of an eastern boundary upwelling system: St Helena Bay
G. C. Pitcher and T. A. Probyn
Biogeosciences Discuss., 12, 13283–13309, https://doi.org/10.5194/bgd-12-13283-2015, https://doi.org/10.5194/bgd-12-13283-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
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Seasonal, sub-seasonal and spatial fluctuations in bottom dissolved oxygen (DO) are examined in St Helena Bay, the largest and most productive bay of the southern Benguela upwelling system. Superimposed on the seasonal decline of DO concentrations in bottom waters were sub-seasonal events of hypoxia and anoxia linked to episodic deposition of organic matter as dictated by cell death processes of exceptional dinoflagellate blooms as indicated by increases in bottom Chl a concentrations.
13 Aug 2015
Technical Note: A simple calculation algorithm to separate high-resolution CH4 flux measurements into ebullition and diffusion-derived components
M. Hoffmann, M. Schulz-Hanke, J. Garcia Alba, N. Jurisch, U. Hagemann, T. Sachs, M. Sommer, and J. Augustin
Biogeosciences Discuss., 12, 12923–12945, https://doi.org/10.5194/bgd-12-12923-2015, https://doi.org/10.5194/bgd-12-12923-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Processes driving the production, transformation and transport of CH4 in wetlands are highly complex. Thus, serious challenges are constitutes in terms of process understanding, potential drivers and the calculation of reliable CH4 emission estimates. We present a simple calculation algorithm to separate CH4 fluxes measured with closed chambers into diffusion- and ebullition-derived components, which helps facilitating the identification of underlying dynamics and potential drivers.
07 Aug 2015
Contribution of Marine Group II Euryarchaeota to cyclopentyl tetraethers in the Pearl River estuary and coastal South China Sea: impact on the TEX86 paleothermometer
J. X. Wang, C. L. Zhang, W. Xie, Y. G. Zhang, and P. Wang
Biogeosciences Discuss., 12, 12455–12484, https://doi.org/10.5194/bgd-12-12455-2015, https://doi.org/10.5194/bgd-12-12455-2015, 2015
Revised manuscript not accepted (discussion: closed, 5 comments)
06 Aug 2015
Projected climate change impacts on North Sea and Baltic Sea: CMIP3 and CMIP5 model based scenarios
D. Pushpadas, C. Schrum, and U. Daewel
Biogeosciences Discuss., 12, 12229–12279, https://doi.org/10.5194/bgd-12-12229-2015, https://doi.org/10.5194/bgd-12-12229-2015, 2015
Manuscript not accepted for further review (discussion: closed, 5 comments)
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We investigated the potential future climate change impacts to the North Sea and the Baltic Sea ecosystem using a coherent regional downscaling strategy. Multi-model ensembles using CMIP3 and CMIP5 scenarios are examined and comparing projected changes with the present day reference condition, we predicted an increase in Sea Surface Temperature in both the seas, decrease in primary production in the North Sea and an increase in primary production in the Baltic Sea.
23 Jul 2015
Technical Note: An improved guideline for rapid and precise sample preparation of tree-ring stable isotope analysis
K. Schollaen, H. Baschek, I. Heinrich, and G. Helle
Biogeosciences Discuss., 12, 11587–11623, https://doi.org/10.5194/bgd-12-11587-2015, https://doi.org/10.5194/bgd-12-11587-2015, 2015
Revised manuscript not accepted (discussion: closed, 6 comments)
21 Jul 2015
Seagrass beds as ocean acidification refuges for mussels? High resolution measurements of pCO2 and O2 in a Zostera marina and Mytilus edulis mosaic habitat
V. Saderne, P. Fietzek, S. Aßmann, A. Körtzinger, and C. Hiebenthal
Biogeosciences Discuss., 12, 11423–11461, https://doi.org/10.5194/bgd-12-11423-2015, https://doi.org/10.5194/bgd-12-11423-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
17 Jul 2015
The abiotic contribution to total CO2 flux for soils in arid zone
J. Ma, Y. Li, and R. Liu
Biogeosciences Discuss., 12, 11217–11244, https://doi.org/10.5194/bgd-12-11217-2015, https://doi.org/10.5194/bgd-12-11217-2015, 2015
Manuscript not accepted for further review (discussion: closed, 3 comments)
09 Jul 2015
Application of clustering techniques to study environmental characteristics of microbialite-bearing aquatic systems
R. Dalinina, V. A. Petryshyn, D. S. Lim, A. J. Braverman, and A. K. Tripati
Biogeosciences Discuss., 12, 10511–10544, https://doi.org/10.5194/bgd-12-10511-2015, https://doi.org/10.5194/bgd-12-10511-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
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Microbialites (rocks formed by the activity of microbes) are important geobiologic structures with a ~3.5 billion year record. Despite this, the formation of microbialites is still poorly understood. This study provides a statistical treatment of the geochemistry of several microbialite-forming environments, as well as ‘control’ environments that do not form microbialtes. It is the aim of this manuscript to discern what characteristics are integral to the formation of microbialites.
09 Jul 2015
Water use strategies of a young Eucalyptus urophylla forest in response to seasonal change of climatic factors in South China
Z. Z. Zhang, P. Zhao, R. Oren, H. R. McCarthy, J. F. Niu, L. W. Zhu, G. Y. Ni, and Y. Q. Huang
Biogeosciences Discuss., 12, 10469–10510, https://doi.org/10.5194/bgd-12-10469-2015, https://doi.org/10.5194/bgd-12-10469-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
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a) More dramatically decreased hydralic conductivity when stomatal conductance was decreasing may shed some light on the mechanism of the high WUE of Eucalyptus when exposed to drought conditions. b) As tree grows, ks is more sensitive to water loss. c) The decrease in stomatal sensitivity of GSref to D along the radiation gradient accounted for an important aspect of “plastic characteristics” for E. urophylla.
08 Jul 2015
Net ecosystem production in a Little Ice Age moraine: the role of plant functional traits
E. Varolo, D. Zanotelli, M. Tagliavini, S. Zerbe, and L. Montagnani
Biogeosciences Discuss., 12, 10271–10310, https://doi.org/10.5194/bgd-12-10271-2015, https://doi.org/10.5194/bgd-12-10271-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
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Vegetation growth after glaciers retreat can be an important feedback to increasing atmospheric CO2. We monitored, with transparent and opaque chambers, the carbon fluxes of two vegetation communities on an alpine glacier forefield over two growing seasons. We showed that different plant physiology determines the sign of the net carbon exchange. A C3 grassland, having higher assimilation rates, was a net CO2 sink, while CAM rosettes were a net source.
16 Jun 2015
Reviews and synthesis: Carbon capture and storage monitoring – an integrated biological, biophysical and chemical approach
N. Hicks, U. Vik, P. Taylor, E. Ladoukakis, J. Park, F. Kolisis, H. Stahl, and K. S. Jakobsen
Biogeosciences Discuss., 12, 8909–8937, https://doi.org/10.5194/bgd-12-8909-2015, https://doi.org/10.5194/bgd-12-8909-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
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Here we review current knowledge about the impact of CO2 leaks from marine carbon capture storage sites, and use a recent case study to assess current monitoring techniques. We integrate aspects of microbiology, geophysics, chemistry and bioinformatics to suggest a future integrative monitoring technique, using metagenomics, to prevent large-scale leakages and associated consequences. This novel approach is generic and can be adapted to other systems of interest for environmental monitoring.
08 Jun 2015
Ideas and perspectives: use of tree-ring width as an indicator of tree growth
R. A. Hember, W. A. Kurz, and J. M. Metsaranta
Biogeosciences Discuss., 12, 8341–8352, https://doi.org/10.5194/bgd-12-8341-2015, https://doi.org/10.5194/bgd-12-8341-2015, 2015
Manuscript not accepted for further review (discussion: closed, 3 comments)
Short summary
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By coring trees, studies can reconstruct growth over the lifespan of a tree. This provides unparalleled sampling of temporal variation of growth. However, many studies focus on the variation of annual ring width. With increasing prevalence of such studies in global change science, we caution that ring width is not directly comparable with primary productivity of the tree and advocate a straightforward solution to facilitate comparison between studies.
02 Jun 2015
Biologically labile photoproducts from riverine non-labile dissolved organic carbon in the coastal waters
V. Kasurinen, H. Aarnos, and A. Vähätalo
Biogeosciences Discuss., 12, 8199–8234, https://doi.org/10.5194/bgd-12-8199-2015, https://doi.org/10.5194/bgd-12-8199-2015, 2015
Revised manuscript not accepted (discussion: closed, 6 comments)
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Irradiations of filtered water samples from ten major rivers stimulated bacterial production and respiration. The stimulus depended on photobleaching of chromophoric dissolved organic matter (CDOM). Assuming complete photobleaching of CDOM in the global coastal ocean, sunlight-induced photochemical reactions transform >15% (>38 Mt yr-1) of riverine dissolved organic carbon flux into biologically labile photoproducts, which are consumed by bacteria with 13% growth efficiency.
12 May 2015
Methane distribution, flux, and budget in the East China Sea and Yellow Sea
M.-S. Sun, G.-L. Zhang, X.-P. Cao, X.-Y. Mao, J. Li, and W.-W. Ye
Biogeosciences Discuss., 12, 7017–7053, https://doi.org/10.5194/bgd-12-7017-2015, https://doi.org/10.5194/bgd-12-7017-2015, 2015
Revised manuscript not accepted (discussion: closed, 6 comments)
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Obvious seasonal variations of the distribution and emission of methane in the ECS and YS were reported based on data collected during five cruises in 2011. A box model was used to calculate the methane budget in the ECS, identify the main sources and sinks of dissolved methane in this area, and estimate the contribution of different sources to total methane quantitatively. It indicated that the most important source of methane in the ECS was in situ production in the water column.
30 Apr 2015
Coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems in the eutrophic and turbid inner Changjiang (Yangtze River) Estuary
W.-D. Zhai and X.-L. Yan
Biogeosciences Discuss., 12, 6405–6443, https://doi.org/10.5194/bgd-12-6405-2015, https://doi.org/10.5194/bgd-12-6405-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
20 Apr 2015
Optimising methodology for determining the effect of ocean acidification on bacterial extracellular enzymes
T. J. Burrell, E. W. Maas, P. Teesdale-Spittle, and C. S. Law
Biogeosciences Discuss., 12, 5841–5870, https://doi.org/10.5194/bgd-12-5841-2015, https://doi.org/10.5194/bgd-12-5841-2015, 2015
Manuscript not accepted for further review (discussion: closed, 4 comments)
Short summary
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pH has a significant effect on the artificial fluorophore for glucosidase and protease activity, while artificial aminopeptidase substrate alters the pH of seawater. Reduction of coastal seawater pH to 7.8 was shown to increase β-glucosidase activity rapidly (0.5h), while no significant response was detected for leucine aminopeptidase. Seawater acidified by bubbling CO2 gas resulted in elevated β-glucosidase activity and bacterial cell numbers, although seasonal effects were observed.
14 Apr 2015
Linking dissolved organic matter composition to metal bioavailability in agricultural soils: effect of anionic surfactants
M. C. Hernandez-Soriano and J. C. Jimenez-Lopez
Biogeosciences Discuss., 12, 5697–5723, https://doi.org/10.5194/bgd-12-5697-2015, https://doi.org/10.5194/bgd-12-5697-2015, 2015
Revised manuscript not accepted (discussion: closed, 7 comments)
Short summary
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Irrigation with greywater can increase the risk of metal toxicity to plants and soil organisms due to the presence of anionic surfactants derived from household products.
Three agricultural soils were treated with anionic surfactants and the total concentration of soluble metal increased. However, that was accompanied by the solubilisation of soil organic compounds that bind metals and yield complexes of low bioavailability, which substantially reduces the potential risk of metal toxicity.
14 Apr 2015
Effects of flooding on organic carbon consumption in the East China Sea
C.-C. Chen, G.-C. Gong, W.-C. Chou, C.-C. Chung, F.-K. Shiah, and K.-P. Chiang
Biogeosciences Discuss., 12, 5609–5639, https://doi.org/10.5194/bgd-12-5609-2015, https://doi.org/10.5194/bgd-12-5609-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
14 Apr 2015
Estimation of nutrient contributions from the ocean across a river basin using stable isotope analysis
K. Nakayama, Y. Maruya, K. Matsumoto, M. Komata, K. Komai, and T. Kuwae
Biogeosciences Discuss., 12, 5535–5557, https://doi.org/10.5194/bgd-12-5535-2015, https://doi.org/10.5194/bgd-12-5535-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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Recycling of total nitrogen (TN) from the ocean to river basin ecosystems has been actively investigated. Previous studies demonstrated that marine-derived nutrients (MDN) play a large role in river ecosystems. However, little research has been devoted to understanding the contribution of runs of salmon to MDN across the entire river basin. Therefore we conducted field experiments to understand the recycling of TN from the ocean across an entire river basin using stable isotope analysis.
13 Apr 2015
Is average chain length of plant lipids a potential proxy for vegetation, environment and climate changes?
M. Wang, W. Zhang, and J. Hou
Biogeosciences Discuss., 12, 5477–5501, https://doi.org/10.5194/bgd-12-5477-2015, https://doi.org/10.5194/bgd-12-5477-2015, 2015
Revised manuscript not accepted (discussion: closed, 6 comments)
23 Mar 2015
A model analysis of climate and CO2 controls on tree growth in a semi-arid woodland
G. Li, S. P. Harrison, and I. C. Prentice
Biogeosciences Discuss., 12, 4769–4800, https://doi.org/10.5194/bgd-12-4769-2015, https://doi.org/10.5194/bgd-12-4769-2015, 2015
Revised manuscript has not been submitted (discussion: closed, 3 comments)
16 Mar 2015
Major constrains of the pelagic food web efficiency in the Mediterranean Sea
L. Zoccarato and S. Fonda Umani
Biogeosciences Discuss., 12, 4365–4403, https://doi.org/10.5194/bgd-12-4365-2015, https://doi.org/10.5194/bgd-12-4365-2015, 2015
Revised manuscript not accepted (discussion: closed, 8 comments)
Short summary
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The paper deals with the possible constrains that can control carbon fluxes in the Mediterranean Sea and affect the microbial part of the pelagic marine food webs.
It is a synthesis and elaboration of more than 80 experiments of predations carried out in the whole Mediterranean Sea and that cover a wide range of trophic conditions.
One of the main result is that always microzooplankton feed on prokaryotic components also in eutrophic conditions when of course herbivory prevails.
10 Feb 2015
Growth and production of the copepod community in the southern area of the Humboldt Current System
R. Escribano, E. Bustos-Ríos, P. Hidalgo, and C. E. Morales
Biogeosciences Discuss., 12, 3057–3099, https://doi.org/10.5194/bgd-12-3057-2015, https://doi.org/10.5194/bgd-12-3057-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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Increasing coastal upwelling in the Humboldt Current is negatively affecting zooplankton biomass and secondary production, as reflected in a gradual decrease in copepod biomass in recent years. A more extended upwelling period causes substantial loss of copepod biomass from the coastal zone due to offshore advection. Excess of upwelling, induced by climate change, may thus negatively impact biological production at lower trophic levels in this highly productive large marine ecosystem.
03 Feb 2015
Relationship between N : P : Si ratio and phytoplankton community composition in a tropical estuarine mangrove ecosystem
A. K. Choudhury and P. Bhadury
Biogeosciences Discuss., 12, 2307–2355, https://doi.org/10.5194/bgd-12-2307-2015, https://doi.org/10.5194/bgd-12-2307-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
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The present work aims at understanding importance of Brzezinski-Redfield ratio as a determinant of natural phytoplankton community composition in a mangrove ecosystem. Results show that nutrient concentrations were intricately balanced that never became limited and complemented well with concept of modified Redfield ratio in study area. Based on microscopy and rbcL sequencing, we show recent concepts of phytoplankton functional traits and elemental stoichiometry also occur in mangrove habitat.
30 Jan 2015
Microbial communities responsible for fixation of CO2 revealed by using mcrA, cbbM, cbbL, fthfs, fefe-hydrogenase genes as molecular biomarkers in petroleum reservoirs of different temperatures
J.-F. Liu, S. M. Mbadinga, X.-B. Sun, G.-C. Yang, S.-Z. Yang, J.-D. Gu, and B.-Z. Mu
Biogeosciences Discuss., 12, 1875–1906, https://doi.org/10.5194/bgd-12-1875-2015, https://doi.org/10.5194/bgd-12-1875-2015, 2015
Revised manuscript not accepted (discussion: closed, 5 comments)
23 Jan 2015
Seasonality of sea ice controls interannual variability of summertime ΩA at the ice shelf in the Eastern Weddell Sea – an ocean acidification sensitivity study
A. Weeber, S. Swart, and P. M. S. Monteiro
Biogeosciences Discuss., 12, 1653–1687, https://doi.org/10.5194/bgd-12-1653-2015, https://doi.org/10.5194/bgd-12-1653-2015, 2015
Revised manuscript not accepted (discussion: closed, 8 comments)
Short summary
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As anthropogenic CO2 increases and sea ice dynamics change with climate, understanding the trend in these characteristics of variability in the seasonal drivers of ΩA will become increasingly important. We investigate the major drivers of interannual to seasonal scale variability of ΩA. We show that the critical climate (physical-biogeochemical) sensitivities for ΩA at the Antarctic ice self are the timing and rate of sea ice thaw and the resulting onset and persistence of phytoplankton blooms.
16 Jan 2015
Primary productivity and its correlation with rainfall on Aldabra Atoll
J. Shekeine, L. A. Turnbull, P. Cherubini, R. de Jong, R. Baxter, D. Hansen, N. Bunbury, F. Fleischer-Dogley, and G. Schaepman-Strub
Biogeosciences Discuss., 12, 981–1013, https://doi.org/10.5194/bgd-12-981-2015, https://doi.org/10.5194/bgd-12-981-2015, 2015
Preprint withdrawn (discussion: closed, 4 comments)
15 Jan 2015
How can effect the synergy of climate change, soil units and vegetation groups the potential global distribution of plants up to 2300: a modelling study for prediction of potential global distribution and migration of the N2 fixing species Alnus spp.
A. Sakalli
Biogeosciences Discuss., 12, 815–864, https://doi.org/10.5194/bgd-12-815-2015, https://doi.org/10.5194/bgd-12-815-2015, 2015
Revised manuscript not accepted (discussion: closed, 4 comments)
13 Jan 2015
Inter- and intra-specific responses of coccolithophores to CO2-induced ocean acidification
D. S. Wang, D. Xu, X. Fan, N. H. Ye, W. Q. Wang, X. W. Zhang, Y. Miao, Z. Guan, and S. Wang
Biogeosciences Discuss., 12, 675–706, https://doi.org/10.5194/bgd-12-675-2015, https://doi.org/10.5194/bgd-12-675-2015, 2015
Revised manuscript has not been submitted (discussion: closed, 3 comments)
08 Jan 2015
Ba, B, and U element partitioning in magnesian calcite skeletons of Octocorallia corals
T. Yoshimura, A. Suzuki, and N. Iwasaki
Biogeosciences Discuss., 12, 413–444, https://doi.org/10.5194/bgd-12-413-2015, https://doi.org/10.5194/bgd-12-413-2015, 2015
Revised manuscript not accepted (discussion: closed, 3 comments)
Short summary
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The variations of element profiles in biogenic CaCO3 are widely used for identifying differences in biological and physicochemical processes associated with element partitioning. Octocorallia coral skeletons can provide long-term records of environmental conditions in intermediate and deep waters. The change in skeletal Ba/Ca with depth parallels that in the dissolved Ba concentration being linked to ocean nutrient cycling. We did not observe pronounced environmental controls in B/Ca and U/Ca.
08 Jan 2015
Mechanism of O and C isotope fractionation in magnesian calcite skeletons of Octocorallia corals and an implication on their calcification response to ocean acidification
T. Yoshimura, A. Suzuki, and N. Iwasaki
Biogeosciences Discuss., 12, 389–412, https://doi.org/10.5194/bgd-12-389-2015, https://doi.org/10.5194/bgd-12-389-2015, 2015
Revised manuscript not accepted (discussion: closed, 3 comments)
Short summary
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Skeletal oxygen and carbon isotope fractionation of Octocorallia corals, composed of more soluble calcium carbonate polymorphs of high-Mg calcite, represent a natural laboratory for the study of the response of coral calcification to pH changes. Skeletal isotopic compositions are enriched in light isotopes when conditions are less alkaline, suggsting an even stronger biological manipulation on the sources of dissolved inorganic carbon (DIC) under lower pH.
