Global Biogeochemical Cycles最新文献

{"title":"Spatial Patterns and Regulation of Nanomolar-Level Nutrients in the Surface Oligotrophic Oceans","authors":"Taketoshi Kodama,&nbsp;Adam C. Martiny,&nbsp;Fuminori Hashihama,&nbsp;Ken Furuya","doi":"10.1029/2025GB008987","DOIUrl":"https://doi.org/10.1029/2025GB008987","url":null,"abstract":"<p>Ambient nutrient concentrations and their ratios regulate phytoplankton physiology and biomass in the ocean. In oligotrophic surface waters, nitrate and ammonium (NH₄) concentrations are often below conventional analytical detection limits (50–100 nM). However, nanomolar-level nutrients can strongly influence phytoplankton growth in oligotrophic regions. Using highly sensitive colorimetry with detection limits of 3 nM, we quantified surface nitrate plus nitrite (NO_X), NH₄, and phosphate (PO₄) concentrations across the low-latitude Pacific and Indian Oceans. Concentrations from over 47,648 measurements were analyzed. NO_X, NH₄, and PO₄ ranged from ≤3 nM to several hundred nM, and after calculations of mean NO_X, NH₄, and PO₄ into 0.5° latitude-longitude intervals, ∼60% of intervals for NO_X and NH₄ showed &lt;5 nM, and ∼80% of them showed &lt;10 nM. Spatial PO₄ patterns were significantly associated with phosphacline depths, highlighting the importance of vertical PO₄ supply. The spatial NO_X pattern was weakly associated with nitracline depth, and several to tens of kilometers processes, including upwelling and rainfall, contribute to its elevations. The combined NO_X + NH₄ to PO₄ ratio was consistently below Redfield ratios. Subtle increases in NO_X and/or NH₄ concentrations corresponded to slight increases in chlorophyll <i>a</i> levels, suggesting that both recycled and newly supplied nitrogenous nutrients contribute to phytoplankton biomass in oligotrophic low-latitude oceans. Overall, our findings emphasize that highly sensitive nanomolar-scale nutrient analyses are important for understanding the environmental controls on phytoplankton in low-latitude oligotrophic oceans.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GB008987","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal Variability in the Vertical Distribution of Phytoplankton Biomass in the Ice-Free Southern Ocean: A Bioregionalization Approach","authors":"N. Mayot,&nbsp;J. Uitz,&nbsp;L. Lacour,&nbsp;R. Sauzède,&nbsp;L. Izard,&nbsp;D. Nerini","doi":"10.1029/2025GB008930","DOIUrl":"https://doi.org/10.1029/2025GB008930","url":null,"abstract":"<p>The Southern Ocean plays a major role in the global oceanic sink of carbon dioxide (CO₂). However, substantial uncertainties remain regarding how phytoplankton production influences this carbon sink. Observations of the spatiotemporal variability in vertical phytoplankton biomass distribution are therefore essential to advance our understanding of the Southern Ocean CO₂ sink. This study analyzes a 25-year (1998–2022) database of spatially gridded, weekly averaged, vertical profiles of chlorophyll-<i>a</i> concentration and particulate backscattering coefficients to characterize seasonal to inter-annual dynamics in phytoplankton biomass. A two-step Principal Component Analysis workflow was used to extract the dominant modes of vertical variability in the profiles and to characterize their seasonal dynamics. The resulting seasonal descriptors were then used as input to a Gaussian Mixture Model to delineate phytoplankton-based bioregions across the Southern Ocean. The bioregionalization was strongly shaped by iron limitation and the position of the Subantarctic Front. Each year, approximately 43% of the Southern Ocean exhibited expected annual cycles of vertical phytoplankton biomass, while the remaining regions were characterized by interannual variability or undefined phenological patterns. At high latitudes in summer, the regional detection of recurring subsurface phytoplankton biomass maxima might be constrained by stratification dynamics. In subtropical regions, interannual variability in spring phytoplankton biomass may be indirectly influenced by the Southern Annular Mode through its modulation of wintertime vertical mixing. This bioregionalization provides a spatial framework for further investigating biologically driven carbon fluxes in the Southern Ocean.