Journal of Geophysical Research: Biogeosciences最新文献_第4页

Distinct Streamflow and Nutrient Export Dynamics in Wildfire-Impacted Nonperennial Streams in Central Coastal California 加州中部沿海野火影响下非多年生河流的独特流量和养分输出动态

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-28 DOI: 10.1029/2024JG008553

Lauren Giggy, Riley Barton, Sasha Wagner, Margaret Zimmer

{"title":"Distinct Streamflow and Nutrient Export Dynamics in Wildfire-Impacted Nonperennial Streams in Central Coastal California","authors":"Lauren Giggy, Riley Barton, Sasha Wagner, Margaret Zimmer","doi":"10.1029/2024JG008553","DOIUrl":"https://doi.org/10.1029/2024JG008553","url":null,"abstract":"Wildfires impact water quality by altering nutrient supply and hydrology with changes often perceptible during the first major storm events. However, many factors influence water quality, including wildfire characteristics, weather patterns, and watershed properties. Such factors create challenges for predicting and mitigating water quality, highlighting the ongoing need for work across diverse hydroclimatic settings. The Santa Clara Unit Lightning Complex (SCU) Fire impacted two adjacent headwater catchments in central coastal California. Previous work showed that despite similar biophysical characteristics, the two catchments are hydrologically distinct with one catchment displaying flashier streamflow and higher dissolved organic carbon (DOC) concentrations likely driven by distinct bedrock. Although prefire data are not available, here we expand on this work with detailed observations of total dissolved nitrogen, phosphate (PO43−), and DOC concentrations and loads, over the first two years following the wildfire. We observed 2–13 times higher annual solute export from the catchment with flashier streamflow behavior. We hypothesize that elevated solute export occurred due to shallow hydrologic flow paths dominating runoff generation regardless of surface-level alterations from the wildfire. Additionally, we did not observe the highest solute concentrations during the first major storms following the wildfire. Instead, solute concentrations peaked during high-intensity rainfall in year two. This work showcases the importance of the hydrogeologic setting and hydrologic routing on solute export. Additionally, these results highlight challenges in predicting water quality responses in disturbed catchments and teasing apart the role of wildfire, ongoing drought, and high-intensity precipitation in semiarid climates.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008553","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144716821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Microorganisms Contributing to the Biological Pump in the Western Arctic Ocean During Late Summer 晚夏北冰洋西部微生物对生物泵的贡献

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-26 DOI: 10.1029/2024JG008568

Hongwei Qin, Hisashi Endo, Akiko Ebihara, Amane Fujiwara, Jonaotaro Onodera, Yosuke Yamada, Hideki Fukuda, Toshi Nagata, Takuhei Shiozaki

{"title":"Microorganisms Contributing to the Biological Pump in the Western Arctic Ocean During Late Summer","authors":"Hongwei Qin, Hisashi Endo, Akiko Ebihara, Amane Fujiwara, Jonaotaro Onodera, Yosuke Yamada, Hideki Fukuda, Toshi Nagata, Takuhei Shiozaki","doi":"10.1029/2024JG008568","DOIUrl":"https://doi.org/10.1029/2024JG008568","url":null,"abstract":"Marine particles can be classified into sinking and suspended particles, and recent studies have revealed that the microbial communities associated with each particle are distinct. The western Arctic Ocean has undergone significant environmental changes due to sea ice loss in recent years, which may impact the biological pump. While microbial communities on suspended particles in this region have been studied, those on sinking particles remain largely unexplored. We analyzed the eukaryotic and prokaryotic community structures of suspended and sinking particles collected from subsurface chlorophyll maximum layers in the western Arctic Ocean during late summer 2021 using a marine snow catcher. A significant difference between the two particle types in overall eukaryotic community structures was observed, while differences in prokaryotic communities were evident at more specific taxonomic levels. Carbon sinking flux ranged from 68.7 to 774 mg C m−2 d−1 and showed a significant positive correlation with chlorophyll a concentrations. Correlation network analysis identified microbial modules, including diatoms, parasites in Syndiniales and Peronosporomycetes as well as Desulfobacterota, which positively correlated with carbon sinking flux. Our findings highlight previously unrecognized microbial contributors to the biological pump in the western Arctic Ocean, and these organisms maybe key to elucidating biogeochemical cycles in the changing Arctic Ocean.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008568","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reduce Revenue Versus Increase Expenditure: Fires and Plant Invasion Drive Soil Carbon Loss With Different Mechanisms in a Mediterranean Shrubland 减少收入与增加支出：火灾和植物入侵以不同机制驱动地中海灌木林地土壤碳损失

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-24 DOI: 10.1029/2025JG008964