19 Dec 2014
A study of the role of wetlands in defining spatial patterns of near-surface (top 1 m) soil carbon in the Northern Latitudes
E. M. Blyth, R. Oliver, and N. Gedney
Biogeosciences Discuss., 11, 17967–18002, https://doi.org/10.5194/bgd-11-17967-2014, https://doi.org/10.5194/bgd-11-17967-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 6 comments)
Short summary
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By studying patterns of soil carbon in the Northern Latitudes alongside vegetation, soil temperatures and wetlands, it is apparent that the main cause of high values of soil carbon is the presence of saturated soils (wetlands). This link can only be modelled if the wetlands are assumed to completely suppress soil respiration. It is important to be able to model wetlands and their effect on soil carbon if we are to understand the long term future of the soil-carbon store in Northern Latitudes.
17 Dec 2014
Rapid establishment of the CO2 sink associated with Kerguelen's bloom observed during the KEOPS2/OISO20 cruise
C. Lo Monaco, N. Metzl, F. D'Ovidio, J. Llort, and C. Ridame
Biogeosciences Discuss., 11, 17543–17578, https://doi.org/10.5194/bgd-11-17543-2014, https://doi.org/10.5194/bgd-11-17543-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 4 comments)
10 Dec 2014
Nitrogen fixation in the Southern Ocean: a case of study of the Fe-fertilized Kerguelen region (KEOPS II cruise)
M. L. González, V. Molina, L. Florez-Leiva, L. Oriol, A. J. Cavagna, F. Dehairs, L. Farias, and C. Fernandez
Biogeosciences Discuss., 11, 17151–17185, https://doi.org/10.5194/bgd-11-17151-2014, https://doi.org/10.5194/bgd-11-17151-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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This study shows for first time N2 fixation is occurring in the HNLC area of Southern Ocean and in naturally iron-fertilized waters, at rates exceeding previous reports for high latitudes (up to 20.11 nmol N L-1 d-1). Diazotrophs were identified as heterotrophic bacterioplankton; with an indirect role of dFe in the regulation of this process. Fertilization enhancing regenerated primary production may control N2 fixation via the availability od DOM for heterotrophic bacterioplankton.
28 Nov 2014
Recycling and fluxes of carbon gases in a stratified boreal lake following experimental carbon addition
H. Nykänen, S. Peura, P. Kankaala, and R. I. Jones
Biogeosciences Discuss., 11, 16447–16495, https://doi.org/10.5194/bgd-11-16447-2014, https://doi.org/10.5194/bgd-11-16447-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
Short summary
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Boreal stratified lakes are important sources of GHG gases to the atmosphere. We found methane consumption mainly from anoxic deeper water layers where methanotrophs turn most of the methane to carbon dioxide. Addition of carbon as cane sugar increased lake emissions further, even especially methane was recycled efficiently in the lake. Stable isotopic analyzes show that added carbon was transferred to carbon dioxide and methane in the lake bottom.
18 Nov 2014
Environmental factors controlling lake diatom communities: a meta-analysis of published data
S. Blanco
Biogeosciences Discuss., 11, 15889–15909, https://doi.org/10.5194/bgd-11-15889-2014, https://doi.org/10.5194/bgd-11-15889-2014, 2014
Manuscript not accepted for further review (discussion: closed, 3 comments)
Short summary
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I re-analyze information published during the last decades concerning the effect of different environmental predictors on the structure of benthic diatom communities in world lakes, providing a scientific basis for the implementation of new paleoenvironmental inference models. I consider highly relevant the publication of this article in a widely known journal, provided the noticeable demand on paleolimnological meta-studies supporting the use of such biological proxies at a pancontinental scale
07 Nov 2014
Technical Note: Artificial coral reef mesocosms for ocean acidification investigations
J. Leblud, L. Moulin, A. Batigny, P. Dubois, and P. Grosjean
Biogeosciences Discuss., 11, 15463–15505, https://doi.org/10.5194/bgd-11-15463-2014, https://doi.org/10.5194/bgd-11-15463-2014, 2014
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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The design and evaluation of artificial mesocosms are presented in the context of a thirteen months experiment on the effects of ocean acidification on tropical coral reefs. Physico-chemical parameters (i.e. pH, pO2, total alkalinity, alkaline earth metals and nutrients) were successfully controlled. Daily pH variations were applied to approach field conditions. Artificial reef mesocosms leave enough degrees of freedom to the studied ecosystem to change and to acclimate to contrasted conditions.
31 Oct 2014
Experimental drought induces short-term changes in soil functionality and microbial community structure after fire in a Mediterranean shrubland
M. B. Hinojosa, A. Parra, V. A. Laudicina, and J. M. Moreno
Biogeosciences Discuss., 11, 15251–15287, https://doi.org/10.5194/bgd-11-15251-2014, https://doi.org/10.5194/bgd-11-15251-2014, 2014
Revised manuscript not accepted (discussion: closed, 6 comments)
Short summary
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This manuscript reports the results of an experimental field study in which the joint effect of both fire and drought is tested. Drought modifies the short-term post-fire soil functionality and microbial community, in a fire-prone xeric ecosystem in which drought is projected to increase with climate change. This study allows to make a step forward on our integrated understanding of the processes underlying impacts of climate extremes in the recovery of ecosystems after fire.
22 Oct 2014
Analysis of water use strategies of the desert riparian forest plant community in inland rivers of two arid regions in northwestern China
Y. N. Chen, W. H. Li, H. H. Zhou, Y. P. Chen, X. M. Hao, A. H. Fu, and J. X. Ma
Biogeosciences Discuss., 11, 14819–14856, https://doi.org/10.5194/bgd-11-14819-2014, https://doi.org/10.5194/bgd-11-14819-2014, 2014
Revised manuscript not accepted (discussion: closed, 5 comments)
13 Oct 2014
Influence of aeolian activities on the distribution of microbial abundance in glacier ice
Y. Chen, X.-K. Li, J. Si, G.-J. Wu, L.-D. Tian, and S.-R. Xiang
Biogeosciences Discuss., 11, 14531–14549, https://doi.org/10.5194/bgd-11-14531-2014, https://doi.org/10.5194/bgd-11-14531-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
02 Oct 2014
Nematode diversity, abundance and community structure 50 years after the formation of the volcanic island of Surtsey
K. Ilieva-Makulec, B. Bjarnadottir, and B. D. Sigurdsson
Biogeosciences Discuss., 11, 14239–14267, https://doi.org/10.5194/bgd-11-14239-2014, https://doi.org/10.5194/bgd-11-14239-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
29 Sep 2014
Dynamics of global atmospheric CO2 concentration from 1850 to 2010: a linear approximation
W. Wang and R. Nemani
Biogeosciences Discuss., 11, 13957–13983, https://doi.org/10.5194/bgd-11-13957-2014, https://doi.org/10.5194/bgd-11-13957-2014, 2014
Revised manuscript not accepted (discussion: closed, 10 comments)
22 Sep 2014
Effect of ammonium input over the distribution of iron in the seawater and the phytoplankton in a mesocosm experiment in a North Patagonian fjord
N. Sanchez, M. V. Ardelan, N. Bizsel, and J. L. Iriarte
Biogeosciences Discuss., 11, 13739–13774, https://doi.org/10.5194/bgd-11-13739-2014, https://doi.org/10.5194/bgd-11-13739-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
10 Sep 2014
Testing functional trait-based mechanisms underpinning plant responses to grazing and linkages to ecosystem functioning in grasslands
S. X. Zheng, W. H. Li, Z. C. Lan, H. Y. Ren, K. B. Wang, and Y. F. Bai
Biogeosciences Discuss., 11, 13157–13186, https://doi.org/10.5194/bgd-11-13157-2014, https://doi.org/10.5194/bgd-11-13157-2014, 2014
Revised manuscript not accepted (discussion: closed, 6 comments)
15 Aug 2014
Are C-loss rates from drained peatlands constant over time? The additive value of soil profile based and flux budget approach
J. Leifeld, C. Bader, E. Borraz, M. Hoffmann, M. Giebels, M. Sommer, and J. Augustin
Biogeosciences Discuss., 11, 12341–12373, https://doi.org/10.5194/bgd-11-12341-2014, https://doi.org/10.5194/bgd-11-12341-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
07 Aug 2014
Volatile Organic Compound emissions from soil: using Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS) for the real time observation of microbial processes
P. R. Veres, T. Behrendt, A. Klapthor, F. X. Meixner, and J. Williams
Biogeosciences Discuss., 11, 12009–12038, https://doi.org/10.5194/bgd-11-12009-2014, https://doi.org/10.5194/bgd-11-12009-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
01 Aug 2014
Modelling the effect of soil moisture and organic matter degradation on biogenic NO emissions from soils in Sahel rangeland (Mali)
C. Delon, E. Mougin, D. Serça, M. Grippa, P. Hiernaux, M. Diawara, C. Galy-Lacaux, and L. Kergoat
Biogeosciences Discuss., 11, 11785–11824, https://doi.org/10.5194/bgd-11-11785-2014, https://doi.org/10.5194/bgd-11-11785-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
31 Jul 2014
Emissions from potential Patagonian dust sources and associated biological response in the Atlantic sector of the Southern Ocean
A. Castagna, H. Evangelista, L. G. Tilstra, and R. Kerr
Biogeosciences Discuss., 11, 11671–11699, https://doi.org/10.5194/bgd-11-11671-2014, https://doi.org/10.5194/bgd-11-11671-2014, 2014
Revised manuscript not accepted (discussion: closed, 6 comments)
29 Jul 2014
A 1-D examination of decadal air–sea re-equilibration induced ocean surface anthropogenic CO2 accumulation: present status, changes from 1960s to 2000s, and future scenarios
W.-D. Zhai and H.-D. Zhao
Biogeosciences Discuss., 11, 11509–11532, https://doi.org/10.5194/bgd-11-11509-2014, https://doi.org/10.5194/bgd-11-11509-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
25 Jul 2014
Riding on the fast lane: how sea turtles behave in post-nesting migration
Y.-H. Wang, I-J. Cheng, and L. Centurioni
Biogeosciences Discuss., 11, 11481–11508, https://doi.org/10.5194/bgd-11-11481-2014, https://doi.org/10.5194/bgd-11-11481-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
11 Jul 2014
Evaluation of carbon stocks in above- and below-ground biomass in Central Africa: case study of Lesio-louna tropical rainforest of Congo
X. Liu, R. Ekoungoulou, J. J. Loumeto, S. A. Ifo, Y. E. Bocko, and F. E. Koula
Biogeosciences Discuss., 11, 10703–10735, https://doi.org/10.5194/bgd-11-10703-2014, https://doi.org/10.5194/bgd-11-10703-2014, 2014
Preprint withdrawn (discussion: closed, 3 comments)
27 Jun 2014
Structural analysis of three global land models on carbon cycle simulations using a traceability framework
R. Rafique, J. Xia, O. Hararuk, and Y. Luo
Biogeosciences Discuss., 11, 9979–10014, https://doi.org/10.5194/bgd-11-9979-2014, https://doi.org/10.5194/bgd-11-9979-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
17 Jun 2014
Performance evaluation of ocean color satellite models for deriving accurate chlorophyll estimates in the Gulf of Saint Lawrence
M. Montes-Hugo, H. Bouakba, and R. Arnone
Biogeosciences Discuss., 11, 9299–9340, https://doi.org/10.5194/bgd-11-9299-2014, https://doi.org/10.5194/bgd-11-9299-2014, 2014
Revised manuscript not accepted (discussion: closed, 5 comments)
16 Jun 2014
Biomass yield development of early, medium and late Maize varieties under a future climate in Lower Saxony, Germany
J. F. Degener and M. Kappas
Biogeosciences Discuss., 11, 9103–9134, https://doi.org/10.5194/bgd-11-9103-2014, https://doi.org/10.5194/bgd-11-9103-2014, 2014
Revised manuscript not accepted (discussion: closed, 6 comments)
06 Jun 2014
The Habitable Zone of Inhabited Planets
J. I. Zuluaga, J. F. Salazar, P. Cuartas-Restrepo, and G. Poveda
Biogeosciences Discuss., 11, 8443–8483, https://doi.org/10.5194/bgd-11-8443-2014, https://doi.org/10.5194/bgd-11-8443-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 2 comments)
03 Jun 2014
Revisiting Mt. Kilimanjaro: Do n-alkane biomarkers in soils reflect the δ2H isotopic composition of precipitation?
M. Zech, R. Zech, K. Rozanski, A. Hemp, G. Gleixner, and W. Zech
Biogeosciences Discuss., 11, 7823–7852, https://doi.org/10.5194/bgd-11-7823-2014, https://doi.org/10.5194/bgd-11-7823-2014, 2014
Preprint withdrawn (discussion: closed, 4 comments)
20 May 2014
Direct and indirect effects of vertical mixing, nutrients and ultraviolet radiation on the bacterioplankton metabolism in high-mountain lakes from southern Europe
C. Durán, J. M. Medina-Sánchez, G. Herrera, M. Villar-Argaiz, V. E. Villafañe, E. W. Helbling, and P. Carrillo
Biogeosciences Discuss., 11, 7291–7325, https://doi.org/10.5194/bgd-11-7291-2014, https://doi.org/10.5194/bgd-11-7291-2014, 2014
Revised manuscript not accepted (discussion: closed, 3 comments)
20 May 2014
Role of extracellular polymeric substances (EPS) from Pseudomonas putida strain MnB1 in dissolution of natural rhodochrosite
H. Wang and X. Pan
Biogeosciences Discuss., 11, 7273–7290, https://doi.org/10.5194/bgd-11-7273-2014, https://doi.org/10.5194/bgd-11-7273-2014, 2014
Revised manuscript not accepted (discussion: closed, 6 comments)
19 May 2014
Dissolved organic carbon concentrations vary with season and land use – investigations from two fens in Northeastern Germany over two years
M. Schwalm and J. Zeitz
Biogeosciences Discuss., 11, 7079–7111, https://doi.org/10.5194/bgd-11-7079-2014, https://doi.org/10.5194/bgd-11-7079-2014, 2014
Preprint withdrawn (discussion: closed, 3 comments)
19 May 2014
Phylogenetic support for the Tropical Niche Conservatism Hypothesis despite the absence of a clear latitudinal species richness gradient in Yunnan's woody flora
G. Tang, M. G. Zhang, C. Liu, Z. Zhou, W. Chen, and J. W. F. Slik
Biogeosciences Discuss., 11, 7055–7077, https://doi.org/10.5194/bgd-11-7055-2014, https://doi.org/10.5194/bgd-11-7055-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 14 comments)
16 May 2014
Progressive eutrophication behind the world-largest super floating macroalgal blooms in the Yellow Sea
Q. Xing, M. Gao, X. Gao, L. Tosi, F. G. Schmitt, Y. Zhang, P. Shi, J. Wei, and Y. Luo
Biogeosciences Discuss., 11, 7029–7054, https://doi.org/10.5194/bgd-11-7029-2014, https://doi.org/10.5194/bgd-11-7029-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
12 May 2014
Surface currents and upwelling in Kerguelen Plateau regions
M. Zhou, Y. Zhu, F. d'Ovidio, Y.-H. Park, I. Durand, E. Kestenare, V. Sanial, P. Van-Beek, B. Queguiner, F. Carlotti, and S. Blain
Biogeosciences Discuss., 11, 6845–6876, https://doi.org/10.5194/bgd-11-6845-2014, https://doi.org/10.5194/bgd-11-6845-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 2 comments)
07 May 2014
Response of plant community composition and productivity to warming and nitrogen deposition in a temperate meadow ecosystem
T. Zhang, R. Guo, S. Gao, J. X. Guo, and W. Sun
Biogeosciences Discuss., 11, 6647–6672, https://doi.org/10.5194/bgd-11-6647-2014, https://doi.org/10.5194/bgd-11-6647-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
04 Apr 2014
Impacts of physical data assimilation on the Global Ocean Carbonate System
L. Visinelli, S. Masina, M. Vichi, and A. Storto
Biogeosciences Discuss., 11, 5399–5441, https://doi.org/10.5194/bgd-11-5399-2014, https://doi.org/10.5194/bgd-11-5399-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
03 Apr 2014
Trace elements in shells of common gastropods in the near vicinity of a natural CO2 vent: no evidence of pH-dependent contamination
J. B. McClintock, C. D. Amsler, M. O. Amsler, A. Duquette, R. A. Angus, J. M. Hall-Spencer, and M. Milazzo
Biogeosciences Discuss., 11, 5215–5237, https://doi.org/10.5194/bgd-11-5215-2014, https://doi.org/10.5194/bgd-11-5215-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 3 comments)
01 Apr 2014
Distribution of ammonia oxidizers in relation to vegetation characteristics in the Qilian Mountains, northwestern China
X. S. Tai, W. L. Mao, G. X. Liu, T. Chen, W. Zhang, X. K. Wu, H. Z. Long, B. G. Zhang, and T. P. Gao
Biogeosciences Discuss., 11, 5123–5146, https://doi.org/10.5194/bgd-11-5123-2014, https://doi.org/10.5194/bgd-11-5123-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 8 comments)
18 Mar 2014
The sensitivity of primary productivity to intra-seasonal mixed layer variability in the sub-Antarctic Zone of the Atlantic Ocean
W. R. Joubert, S. Swart, A. Tagliabue, S. J. Thomalla, and P. M. S. Monteiro
Biogeosciences Discuss., 11, 4335–4358, https://doi.org/10.5194/bgd-11-4335-2014, https://doi.org/10.5194/bgd-11-4335-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
07 Mar 2014
Recolonization of the intertidal and shallow subtidal community following the 2008 eruption of Alaska's Kasatochi Volcano
S. C. Jewett and G. S. Drew
Biogeosciences Discuss., 11, 3799–3836, https://doi.org/10.5194/bgd-11-3799-2014, https://doi.org/10.5194/bgd-11-3799-2014, 2014
Preprint withdrawn (discussion: closed, 2 comments)
20 Feb 2014
C, N and P stoichiometric mismatch between resources and consumers influence the dynamics of a marine microbial food web model and its response to atmospheric N and P inputs
P. Pondaven, P. Pivière, C. Ridame, and C. Guien
Biogeosciences Discuss., 11, 2933–2971, https://doi.org/10.5194/bgd-11-2933-2014, https://doi.org/10.5194/bgd-11-2933-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 2 comments)
20 Feb 2014
Stable isotope ratio (13C/12C) mass spectrometry to evaluate carbon sources and sinks: changes and trends during the decomposition of vegetal debris from eucalyptus clone plantations (NW Spain)
I. Fernandez and A. Cabaneiro
Biogeosciences Discuss., 11, 2823–2845, https://doi.org/10.5194/bgd-11-2823-2014, https://doi.org/10.5194/bgd-11-2823-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
14 Feb 2014
On the apparent CO2 absorption by alkaline soils
X. Chen and W. F. Wang
Biogeosciences Discuss., 11, 2665–2683, https://doi.org/10.5194/bgd-11-2665-2014, https://doi.org/10.5194/bgd-11-2665-2014, 2014
Preprint withdrawn (discussion: closed, 2 comments)
04 Feb 2014
Challenges and opportunities to reduce uncertainty in projections of future atmospheric CO2: a combined marine and terrestrial biosphere perspective
D. Dalmonech, A. M. Foley, A. Anav, P. Friedlingstein, A. D. Friend, M. Kidston, M. Willeit, and S. Zaehle
Biogeosciences Discuss., 11, 2083–2153, https://doi.org/10.5194/bgd-11-2083-2014, https://doi.org/10.5194/bgd-11-2083-2014, 2014
Revised manuscript has not been submitted (discussion: closed, 4 comments)
04 Feb 2014
Impact of nitrogen fertilization on carbon and water fluxes in a chronosequence of three Douglas-fir stands in the Pacific Northwest
X. Dou, B. Chen, T. A. Black, R. S. Jassal, M. Che, and Y. Liu
Biogeosciences Discuss., 11, 2001–2043, https://doi.org/10.5194/bgd-11-2001-2014, https://doi.org/10.5194/bgd-11-2001-2014, 2014
Revised manuscript not accepted (discussion: closed, 8 comments)
04 Feb 2014
How well can we predict soil respiration with climate indicators, now and in the future?