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GB008930","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local and Global-Scale Soil Nitrogen Stocks and Burial Rates in Mangroves","authors":"Havalend E. Steinmuller,&nbsp;Joshua L. Breithaupt,&nbsp;André S. Rovai","doi":"10.1029/2025GB008959","DOIUrl":"https://doi.org/10.1029/2025GB008959","url":null,"abstract":"<p>Coastal marine environments can mitigate the deleterious effects of terrestrial reactive nitrogen (N) loads through burial and long-term storage in soils and sediments, although the quantification of these values is limited and poorly constrained. We utilized a spatially explicit global coastal typology for sedimentary settings and combined sedimentary-geomorphic settings (SGS) to characterize global mangrove soil N stocks and burial rates. We found that carbonate setting mangroves store 24.64 (95% CI: 23.03–25.92) Mg N ha⁻¹ in the top 1 m of soil, which is more than the 11.73 (95% CI: 11.41–12.26) Mg ha⁻¹ stored by terrigenous settings. Burial rates were similar between terrigenous and carbonate settings, with 3.43 (95% CI: 2.80, 4.25) and 4.80 (95% CI: 3.95, 6.00) g N m⁻² y⁻¹, respectively. Scaled to SGS land area, global N stocks and burial rates summed to 190.5 (95% CI: 95.9–264) Tg and 686.1 (95% CI: 583.2–803.6) Gg y⁻¹, the latter accounting for 3% of all marine burial, 5.6% of all coastal burial, and 1.4% of estimated annual N riverine fluxes. Our estimates constrain uncertainties in mangrove N stocks and burial across distinct coastal typologies and help place mangrove N storage and burial in a global biogeochemical context relevant to coastal water quality.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ecological Variability and Controls on Denitrifying Anaerobic Methane Oxidation","authors":"Meng Jiang,&nbsp;Chen Ye,&nbsp;Hao Jiang,&nbsp;Yu Gong,&nbsp;Quanfa Zhang","doi":"10.1029/2025GB008766","DOIUrl":"https://doi.org/10.1029/2025GB008766","url":null,"abstract":"<p>Denitrifying anaerobic methane oxidation (DAMO) constitutes a key biogeochemical nexus, concurrently mitigating atmospheric methane emissions and coupling global carbon and nitrogen cycles. However, a quantitative and mechanistic understanding of its ecological variability and global-scale drivers is lacking, hindering its realistic representation in Earth system models. This study provides a comprehensive global synthesis of DAMO rates and their environmental controls across diverse ecosystems. Nitrate- and nitrite-dependent anaerobic methane oxidation (Nitrate- and Nitrite-AOM) exhibited mean rates of 8.4 ± 0.8 (mean ± SE) and 5.4 ± 0.7 nmol CO₂ (g dry weight)⁻¹ day⁻¹, respectively. Paddy ecosystems were identified as global hotspots, with rates significantly exceeding those in estuaries, forests and grasslands. Functional gene (<i>mcrA</i>, <i>pmoA</i>) abundance, mean monthly temperature and depth jointly explained more than 60% of the rate variance across ecosystems in our analysis, indicating that they represent major drivers within the compiled data set. Notably, depth exerted an indirect control by regulating gene abundance, leading to a depth zonation where Nitrite-AOM dominated in shallower zones over Nitrate-AOM. Globally, DAMO mitigated more than 24% of the CH₄ consumed by anaerobic oxidation, with paddies alone offsetting over 25% of their total CH₄ production. By resolving the multi-level controls from genes to climate, this work bridges microbial ecology and Earth system science, providing a predictive framework to incorporate this key methane sink into global models and inform targeted mitigation strategies.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drivers of Benthic Iron Fluxes and the Pore-Water Iron Isotopic Signature in Surface Sediments of South Georgia Fjords, Sub-Antarctica","authors":"Berenice Ebner,&nbsp;Susann Henkel,&nbsp;Peter Kraal,&nbsp;Daniel Müller,&nbsp;Male Köster,&nbsp;Michael Staubwasser,&nbsp;Katja Laufer-Meiser,&nbsp;Laura Kattein,&nbsp;Walter Geibert,&nbsp;Sabine Kasten","doi":"10.1029/2025GB008856","DOIUrl":"https://doi.org/10.1029/2025GB008856","url":null,"abstract":"<p>Benthic iron (Fe) fluxes from coastal sediments support phytoplankton blooms downstream of subpolar islands. We combine solid-phase and pore-water geochemical data, including its iron isotopic signature (δ⁵⁶Fe_aq), to identify the main drivers of benthic Fe fluxes from sub-Antarctic fjord and shelf sediments of South Georgia, and to evaluate the potential of δ⁵⁶Fe_aq as a proxy for benthic Fe fluxes. A high accumulation rate of total organic carbon compresses the redox zonation in the near-surface sediment column and controls benthic Fe efflux. Sites with low diffusive Fe fluxes show a broad δ⁵⁶Fe_aq range close to the sediment-water interface (−3.94 ± 0.14‰ to −0.98 ± 0.11‰), while sites with high benthic Fe fluxes exhibit a slightly narrower range (−3.14 ± 0.02‰ and −1.64 ± 0.06‰). The broader isotopic range in low benthic Fe flux settings reflects the diverse processes that entail low net benthic Fe fluxes into the bottom water. Low- and high rates of microbial iron reduction may result in similar Fe isotope composition of diffusive benthic Fe efflux, if the latter is combined with high rates of Fe removal from pore-water by iron sulfide formation. A narrow range of δ⁵⁶Fe_aq within the oxic redox zone appears to be a recurrent feature at sites of high benthic Fe fluxes, but we recommend accounting for all early diagenetic Fe cycling processes and the depositional regime when interpreting low δ⁵⁶Fe_aq values in the near bottom water.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GB008856","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Natural Soil N2O Emissions: An Analysis With a Global Biogeochemistry Model From 1990 to 2023","authors":"Ye Yuan,&nbsp;Qianlai Zhuang","doi":"10.1029/2025GB008804","DOIUrl":"https://doi.org/10.1029/2025GB008804","url":null,"abstract":"<p>Atmospheric N₂O, the dominant ozone-depleting substance and a potent greenhouse gas, has risen notably over recent decades. Using a process-based model, we simulated the sensitivity of N₂O emissions from undisturbed natural soils to the representation of historical land-cover change from 1990 to 2023 by factoring the effects of atmospheric nitrogen deposition, biological nitrogen fixation, rock weathering, and soil uptake. Simulations based on the potential vegetation distribution data show average emissions of 6.24 ± 0.72 Tg N yr⁻¹ with a significant upward trend (+0.021 Tg N yr⁻¹) from 1990 to 2023, while European Space Agency Climate Change Initiative land cover estimates were 30% lower, underscoring the sensitivity of N₂O estimates to land-cover representation. Most emissions stem from background processes (69.8% ± 4.5%), followed by nitrogen fixation (16.3% ± 2.6%), atmospheric deposition (9.2% ± 1.3%), and rock weathering (4.7% ± 1.1%). The accelerating trend of N₂O emissions under changing climate conditions and key uncertainties are tied to used land-cover data sets, limited observation data, and unresolved hydrological extremes.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GB008804","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogenous Thermochemical Stability of Sedimentary Organic Carbon in High-Arctic Svalbard Fjords","authors":"Xiaowen Zhang,&nbsp;Katarzyna Koziorowska,&nbsp;Huiyuan Yang,&nbsp;Songfan He,&nbsp;Kuan Hao,&nbsp;Maojun Yan,&nbsp;Craig Smeaton,&nbsp;Thomas S. Bianchi,&nbsp;Xingqian Cui","doi":"10.1029/2025GB008788","DOIUrl":"https://doi.org/10.1029/2025GB008788","url":null,"abstract":"<p>The modern carbon cycle in Arctic fjords is being disrupted by Arctic warming as permafrost thaw and glacier retreat intensify. Consequently, the erosion and export of terrestrial organic carbon (OC) to the ocean have accelerated. However, it is still largely unknown how this carbon cycle perturbation impacts the fate of mobilized OC in sediments. Here, we applied the ramped-temperature pyrolysis oxidation (RPO) technique to investigate the thermochemical decomposition potential of sedimentary OC in Svalbard fjords. The thermochemically labile, moderate, and refractory OCs are classified by specific energy thresholds. Our results show that sedimentary OC in Svalbard fjords exhibits overall high thermochemical heterogeneity. Fractions of refractory OC, as defined thermochemically, increase on a per-fjord basis from northern to southern fjords and are generally higher near the head of each fjord. The spatial pattern of refractory OC is most likely attributed to the delivery and sorting of petrogenic OC derived from bedrock erosion. By compiling published data sets with our results, we estimate an OC burial rate of 7.3 ± 6.2 × 10¹¹ gC yr⁻¹ in Svalbard fjords, with 1.2 ± 1.1 × 10¹¹ gC yr⁻¹ and 2.7 ± 2.4 × 10¹¹ gC yr⁻¹ attributed to labile and refractory components, respectively. Although a thermochemical moderate fraction still dominates the sediment OC pool, this work highlights that Svalbard fjords also serve as significant reservoirs of both labile and refractory sedimentary OC.