Liyuan He, David A. Lipson, Elsa E. Cleland, Xiaofeng Xu

{"title":"Reduce Revenue Versus Increase Expenditure: Fires and Plant Invasion Drive Soil Carbon Loss With Different Mechanisms in a Mediterranean Shrubland","authors":"Liyuan He, David A. Lipson, Elsa E. Cleland, Xiaofeng Xu","doi":"10.1029/2025JG008964","DOIUrl":"https://doi.org/10.1029/2025JG008964","url":null,"abstract":"Fires and plant invasions threaten Mediterranean ecosystems substantially, particularly in the context of changing climate. Our study utilized a data-model integration approach to assess the response of soil organic carbon (SOC) to fires and plant invasion under three Shared Socio-Economic Pathway (SSP) scenarios (SSP1-26, SSP2-45, and SSP5-85). We parameterized the CLM-Microbe model and then investigated the individual and interactive impacts of fires and plant invasion on soil C by comparing factorial simulations of initialization (fire/no wildfire in 2021), fire module on/off, and with and without plant invasion during 2023–2100 in a Mediterranean ecosystem. The simulations indicated a marked C loss due to the 2021 wildfire, projected fires, and plant invasion across all future climate scenarios. Specifically, the 2021 wildfire, projected fires, and plant invasion reduced the SOC (0–30 cm) by 0.12, 0.26, and 0.15 kg C m−2 under SSP1-26, 0.12, 0.30, and 0.12 kg C m−2 under SSP2-45, and 0.12, 0.24, and 0.13 kg C m−2 under SSP5-85, respectively. However, fires and plant invasion decreased SOC through distinct mechanisms. The effects of the 2021 wildfire occurred due to its negative legacy on soil microbial community and, thus, litter accumulation, suppressing the formation of soil carbon via decomposition. Influences of projected fires happen via consuming fuel and suppressing carbon input to soils. In contrast, the impacts of plant invasions were due to enhanced microbial respiration, leading to C loss. These findings emphasize the need for tailored C sequestration strategies considering the disparate effects of fires and plant invasions in the Mediterranean climate.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144688146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Longitudinal Patterns in Nitrate Revealed Through Drone-Based Measurements in an Agriculturally Influenced Midwestern U.S. River 在美国中西部一条受农业影响的河流中，通过无人机测量揭示了硝酸盐的纵向模式

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-23 DOI: 10.1029/2024JG008342

Alyssa Gerhardt, Peter S. Levi, Natalie A. Griffiths, Christopher R. DeRolph, Jeffery S. Riggs, Allison M. Fortner

{"title":"Longitudinal Patterns in Nitrate Revealed Through Drone-Based Measurements in an Agriculturally Influenced Midwestern U.S. River","authors":"Alyssa Gerhardt, Peter S. Levi, Natalie A. Griffiths, Christopher R. DeRolph, Jeffery S. Riggs, Allison M. Fortner","doi":"10.1029/2024JG008342","DOIUrl":"https://doi.org/10.1029/2024JG008342","url":null,"abstract":"Nitrate concentrations in streams and rivers in the Midwestern United States are often elevated, reflecting the predominance of agriculture in the surrounding landscape. Recent advances in technology, including surface water drones and more precise sensors, provide opportunities to investigate nitrate dynamics with high spatial and temporal resolution. We deployed an aquatic drone, the AquaBOT, in a sixth-order, agriculturally influenced river to examine longitudinal patterns in water quality. Our goal was to measure the spatial and temporal heterogeneity in nitrate and nitrate removal processes and determine the influence of tributary inputs on main stem chemistry. We navigated the drone along a 12-km reach of the Des Moines River (Iowa, USA) nine times between June 2021 and August 2022. Across the deployments, mean nitrate concentration was positively related to discharge and was nearly two orders of magnitude higher in spring than summer. We observed contrasting patterns in main stem nitrate, which decreased downstream during some runs (e.g., 3.1–2.7 mg N L−1 in June 2021), demonstrating net nitrate uptake along the reach, and remained constant on other dates. Similarly, tributaries to the Des Moines had a varied influence on riverine nitrate. Tributaries either increased or decreased main stem nitrate concentrations depending on the tributary and the date. Nitrate removal rates were spatially and temporally variable but showed some consistency at the subreach (2 km) scale, with two subreaches often showing elevated rates of nitrate removal across dates. Our study reveals nuanced heterogeneity in nitrate dynamics of the Des Moines River despite the homogeneity of agricultural land cover in the watershed.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144681175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Increased Ecosystem Productivity Boosts Methane Production in Arctic Lake Sediments 生态系统生产力的提高促进了北极湖泊沉积物中甲烷的产生

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-23 DOI: 10.1029/2024JG008508

Marie Bulínová, Anders Schomacker, Sofia E. Kjellman, Cristian Gudasz, Carolina Olid, Johan Rydberg, Giuliana Panieri, Andrew Hodson, Willem G. M. van der Bilt, Torgeir Opeland Røthe, Richard Bindler, Alexandra Rouillard