C. T. Berridge, L. H. Hadju, and A. J. Dolman
Biogeosciences Discuss., 11, 1977–1999, https://doi.org/10.5194/bgd-11-1977-2014, https://doi.org/10.5194/bgd-11-1977-2014, 2014
Revised manuscript not accepted (discussion: closed, 9 comments)
03 Feb 2014
Physical processes mediating climate change impacts on regional sea ecosystems
J. Holt, C. Schrum, H. Cannaby, U. Daewel, I. Allen, Y. Artioli, L. Bopp, M. Butenschon, B. A. Fach, J. Harle, D. Pushpadas, B. Salihoglu, and S. Wakelin
Biogeosciences Discuss., 11, 1909–1975, https://doi.org/10.5194/bgd-11-1909-2014, https://doi.org/10.5194/bgd-11-1909-2014, 2014
Revised manuscript not accepted (discussion: closed, 5 comments)
29 Jan 2014
A model–data intercomparison of simulated runoff in the contiguous United States: results from the North America Carbon Regional and Continental Interim-Synthesis
C. R. Schwalm, D. N. Huntinzger, R. B. Cook, Y. Wei, I. T. Baker, R. P. Neilson, B. Poulter, P. Caldwell, G. Sun, H. Q. Tian, and N. Zeng
Biogeosciences Discuss., 11, 1801–1826, https://doi.org/10.5194/bgd-11-1801-2014, https://doi.org/10.5194/bgd-11-1801-2014, 2014
Revised manuscript not accepted (discussion: closed, 3 comments)
29 Jan 2014
Mechanisms for the suppression of methane production in peatland soils by a humic substance analog
R. Ye, J. K. Keller, Q. Jin, B. J. M. Bohannan, and S. D. Bridgham
Biogeosciences Discuss., 11, 1739–1771, https://doi.org/10.5194/bgd-11-1739-2014, https://doi.org/10.5194/bgd-11-1739-2014, 2014
Revised manuscript not accepted (discussion: closed, 4 comments)
23 Jan 2014
Future climate variability impacts on potential erosion and soil organic carbon in European croplands
M. van der Velde, J. Balkovič, C. Beer, N. Khabarov, M. Kuhnert, M. Obersteiner, R. Skalský, W. Xiong, and P. Smith
Biogeosciences Discuss., 11, 1561–1585, https://doi.org/10.5194/bgd-11-1561-2014, https://doi.org/10.5194/bgd-11-1561-2014, 2014
Revised manuscript not accepted (discussion: closed, 5 comments)
16 Jan 2014
The effect of land-use change on the net exchange rates of greenhouse gases: a meta-analytical approach
D.-G. Kim and M. U. F. Kirschbaum
Biogeosciences Discuss., 11, 1053–1095, https://doi.org/10.5194/bgd-11-1053-2014, https://doi.org/10.5194/bgd-11-1053-2014, 2014
Revised manuscript not accepted (discussion: closed, 6 comments)
15 Jan 2014
Controls on pH in surface waters of northwestern European shelf seas
V. M. C. Rérolle, M. Ribas-Ribas, V. Kitidis, I. Brown, D. C. E. Bakker, G. A. Lee, T. Shi, M. C. Mowlem, and E. P. Achterberg
Biogeosciences Discuss., 11, 943–974, https://doi.org/10.5194/bgd-11-943-2014, https://doi.org/10.5194/bgd-11-943-2014, 2014
Preprint retracted (discussion: closed, 2 comments)
13 Jan 2014
Magnetic quantification of Fe and S bound as magnetosomal greigite in laminated sapropels in deeper basins of the Baltic Sea
M. Reinholdsson and I. Snowball
Biogeosciences Discuss., 11, 729–752, https://doi.org/10.5194/bgd-11-729-2014, https://doi.org/10.5194/bgd-11-729-2014, 2014
Revised manuscript not accepted (discussion: closed, 3 comments)
17 Dec 2013
Impacts of a weather event on shelf circulation and CO2 and O2 dynamics on the Louisiana shelf during summer 2009
W.-J. Huang, W.-J. Cai, Y. Wang, and C. S. Hopkinson
Biogeosciences Discuss., 10, 19867–19893, https://doi.org/10.5194/bgd-10-19867-2013, https://doi.org/10.5194/bgd-10-19867-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 3 comments)
17 Dec 2013
Global land-atmosphere exchange of methane and nitrous oxide: magnitude and spatiotemporal patterns
H. Tian, G. Chen, C. Lu, X. Xu, W. Ren, K. Banger, B. Zhang, B. Tao, S. Pan, M. Liu, and C. Zhang
Biogeosciences Discuss., 10, 19811–19865, https://doi.org/10.5194/bgd-10-19811-2013, https://doi.org/10.5194/bgd-10-19811-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 3 comments)
13 Dec 2013
The role of iron species on the competition of two coastal diatoms, Skeletonema costatum and Thalassosira weissflogii
S.-X. Li, F.-J. Liu, F.-Y. Zheng, Y.-G. Zuo, and X.-G. Huang
Biogeosciences Discuss., 10, 19603–19631, https://doi.org/10.5194/bgd-10-19603-2013, https://doi.org/10.5194/bgd-10-19603-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
09 Dec 2013
Effects of mowing on N2O emission from a temperate grassland in Inner Mongolia, Northern China
L. Zhang, Q. Wang, H. J. Laanbroek, C. Wang, D. Guo, and L. Li
Biogeosciences Discuss., 10, 19219–19243, https://doi.org/10.5194/bgd-10-19219-2013, https://doi.org/10.5194/bgd-10-19219-2013, 2013
Revised manuscript not accepted (discussion: closed, 6 comments)
25 Nov 2013
Methane production correlates positively with methanogens, sulfate-reducing bacteria and pore water acetate at an estuarine brackish-marsh landscape scale
C. Tong, C. X. She, Y. F. Jin, P. Yang, and J. F. Huang
Biogeosciences Discuss., 10, 18241–18275, https://doi.org/10.5194/bgd-10-18241-2013, https://doi.org/10.5194/bgd-10-18241-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
22 Nov 2013
Technical Note: Constraining stable carbon isotope values of microphytobenthos (C3 photosynthesis) in the Arctic for application to food web studies
L. E. Oxtoby, J. T. Mathis, L. W. Juranek, and M. J. Wooller
Biogeosciences Discuss., 10, 18151–18174, https://doi.org/10.5194/bgd-10-18151-2013, https://doi.org/10.5194/bgd-10-18151-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
21 Nov 2013
Stable soil organic carbon is positively linked to microbial-derived compounds in four plantations of subtropical China
H. Wang, S. Liu, S. X. Chang, J. Wang, Z. Shi, X. Huang, Y. Wen, L. Lu, and D. Cai
Biogeosciences Discuss., 10, 18093–18119, https://doi.org/10.5194/bgd-10-18093-2013, https://doi.org/10.5194/bgd-10-18093-2013, 2013
Revised manuscript not accepted (discussion: closed, 6 comments)
12 Nov 2013
Late holocene trends of phytoplankton productivity and anoxia as inferred from diatom and geochemical proxies in Lake Victoria, Eastern Africa
M. Andama, J. B. Lejju, and C. U. Tolo
Biogeosciences Discuss., 10, 17663–17682, https://doi.org/10.5194/bgd-10-17663-2013, https://doi.org/10.5194/bgd-10-17663-2013, 2013
Preprint withdrawn (discussion: closed, 2 comments)
04 Nov 2013
Plankton community response to Saharan dust fertilization in subtropical waters off the Canary Islands
G. Franchy, A. Ojeda, J. López-Cancio, and S. Hernández-León
Biogeosciences Discuss., 10, 17275–17307, https://doi.org/10.5194/bgd-10-17275-2013, https://doi.org/10.5194/bgd-10-17275-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
04 Nov 2013
The distribution, dominance patterns and ecological niches of plankton functional types in Dynamic Green Ocean Models and satellite estimates
M. Vogt, T. Hashioka, M. R. Payne, E. T. Buitenhuis, C. Le Quéré, S. Alvain, M. N. Aita, L. Bopp, S. C. Doney, T. Hirata, I. Lima, S. Sailley, and Y. Yamanaka
Biogeosciences Discuss., 10, 17193–17247, https://doi.org/10.5194/bgd-10-17193-2013, https://doi.org/10.5194/bgd-10-17193-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 2 comments)
24 Oct 2013
Exploring the response of West Siberian wetland methane emissions to future changes in climate, vegetation, and soil microbial communities
T. J. Bohn and D. P. Lettenmaier
Biogeosciences Discuss., 10, 16329–16369, https://doi.org/10.5194/bgd-10-16329-2013, https://doi.org/10.5194/bgd-10-16329-2013, 2013
Preprint withdrawn (discussion: closed, 4 comments)
22 Oct 2013
Characteristics and assessment of biogenic phosphorus in sediments from the multi-polluted Haihe River, China, using phosphorus fractionation and phosphorus-31 nuclear magnetic resonance (31P-NMR)
W. Q. Zhang, H. Zhang, W. Z. Tang, and B. Q. Shan
Biogeosciences Discuss., 10, 16269–16294, https://doi.org/10.5194/bgd-10-16269-2013, https://doi.org/10.5194/bgd-10-16269-2013, 2013
Preprint withdrawn (discussion: closed, 3 comments)
22 Oct 2013
Evolution of cyclonic eddies and biogenic fluxes in the northern Bay of Bengal
M. Nuncio and S. Prasanna Kumar
Biogeosciences Discuss., 10, 16213–16236, https://doi.org/10.5194/bgd-10-16213-2013, https://doi.org/10.5194/bgd-10-16213-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
18 Oct 2013
Extreme dissolved organic nitrogen fluxes in the human impacted Pamba River, Kerala, India
S. Elizabeth David and T. C. Jennerjahn
Biogeosciences Discuss., 10, 16137–16171, https://doi.org/10.5194/bgd-10-16137-2013, https://doi.org/10.5194/bgd-10-16137-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 4 comments)
11 Oct 2013
Recovery dynamics and invasibility of herbaceous plant communities after exposure to fifty-year climate extremes in different seasons
F. E. Dreesen, H. J. De Boeck, I. A. Janssens, and I. Nijs
Biogeosciences Discuss., 10, 15851–15877, https://doi.org/10.5194/bgd-10-15851-2013, https://doi.org/10.5194/bgd-10-15851-2013, 2013
Revised manuscript not accepted (discussion: closed, 3 comments)
13 Sep 2013
The coccolithophores Emiliania huxleyi and Coccolithus pelagicus: extant populations from the Norwegian-Iceland Sea and Fram Strait
C. V. Dylmer, J. Giraudeau, V. Hanquiez, and K. Husum
Biogeosciences Discuss., 10, 15077–15106, https://doi.org/10.5194/bgd-10-15077-2013, https://doi.org/10.5194/bgd-10-15077-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 4 comments)
05 Sep 2013
Mechanism for initiation of the offshore phytoplankton bloom in the Taiwan Strait during winter: a physical–biological coupled modeling study
J. Wang, H. Hong, Y. Jiang, and X.-H. Yan
Biogeosciences Discuss., 10, 14685–14714, https://doi.org/10.5194/bgd-10-14685-2013, https://doi.org/10.5194/bgd-10-14685-2013, 2013
Revised manuscript not accepted (discussion: closed, 6 comments)
07 Aug 2013
A~simple model for predicting the global distribution of the N2 fixing host genus Alnus Mill.: impact of climate change on the global distribution in 2100
A. Sakalli
Biogeosciences Discuss., 10, 13049–13095, https://doi.org/10.5194/bgd-10-13049-2013, https://doi.org/10.5194/bgd-10-13049-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
07 Aug 2013
Response of ecosystem respiration to experimental warming and clipping in Tibetan alpine meadow at three elevations
G. Fu, Y.-J. Zhang, X.-Z. Zhang, P.-L. Shi, Y.-T. Zhou, Y.-L. Li, and Z.-X. Shen
Biogeosciences Discuss., 10, 13015–13047, https://doi.org/10.5194/bgd-10-13015-2013, https://doi.org/10.5194/bgd-10-13015-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
07 Aug 2013
Assessing the relationship between the δ18O signatures of siliceous sponge spicules and water in a~tropical lacustrine environment (Minas Gerais, Brazil)
M. C. Matteuzzo, A. Alexandre, A. F. D. C. Varajão, C. Volkmer-Ribeiro, A. C. S. Almeida, C. A. C. Varajão, C. Vallet-Coulomb, C. Sonzogni, and H. Miche
Biogeosciences Discuss., 10, 12887–12918, https://doi.org/10.5194/bgd-10-12887-2013, https://doi.org/10.5194/bgd-10-12887-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
26 Jul 2013
Physical-biological interactions to the west of Hawaiian Islands: impact of submesoscale dynamics on biological productivity
P. Xiu and F. Chai
Biogeosciences Discuss., 10, 12529–12549, https://doi.org/10.5194/bgd-10-12529-2013, https://doi.org/10.5194/bgd-10-12529-2013, 2013
Preprint withdrawn (discussion: closed, 3 comments)
22 Jul 2013
Modelling the population dynamics of Temora longicornis in the Basin Gdańsk (southern Baltic Sea)
L. Dzierzbicka-Glowacka, A. Lemieszek, M. Kalarus, and I. M. Żmijewska
Biogeosciences Discuss., 10, 12347–12384, https://doi.org/10.5194/bgd-10-12347-2013, https://doi.org/10.5194/bgd-10-12347-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Jul 2013
Absorption features of chromophoric dissolved organic matter (CDOM) and tracing implication for dissolved organic carbon (DOC) in Changjiang Estuary, China
X. Y. Zhang, X. Chen, H. Deng, Y. Du, and H. Y. Jin
Biogeosciences Discuss., 10, 12217–12250, https://doi.org/10.5194/bgd-10-12217-2013, https://doi.org/10.5194/bgd-10-12217-2013, 2013
Preprint withdrawn (discussion: closed, 3 comments)
19 Jul 2013
Photophysiological state of natural phytoplankton communities in the South China Sea and Sulu Sea
W. Cheah, B. B. Taylor, S. Wiegmann, S. Raimund, G. Krahmann, B. Quack, and A. Bracher
Biogeosciences Discuss., 10, 12115–12153, https://doi.org/10.5194/bgd-10-12115-2013, https://doi.org/10.5194/bgd-10-12115-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
16 Jul 2013
Nutrient dynamics along a precipitation gradient in European beech forests
I. C. Meier and C. Leuschner
Biogeosciences Discuss., 10, 11899–11933, https://doi.org/10.5194/bgd-10-11899-2013, https://doi.org/10.5194/bgd-10-11899-2013, 2013
Revised manuscript not accepted (discussion: closed, 3 comments)
15 Jul 2013
Diagenesis and benthic fluxes of nutrients and metals during experimentally induced anoxia in the Gulf of Trieste (northern Adriatic Sea)
N. Koron, N. Ogrinc, E. Metzger, B. Riedel, and J. Faganeli
Biogeosciences Discuss., 10, 11729–11755, https://doi.org/10.5194/bgd-10-11729-2013, https://doi.org/10.5194/bgd-10-11729-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
09 Jul 2013
Sensitivity of pelagic CaCO3 dissolution to ocean acidification in an ocean biogeochemical model
A. Regenberg, B. Schneider, and R. Gangstø
Biogeosciences Discuss., 10, 11343–11373, https://doi.org/10.5194/bgd-10-11343-2013, https://doi.org/10.5194/bgd-10-11343-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
08 Jul 2013
Temperature and phytoplankton cell size regulate carbon uptake and carbon overconsumption in the ocean
S. E. Craig, H. Thomas, C. T. Jones, W. K. W. Li, B. J. W. Greenan, E. H. Shadwick, and W. J. Burt
Biogeosciences Discuss., 10, 11255–11282, https://doi.org/10.5194/bgd-10-11255-2013, https://doi.org/10.5194/bgd-10-11255-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
27 Jun 2013
Eddy- and wind-sustained moderate primary productivity in the temperate East Sea (Sea of Japan)
G.-H. Hong, D.-K. Lee, D.-B. Yang, Y. I. Kim, J.-H. Park, and C.-H. Park
Biogeosciences Discuss., 10, 10429–10458, https://doi.org/10.5194/bgd-10-10429-2013, https://doi.org/10.5194/bgd-10-10429-2013, 2013
Preprint withdrawn (discussion: closed, 2 comments)
26 Jun 2013
Contribution of dinitrogen fixation to bacterial and primary productivity in the Gulf of Aqaba (Red Sea)
E. Rahav, B. Herut, M. R. Mulholland, B. Voß, D. Stazic, C. Steglich, W. R. Hess, and I. Berman-Frank
Biogeosciences Discuss., 10, 10327–10361, https://doi.org/10.5194/bgd-10-10327-2013, https://doi.org/10.5194/bgd-10-10327-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 2 comments)
20 Jun 2013
Partial pressure of CO2 and CO2 emission in a monsoon-driven hydroelectric reservoir (Danjiangkou Reservoir), China
S. Y. Li and Q. F. Zhang
Biogeosciences Discuss., 10, 10055–10094, https://doi.org/10.5194/bgd-10-10055-2013, https://doi.org/10.5194/bgd-10-10055-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Jun 2013
Forward modeling analysis of regional scale tree-ring patterns around the northeastern Tibetan Plateau, Northwest China
X. Gou, F. Zhou, Y. Zhang, Q. Chen, and J. Zhang
Biogeosciences Discuss., 10, 9969–9988, https://doi.org/10.5194/bgd-10-9969-2013, https://doi.org/10.5194/bgd-10-9969-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 2 comments)
14 May 2013