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrological Cycle Intensification and Permafrost Thaw Drive Increased Freshwater and Organic Carbon Inputs to Northern Alaska Estuaries","authors":"Michael A. Rawlins,&nbsp;Craig T. Connolly,&nbsp;James W. McClelland","doi":"10.1029/2025GB008822","DOIUrl":"https://doi.org/10.1029/2025GB008822","url":null,"abstract":"<p>Understanding how hydrological inflows and climate change influence individual estuaries across northern Alaska is limited by a paucity of measured data, necessitating the application of suitably scaled numerical process models. This study uses an updated model to quantify freshwater discharge and dissolved organic carbon (DOC) export from the North Slope of Alaska (NSA) to coastal waters of the Beaufort Sea and examines climate-linked temporal changes. The model was applied at 1 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mtext>km</mtext>\u0000 </mrow>\u0000 <annotation> $text{km}$</annotation>\u0000 </semantics></math> resolution across the 166,483 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mtext>km</mtext>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${text{km}}^{2}$</annotation>\u0000 </semantics></math> NSA domain over 1980–2023. Watershed inputs to coastal waters were estimated by routing along river networks to 1,039 outlets at the land-sea boundary. Key simulation parameters were evaluated to demonstrate model efficacy, then spatial and temporal patterns were quantified. Exports to specific lagoons, bays, and sounds demonstrate how landscape composition, terrestrial drainage basin size, and estuary area modulate watershed influence on coastal ecosystems across the region. Freshwater discharge and DOC export increased over the greater than four decades, associated with changes in precipitation and permafrost thaw. Surface and supra-permafrost subsurface fluxes also increased, with pronounced rises in proportional contributions via subsurface flow during summer and autumn. These changes have the potential to substantially impact salinity and trophic conditions along Alaska's Beaufort Sea coast. Our study highlights the value of model-data syntheses that resolve regional-to-local scale fluxes where observational measurements are sparse, and provides novel quantitative export metrics that will be useful to researchers, resource managers, and other stakeholders with interests in the climate, hydrology, and biogeochemistry of coastal northern Alaska.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GB008822","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using Machine Learning to Uncover Ecological Mechanisms Controlling Abundance of Phytoplankton Size Classes From Large-Scale Observations","authors":"Sandupal Dutta,&nbsp;Anand Gnanadesikan","doi":"10.1029/2025GB009036","DOIUrl":"https://doi.org/10.1029/2025GB009036","url":null,"abstract":"<p>Phytoplankton size classes (PSCs) and Phytoplankton functional types (PFTs) determine many fundamental biogeochemical processes including nutrient uptake, energy transfer through marine food webs, ocean carbon export, and gas exchange with the atmosphere. Discerning the causes of spatio-temporal variability of PSCs is a scientific priority for understanding the ocean's role in and response to climate change. This study intends to decipher the relationships between the abundance of PSCs and environmental predictors using explainable machine learning (XAI) techniques. The target variables were PSCs obtained using three different satellite products: size-resolved phytoplankton carbon from Kostadinov, Milutinović, et al. (2016), https://doi.org/10.5194/os-12-561-2016, chlorophyll from MODIS divided according to the algorithm of Hirata et al. (2011), https://doi.org/10.5194/bg-8-311-2011, and a third product from the Copernicus Marine Service. The environmental predictors