Fertilization success of an arctic sea urchin species, Strongylocentrotus droebachiensis (O. F. Müller, 1776) under CO2-induced ocean acidification
D. Bögner, U. Bickmeyer, and A. Köhler
Biogeosciences Discuss., 10, 8027–8064, https://doi.org/10.5194/bgd-10-8027-2013, https://doi.org/10.5194/bgd-10-8027-2013, 2013
Revised manuscript not accepted (discussion: closed, 7 comments)
29 Apr 2013
Effects of ocean acidification on the larval growth of olive flounder (Paralichthys olivaceus)
K.-S. Kim, J. H. Shim, and S. Kim
Biogeosciences Discuss., 10, 7413–7431, https://doi.org/10.5194/bgd-10-7413-2013, https://doi.org/10.5194/bgd-10-7413-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
16 Apr 2013
Repercussions of differential settling on sediment assemblages and multi-proxy palaeo-reconstructions
A. G. M. Caromel, D. N. Schmidt, and J. C. Phillips
Biogeosciences Discuss., 10, 6763–6781, https://doi.org/10.5194/bgd-10-6763-2013, https://doi.org/10.5194/bgd-10-6763-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
10 Apr 2013
Responses of lower trophic-level organisms to typhoon passage on the outer shelf of the East China Sea: an incubation experiment
N. Yasuki, K. Suzuki, and A. Tsuda
Biogeosciences Discuss., 10, 6605–6635, https://doi.org/10.5194/bgd-10-6605-2013, https://doi.org/10.5194/bgd-10-6605-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 4 comments)
03 Apr 2013
Altered phenology and temperature sensitivity of invasive annual grasses and forbs changes autotrophic and heterotrophic respiration rates in a semi-arid shrub community
M. Mauritz and D. L. Lipson
Biogeosciences Discuss., 10, 6335–6375, https://doi.org/10.5194/bgd-10-6335-2013, https://doi.org/10.5194/bgd-10-6335-2013, 2013
Revised manuscript not accepted (discussion: closed, 3 comments)
12 Mar 2013
Decoupling of above and belowground C and N pools within predominant plant species Stipa grandis along a precipitation gradient in Chinese steppe zone
X. H. Ye, X. Pan, W. K. Cornwell, J. H. C. Cornelissen, Y. Chu, S. Q. Gao, R. Q. Li, J. J. Qiao, and M. Dong
Biogeosciences Discuss., 10, 4995–5013, https://doi.org/10.5194/bgd-10-4995-2013, https://doi.org/10.5194/bgd-10-4995-2013, 2013
Revised manuscript not accepted (discussion: closed, 3 comments)
05 Mar 2013
Carbon dioxide fluxes at an intensively cultivated temperate lowland peatland in the East Anglian Fens, UK
R. Morrison, A. M. J. Cumming, H. E. Taft, J. Kaduk, S. E. Page, D. L. Jones, R. J. Harding, and H. Balzter
Biogeosciences Discuss., 10, 4193–4223, https://doi.org/10.5194/bgd-10-4193-2013, https://doi.org/10.5194/bgd-10-4193-2013, 2013
Preprint withdrawn (discussion: closed, 6 comments)
21 Feb 2013
Food quality regulates the metabolism and reproduction of Temora longicornis
R. Nobili, C. Robinson, E. Buitenhuis, and C. Castellani
Biogeosciences Discuss., 10, 3203–3239, https://doi.org/10.5194/bgd-10-3203-2013, https://doi.org/10.5194/bgd-10-3203-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
05 Feb 2013
The submarine groundwater discharge as a carbon source to the Baltic Sea
B. Szymczycha, A. Maciejewska, A. Szczepanska, and J. Pempkowiak
Biogeosciences Discuss., 10, 2069–2091, https://doi.org/10.5194/bgd-10-2069-2013, https://doi.org/10.5194/bgd-10-2069-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
05 Feb 2013
Differential gene expression in the mussel Bathymodiolus azoricus from the Menez Gwen and Lucky Strike deep-sea hydrothermal vent sites
R. Bettencourt, M. I. Rodrigues, I. Barros, T. Cerqueira, C. Freitas, V. Costa, M. Pinheiro, C. Egas, and R. S. Santos
Biogeosciences Discuss., 10, 2013–2038, https://doi.org/10.5194/bgd-10-2013-2013, https://doi.org/10.5194/bgd-10-2013-2013, 2013
Revised manuscript not accepted (discussion: closed, 6 comments)
31 Jan 2013
Multiyear precipitation reduction strongly decrease carbon uptake over North China
W. P. Yuan, D. Liu, W. J. Dong, S. G. Liu, G. S. Zhou, G. R. Yu, T. B. Zhao, J. M. Feng, Z. G. Ma, J. Q. Chen, Y. Chen, S. P. Chen, S. J. Han, J. P. Huang, L. H. Li, H. Z. Liu, S. M. Liu, M. G. Ma, Y. F. Wang, J. Z. Xia, W. F. Xu, Q. Zhang, X. Q. Zhao, and L. Zhao
Biogeosciences Discuss., 10, 1605–1634, https://doi.org/10.5194/bgd-10-1605-2013, https://doi.org/10.5194/bgd-10-1605-2013, 2013
Revised manuscript not accepted (discussion: closed, 8 comments)
31 Jan 2013
Impact of physical processes on the phytoplankton blooms in the South China Sea: an eddy-resolving physical-biological model study
Y. Sasai, H. Sasaki, and K. J. Richards
Biogeosciences Discuss., 10, 1577–1604, https://doi.org/10.5194/bgd-10-1577-2013, https://doi.org/10.5194/bgd-10-1577-2013, 2013
Revised manuscript not accepted (discussion: closed, 5 comments)
30 Jan 2013
Detailed regional predictions of N2O and NO emissions from a tropical highland rainforest
N. Gharahi Ghehi, C. Werner, K. Hufkens, R. Kiese, E. Van Ranst, D. Nsabimana, G. Wallin, L. Klemedtsson, K. Butterbach-Bahl, and P. Boeckx
Biogeosciences Discuss., 10, 1483–1516, https://doi.org/10.5194/bgd-10-1483-2013, https://doi.org/10.5194/bgd-10-1483-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
24 Jan 2013
Satellite views of global phytoplankton community distributions using an empirical algorithm and a numerical model
C. S. Rousseaux, T. Hirata, and W. W. Gregg
Biogeosciences Discuss., 10, 1083–1109, https://doi.org/10.5194/bgd-10-1083-2013, https://doi.org/10.5194/bgd-10-1083-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
24 Jan 2013
Contributions of riverborne inorganic and organic matters to the benthic food web in the East China Sea as inferred from stable isotope ratios
N. N. Chang, J. C. Shiao, G. C. Gong, S. J. Kao, and C. H. Hsieh
Biogeosciences Discuss., 10, 1051–1081, https://doi.org/10.5194/bgd-10-1051-2013, https://doi.org/10.5194/bgd-10-1051-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
16 Jan 2013
Biological soil crusts on initial soils: organic carbon dynamics and chemistry under temperate climatic conditions
A. Dümig, M. Veste, F. Hagedorn, T. Fischer, P. Lange, R. Spröte, and I. Kögel-Knabner
Biogeosciences Discuss., 10, 851–894, https://doi.org/10.5194/bgd-10-851-2013, https://doi.org/10.5194/bgd-10-851-2013, 2013
Revised manuscript has not been submitted (discussion: closed, 7 comments)
15 Jan 2013
Incorporating genomic information and predicting gene expression patterns in a simplified biogeochemical model
P. Wang, A. B. Burd, M. A. Moran, R. R. Hood, V. J. Coles, and P. L. Yager
Biogeosciences Discuss., 10, 815–850, https://doi.org/10.5194/bgd-10-815-2013, https://doi.org/10.5194/bgd-10-815-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
07 Jan 2013
Coupling of the spatial dynamic of picoplankton and nanoflagellate grazing pressure and carbon flow of the microbial food web in the subtropical pelagic continental shelf ecosystem
K.-P. Chiang, A.-Y. Tsai, P.-J. Tsai, G.-C. Gong, and S.-F. Tsai
Biogeosciences Discuss., 10, 233–263, https://doi.org/10.5194/bgd-10-233-2013, https://doi.org/10.5194/bgd-10-233-2013, 2013
Revised manuscript not accepted (discussion: closed, 4 comments)
18 Dec 2012
Abiotic ammonification and gross ammonium photoproduction in the upwelling system off central Chile (36° S)
A. Rain-Franco, C. Muñoz, and C. Fernandez
Biogeosciences Discuss., 9, 18479–18518, https://doi.org/10.5194/bgd-9-18479-2012, https://doi.org/10.5194/bgd-9-18479-2012, 2012
Revised manuscript not accepted (discussion: closed, 3 comments)
17 Dec 2012
Influence of increasing dissolved inorganic carbon concentrations and decreasing pH on chemolithoautrophic bacteria from oxic-sulfidic interfaces
K. Mammitzsch, G. Jost, and K. Jürgens
Biogeosciences Discuss., 9, 18371–18395, https://doi.org/10.5194/bgd-9-18371-2012, https://doi.org/10.5194/bgd-9-18371-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
04 Dec 2012
Chemosynthesis in the deep-sea: life without the sun
C. Smith
Biogeosciences Discuss., 9, 17037–17052, https://doi.org/10.5194/bgd-9-17037-2012, https://doi.org/10.5194/bgd-9-17037-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 5 comments)
03 Dec 2012
Comprehensive phylogenetic reconstruction of relationships in Octocorallia (Cnidaria: Anthozoa) from the Atlantic ocean using mtMutS and nad2 genes tree reconstructions
K. J. Morris, S. Herrera, C. Gubili, P. A. Tyler, A. Rogers, and C. Hauton
Biogeosciences Discuss., 9, 16977–16998, https://doi.org/10.5194/bgd-9-16977-2012, https://doi.org/10.5194/bgd-9-16977-2012, 2012
Revised manuscript not accepted (discussion: closed, 3 comments)
22 Nov 2012
Lingulodinium machaerophorum expansion over the last centuries in the Caspian Sea reflects global warming
S. A. G. Leroy, H. A. K. Lahijani, J.-L. Reyss, F. Chalié, S. Haghani, M. Shah-Hosseini, S. Shahkarami, A. Tudryn, K. Arpe, P. Habibi, H. S. Nasrollahzadeh, and A. Makhlough
Biogeosciences Discuss., 9, 16663–16704, https://doi.org/10.5194/bgd-9-16663-2012, https://doi.org/10.5194/bgd-9-16663-2012, 2012
Preprint withdrawn (discussion: closed, 2 comments)
16 Nov 2012
Thermal and haline effects on the calculation of air-sea CO2 fluxes revisited
D. K. Woolf, P. E. Land, J. D. Shutler, and L. M. Goddijn-Murphy
Biogeosciences Discuss., 9, 16381–16417, https://doi.org/10.5194/bgd-9-16381-2012, https://doi.org/10.5194/bgd-9-16381-2012, 2012
Revised manuscript not accepted (discussion: closed, 6 comments)
05 Nov 2012
Marine carbonate system evolution during the EPOCA Arctic pelagic ecosystem experiment in the context of simulated Arctic ocean acidification
R. G. J. Bellerby, A. Silyakova, G. Nondal, D. Slagstad, J. Czerny, T. de Lange, and A. Ludwig
Biogeosciences Discuss., 9, 15541–15565, https://doi.org/10.5194/bgd-9-15541-2012, https://doi.org/10.5194/bgd-9-15541-2012, 2012
Preprint withdrawn (discussion: closed, 4 comments)
22 Oct 2012
Spatial scale dependency of the modelled climatic response to deforestation
P. Longobardi, A. Montenegro, H. Beltrami, and M. Eby
Biogeosciences Discuss., 9, 14639–14687, https://doi.org/10.5194/bgd-9-14639-2012, https://doi.org/10.5194/bgd-9-14639-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 2 comments)
17 Oct 2012
Methane emission measurements in a cattle grazed pasture: a comparison of four methods
T. Tallec, K. Klumpp, A. Hensen, Y. Rochette, and J.-F. Soussana
Biogeosciences Discuss., 9, 14407–14436, https://doi.org/10.5194/bgd-9-14407-2012, https://doi.org/10.5194/bgd-9-14407-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 3 comments)
05 Oct 2012
Nitrogen cycling in the Central Arabian Sea: a model study
A. Beckmann and I. Hense
Biogeosciences Discuss., 9, 13581–13625, https://doi.org/10.5194/bgd-9-13581-2012, https://doi.org/10.5194/bgd-9-13581-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
18 Sep 2012
Primary production and respiration of hypersaline microbial mats as a response for high and low CO2 availability
L. Bento, A. Enrich-Prast, and L. P. Nielsen
Biogeosciences Discuss., 9, 12735–12755, https://doi.org/10.5194/bgd-9-12735-2012, https://doi.org/10.5194/bgd-9-12735-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
18 Sep 2012
Microstructure and hydraulic properties of biological soil crusts on sand dunes: a comparison between arid and temperate climates
T. Fischer, A. Yair, and M. Veste
Biogeosciences Discuss., 9, 12711–12734, https://doi.org/10.5194/bgd-9-12711-2012, https://doi.org/10.5194/bgd-9-12711-2012, 2012
Revised manuscript not accepted (discussion: closed, 6 comments)
06 Aug 2012
CO2 exchange in a temperate marginal sea of the Mediterranean Sea: processes and carbon budget
G. Cossarini, S. Querin, and C. Solidoro
Biogeosciences Discuss., 9, 10331–10370, https://doi.org/10.5194/bgd-9-10331-2012, https://doi.org/10.5194/bgd-9-10331-2012, 2012
Revised manuscript not accepted (discussion: closed, 6 comments)
31 Jul 2012
Technical Note: n-Alkane lipid biomarkers in loess: post-sedimentary or syn-sedimentary?
M. Zech, S. Kreutzer, T. Goslar, S. Meszner, T. Krause, D. Faust, and M. Fuchs
Biogeosciences Discuss., 9, 9875–9896, https://doi.org/10.5194/bgd-9-9875-2012, https://doi.org/10.5194/bgd-9-9875-2012, 2012
Revised manuscript not accepted (discussion: closed, 6 comments)
31 Jul 2012
Tracing biogeochemical processes and pollution sources with stable isotopes in river systems: Kamniška Bistrica, North Slovenia
T. Kanduč, M. Šturm, S. Žigon, and J. McIntosh
Biogeosciences Discuss., 9, 9711–9757, https://doi.org/10.5194/bgd-9-9711-2012, https://doi.org/10.5194/bgd-9-9711-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 6 comments)
27 Jul 2012
Isotope data improve the predictive capabilities of a marine biogeochemical model
T. Van Engeland, A. De Kluijver, K. Soetaert, F. J. R. Meysman, and J. J. Middelburg
Biogeosciences Discuss., 9, 9453–9486, https://doi.org/10.5194/bgd-9-9453-2012, https://doi.org/10.5194/bgd-9-9453-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
23 Jul 2012
Two thresholds determine climatic control of forest-fire size in Europe
L. Loepfe, A. Rodrigo, and F. Lloret
Biogeosciences Discuss., 9, 9065–9089, https://doi.org/10.5194/bgd-9-9065-2012, https://doi.org/10.5194/bgd-9-9065-2012, 2012
Revised manuscript not accepted (discussion: closed, 3 comments)
17 Jul 2012
Mediterranean basin-wide correlations between Saharan dust deposition and ocean chlorophyll concentration
R. Gallisai, F. Peters, S. Basart, and J. M. Baldasano
Biogeosciences Discuss., 9, 8611–8639, https://doi.org/10.5194/bgd-9-8611-2012, https://doi.org/10.5194/bgd-9-8611-2012, 2012
Preprint withdrawn (discussion: closed, 3 comments)
17 Jul 2012
UV-induced carbon monoxide emission from sand and living vegetation
D. Bruhn, K. R. Albert, T. N. Mikkelsen, and P. Ambus
Biogeosciences Discuss., 9, 8449–8473, https://doi.org/10.5194/bgd-9-8449-2012, https://doi.org/10.5194/bgd-9-8449-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
12 Jul 2012
Can whales mix the ocean?
T. J. Lavery, B. Roudnew, L. Seuront, J. G. Mitchell, and J. Middleton
Biogeosciences Discuss., 9, 8387–8403, https://doi.org/10.5194/bgd-9-8387-2012, https://doi.org/10.5194/bgd-9-8387-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 8 comments)
10 Jul 2012
Measuring gross and net calcification of a reef coral under ocean acidification conditions: methodological considerations
S. Cohen and M. Fine
Biogeosciences Discuss., 9, 8241–8272, https://doi.org/10.5194/bgd-9-8241-2012, https://doi.org/10.5194/bgd-9-8241-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 4 comments)
02 Jul 2012
Feedbacks of CO2 dependent dissolved organic carbon production on atmospheric CO2 in an ocean biogeochemical model
L. A. Bordelon-Katrynski and B. Schneider
Biogeosciences Discuss., 9, 7983–8011, https://doi.org/10.5194/bgd-9-7983-2012, https://doi.org/10.5194/bgd-9-7983-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Jun 2012
Modeling the seasonal cycle of the oxygen minimum zone over the continental shelf off Concepción, Chile (36.5° S)
J. Charpentier, D. Mediavilla, and O. Pizarro
Biogeosciences Discuss., 9, 7227–7256, https://doi.org/10.5194/bgd-9-7227-2012, https://doi.org/10.5194/bgd-9-7227-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 4 comments)
18 Jun 2012
Are small mountainous tropical watersheds of oceanic islands important for carbon export?
E. Lloret, C. Dessert, E. Lajeunesse, O. Crispi, L. Pastor, J. Gaillardet, and M. F. Benedetti
Biogeosciences Discuss., 9, 7117–7163, https://doi.org/10.5194/bgd-9-7117-2012, https://doi.org/10.5194/bgd-9-7117-2012, 2012
Revised manuscript not accepted (discussion: closed, 6 comments)
04 Jun 2012
Sensitivity of North Patagonian temperate rainforests to changes in rainfall regimes: a process-based, dynamic forest model
A. G. Gutiérrez, J. J. Armesto, M. F. Díaz, and A. Huth
Biogeosciences Discuss., 9, 6293–6333, https://doi.org/10.5194/bgd-9-6293-2012, https://doi.org/10.5194/bgd-9-6293-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
01 Jun 2012
Historical records of eutrophication in Changjiang (Yangtze) River estuary and its adjacent East China Sea
F. Cheng, X. Song, Z. Yu, and D. Liu
Biogeosciences Discuss., 9, 6261–6291, https://doi.org/10.5194/bgd-9-6261-2012, https://doi.org/10.5194/bgd-9-6261-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
30 May 2012
Effect of carbonate chemistry manipulations on calcification, respiration, and excretion of a Mediterranean pteropod
S. Comeau, J.-P. Gattuso, R. Jeffree, and F. Gazeau
Biogeosciences Discuss., 9, 6169–6189, https://doi.org/10.5194/bgd-9-6169-2012, https://doi.org/10.5194/bgd-9-6169-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 2 comments)
25 May 2012
Primary Productivity and heterotrophic activity in an enclosed marine area of central Patagonia (Puyuhuapi channel; 44° S, 73° W)
G. Daneri, P. Montero, L. Lizárraga, R. Torres, J. L. Iriarte, B. Jacob, H. E. González, and F. J. Tapia
Biogeosciences Discuss., 9, 5929–5968, https://doi.org/10.5194/bgd-9-5929-2012, https://doi.org/10.5194/bgd-9-5929-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 4 comments)
07 May 2012
Impact of mire reclamation on export potential and characteristics of dissolved carbons in the Sanjiang Plain, Northeast China
Y. D. Guo, C. C. Song, Y. Z. Lu, Y. Y. Song, and Z. M. Wan
Biogeosciences Discuss., 9, 5347–5371, https://doi.org/10.5194/bgd-9-5347-2012, https://doi.org/10.5194/bgd-9-5347-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
25 Apr 2012
Annual hypoxia dynamics in an enclosed gulf
K. Kountoura and I. Zacharias
Biogeosciences Discuss., 9, 5049–5071, https://doi.org/10.5194/bgd-9-5049-2012, https://doi.org/10.5194/bgd-9-5049-2012, 2012
Revised manuscript not accepted (discussion: closed, 8 comments)
20 Apr 2012
Biological productivity in the Mauritanian upwelling estimated with a triple gas approach
T. Steinhoff, H. W. Bange, A. Kock, D. W. R. Wallace, and A. Körtzinger
Biogeosciences Discuss., 9, 4853–4875, https://doi.org/10.5194/bgd-9-4853-2012, https://doi.org/10.5194/bgd-9-4853-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 9 comments)
23 Mar 2012
Effect of Ocean acidification on growth, calcification and recruitment of calcifying and non-calcifying epibionts of brown algae
V. Saderne and M. Wahl
Biogeosciences Discuss., 9, 3739–3766, https://doi.org/10.5194/bgd-9-3739-2012, https://doi.org/10.5194/bgd-9-3739-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
20 Mar 2012
Spatial and temporal variations of dissolved organic carbon and inorganic carbon concentrations and δ13C in a peatland-stream continuum: implications of peatland invasion by vascular plants
S. Gogo, P. Albéric, F. Laggoun-Défarge, S. Binet, and A. Aurouet
Biogeosciences Discuss., 9, 3515–3544, https://doi.org/10.5194/bgd-9-3515-2012, https://doi.org/10.5194/bgd-9-3515-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 4 comments)
14 Mar 2012
Improved determination of daytime net ecosystem exchange of carbon dioxide at croplands
P. Zhao and J. Lüers
Biogeosciences Discuss., 9, 2883–2919, https://doi.org/10.5194/bgd-9-2883-2012, https://doi.org/10.5194/bgd-9-2883-2012, 2012
Revised manuscript not accepted (discussion: closed, 3 comments)
12 Mar 2012
Distributions of the carbonate system properties, anthropogenic CO2, and acidification during the 2008 BOUM cruise (Mediterranean Sea)
F. Touratier, V. Guglielmi, C. Goyet, L. Prieur, M. Pujo-Pay, P. Conan, and C. Falco
Biogeosciences Discuss., 9, 2709–2753, https://doi.org/10.5194/bgd-9-2709-2012, https://doi.org/10.5194/bgd-9-2709-2012, 2012
Revised manuscript not accepted (discussion: closed, 9 comments)
03 Feb 2012
Dissolved organic carbon release by marine macrophytes
C. Barrón, E. T. Apostolaki, and C. M. Duarte
Biogeosciences Discuss., 9, 1529–1555, https://doi.org/10.5194/bgd-9-1529-2012, https://doi.org/10.5194/bgd-9-1529-2012, 2012
Revised manuscript has not been submitted (discussion: closed, 6 comments)
03 Feb 2012
Progress on quantitative assessment methods of biological aerosols in the atmosphere
L. Liang, K. He, and F. Duan
Biogeosciences Discuss., 9, 1511–1528, https://doi.org/10.5194/bgd-9-1511-2012, https://doi.org/10.5194/bgd-9-1511-2012, 2012
Preprint withdrawn (discussion: closed, 2 comments)
26 Jan 2012
Environmental factors regulating winter CO2 flux in snow-covered boreal forest soil, interior Alaska
Y. Kim and Y. Kodama
Biogeosciences Discuss., 9, 1129–1159, https://doi.org/10.5194/bgd-9-1129-2012, https://doi.org/10.5194/bgd-9-1129-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
16 Jan 2012
Pyrite Oxidation under initially neutral pH conditions and in the presence of Acidithiobacillus ferrooxidans and micromolar hydrogen peroxide
Y. Ma and C. Lin
Biogeosciences Discuss., 9, 557–579, https://doi.org/10.5194/bgd-9-557-2012, https://doi.org/10.5194/bgd-9-557-2012, 2012
Revised manuscript not accepted (discussion: closed, 10 comments)
16 Jan 2012
Seasonal and latitudinal patterns of pelagic community metabolism in surface waters of the Atlantic Ocean
S. Agusti
Biogeosciences Discuss., 9, 507–525, https://doi.org/10.5194/bgd-9-507-2012, https://doi.org/10.5194/bgd-9-507-2012, 2012
Revised manuscript not accepted (discussion: closed, 4 comments)
04 Jan 2012
Nitrous oxide emission reduction in temperate biochar-amended soils
R. Felber, R. Hüppi, J. Leifeld, and A. Neftel
Biogeosciences Discuss., 9, 151–189, https://doi.org/10.5194/bgd-9-151-2012, https://doi.org/10.5194/bgd-9-151-2012, 2012
Preprint withdrawn (discussion: closed, 4 comments)
14 Dec 2011
Spatio-temporal variability of the CO2 system on the Scotian Shelf
E. H. Shadwick, H. Thomas, A. E. F. Prowe, and E. Horne
Biogeosciences Discuss., 8, 12013–12050, https://doi.org/10.5194/bgd-8-12013-2011, https://doi.org/10.5194/bgd-8-12013-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
14 Dec 2011
Changes in carbon fluxes and pools induced by cropland expansion in South and Southeast Asia in the 20th century
B. Tao, H. Tian, G. Chen, W. Ren, C. Lu, K. D. Alley, X. Xu, M. Liu, S. Pan, and H. Virji
Biogeosciences Discuss., 8, 11979–12012, https://doi.org/10.5194/bgd-8-11979-2011, https://doi.org/10.5194/bgd-8-11979-2011, 2011
Revised manuscript not accepted (discussion: closed, 8 comments)
18 Nov 2011
Soil carbon dynamics during secondary succession in a semi-arid Mediterranean environment
A. Novara, L. Gristina, T. La Mantia, and J. Rühl
Biogeosciences Discuss., 8, 11107–11138, https://doi.org/10.5194/bgd-8-11107-2011, https://doi.org/10.5194/bgd-8-11107-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
08 Nov 2011
Landscape patterns of soil oxygen and atmospheric greenhouse gases in a northern hardwood forest landscape
S. F. Werner, C. T. Driscoll, P. M. Groffman, and J. B. Yavitt
Biogeosciences Discuss., 8, 10859–10893, https://doi.org/10.5194/bgd-8-10859-2011, https://doi.org/10.5194/bgd-8-10859-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 3 comments)
08 Nov 2011
A model study on the sensitivity of surface ocean CO2 pressure with respect to the CO2 gas exchange rate
P. Landschützer, J. F. Tjiputra, K. Assmann, and C. Heinze
Biogeosciences Discuss., 8, 10797–10821, https://doi.org/10.5194/bgd-8-10797-2011, https://doi.org/10.5194/bgd-8-10797-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 6 comments)
28 Oct 2011
Daily CO2 partial pressure and CO2 outgassing in the upper Yangtze River basin: a case study of Longchuanjiang, China
S. Y. Li, X. X. Lu, M. He, Y. Zhou, L. Li, and A. D. Ziegler
Biogeosciences Discuss., 8, 10645–10676, https://doi.org/10.5194/bgd-8-10645-2011, https://doi.org/10.5194/bgd-8-10645-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 2 comments)
29 Sep 2011
New products for a better characterisation of smoke plume and gas/aerosol dispersion from boreal eurasian forest fires: the ALANIS Smoke Plume project
J.-P. Muller, V. Yershov, D. Fisher, M. Krol, W. Peters, J. San-Miguel, I. Palumbo, F. Sedano, P. Strobl, C. Clerbaux, M. George, J. Helbert, and B. Guillaume
Biogeosciences Discuss., 8, 9747–9761, https://doi.org/10.5194/bgd-8-9747-2011, https://doi.org/10.5194/bgd-8-9747-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 2 comments)
20 Sep 2011
Transformation of dissolved inorganic carbon (DIC) into particulate organic carbon (POC) in the lower Xijiang River, SE China: an isotopic approach
H. G. Sun, J. T. Han, S. R. Zhang, and X. X. Lu
Biogeosciences Discuss., 8, 9471–9501, https://doi.org/10.5194/bgd-8-9471-2011, https://doi.org/10.5194/bgd-8-9471-2011, 2011
Revised manuscript not accepted (discussion: closed, 5 comments)
12 Sep 2011
An approach to the investigation of CO2 uptake by soil microorganisms
K. M. Hart, B. W. Moran, C. C. R. Allen, V. Kouloumbos, S. F. Oppenheimer, L. Barron, A. J. Simpson, L. A. Kulakov, and B. P. Kelleher
Biogeosciences Discuss., 8, 9235–9281, https://doi.org/10.5194/bgd-8-9235-2011, https://doi.org/10.5194/bgd-8-9235-2011, 2011
Preprint withdrawn (discussion: closed, 4 comments)
09 Sep 2011
Non-lethal effects of ocean acidification on two symbiont-bearing benthic foraminiferal species
A. McIntyre-Wressnig, J. M. Bernhard, D. C. McCorkle, and P. Hallock
Biogeosciences Discuss., 8, 9165–9200, https://doi.org/10.5194/bgd-8-9165-2011, https://doi.org/10.5194/bgd-8-9165-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 4 comments)
26 Aug 2011
Seasonality of ecosystem respiration in a double-cropping paddy field in Bangladesh
M. S. Hossen, M. Mano, A. Miyata, M. A. Baten, and T. Hiyama
Biogeosciences Discuss., 8, 8693–8721, https://doi.org/10.5194/bgd-8-8693-2011, https://doi.org/10.5194/bgd-8-8693-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 2 comments)
23 Aug 2011
On the use of satellites to obtain information on the occurrence of natural and anthropogenic aerosols over the boreal eurasian forest
G. de Leeuw, A. Arola, L. Sogacheva, N. Kivekäs, V.-M. Kerminen, A. Arneth, T. Christensen, H. Korhonen, A.-I. Partanen, H. Lappalainen, P. Kolmonen, T. Mielonen, M. Sofiev, M. Kulmala, and S. Pinnock
Biogeosciences Discuss., 8, 8451–8483, https://doi.org/10.5194/bgd-8-8451-2011, https://doi.org/10.5194/bgd-8-8451-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 4 comments)
23 Aug 2011
Effect of salinity induced pH changes on benthic foraminifera: a laboratory culture experiment
R. Saraswat, M. Kouthanker, S. Kurtarkar, R. Nigam, and V. N. Linshy
Biogeosciences Discuss., 8, 8423–8450, https://doi.org/10.5194/bgd-8-8423-2011, https://doi.org/10.5194/bgd-8-8423-2011, 2011
Revised manuscript not accepted (discussion: closed, 6 comments)
11 Aug 2011
Controls on benthic biomass size spectra in shelf and deep-sea sediments – a modelling study
B. A. Kelly-Gerreyn, T. R. Anderson, B. J. Bett, A. P. Martin, and J. I. Kaariainen
Biogeosciences Discuss., 8, 8189–8240, https://doi.org/10.5194/bgd-8-8189-2011, https://doi.org/10.5194/bgd-8-8189-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 2 comments)
22 Jul 2011
Mineral dust aerosol from Saharan desert by means of atmospheric, emission, dispersion modelling
F. Guarnieri, F. Calastrini, C. Busillo, M. Pasqui, S. Becagli, F. Lucarelli, G. Calzolai, S. Nava, and R. Udisti
Biogeosciences Discuss., 8, 7313–7338, https://doi.org/10.5194/bgd-8-7313-2011, https://doi.org/10.5194/bgd-8-7313-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 3 comments)
21 Jul 2011
Modeling the vertical soil organic matter profile using 210Pbex measurements and Bayesian inversion
M. C. Braakhekke, T. Wutzler, M. Reichstein, J. Kattge, C. Beer, M. Schrumpf, I. Schöning, M. R. Hoosbeek, B. Kruijt, and P. Kabat
Biogeosciences Discuss., 8, 7257–7312, https://doi.org/10.5194/bgd-8-7257-2011, https://doi.org/10.5194/bgd-8-7257-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 2 comments)
19 Jul 2011
Above- and below-ground response to soil moisture change on an alpine wetland ecosystem in the Qinghai-Tibetan Plateau, China
G.-L. Wu, W. Li, L.-P. Zhao, Z.-H. Shi, and Z.-P. Shangguan
Biogeosciences Discuss., 8, 7141–7164, https://doi.org/10.5194/bgd-8-7141-2011, https://doi.org/10.5194/bgd-8-7141-2011, 2011
Preprint withdrawn (discussion: closed, 7 comments)
13 Jul 2011
Phytoplankton distribution in the Western Arctic Ocean during a summer of exceptional ice retreat
P. Coupel, H. Y. Jin, D. Ruiz-Pino, J. F. Chen, S. H. Lee, H. L. Li, M. Rafizadeh, V. Garçon, and J. C. Gascard
Biogeosciences Discuss., 8, 6919–6970, https://doi.org/10.5194/bgd-8-6919-2011, https://doi.org/10.5194/bgd-8-6919-2011, 2011
Revised manuscript not accepted (discussion: closed, 9 comments)
08 Jul 2011
Volatile diterpene emission from dominant conifers in Japan
S. N. Matsunaga, S. Chatani, S. Nakatsuka, D. Kusumoto, K. Kubota, Y. Utsumi, T. Enoki, A. Tani, and T. Hiura
Biogeosciences Discuss., 8, 6681–6700, https://doi.org/10.5194/bgd-8-6681-2011, https://doi.org/10.5194/bgd-8-6681-2011, 2011
Revised manuscript not accepted (discussion: closed, 5 comments)
08 Jul 2011
A Holocene record of mercury accumulation in a pristine lake in Southernmost South America (53° S) – climatic and environmental drivers
Y.-M. Hermanns and H. Biester
Biogeosciences Discuss., 8, 6555–6588, https://doi.org/10.5194/bgd-8-6555-2011, https://doi.org/10.5194/bgd-8-6555-2011, 2011
Revised manuscript not accepted (discussion: closed, 6 comments)
08 Jul 2011
Can Mg isotopes be used to trace cyanobacteria-mediated magnesium carbonate precipitation in alkaline lakes?
L. S. Shirokova, V. Mavromatis, I. Bundeleva, O. S. Pokrovsky, P. Bénézeth, C. Pearce, E. Gérard, S. Balor, and E. H. Oelkers
Biogeosciences Discuss., 8, 6473–6517, https://doi.org/10.5194/bgd-8-6473-2011, https://doi.org/10.5194/bgd-8-6473-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
07 Jul 2011
Soil warming in a cool-temperate mixed forest with peat soil enhanced heterotrophic and basal respiration rates but Q10 remained unchanged
M. Aguilos, K. Takagi, N. Liang, Y. Watanabe, S. Goto, Y. Takahashi, H. Mukai, and K. Sasa
Biogeosciences Discuss., 8, 6415–6445, https://doi.org/10.5194/bgd-8-6415-2011, https://doi.org/10.5194/bgd-8-6415-2011, 2011
Revised manuscript not accepted (discussion: closed, 6 comments)
30 Jun 2011
The combined impact of CO2-dependent parameterisations of Redfield and Rain ratios on ocean carbonate saturation
K. F. Kvale, K. J. Meissner, M. d'Orgeville, R. J. Matear, B. I. McNeil, and M. H. England
Biogeosciences Discuss., 8, 6265–6280, https://doi.org/10.5194/bgd-8-6265-2011, https://doi.org/10.5194/bgd-8-6265-2011, 2011
Revised manuscript not accepted (discussion: closed, 7 comments)
29 Jun 2011
Ecological research and large scale land-atmosphere feedbacks: lesson from the Bouchet's complementary relationship
E. Lugato, G. Alberti, B. Gioli, J. O. Kaplan, A. Peressotti, and F. Miglietta
Biogeosciences Discuss., 8, 6077–6094, https://doi.org/10.5194/bgd-8-6077-2011, https://doi.org/10.5194/bgd-8-6077-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 4 comments)
29 Jun 2011
Effects of flooding cycles in the Pantanal on the turnover of soil nitrogen pools and emission of N2O
L. Liengaard, L. P. Nielsen, N. P. Revsbech, B. Elberling, A. Priemé, A. E. Prast, and M. Kühl
Biogeosciences Discuss., 8, 5991–6030, https://doi.org/10.5194/bgd-8-5991-2011, https://doi.org/10.5194/bgd-8-5991-2011, 2011
Revised manuscript not accepted (discussion: closed, 6 comments)
09 Jun 2011
Contributions of agricultural plants and soils to N2O emission in a farmland
J. Li, X. Lee, Q. Yu, X. Tong, Z. Qin, and B. Macdonald
Biogeosciences Discuss., 8, 5505–5535, https://doi.org/10.5194/bgd-8-5505-2011, https://doi.org/10.5194/bgd-8-5505-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
27 May 2011
Coexisting methane and oxygen excesses in nitrate-limited polar water (Fram Strait) during ongoing sea ice melting
E. Damm, S. Thoms, G. Kattner, A. Beszczynska-Möller, E. M. Nöthig, and I. Stimac
Biogeosciences Discuss., 8, 5179–5195, https://doi.org/10.5194/bgd-8-5179-2011, https://doi.org/10.5194/bgd-8-5179-2011, 2011
Revised manuscript not accepted (discussion: closed, 3 comments)
06 May 2011
Response of δ13C in plant and soil respiration to a water pulse
Y. Salmon, N. Buchmann, and R. L. Barnard
Biogeosciences Discuss., 8, 4493–4527, https://doi.org/10.5194/bgd-8-4493-2011, https://doi.org/10.5194/bgd-8-4493-2011, 2011
Preprint withdrawn (discussion: closed, 4 comments)
06 May 2011
Paleofires and the dynamics of carbon cycling in Chinese Loess Plateau over the last two glacial cycles
X. Wang and Z. L. Ding
Biogeosciences Discuss., 8, 4459–4492, https://doi.org/10.5194/bgd-8-4459-2011, https://doi.org/10.5194/bgd-8-4459-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
20 Apr 2011
Recovery of GPP monthly pattern in a eucalypt site in Portugal after felling
A. Rodrigues and G. Pita
Biogeosciences Discuss., 8, 3999–4014, https://doi.org/10.5194/bgd-8-3999-2011, https://doi.org/10.5194/bgd-8-3999-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
12 Apr 2011
Environmental factors associated with long-term changes in chlorophyll-a concentration in the Amazon floodplain
E. Alcântara, E. M. Novo, C. F. Barbosa, M.-P. Bonnet, J. Stech, and J. P. Ometto
Biogeosciences Discuss., 8, 3739–3770, https://doi.org/10.5194/bgd-8-3739-2011, https://doi.org/10.5194/bgd-8-3739-2011, 2011
Manuscript not accepted for further review (discussion: closed, 1 comment)
02 Mar 2011
Impact of extreme precipitation and water table change on N2O fluxes in a bio-energy poplar plantation
D. Zona, I. A. Janssens, M. S. Verlinden, L. S. Broeckx, J. Cools, B. Gioli, A. Zaldei, and R. Ceulemans
Biogeosciences Discuss., 8, 2057–2092, https://doi.org/10.5194/bgd-8-2057-2011, https://doi.org/10.5194/bgd-8-2057-2011, 2011
Revised manuscript not accepted (discussion: closed, 7 comments)
02 Mar 2011
Evidence for microbial dissolution of pyrite from the Lower Cambrian oolitic limestone, South China
W. Liu and X.-L. Zhang
Biogeosciences Discuss., 8, 2035–2056, https://doi.org/10.5194/bgd-8-2035-2011, https://doi.org/10.5194/bgd-8-2035-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
01 Mar 2011
Role of net radiation on energy balance closure in heterogeneous grasslands
C. Shao, J. Chen, L. Li, G. Tenney, W. Xu, and J. Xu
Biogeosciences Discuss., 8, 2001–2033, https://doi.org/10.5194/bgd-8-2001-2011, https://doi.org/10.5194/bgd-8-2001-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
23 Feb 2011
Effects of cloudiness on carbon dioxide exchange over an irrigated maize cropland in northwestern China
B. C. Zhang, J. J. Cao, Y. F. Bai, S. J. Yang, L. Hu, and Z. G. Ning
Biogeosciences Discuss., 8, 1669–1691, https://doi.org/10.5194/bgd-8-1669-2011, https://doi.org/10.5194/bgd-8-1669-2011, 2011
Revised manuscript not accepted (discussion: closed, 6 comments)
21 Feb 2011
Soil organic carbon (SOC) accumulation in rice paddies under long-term agro-ecosystem experiments in southern China – VI. Changes in microbial community structure and respiratory activity
D. Liu, X. Liu, Y. Liu, L. Li, G. Pan, D. Crowley, and R. Tippkötter
Biogeosciences Discuss., 8, 1529–1554, https://doi.org/10.5194/bgd-8-1529-2011, https://doi.org/10.5194/bgd-8-1529-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
14 Feb 2011
Examining moisture and temperature sensitivity of soil organic matter decomposition in a temperate coniferous forest soil