were nutrients, light, mixed layer depth, salinity, sea surface temperature (sst), and upwelling. The ML algorithm used was the Random Forest Regressor (RFR). XAI techniques were used to discern the relationship between predictors and PSCs abundance. About 85%–95% of the variability of the size classes in the observational data sets was accounted for by environmental variables known to influence phytoplankton biomass. Although different size classes responded similarly to the environmental drivers (with the exception of Copernicus picoplankton) their scale of response varied. The dominant predictors were found to be shortwave radiation, ammonia, dissolved iron and sea surface temperature. The different satellite products show sensitivity to iron, shortwave radiation, sst and ammonia across the same range of values, but with different magnitudes. Copernicus picoplankton is the only product which is positively related to sst.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 4","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GB009036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147666256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Net CO2 Emissions From Dry Inland Waters Persist in the Presence of Vegetation","authors":"Krati Sharma,&nbsp;Soren Brothers,&nbsp;Susana Bernal,&nbsp;Núria Catalán,&nbsp;Philipp Keller,&nbsp;Matthias Koschorreck,&nbsp;Sarian Kosten,&nbsp;Catherine Leigh,&nbsp;Daniel von Schiller,&nbsp;Ada Pastor,&nbsp;Aitor Larrañaga,&nbsp;Akif Arı,&nbsp;Alba Camacho-Santamans,&nbsp;Alistair Grinham,&nbsp;Anna Lupon,&nbsp;Annika Linkhorst,&nbsp;Arturo Elosegi,&nbsp;Biel Obrador,&nbsp;Bradley D. Eyre,&nbsp;Carolina Trochine,&nbsp;Claumir Cesar Muniz,&nbsp;Claudia Feijoo,&nbsp;Clément Duvert,&nbsp;Enrique Moreno-Ostos,&nbsp;Erica Garcia,&nbsp;Ernades Sobreira Oliveira,&nbsp;Florencia Cuassolo,&nbsp;Hugo Rafael Fernandez,&nbsp;Jacob Yeo,&nbsp;Joanne Oakes,&nbsp;José R. Paranaíba,&nbsp;Josephine Pegg,&nbsp;Julieta Anselmo,&nbsp;Jorge Juan Montes-Perez,&nbsp;Laura van den Heuvel,&nbsp;Lishan Ran,&nbsp;Lopes Lazaro Wilkinson,&nbsp;Lluís Gómez-Gener,&nbsp;Maite Arroita,&nbsp;Margaret Shanafield,&nbsp;Maria de Lourdes Gultemirian,&nbsp;Maria Isabel Arce,&nbsp;Melissa Cobo,&nbsp;María Mar Sánchez-Montoya,&nbsp;Nathan Barros,&nbsp;Naomi Wells,&nbsp;Nusret Karakaya,&nbsp;Pelin Ertürk Arı,&nbsp;Quinten Struik,&nbsp;Ralf Aben,&nbsp;Ryan Rimas,&nbsp;Sanjeev Kumar,&nbsp;Sheel Bansal,&nbsp;Siddhartha Sarkar,&nbsp;Sofía Rodríguez-Gómez,&nbsp;Tao Huang,&nbsp;Teresa Silverthorn,&nbsp;Thibault Datry,&nbsp;Veronica Diaz Villanueva,&nbsp;Rafael Marcé","doi":"10.1029/2025GB008801","DOIUrl":"https://doi.org/10.1029/2025GB008801","url":null,"abstract":"<p>Many inland waters are shrinking due to shifts in climate and water diversion for human uses. As they dry out, their exposed sediments emit large amounts of carbon dioxide (CO₂) to the atmosphere. However, current global estimates of CO₂ emissions from dry inland waters are derived exclusively from bare sediment dark-chamber measurements that do not account for the colonization of desiccated areas by vegetation. To understand the impact of vegetation on CO₂ emissions from dry sediments, we analyzed 164 dry inland water bodies across five climatic regions and five inland water body types (lakes, ponds, reservoirs, streams and wetlands). On average, within vegetated zones, vegetation occupied 47 ± 35% in measured biomass quadrants. Light-induced decreases in instantaneous CO₂ emissions in vegetated dry sediments were lower (mean ± SD = −3.7 ± 12.9 mmol CO₂ m⁻² hr⁻¹) than increases during dark conditions (14.7 ± 20.1 mmol CO₂ m⁻² hr⁻¹). Diel (24-hr) CO₂ emissions from dry, vegetated sediments (mean ± SD = 100 ± 261 mmol CO₂ m⁻² d⁻¹) were 25% lower than in bare sediments (133 ± 245 mmol CO₂ m⁻² d⁻¹). These results indicate that vegetation can partially off-set sediment respiration, although the magnitude of this effect is insufficient to switch dry beds from net sources to net sinks of carbon.</p>","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 3","pages":""},"PeriodicalIF":5.5,"publicationDate":"2026-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025GB008801","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147567948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}