C. E. Gabriel and L. Kellman
Biogeosciences Discuss., 8, 1369–1409, https://doi.org/10.5194/bgd-8-1369-2011, https://doi.org/10.5194/bgd-8-1369-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
10 Feb 2011
Biogeochemistry of sediments from restricted exchange environments of Kandalaksha Bay, White Sea, Russian Arctic
S. Koukina, A. Vetrov, and N. Belyaev
Biogeosciences Discuss., 8, 1309–1333, https://doi.org/10.5194/bgd-8-1309-2011, https://doi.org/10.5194/bgd-8-1309-2011, 2011
Preprint withdrawn (discussion: closed, 5 comments)
31 Jan 2011
Stable carbon isotope as a proxy for the change of phytoplankton community structure in cascade reservoirs from Wujiang River, China
B. Wang, C. Q. Liu, X. Peng, F. Wang, and C. Chen
Biogeosciences Discuss., 8, 831–856, https://doi.org/10.5194/bgd-8-831-2011, https://doi.org/10.5194/bgd-8-831-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
18 Jan 2011
Phytoplankton diversity and productivity in a highly turbid, tropical coastal system (Bach Dang Estuary, Vietnam)
E. J. Rochelle-Newall, V. T. Chu, O. Pringault, D. Amouroux, R. Arfi, Y. Bettarel, T. Bouvier, C. Bouvier, P. Got, T. M. H. Nguyen, X. Mari, P. Navarro, T. N. Duong, T. T. T. Cao, T. T. Pham, S. Ouillon, and J.-P. Torréton
Biogeosciences Discuss., 8, 487–525, https://doi.org/10.5194/bgd-8-487-2011, https://doi.org/10.5194/bgd-8-487-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
11 Jan 2011
Manganese redox cycling in Lake Imandra: impact on nitrogen and the trace metal sediment record
J. Ingri, L. Pekka, V. Dauvalter, I. Rodushkin, and E. Peinerud
Biogeosciences Discuss., 8, 273–321, https://doi.org/10.5194/bgd-8-273-2011, https://doi.org/10.5194/bgd-8-273-2011, 2011
Revised manuscript has not been submitted (discussion: closed, 3 comments)
04 Jan 2011
Carbon isotope discrimination during litter decomposition can be explained by selective use of substrate with differing δ13C
J. Ngao and M. F. Cotrufo
Biogeosciences Discuss., 8, 51–82, https://doi.org/10.5194/bgd-8-51-2011, https://doi.org/10.5194/bgd-8-51-2011, 2011
Revised manuscript not accepted (discussion: closed, 4 comments)
15 Dec 2010
Spatial and seasonal variability of heterotrophic and autotrophic soil respiration in a winter wheat stand
N. Prolingheuer, B. Scharnagl, A. Graf, H. Vereecken, and M. Herbst
Biogeosciences Discuss., 7, 9137–9173, https://doi.org/10.5194/bgd-7-9137-2010, https://doi.org/10.5194/bgd-7-9137-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
13 Dec 2010
The influence of pulsed redox conditions on soil phosphorus
R. Scalenghe, A. C. Edwards, E. Barberis, and F. Ajmone Marsan
Biogeosciences Discuss., 7, 9009–9037, https://doi.org/10.5194/bgd-7-9009-2010, https://doi.org/10.5194/bgd-7-9009-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
27 Oct 2010
Production and consumption mechanisms of N2O in the Southern Ocean revealed from its isotopomer ratios
N. Boontanon, S. Watanabe, T. Odate, and N. Yoshida
Biogeosciences Discuss., 7, 7821–7848, https://doi.org/10.5194/bgd-7-7821-2010, https://doi.org/10.5194/bgd-7-7821-2010, 2010
Revised manuscript has not been submitted (discussion: closed, 4 comments)
20 Oct 2010
Anthropogenic stressors and eutrophication processes as recorded by stable isotopes compositions in coral skeletons
O. Levy, M. Rosenfeld, Y. Loya, R. Yam, I. Mizrachi, and A. Shemesh
Biogeosciences Discuss., 7, 7657–7672, https://doi.org/10.5194/bgd-7-7657-2010, https://doi.org/10.5194/bgd-7-7657-2010, 2010
Revised manuscript has not been submitted (discussion: closed, 3 comments)
29 Sep 2010
Methane production, consumption and its carbon isotope ratios in the Southern Ocean during the austral summer
N. Boontanon, S. Watanabe, T. Odate, and N. Yoshida
Biogeosciences Discuss., 7, 7207–7225, https://doi.org/10.5194/bgd-7-7207-2010, https://doi.org/10.5194/bgd-7-7207-2010, 2010
Revised manuscript has not been submitted (discussion: closed, 4 comments)
24 Sep 2010
The influence of leaf photosynthetic efficiency and stomatal closure on canopy carbon uptake and evapotranspiration – a model study in wheat and sugar beet
A. Schickling, A. Graf, R. Pieruschka, C. Plückers, H. Geiß, I.-L. Lai, J. H. Schween, K. Erentok, M. Schmidt, A. Wahner, S. Crewell, and U. Rascher
Biogeosciences Discuss., 7, 7131–7172, https://doi.org/10.5194/bgd-7-7131-2010, https://doi.org/10.5194/bgd-7-7131-2010, 2010
Revised manuscript has not been submitted (discussion: closed, 7 comments)
09 Sep 2010
Temporal and spatial variations of soil carbon dioxide, methane, and nitrous oxide fluxes in a Southeast Asian tropical rainforest
M. Itoh, Y. Kosugi, S. Takanashi, Y. Hayashi, S. Kanemitsu, K. Osaka, M. Tani, and A. R. Nik
Biogeosciences Discuss., 7, 6847–6887, https://doi.org/10.5194/bgd-7-6847-2010, https://doi.org/10.5194/bgd-7-6847-2010, 2010
Revised manuscript not accepted (discussion: closed, 6 comments)
03 Sep 2010
Transport and characterization of ambient biological aerosol near Laurel, MD
J. L. Santarpia, D. Cunningham, J. Gilberry, S. Kim, E. E. Smith, S. Ratnesar-Shumate, and J. Quizon
Biogeosciences Discuss., 7, 6725–6747, https://doi.org/10.5194/bgd-7-6725-2010, https://doi.org/10.5194/bgd-7-6725-2010, 2010
Revised manuscript not accepted (discussion: closed, 3 comments)
02 Sep 2010
High production of nitrous oxide (N2O), methane (CH4) and dimethylsulphoniopropionate (DMSP) in a massive marine phytoplankton culture
L. Florez-Leiva, E. Tarifeño, M. Cornejo, R. Kiene, and L. Farías
Biogeosciences Discuss., 7, 6705–6723, https://doi.org/10.5194/bgd-7-6705-2010, https://doi.org/10.5194/bgd-7-6705-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Aug 2010
Assessing the ecological status of plankton in Anjos Bay: a flow cytometry approach
G. C. Pereira, A. R. de Figuiredo, P. M. Jabor, and N. F. F. Ebecken
Biogeosciences Discuss., 7, 6243–6264, https://doi.org/10.5194/bgd-7-6243-2010, https://doi.org/10.5194/bgd-7-6243-2010, 2010
Revised manuscript not accepted (discussion: closed, 9 comments)
13 Aug 2010
Impact of seasonal oxygen deficiency on the phosphorous geochemistry of surface sediments along the Western Continental Shelf of India
Josia Jacob, Prosenjit Ghosh, K. K. Balchandran, and Rejomon George
Biogeosciences Discuss., 7, 6089–6119, https://doi.org/10.5194/bgd-7-6089-2010, https://doi.org/10.5194/bgd-7-6089-2010, 2010
Preprint withdrawn (discussion: closed, 8 comments)
13 Aug 2010
Seasonal variations in nitrate isotope composition of three rivers draining into the North Sea
A. Deek, K. Emeis, and U. Struck
Biogeosciences Discuss., 7, 6051–6088, https://doi.org/10.5194/bgd-7-6051-2010, https://doi.org/10.5194/bgd-7-6051-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
13 Aug 2010
The greenhouse gas balance of European grasslands
P. Ciais, J. F. Soussana, N. Vuichard, S. Luyssaert, A. Don, I. A. Janssens, S. L. Piao, R. Dechow, J. Lathière, F. Maignan, M. Wattenbach, P. Smith, C. Ammann, A. Freibauer, E. D. Schulze, and the CARBOEUROPE Synthesis Team
Biogeosciences Discuss., 7, 5997–6050, https://doi.org/10.5194/bgd-7-5997-2010, https://doi.org/10.5194/bgd-7-5997-2010, 2010
Revised manuscript has not been submitted (discussion: closed, 2 comments)
13 Aug 2010
Impact of nutrient starvation on the biochemical composition of the marine diatom Thalassiosira weissflogii: from the whole cell to the frustule fraction
C. Soler, P. Claquin, M. Goutx, O. Ragueneau, and B. Moriceau
Biogeosciences Discuss., 7, 5953–5995, https://doi.org/10.5194/bgd-7-5953-2010, https://doi.org/10.5194/bgd-7-5953-2010, 2010
Revised manuscript has not been submitted (discussion: closed, 3 comments)
03 Aug 2010
Impacts of increasing water and nitrogen availability on ecosystem CO2 fluxes in a temperate steppe of Northern China
L. Yan, S. Chen, J. Huang, and G. Lin
Biogeosciences Discuss., 7, 5829–5858, https://doi.org/10.5194/bgd-7-5829-2010, https://doi.org/10.5194/bgd-7-5829-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Jul 2010
Impact of climate and land use/cover changes on the carbon cycle in China (1981–2000): a system-based assessment
Z. Gao, W. Gao, and N.-B. Chang
Biogeosciences Discuss., 7, 5517–5555, https://doi.org/10.5194/bgd-7-5517-2010, https://doi.org/10.5194/bgd-7-5517-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
08 Jun 2010
Crustal uplifting rate associated with late-Holocene glacial-isostatic rebound at Skallen and Skarvsnes, Lützow-Holm Bay, East Antarctica: evidence of a synchrony in sedimentary and biological facies on geological setting
Y. Takano, Y. Yokoyama, J. J. Tyler, H. Kojima, M. Fukui, T. Sato, N. O. Ogawa, N. Suzuki, H. Kitazato, and N. Ohkouchi
Biogeosciences Discuss., 7, 4341–4384, https://doi.org/10.5194/bgd-7-4341-2010, https://doi.org/10.5194/bgd-7-4341-2010, 2010
Revised manuscript not accepted (discussion: closed, 5 comments)
31 May 2010
Organic nutrients as sources of N and P to the upper layers of the North Atlantic subtropical gyre along 24.5° N
A. Landolfi, H. Dietze, W. Koeve, R. Mather, and R. Sanders
Biogeosciences Discuss., 7, 4001–4044, https://doi.org/10.5194/bgd-7-4001-2010, https://doi.org/10.5194/bgd-7-4001-2010, 2010
Manuscript not accepted for further review (discussion: closed, 4 comments)
25 May 2010
Spatial and temporal variations in the sea surface pCO2 and air-sea CO2 flux in the equatorial Pacific: model sensitivity to gas exchange and biological formulations
X. J. Wang
Biogeosciences Discuss., 7, 3879–3910, https://doi.org/10.5194/bgd-7-3879-2010, https://doi.org/10.5194/bgd-7-3879-2010, 2010
Revised manuscript not accepted (discussion: closed, 3 comments)
21 May 2010
Comprehensive description of the carbon cycle of an ancient temperate broadleaved woodland
K. Fenn, Y. Malhi, M. Morecroft, C. Lloyd, and M. Thomas
Biogeosciences Discuss., 7, 3735–3763, https://doi.org/10.5194/bgd-7-3735-2010, https://doi.org/10.5194/bgd-7-3735-2010, 2010
Revised manuscript not accepted (discussion: closed, 5 comments)
19 May 2010
Altered response to nitrogen supply of mixed grassland communities in a future climate: a controlled environment microcosm study
J. Van den Berge, K. Naudts, C. Zavalloni, I. A. Janssens, R. Ceulemans, and I. Nijs
Biogeosciences Discuss., 7, 3579–3604, https://doi.org/10.5194/bgd-7-3579-2010, https://doi.org/10.5194/bgd-7-3579-2010, 2010
Preprint withdrawn (discussion: closed, 2 comments)
04 May 2010
Quantification of DOC concentrations in relation with soil properties of soils in tundra and taiga of Northern European Russia
M. R. Oosterwoud, E. J. M. Temminghoff, and S. E. A. T. M. van der Zee
Biogeosciences Discuss., 7, 3189–3226, https://doi.org/10.5194/bgd-7-3189-2010, https://doi.org/10.5194/bgd-7-3189-2010, 2010
Revised manuscript not accepted (discussion: closed, 3 comments)
08 Apr 2010
Factors controlling the temporal variability of mass and trace metal downward flux at 1000 m depth at the DYFAMED site (Northwestern Mediterranean Sea)
L.-E. Heimbürger, C. Migon, R. Losno, J.-C. Miquel, N. Leblond, and D. Cossa
Biogeosciences Discuss., 7, 2549–2567, https://doi.org/10.5194/bgd-7-2549-2010, https://doi.org/10.5194/bgd-7-2549-2010, 2010
Revised manuscript not accepted (discussion: closed, 6 comments)
29 Mar 2010
No change in topsoil carbon levels of Great Britain, 1978–2007
P. M. Chamberlain, B. A. Emmett, W. A. Scott, H. I. J. Black, M. Hornung, and Z. L. Frogbrook
Biogeosciences Discuss., 7, 2267–2311, https://doi.org/10.5194/bgd-7-2267-2010, https://doi.org/10.5194/bgd-7-2267-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
26 Mar 2010
Climate driven decadal variations of biological production and plankton biomass in the equatorial Pacific Ocean: is this a regime shift?
X. J. Wang, R. Murtugudde, and R. Le Borgne
Biogeosciences Discuss., 7, 2169–2193, https://doi.org/10.5194/bgd-7-2169-2010, https://doi.org/10.5194/bgd-7-2169-2010, 2010
Revised manuscript not accepted (discussion: closed, 5 comments)
15 Mar 2010
Formation of anoxia and denitrification in the bottom waters of a tropical estuary, southwest coast of India
G. D. Martin, K. R. Muraleedharan, J. G. Vijay, G. Rejomon, N. V. Madhu, A. Shivaprasad, C. K. Haridevi, M. Nair, K. K. Balachandran, C. Revichandran, K. V. Jayalakshmy, and N. Chandramohanakumar
Biogeosciences Discuss., 7, 1751–1782, https://doi.org/10.5194/bgd-7-1751-2010, https://doi.org/10.5194/bgd-7-1751-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
08 Mar 2010
On CO2 pertubation experiments: over-determination of carbonate chemistry reveals inconsistencies
C. J. M. Hoppe, G. Langer, S. D. Rokitta, D. A. Wolf-Gladrow, and B. Rost
Biogeosciences Discuss., 7, 1707–1726, https://doi.org/10.5194/bgd-7-1707-2010, https://doi.org/10.5194/bgd-7-1707-2010, 2010
Revised manuscript not accepted (discussion: closed, 7 comments)
03 Mar 2010
Technical Note: A combined soil/canopy chamber system for tracing δ13C in soil respiration after a 13CO2 canopy pulse labelling
M. Barthel, P. Sturm, L. Gentsch, and A. Knohl
Biogeosciences Discuss., 7, 1603–1631, https://doi.org/10.5194/bgd-7-1603-2010, https://doi.org/10.5194/bgd-7-1603-2010, 2010
Revised manuscript not accepted (discussion: closed, 3 comments)
03 Mar 2010
Carbon input control over soil organic matter dynamics in a temperate grassland exposed to elevated CO2 and warming
Y. Carrillo, E. Pendall, F. A. Dijkstra, J. A. Morgan, and J. M. Newcomb
Biogeosciences Discuss., 7, 1575–1602, https://doi.org/10.5194/bgd-7-1575-2010, https://doi.org/10.5194/bgd-7-1575-2010, 2010
Revised manuscript not accepted (discussion: closed, 9 comments)
17 Feb 2010
Estimation of nighttime ecosystem respiration over a paddy field in China
M. S. Hossen, T. Hiyama, and H. Tanaka
Biogeosciences Discuss., 7, 1201–1232, https://doi.org/10.5194/bgd-7-1201-2010, https://doi.org/10.5194/bgd-7-1201-2010, 2010
Revised manuscript has not been submitted (discussion: closed, 4 comments)
16 Feb 2010
Satellites reveal an increase in gross primary production in a greenlandic high arctic fen 1992–2008
T. Tagesson, M. Mastepanov, M. P. Tamstorf, L. Eklundh, P. Schubert, A. Ekberg, C. Sigsgaard, T. R. Christensen, and L. Ström
Biogeosciences Discuss., 7, 1101–1129, https://doi.org/10.5194/bgd-7-1101-2010, https://doi.org/10.5194/bgd-7-1101-2010, 2010
Revised manuscript not accepted (discussion: closed, 5 comments)
02 Feb 2010
Nitrogen storage and variability in paddy soils of China
J. S. Lin, X. Z. Shi, D. S. Yu, D. C. Weindorf, H. J. Wang, Y. C. Zhao, W. X. Sun, and Q. H. Liu
Biogeosciences Discuss., 7, 855–877, https://doi.org/10.5194/bgd-7-855-2010, https://doi.org/10.5194/bgd-7-855-2010, 2010
Preprint withdrawn (discussion: closed, 6 comments)
02 Feb 2010
VOC emissions from dry leaf litter and their dependence on temperature
L. Derendorp, R. Holzinger, A. Wishkerman, F. Keppler, and T. Röckmann
Biogeosciences Discuss., 7, 823–854, https://doi.org/10.5194/bgd-7-823-2010, https://doi.org/10.5194/bgd-7-823-2010, 2010
Revised manuscript not accepted (discussion: closed, 7 comments)
21 Jan 2010
Alkenone-based temperature patterns along the eastern South Pacific Coastal Ocean: the effect of upwelling and advection on the sedimentary alkenone unsaturation-index (U37K')
J. A. Placencia, J. Garcés-Vargas, C. B. Lange, and D. Hebbeln
Biogeosciences Discuss., 7, 545–564, https://doi.org/10.5194/bgd-7-545-2010, https://doi.org/10.5194/bgd-7-545-2010, 2010
Revised manuscript not accepted (discussion: closed, 6 comments)
05 Jan 2010
Vertical patterns of soil carbon, nitrogen and carbon: nitrogen stoichiometry in Tibetan grasslands
Y. H. Yang, J. Y. Fang, D. L. Guo, C. J. Ji, and W. H. Ma
Biogeosciences Discuss., 7, 1–24, https://doi.org/10.5194/bgd-7-1-2010, https://doi.org/10.5194/bgd-7-1-2010, 2010
Revised manuscript not accepted (discussion: closed, 4 comments)
16 Nov 2009
Fast and accurate irradiance calculations for ecosystem models
C. D. Mobley, L. K. Sundman, W. P. Bissett, and B. Cahill
Biogeosciences Discuss., 6, 10625–10662, https://doi.org/10.5194/bgd-6-10625-2009, https://doi.org/10.5194/bgd-6-10625-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 4 comments)
11 Nov 2009
Reducing impacts of systematic errors in the observation data on inversing ecosystem model parameters using different normalization methods
L. Zhang, M. Xu, M. Huang, and G. Yu
Biogeosciences Discuss., 6, 10447–10477, https://doi.org/10.5194/bgd-6-10447-2009, https://doi.org/10.5194/bgd-6-10447-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 6 comments)
28 Oct 2009
Local ecosystem feedbacks and critical transitions in the climate
M. Rietkerk, V. Brovkin, P. M. van Bodegom, M. Claussen, S. C. Dekker, H. A. Dijkstra, S. V. Goryachkin, P. Kabat, E. H. van Nes, A.-M. Neutel, S. E. Nicholson, C. Nobre, V. Petoukhov, A. Provenzale, M. Scheffer, and S. I. Seneviratne
Biogeosciences Discuss., 6, 10121–10136, https://doi.org/10.5194/bgd-6-10121-2009, https://doi.org/10.5194/bgd-6-10121-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 3 comments)
27 Oct 2009
Seasonal and interannual study of volatile reduced sulfur compounds (VRSC) in coastal environment: the Bay of Quiberon (Brittany, France)
A. Cozic-Houly, E. Viollier, G. Sarazin, and J. Knoery
Biogeosciences Discuss., 6, 10057–10088, https://doi.org/10.5194/bgd-6-10057-2009, https://doi.org/10.5194/bgd-6-10057-2009, 2009
Revised manuscript not accepted (discussion: closed, 4 comments)
22 Oct 2009
Small scale spatial heterogeneity of soil respiration in an old growth temperate deciduous forest
A. Jordan, G. Jurasinski, and S. Glatzel
Biogeosciences Discuss., 6, 9977–10005, https://doi.org/10.5194/bgd-6-9977-2009, https://doi.org/10.5194/bgd-6-9977-2009, 2009
Revised manuscript not accepted (discussion: closed, 3 comments)
29 Sep 2009
Forest floor CO2 flux measurements with a dark-light chamber
H. J. M. Lankreijer, A. Lindroth, M. Strömgren, L. Kulmala, and J. Pumpanen
Biogeosciences Discuss., 6, 9301–9329, https://doi.org/10.5194/bgd-6-9301-2009, https://doi.org/10.5194/bgd-6-9301-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 2 comments)
24 Sep 2009
Effects of thinning and fertilization on soil respiration in a cottonwood plantation in Iceland
J. Á. Jónsson and B. D. Sigurdsson
Biogeosciences Discuss., 6, 9257–9278, https://doi.org/10.5194/bgd-6-9257-2009, https://doi.org/10.5194/bgd-6-9257-2009, 2009
Revised manuscript not accepted (discussion: closed, 4 comments)
21 Sep 2009
Surface energy exchanges above two grassland ecosystems on the Qinghai-Tibetan Plateau
S. Liu, S.-G. Li, G.-R. Yu, X.-M. Sun, L.-M. Zhang, Z.-M. Hu, Y.-N. Li, and X.-Z. Zhang
Biogeosciences Discuss., 6, 9161–9192, https://doi.org/10.5194/bgd-6-9161-2009, https://doi.org/10.5194/bgd-6-9161-2009, 2009
Revised manuscript not accepted (discussion: closed, 6 comments)
10 Aug 2009
Enhanced biological carbon consumption in a high CO2 ocean: a revised estimate of the atmospheric uptake efficiency
R. Matear and B. McNeil
Biogeosciences Discuss., 6, 8101–8128, https://doi.org/10.5194/bgd-6-8101-2009, https://doi.org/10.5194/bgd-6-8101-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 3 comments)
23 Jul 2009
Modeling the variability in annual carbon fluxes related to biological soil crusts in a Mediterranean shrubland
B. Wilske, J. Burgheimer, K. Maseyk, A. Karnieli, E. Zaady, M. O. Andreae, D. Yakir, and J. Kesselmeier
Biogeosciences Discuss., 6, 7295–7324, https://doi.org/10.5194/bgd-6-7295-2009, https://doi.org/10.5194/bgd-6-7295-2009, 2009
Revised manuscript not accepted (discussion: closed, 4 comments)
14 Jul 2009
Regionalization of turbulent fluxes by combining aircraft measurements with footprint analysis
T. El-Madany, H. Geiß, A. Schmidt, and O. Klemm
Biogeosciences Discuss., 6, 7017–7051, https://doi.org/10.5194/bgd-6-7017-2009, https://doi.org/10.5194/bgd-6-7017-2009, 2009
Revised manuscript not accepted (discussion: closed, 3 comments)
14 Jul 2009
Microbiotic crusts on soil, rock and plants: neglected major players in the global cycles of carbon and nitrogen?
W. Elbert, B. Weber, B. Büdel, M. O. Andreae, and U. Pöschl
Biogeosciences Discuss., 6, 6983–7015, https://doi.org/10.5194/bgd-6-6983-2009, https://doi.org/10.5194/bgd-6-6983-2009, 2009
Preprint withdrawn (discussion: closed, 6 comments)
06 Jul 2009
Linking the lithogenic, atmospheric, and biogenic cycles of silicate, carbonate, and organic carbon in the ocean
S. V. Smith and J.-P. Gattuso
Biogeosciences Discuss., 6, 6579–6599, https://doi.org/10.5194/bgd-6-6579-2009, https://doi.org/10.5194/bgd-6-6579-2009, 2009
Revised manuscript not accepted (discussion: closed, 6 comments)
24 Jun 2009
Contribution of root and rhizosphere respiration to the annual variation of carbon balance of a boreal Scots pine forest
J. F. J. Korhonen, J. Pumpanen, P. Kolari, E. Juurola, and E. Nikinmaa
Biogeosciences Discuss., 6, 6179–6203, https://doi.org/10.5194/bgd-6-6179-2009, https://doi.org/10.5194/bgd-6-6179-2009, 2009
Revised manuscript not accepted (discussion: closed, 6 comments)
24 Jun 2009
Measurements of soil respiration and simple models dependent on moisture and temperature for an Amazonian southwest tropical forest
F. B. Zanchi, H. R. da Rocha, H. C. de Freitas, B. Kruijt, M. J. Waterloo, and A. O. Manzi
Biogeosciences Discuss., 6, 6147–6177, https://doi.org/10.5194/bgd-6-6147-2009, https://doi.org/10.5194/bgd-6-6147-2009, 2009
Revised manuscript not accepted (discussion: closed, 6 comments)
04 Jun 2009
Mapping landscape scale variations of forest structure, biomass, and productivity in Amazonia
S. Saatchi, Y. Malhi, B. Zutta, W. Buermann, L. O. Anderson, A. M. Araujo, O. L. Phillips, J. Peacock, H. ter Steege, G. Lopez Gonzalez, T. Baker, L. Arroyo, S. Almeida, N. Higuchi, T. Killeen, A. Monteagudo, D. Neill, N. Pitman, A. Prieto, R. Salomão, N. Silva, R. Vásquez Martínez, W. Laurance, and H. A. Ramírez
Biogeosciences Discuss., 6, 5461–5505, https://doi.org/10.5194/bgd-6-5461-2009, https://doi.org/10.5194/bgd-6-5461-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 2 comments)
28 May 2009
Carbon fixation prediction during a bloom of Emiliania huxleyi is highly sensitive to the assumed regulation mechanism
O. Bernard, A. Sciandra, and S. Rabouille
Biogeosciences Discuss., 6, 5339–5372, https://doi.org/10.5194/bgd-6-5339-2009, https://doi.org/10.5194/bgd-6-5339-2009, 2009
Revised manuscript not accepted (discussion: closed, 5 comments)
12 May 2009
Response of Halimeda to ocean acidification: field and laboratory evidence
L. L. Robbins, P. O. Knorr, and P. Hallock
Biogeosciences Discuss., 6, 4895–4918, https://doi.org/10.5194/bgd-6-4895-2009, https://doi.org/10.5194/bgd-6-4895-2009, 2009
Revised manuscript not accepted (discussion: closed, 4 comments)
06 May 2009
Influence of hydrological fluxes on bio-geochemical processes in a peatland
N. Bougon, L. Aquilina, C. Auterives, and P. Vandenkoornhuyse
Biogeosciences Discuss., 6, 4829–4863, https://doi.org/10.5194/bgd-6-4829-2009, https://doi.org/10.5194/bgd-6-4829-2009, 2009
Revised manuscript not accepted (discussion: closed, 4 comments)
04 May 2009
Seasonal pH and aragonite saturation horizons in the Gulf of Alaska during the North Pacific Survey, 1956–1957
S. McKinnell and J. R. Christian
Biogeosciences Discuss., 6, 4587–4602, https://doi.org/10.5194/bgd-6-4587-2009, https://doi.org/10.5194/bgd-6-4587-2009, 2009
Revised manuscript not accepted (discussion: closed, 5 comments)
29 Apr 2009
An upgraded carbon-based method to estimate the anthropogenic fraction of dissolved CO2 in the Atlantic Ocean
M. Vázquez-Rodríguez, X. A. Padin, A. F. Ríos, R. G. J. Bellerby, and F. F. Pérez
Biogeosciences Discuss., 6, 4527–4571, https://doi.org/10.5194/bgd-6-4527-2009, https://doi.org/10.5194/bgd-6-4527-2009, 2009
Revised manuscript not accepted (discussion: closed, 6 comments)
15 Apr 2009
Impacts of elevated CO2 on phytoplankton community composition and organic carbon dynamics in nutrient-depleted Okhotsk Sea surface waters
T. Yoshimura, J. Nishioka, K. Suzuki, H. Hattori, H. Kiyosawa, and Y. W. Watanabe
Biogeosciences Discuss., 6, 4143–4163, https://doi.org/10.5194/bgd-6-4143-2009, https://doi.org/10.5194/bgd-6-4143-2009, 2009
Revised manuscript not accepted (discussion: closed, 5 comments)
01 Apr 2009
Conditional CO2 flux analysis of a managed grassland with the aid of stable isotopes
M. J. Zeeman, B. Tuzson, L. Emmenegger, A. Knohl, N. Buchmann, and W. Eugster
Biogeosciences Discuss., 6, 3481–3510, https://doi.org/10.5194/bgd-6-3481-2009, https://doi.org/10.5194/bgd-6-3481-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 4 comments)
30 Mar 2009
Turbulence in a coastal Mediterranean area: surface fluxes and related parameters at Castel Porziano, Italy
S. A. Cieslik, G. Gerosa, A. Finco, G. Matteucci, N. Cape, and P. Misztal
Biogeosciences Discuss., 6, 3355–3372, https://doi.org/10.5194/bgd-6-3355-2009, https://doi.org/10.5194/bgd-6-3355-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 2 comments)
18 Mar 2009
Impact of CO2-driven ocean acidification on invertebrates early life-history – What we know, what we need to know and what we can do
S. Dupont and M. C. Thorndyke
Biogeosciences Discuss., 6, 3109–3131, https://doi.org/10.5194/bgd-6-3109-2009, https://doi.org/10.5194/bgd-6-3109-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 4 comments)
11 Mar 2009
Carbon dioxide and methane annual emissions from two boreal reservoirs and nearby lakes in Quebec, Canada
M. Demarty, J. Bastien, and A. Tremblay
Biogeosciences Discuss., 6, 2939–2963, https://doi.org/10.5194/bgd-6-2939-2009, https://doi.org/10.5194/bgd-6-2939-2009, 2009
Revised manuscript not accepted (discussion: closed, 4 comments)
11 Mar 2009
A comparison of CO2 fluxes via eddy covariance measurements with model predictions in a dominant subtropical forest ecosystem
J.-H. Yan, G.-Y. Zhou, Y.-L. Li, D.-Q. Zhang, D. Otieno, and J. Tenhunen
Biogeosciences Discuss., 6, 2913–2937, https://doi.org/10.5194/bgd-6-2913-2009, https://doi.org/10.5194/bgd-6-2913-2009, 2009
Revised manuscript not accepted (discussion: closed, 6 comments)
11 Mar 2009
Seasonal variation in ecosystem parameters derived from FLUXNET data
M. Groenendijk, M. K. van der Molen, and A. J. Dolman
Biogeosciences Discuss., 6, 2863–2912, https://doi.org/10.5194/bgd-6-2863-2009, https://doi.org/10.5194/bgd-6-2863-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 3 comments)
03 Mar 2009
Effect of land use on carbon dioxide, water vapour and energy exchange over terrestrial ecosystems in Southwestern France during the CERES campaign
N. Jarosz, P. Béziat, J. M. Bonnefond, Y. Brunet, J. C. Calvet, E. Ceschia, J. A. Elbers, R. W. A. Hutjes, and O. Traullé
Biogeosciences Discuss., 6, 2755–2784, https://doi.org/10.5194/bgd-6-2755-2009, https://doi.org/10.5194/bgd-6-2755-2009, 2009
Revised manuscript not accepted (discussion: closed, 4 comments)
24 Feb 2009
Calcification, a physiological process to be considered in the context of the whole organism
H. S. Findlay, H. L. Wood, M. A. Kendall, J. I. Spicer, R. J. Twitchett, and S. Widdicombe
Biogeosciences Discuss., 6, 2267–2284, https://doi.org/10.5194/bgd-6-2267-2009, https://doi.org/10.5194/bgd-6-2267-2009, 2009
Manuscript not accepted for further review (discussion: closed, 4 comments)
06 Feb 2009
A process-based model to estimate gas exchange and monoterpene emission rates in the mediterranean maquis – comparisons between modelled and measured fluxes at different scales
M. Vitale, G. Matteucci, S. Fares, and B. Davison
Biogeosciences Discuss., 6, 1747–1776, https://doi.org/10.5194/bgd-6-1747-2009, https://doi.org/10.5194/bgd-6-1747-2009, 2009
Manuscript not accepted for further review (discussion: closed, 4 comments)
30 Jan 2009
The effects of management on ammonia fluxes over a cut grassland as measured by use of dynamic chambers
M. David, R. Roche, M. Mattsson, M. A. Sutton, U. Dämmgen, J. K. Schjoerring, and P. Cellier
Biogeosciences Discuss., 6, 1599–1623, https://doi.org/10.5194/bgd-6-1599-2009, https://doi.org/10.5194/bgd-6-1599-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 2 comments)
30 Jan 2009
Simulating the optical properties of phytoplankton cells using a two-layered spherical geometry
S. Bernard, T. A. Probyn, and A. Quirantes
Biogeosciences Discuss., 6, 1497–1563, https://doi.org/10.5194/bgd-6-1497-2009, https://doi.org/10.5194/bgd-6-1497-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 3 comments)
23 Jan 2009
Short scale (6 h) temporal variation of sinking fluxes of planktonic and terrigeneous lipids at 200 m in the NW Mediterranean Sea
L. Méjanelle and J. Dachs
Biogeosciences Discuss., 6, 1229–1265, https://doi.org/10.5194/bgd-6-1229-2009, https://doi.org/10.5194/bgd-6-1229-2009, 2009
Preprint withdrawn (discussion: closed, 6 comments)
21 Jan 2009
Contribution of riverine nutrients to the silicon biogeochemistry of the global ocean – a model study
C. Y. Bernard, H. H. Dürr, C. Heinze, J. Segschneider, and E. Maier-Reimer
Biogeosciences Discuss., 6, 1091–1119, https://doi.org/10.5194/bgd-6-1091-2009, https://doi.org/10.5194/bgd-6-1091-2009, 2009
Preprint withdrawn (discussion: closed, 2 comments)
16 Jan 2009
A one-month study of the zooplankton community at a fixed station in the Ligurian Sea: the potential impact of the species composition on the mineralization of organic matter
L. Mousseau, D. Lefevre, F. Narcy, P. Nival, and V. Andersen
Biogeosciences Discuss., 6, 995–1019, https://doi.org/10.5194/bgd-6-995-2009, https://doi.org/10.5194/bgd-6-995-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 4 comments)
16 Jan 2009
Carbon cycling in the Arctic Archipelago: the export of Pacific carbon to the North Atlantic
E. H. Shadwick, T. Papakyriakou, A. E. F. Prowe, D. Leong, S. A. Moore, and H. Thomas
Biogeosciences Discuss., 6, 971–994, https://doi.org/10.5194/bgd-6-971-2009, https://doi.org/10.5194/bgd-6-971-2009, 2009
Manuscript not accepted for further review (discussion: closed, 5 comments)
13 Jan 2009
Soil carbon stocks in ecoregions of Africa
M. Henry, R. Valentini, and M. Bernoux
Biogeosciences Discuss., 6, 797–823, https://doi.org/10.5194/bgd-6-797-2009, https://doi.org/10.5194/bgd-6-797-2009, 2009
Manuscript not accepted for further review (discussion: closed, 4 comments)
13 Jan 2009
Nitrate and dissolved nitrous oxide in groundwater within cropped fields and riparian buffers
D.-G. Kim, T. M. Isenhart, T. B. Parkin, R. C. Schultz, and T. E. Loynachan
Biogeosciences Discuss., 6, 651–685, https://doi.org/10.5194/bgd-6-651-2009, https://doi.org/10.5194/bgd-6-651-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 3 comments)
13 Jan 2009
Nitrous oxide emissions from riparian forest buffers, warm-season and cool-season grass filters, and crop fields
D.-G. Kim, T. M. Isenhart, T. B. Parkin, R. C. Schultz, T. E. Loynachan, and J. W. Raich
Biogeosciences Discuss., 6, 607–650, https://doi.org/10.5194/bgd-6-607-2009, https://doi.org/10.5194/bgd-6-607-2009, 2009
Revised manuscript has not been submitted (discussion: closed, 6 comments)
09 Jan 2009
Effects of pH on aquatic biodegradation processes
R. F. Krachler, R. Krachler, A. Stojanovic, B. Wielander, and A. Herzig
Biogeosciences Discuss., 6, 491–514, https://doi.org/10.5194/bgd-6-491-2009, https://doi.org/10.5194/bgd-6-491-2009, 2009
Manuscript not accepted for further review (discussion: closed, 4 comments)
06 Jan 2009
S. Schmidt, M. Goutx, P. Raimbault, N. Garcia, P. Guibert, and V. Andersen
Biogeosciences Discuss., 6, 143–161, https://doi.org/10.5194/bgd-6-143-2009, https://doi.org/10.5194/bgd-6-143-2009, 2009
Preprint withdrawn (discussion: closed, 3 comments)
06 Jan 2009
Significant non-linearity in nitrous oxide chamber data and its effect on calculated annual emissions
P. C. Stolk, C. M. J. Jacobs, E. J. Moors, A. Hensen, G. L. Velthof, and P. Kabat
Biogeosciences Discuss., 6, 115–141, https://doi.org/10.5194/bgd-6-115-2009, https://doi.org/10.5194/bgd-6-115-2009, 2009
Manuscript not accepted for further review (discussion: closed, 7 comments)
23 Dec 2008
Biogeochemical plant site conditions in stream valleys after winter flooding: a phytometer approach
V. Beumer, J. N. Ohm, G. van Wirdum, B. Beltman, J. Griffioen, and J. T. A. Verhoeven
Biogeosciences Discuss., 5, 5203–5232, https://doi.org/10.5194/bgd-5-5203-2008, https://doi.org/10.5194/bgd-5-5203-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 2 comments)
18 Dec 2008
Distributions of surface water CO2 and air-sea flux of CO2 in coastal regions of the Canadian Beaufort Sea in late summer
A. Murata, K. Shimada, S. Nishino, and M. Itoh
Biogeosciences Discuss., 5, 5093–5132, https://doi.org/10.5194/bgd-5-5093-2008, https://doi.org/10.5194/bgd-5-5093-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 2 comments)
03 Dec 2008
Use of laboratory and remote sensing techniques to estimate vegetation patch scale emissions of nitric oxide from an arid Kalahari savanna
G. T. Feig, B. Mamtimin, and F. X. Meixner
Biogeosciences Discuss., 5, 4621–4680, https://doi.org/10.5194/bgd-5-4621-2008, https://doi.org/10.5194/bgd-5-4621-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 3 comments)
02 Dec 2008
Nutrient limitation of phytoplankton in anticyclonic eddies of the northern South China Sea
X. Ning, X. Peng, F. Le, Q. Hao, J. Sun, C. Liu, and Y. Cai
Biogeosciences Discuss., 5, 4591–4619, https://doi.org/10.5194/bgd-5-4591-2008, https://doi.org/10.5194/bgd-5-4591-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 2 comments)
26 Nov 2008
Characterisation of ecosystem water-use efficiency of european forests from eddy covariance measurements
F. G. Kuglitsch, M. Reichstein, C. Beer, A. Carrara, R. Ceulemans, A. Granier, I. A. Janssens, B. Koestner, A. Lindroth, D. Loustau, G. Matteucci, L. Montagnani, E. J. Moors, D. Papale, K. Pilegaard, S. Rambal, C. Rebmann, E. D. Schulze, G. Seufert, H. Verbeeck, T. Vesala, M. Aubinet, C. Bernhofer, T. Foken, T. Grünwald, B. Heinesch, W. Kutsch, T. Laurila, B. Longdoz, F. Miglietta, M. J. Sanz, and R. Valentini
Biogeosciences Discuss., 5, 4481–4519, https://doi.org/10.5194/bgd-5-4481-2008, https://doi.org/10.5194/bgd-5-4481-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 7 comments)
26 Nov 2008
Interannual variability of pteropod shell weights in the high-CO2 Southern Ocean
D. Roberts, W. R. Howard, A. D. Moy, J. L. Roberts, T. W. Trull, S. G. Bray, and R. R. Hopcroft
Biogeosciences Discuss., 5, 4453–4480, https://doi.org/10.5194/bgd-5-4453-2008, https://doi.org/10.5194/bgd-5-4453-2008, 2008
Manuscript not accepted for further review (discussion: closed, 5 comments)
06 Nov 2008
Methanol and other VOC fluxes from a Danish beech forest during springtime
G. W. Schade, S. J. Solomon, E. Dellwik, K. Pilegaard, and A. Ladstätter-Weissenmayer
Biogeosciences Discuss., 5, 4315–4352, https://doi.org/10.5194/bgd-5-4315-2008, https://doi.org/10.5194/bgd-5-4315-2008, 2008
Revised manuscript not accepted (discussion: closed, 11 comments)
28 Oct 2008
Soil carbon and plant diversity distribution at the farm level in the savannah region of Northern Togo (West Africa)
M.-T. Sebastià, E. Marks, and R. M. Poch
Biogeosciences Discuss., 5, 4107–4127, https://doi.org/10.5194/bgd-5-4107-2008, https://doi.org/10.5194/bgd-5-4107-2008, 2008
Revised manuscript not accepted (discussion: closed, 3 comments)
02 Oct 2008
CO2 radiative forcing during the Holocene Thermal Maximum revealed by stomatal frequency of Iberian oak leaves
I. García-Amorena, F. Wagner-Cremer, F. Gomez Manzaneque, T. B. van Hoof, S. García Álvarez, and H. Visscher
Biogeosciences Discuss., 5, 3945–3964, https://doi.org/10.5194/bgd-5-3945-2008, https://doi.org/10.5194/bgd-5-3945-2008, 2008
Revised manuscript not accepted (discussion: closed, 5 comments)
26 Sep 2008
Phytoplankton blooms induced/sustained by cyclonic eddies during the Indian Ocean Dipole event of 1997 along the southern coasts of Java and Sumatra
P. Rahul Chand Reddy and P. S. Salvekar
Biogeosciences Discuss., 5, 3905–3918, https://doi.org/10.5194/bgd-5-3905-2008, https://doi.org/10.5194/bgd-5-3905-2008, 2008
Revised manuscript not accepted (discussion: closed, 4 comments)
17 Sep 2008
C allocation among fine roots, above-, and belowground wood in a deciduous forest and its implication to ecosystem C cycling: a modelling analysis
M. Campioli, H. Verbeeck, R. Lemeur, and R. Samson
Biogeosciences Discuss., 5, 3781–3823, https://doi.org/10.5194/bgd-5-3781-2008, https://doi.org/10.5194/bgd-5-3781-2008, 2008
Revised manuscript not accepted (discussion: closed, 4 comments)
10 Sep 2008
Greenhouse gas emissions (CO2, CH4 and N2O) from perialpine and alpine hydropower reservoirs
T. Diem, S. Koch, S. Schwarzenbach, B. Wehrli, and C. J. Schubert
Biogeosciences Discuss., 5, 3699–3736, https://doi.org/10.5194/bgd-5-3699-2008, https://doi.org/10.5194/bgd-5-3699-2008, 2008
Revised manuscript not accepted (discussion: closed, 6 comments)
28 Aug 2008
Carbonate precipitation by the thermophilic archaeon Archaeoglobus fulgidus: a model of carbon flow for an ancient microorganism
L. L. Robbins, K. A. Van Cleave, and P. Ostrom
Biogeosciences Discuss., 5, 3409–3432, https://doi.org/10.5194/bgd-5-3409-2008, https://doi.org/10.5194/bgd-5-3409-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 2 comments)
09 Jul 2008
Seaglider observations of variability in daytime fluorescence quenching of chlorophyll-a in Northeastern Pacific coastal waters
B. S. Sackmann, M. J. Perry, and C. C. Eriksen
Biogeosciences Discuss., 5, 2839–2865, https://doi.org/10.5194/bgd-5-2839-2008, https://doi.org/10.5194/bgd-5-2839-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 2 comments)
09 Jun 2008
Mass extinctions past and present: a unifying hypothesis
S. A. Wooldridge
Biogeosciences Discuss., 5, 2401–2423, https://doi.org/10.5194/bgd-5-2401-2008, https://doi.org/10.5194/bgd-5-2401-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 11 comments)
08 Apr 2008
Incorporating changes in albedo in estimating the climate mitigation benefits of land use change projects
D. N. Bird, M. Kunda, A. Mayer, B. Schlamadinger, L. Canella, and M. Johnston
Biogeosciences Discuss., 5, 1511–1543, https://doi.org/10.5194/bgd-5-1511-2008, https://doi.org/10.5194/bgd-5-1511-2008, 2008
Revised manuscript not accepted (discussion: closed, 4 comments)
04 Apr 2008
Methylated arsenic and antimony species in suspended matter of the river Ruhr, Germany
L. Duester, L. M. Hartmann, and A. V. Hirner
Biogeosciences Discuss., 5, 1361–1378, https://doi.org/10.5194/bgd-5-1361-2008, https://doi.org/10.5194/bgd-5-1361-2008, 2008
Revised manuscript not accepted (discussion: closed, 6 comments)
27 Mar 2008
Spatial and temporal variation of methane emissions in drained eutrophic peat agro-ecosystems: drainage ditches as emission hotspots
A. P. Schrier-Uijl, E. M. Veenendaal, P. A. Leffelaar, J. C. van Huissteden, and F. Berendse
Biogeosciences Discuss., 5, 1237–1261, https://doi.org/10.5194/bgd-5-1237-2008, https://doi.org/10.5194/bgd-5-1237-2008, 2008
Preprint withdrawn (discussion: closed, 5 comments)
05 Mar 2008
Reflectance properties of selected arctic-boreal land cover types: field measurements and their application in remote sensing
J. I. Peltoniemi, J. Suomalainen, E. Puttonen, J. Näränen, and M. Rautiainen
Biogeosciences Discuss., 5, 1069–1095, https://doi.org/10.5194/bgd-5-1069-2008, https://doi.org/10.5194/bgd-5-1069-2008, 2008
Revised manuscript not accepted (discussion: closed, 5 comments)
15 Feb 2008
A mathematical modelling of bloom of the coccolithophore Emiliania huxleyi in a mesocosm experiment
P. Joassin, B. Delille, K. Soetaert, A. V. Borges, L. Chou, A. Engel, J.-P. Gattuso, J. Harlay, U. Riebesell, K. Suykens, and M. Gregoire
Biogeosciences Discuss., 5, 787–840, https://doi.org/10.5194/bgd-5-787-2008, https://doi.org/10.5194/bgd-5-787-2008, 2008
Revised manuscript not accepted (discussion: closed, 16 comments)
31 Jan 2008
Diel variability of heterotrophic bacterial production and UV doses in the South East Pacific
F. Van Wambeke, M. Tedetti, S. Duhamel, and R. Sempéré
Biogeosciences Discuss., 5, 435–462, https://doi.org/10.5194/bgd-5-435-2008, https://doi.org/10.5194/bgd-5-435-2008, 2008
Revised manuscript not accepted (discussion: closed, 3 comments)
04 Jan 2008
Iodine speciation and cycling in limnic systems: observations from a humic rich headwater lake (Mummelsee)
B. S. Gilfedder, M. Petri, and H. Biester
Biogeosciences Discuss., 5, 25–64, https://doi.org/10.5194/bgd-5-25-2008, https://doi.org/10.5194/bgd-5-25-2008, 2008
Revised manuscript not accepted (discussion: closed, 4 comments)
02 Jan 2008
Dissolution of coccolithophorid calcite by microzooplankton and copepod grazing
A. N. Antia, K. Suffrian, L. Holste, M. N. Müller, J. C. Nejstgaard, P. Simonelli, Y. Carotenuto, and S. Putzeys
Biogeosciences Discuss., 5, 1–23, https://doi.org/10.5194/bgd-5-1-2008, https://doi.org/10.5194/bgd-5-1-2008, 2008
Revised manuscript has not been submitted (discussion: closed, 3 comments)
27 Nov 2007
Influences of initial plankton biomass and mixed layer depths on the outcome of iron-fertilization experiments
M. Fujii and F. Chai
Biogeosciences Discuss., 4, 4411–4441, https://doi.org/10.5194/bgd-4-4411-2007, https://doi.org/10.5194/bgd-4-4411-2007, 2007
Revised manuscript not accepted (discussion: closed, 4 comments)
25 Oct 2007
Copepod feeding and reproduction in relation to phytoplankton development during the PeECE III mesocosm experiment
Y. Carotenuto, S. Putzeys, P. Simonelli, A. Paulino, M. Meyerhöfer, K. Suffrian, A. Antia, and J. C. Nejstgaard
Biogeosciences Discuss., 4, 3913–3936, https://doi.org/10.5194/bgd-4-3913-2007, https://doi.org/10.5194/bgd-4-3913-2007, 2007
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Oct 2007
Mechanisms of soil carbon storage in experimental grasslands
S. Steinbeiss, V. M. Temperton, and G. Gleixner
Biogeosciences Discuss., 4, 3829–3862, https://doi.org/10.5194/bgd-4-3829-2007, https://doi.org/10.5194/bgd-4-3829-2007, 2007
Revised manuscript has not been submitted (discussion: closed, 5 comments)
10 Sep 2007
Precambrian palaeontology in the light of molecular phylogeny – an example: the radiation of the green algae
B. Teyssèdre
Biogeosciences Discuss., 4, 3123–3142, https://doi.org/10.5194/bgd-4-3123-2007, https://doi.org/10.5194/bgd-4-3123-2007, 2007
Revised manuscript has not been submitted (discussion: closed, 4 comments)
06 Aug 2007
Nitrogen retention patterns and their controlling factors in an alpine meadow: implications for carbon sequestration
X. L. Xu, H. Ouyang, and G. M. Cao
Biogeosciences Discuss., 4, 2641–2665, https://doi.org/10.5194/bgd-4-2641-2007, https://doi.org/10.5194/bgd-4-2641-2007, 2007
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Jun 2007
Composition of microbial communities in aerosol, snow and ice samples from remote glaciated areas (Antarctica, Alps, Andes)
J. Elster, R. J. Delmas, J.-R. Petit, and K. Řeháková
Biogeosciences Discuss., 4, 1779–1813, https://doi.org/10.5194/bgd-4-1779-2007, https://doi.org/10.5194/bgd-4-1779-2007, 2007
Revised manuscript has not been submitted (discussion: closed, 3 comments)
21 May 2007
Variation of phytoplankton absorption coefficients in the northern South China Sea during spring and autumn
J. Wu, H. Hong, S. Shang, M. Dai, and Z. Lee
Biogeosciences Discuss., 4, 1555–1584, https://doi.org/10.5194/bgd-4-1555-2007, https://doi.org/10.5194/bgd-4-1555-2007, 2007
Revised manuscript has not been submitted (discussion: closed, 4 comments)
25 Apr 2007
Observations of dissolved iron concentrations in the World Ocean: implications and constraints for ocean biogeochemical models
J. K. Moore and O. Braucher
Biogeosciences Discuss., 4, 1241–1277, https://doi.org/10.5194/bgd-4-1241-2007, https://doi.org/10.5194/bgd-4-1241-2007, 2007
Revised manuscript not accepted (discussion: closed, 4 comments)
04 Apr 2007
Predicting the global warming potential of agro-ecosystems
S. Lehuger, B. Gabrielle, E. Larmanou, P. Laville, P. Cellier, and B. Loubet
Biogeosciences Discuss., 4, 1059–1092, https://doi.org/10.5194/bgd-4-1059-2007, https://doi.org/10.5194/bgd-4-1059-2007, 2007
Revised manuscript has not been submitted (discussion: closed, 5 comments)
27 Mar 2007
Chlorophyll signatures and nutrient cycles in the Mediterranean Sea: a model sensitivity study to nitrogen and phosphorus atmospheric inputs
M. Pacciaroni and G. Crispi
Biogeosciences Discuss., 4, 909–959, https://doi.org/10.5194/bgd-4-909-2007, https://doi.org/10.5194/bgd-4-909-2007, 2007
Revised manuscript not accepted (discussion: closed, 6 comments)
31 Jan 2007
Co-limitation by iron, silicate, and light of three Southern Ocean diatom species
L. J. Hoffmann, I. Peeken, and K. Lochte
Biogeosciences Discuss., 4, 209–247, https://doi.org/10.5194/bgd-4-209-2007, https://doi.org/10.5194/bgd-4-209-2007, 2007
Revised manuscript not accepted (discussion: closed, 4 comments)
17 Jul 2006
Co-evolution of phytoplankton C:N:P stoichiometry and the deep ocean N:P ratio
T. M. Lenton and C. A. Klausmeier
Biogeosciences Discuss., 3, 1023–1047, https://doi.org/10.5194/bgd-3-1023-2006, https://doi.org/10.5194/bgd-3-1023-2006, 2006
Revised manuscript not accepted (discussion: closed, 4 comments)
26 Apr 2006
A system in balance? – Implications of deep vertical mixing for the nitrogen budget in the northern Red Sea, including the Gulf of Aqaba (Eilat)
C. Häse, M. Al-Qutob, Z. Dubinsky, E. A. Ibrahim, B. Lazar, N. Stambler, and M. M. Tilzer
Biogeosciences Discuss., 3, 383–408, https://doi.org/10.5194/bgd-3-383-2006, https://doi.org/10.5194/bgd-3-383-2006, 2006
Revised manuscript has not been submitted (discussion: closed, 4 comments)
10 Apr 2006
Identification of the accretion rate for annually resolved archives
F. De Ridder, A. de Brauwere, R. Pintelon, J. Schoukens, and F. Dehairs
Biogeosciences Discuss., 3, 321–344, https://doi.org/10.5194/bgd-3-321-2006, https://doi.org/10.5194/bgd-3-321-2006, 2006
Preprint withdrawn (discussion: closed, 6 comments)
07 Mar 2006
Microbial colonization and alteration of basaltic glass
J. Einen, C. Kruber, L. Øvreås, I. H. Thorseth, and T. Torsvik
Biogeosciences Discuss., 3, 273–307, https://doi.org/10.5194/bgd-3-273-2006, https://doi.org/10.5194/bgd-3-273-2006, 2006
Revised manuscript not accepted (discussion: closed, 4 comments)
27 Jan 2006
Comets, carbonaceous meteorites, and the origin of the biosphere
r. b. Hoover
Biogeosciences Discuss., 3, 23–70, https://doi.org/10.5194/bgd-3-23-2006, https://doi.org/10.5194/bgd-3-23-2006, 2006
Revised manuscript has not been submitted (discussion: closed, 15 comments)
16 Dec 2005
Atmospheric concentrations of carbon dioxide and its isotopic composition in southern Poland: comparison of high-altitude mountain site and a near-by urban environment
L. Chmura, K. Rozanski, J. M. Necki, M. Zimnoch, T. Kuc, and A. Korus
Biogeosciences Discuss., 2, 1849–1865, https://doi.org/10.5194/bgd-2-1849-2005, https://doi.org/10.5194/bgd-2-1849-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 5 comments)
16 Nov 2005
Mini-ribozymes and freezing environment: a new scenario for the early RNA world
A. V. Vlassov
Biogeosciences Discuss., 2, 1719–1737, https://doi.org/10.5194/bgd-2-1719-2005, https://doi.org/10.5194/bgd-2-1719-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 2 comments)
06 Sep 2005
Effect of incubation time and substrate concentration on N-uptake rates by phytoplankton in the Bay of Bengal
S. Kumar, R. Ramesh, S. Sardesai, and M. S. Sheshshayee
Biogeosciences Discuss., 2, 1331–1352, https://doi.org/10.5194/bgd-2-1331-2005, https://doi.org/10.5194/bgd-2-1331-2005, 2005
Revised manuscript not accepted (discussion: closed, 3 comments)
30 Aug 2005
A simple parameterization of nitrogen limitation on primary productivity for global vegetation models
G. Krinner, P. Ciais, N. Viovy, and P. Friedlingstein
Biogeosciences Discuss., 2, 1243–1282, https://doi.org/10.5194/bgd-2-1243-2005, https://doi.org/10.5194/bgd-2-1243-2005, 2005
Revised manuscript not accepted (discussion: closed, 4 comments)
30 Aug 2005
Sources and transfers of particulate organic matter in a tropical reservoir (Petit Saut, French Guiana): a multi-tracers analysis using δ13C, C/N ratio and pigments
A. de Junet, G. Abril, F. Guérin, I. Billy, and R. de Wit
Biogeosciences Discuss., 2, 1159–1196, https://doi.org/10.5194/bgd-2-1159-2005, https://doi.org/10.5194/bgd-2-1159-2005, 2005
Revised manuscript not accepted (discussion: closed, 6 comments)
25 Aug 2005
Profiles of C- and N-trace gas production in N-saturated forest soils
K. Butterbach-Bahl, U. Berger, N. Brüggemann, and J. Duyzer
Biogeosciences Discuss., 2, 1127–1157, https://doi.org/10.5194/bgd-2-1127-2005, https://doi.org/10.5194/bgd-2-1127-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 2 comments)
17 Aug 2005
A simple model to estimate exchange rates of nitrogen dioxide between the atmosphere and forests
J. Duyzer, K. Pilegaard, D. Simpson, H. Weststrate, and S. Walton
Biogeosciences Discuss., 2, 1033–1065, https://doi.org/10.5194/bgd-2-1033-2005, https://doi.org/10.5194/bgd-2-1033-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 5 comments)
03 Aug 2005
Impact of 40 years poplar cultivation on soil carbon stocks and greenhouse gas fluxes
C. Ferré, A. Leip, G. Matteucci, F. Previtali, and G. Seufert
Biogeosciences Discuss., 2, 897–931, https://doi.org/10.5194/bgd-2-897-2005, https://doi.org/10.5194/bgd-2-897-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 3 comments)
21 Jul 2005
Pollen transport to southern Greenland: new evidences of a late spring long distance transport
D.-D. Rousseau, P. Schevin, D. Duzer, G. Cambon, J. Ferrier, D. Jolly, and U. Poulsen
Biogeosciences Discuss., 2, 829–847, https://doi.org/10.5194/bgd-2-829-2005, https://doi.org/10.5194/bgd-2-829-2005, 2005
Revised manuscript not accepted (discussion: closed, 6 comments)
01 Jul 2005
On the available evidence for the temperature dependence of soil organic carbon
W. Knorr, I. C. Prentice, I. J. House, and E. A. Holland
Biogeosciences Discuss., 2, 749–755, https://doi.org/10.5194/bgd-2-749-2005, https://doi.org/10.5194/bgd-2-749-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 3 comments)
24 Jun 2005
Nitric oxide and nitrous oxide emission from Hungarian forest soils; link with atmospheric N-deposition
L. Horváth, E. Führer, and K. Lajtha
Biogeosciences Discuss., 2, 703–723, https://doi.org/10.5194/bgd-2-703-2005, https://doi.org/10.5194/bgd-2-703-2005, 2005
Revised manuscript not accepted (discussion: closed, 4 comments)
26 May 2005
The role of N2-fixation to simulate the pCO2 observations from the Baltic Sea
A. Leinweber, T. Neumann, and B. Schneider
Biogeosciences Discuss., 2, 609–636, https://doi.org/10.5194/bgd-2-609-2005, https://doi.org/10.5194/bgd-2-609-2005, 2005
Revised manuscript not accepted (discussion: closed, 4 comments)
06 Apr 2005
Pure stands of temperate forest tree species modify soil respiration and N turnover
N. Brüggemann, P. Rosenkranz, H. Papen, K. Pilegaard, and K. Butterbach-Bahl
Biogeosciences Discuss., 2, 303–331, https://doi.org/10.5194/bgd-2-303-2005, https://doi.org/10.5194/bgd-2-303-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 5 comments)
15 Mar 2005
Inhibition of nitrogenase by oxygen in marine cyanobacteria controls the global nitrogen and oxygen cycles
I. Berman-Frank, Y.-B. Chen, Y. Gerchman, G. C. Dismukes, and P. G. Falkowski
Biogeosciences Discuss., 2, 261–273, https://doi.org/10.5194/bgd-2-261-2005, https://doi.org/10.5194/bgd-2-261-2005, 2005
Preprint withdrawn (discussion: closed, 3 comments)
27 Jan 2005
Emission of monoterpenes from European beech (Fagus sylvatica L.) as a function of light and temperature
T. Dindorf, U. Kuhn, L. Ganzeveld, G. Schebeske, P. Ciccioli, C. Holzke, R. Köble, G. Seufert, and J. Kesselmeier
Biogeosciences Discuss., 2, 137–182, https://doi.org/10.5194/bgd-2-137-2005, https://doi.org/10.5194/bgd-2-137-2005, 2005
Revised manuscript has not been submitted (discussion: closed, 7 comments)
29 Oct 2004
Biogeochemical processes in sediments of the Manfredonia Gulf (Southern Adriatic Sea): early diagenesis of carbon and nutrient and benthic exchange
F. Spagnoli, G. Bartholini, M. Marini, and P. Giordano
Biogeosciences Discuss., 1, 803–823, https://doi.org/10.5194/bgd-1-803-2004, https://doi.org/10.5194/bgd-1-803-2004, 2004
Revised manuscript has not been submitted (discussion: closed, 3 comments)
20 Oct 2004
Investigation on the trophic state of the North Sea for three years (1994–1996) simulated with the ecosystem model ERSEM – the role of a sharp NAOI decline
H. J. Lenhart, J. Pätsch, W. Kühn, A. Moll, and T. Pohlmann
Biogeosciences Discuss., 1, 725–754, https://doi.org/10.5194/bgd-1-725-2004, https://doi.org/10.5194/bgd-1-725-2004, 2004
Revised manuscript not accepted (discussion: closed, 4 comments)
19 Oct 2004
Hydroxylamine (NH2OH) in the Baltic Sea
S. Gebhardt, S. Walter, G. Nausch, and H. W. Bange
Biogeosciences Discuss., 1, 709–724, https://doi.org/10.5194/bgd-1-709-2004, https://doi.org/10.5194/bgd-1-709-2004, 2004
Revised manuscript has not been submitted (discussion: closed, 2 comments)
26 Aug 2004
CO2 air-sea exchange due to calcium carbonate and organic matter storage: pre-industrial and Last Glacial Maximum estimates
A. Lerman and F. T. Mackenzie
Biogeosciences Discuss., 1, 429–495, https://doi.org/10.5194/bgd-1-429-2004, https://doi.org/10.5194/bgd-1-429-2004, 2004
Revised manuscript not accepted (discussion: closed, 5 comments)
22 Jul 2004
Environmental proteomics – what proteins from soil and surface water can tell us: a perspective
W. Schulze
Biogeosciences Discuss., 1, 195–218, https://doi.org/10.5194/bgd-1-195-2004, https://doi.org/10.5194/bgd-1-195-2004, 2004
Revised manuscript has not been submitted (discussion: closed, 2 comments)