{"title":"Increased Ecosystem Productivity Boosts Methane Production in Arctic Lake Sediments","authors":"Marie Bulínová, Anders Schomacker, Sofia E. Kjellman, Cristian Gudasz, Carolina Olid, Johan Rydberg, Giuliana Panieri, Andrew Hodson, Willem G. M. van der Bilt, Torgeir Opeland Røthe, Richard Bindler, Alexandra Rouillard","doi":"10.1029/2024JG008508","DOIUrl":"https://doi.org/10.1029/2024JG008508","url":null,"abstract":"Global estimates of methane (CH4) emissions from lakes to the atmosphere rely on understanding CH4 processes at the sediment-water interface (SWI). However, in the Arctic, the variability, magnitude, and environmental drivers of CH4 production and flux across the SWI are poorly understood. Here, we estimate CH4 diffusive fluxes from the sediment into the water column in 10 lakes in Arctic Scandinavia and Svalbard using porewater modeling and mass transfer estimates, which we then compare with 60 published estimates from the Arctic to the tropics. Diffusion of CH4 in the sampled lake sediments ranged from −0.46 to 3.1 mmol m−2 day−1, which is consistent with previous reports for Arctic and boreal lakes, and lower than for temperate and tropical biomes. Methane production occurs primarily within the top ∼10 cm of sediment, indicating a biogenic origin. Random forest predictive modeling of the sampled lakes revealed that conditions promoting production and deposition of autochthonous organic carbon in Arctic lakes drive CH4 diffusion into the water column by fueling sediment CH4 production. For small lakes across biomes, determinants of the estimated CH4 flux were also best captured by climate predictors, with warmer and wetter conditions favoring ecosystem productivity and enhancing flux but also lake morphometry resulting in important regional variability in estimates. Our study emphasizes the importance of quantifying diffusive CH4 fluxes from sediments in diverse lake types to account for differences in the controls on primary production and the preservation of organic carbon across and within different biomes, to refine CH4 emission estimates in a warming climate.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144681546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seasonal Variation of Enzymatically Hydrolyzable Organic Phosphorus in Agricultural Drainage Waters 农业排水中酶解有机磷的季节变化

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-22 DOI: 10.1029/2024JG008358

Rebecca J. Pitcock, Pierre-Andre Jacinthe

{"title":"Seasonal Variation of Enzymatically Hydrolyzable Organic Phosphorus in Agricultural Drainage Waters","authors":"Rebecca J. Pitcock, Pierre-Andre Jacinthe","doi":"10.1029/2024JG008358","DOIUrl":"https://doi.org/10.1029/2024JG008358","url":null,"abstract":"Phosphorus (P) export studies in agricultural watersheds have generally focused on soluble reactive P (SRP), the P fraction generally considered as readily available for biological uptake. However, in some settings, the amount of dissolved organic P (DOP) in agricultural drainage waters can be significant and may represent another important source of P to fuel algal growth. Using the iron-oxide (FeO) strip method and a suite of assays to measure enzymatically hydrolyzable P (EHP), the potential bioavailability of DOP in drainage waters from an agricultural field (Indiana, USA) was investigated to assess the effect of season and hydrologic flow path on DOP attributes. Results showed that DOP accounted for 60%–85% of the total dissolved P (TDP), and that 39% of DOP in surface runoff and 62% of DOP in subsurface tile waters was enzymatically hydrolyzable. Taking the FeO-strip P as another measure of potentially bioavailable P, regression analysis and concentration balance calculations showed that the FeO-strip P mostly included SRP and EHP (monoesterase-, diesterase-, and phytase-hydrolyzable P). For both subsurface and surface pathways, EHP (especially phytase-hydrolyzable P) and FeO-strip P concentration was highly sensitive to dry/wet cycles of soil moisture. Thus, if these dry/wet hydroclimatic events were to become more frequent in the region, as suggested by some climate models, they could accelerate the export of bioavailable P from croplands and further exacerbate water quality degradation in receiving water bodies.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008358","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144681516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Parsimonious Downscaling Method for Global Potential Net Primary Production: From 30 arcmin to 30 arcsec Resolution 全球潜在净初级产量的简约降尺度方法：从30角秒分辨率到30角秒分辨率

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-22 DOI: 10.1029/2025JG009019

Florian Weidinger, Sarah Matej, Lukas Baumbach, Thomas Hickler, Christian Werner, Karl-Heinz Erb

{"title":"A Parsimonious Downscaling Method for Global Potential Net Primary Production: From 30 arcmin to 30 arcsec Resolution","authors":"Florian Weidinger, Sarah Matej, Lukas Baumbach, Thomas Hickler, Christian Werner, Karl-Heinz Erb","doi":"10.1029/2025JG009019","DOIUrl":"https://doi.org/10.1029/2025JG009019","url":null,"abstract":"The impact of land use on ecosystems has reached critical levels, jeopardizing biosphere integrity. A key indicator that quantifies, monitors, and analyses such impacts is the Human Appropriation of Net Primary Production (HANPP). Assessing HANPP consists of a comparison of actual net primary production and potential vegetation properties—i.e., vegetation properties that would prevail in the absence of land use (i.e., the NPP of the potential vegetation; NPPpot). While technical advancements in remote sensing have led to global land cover data at high spatial resolution up to 30 arcsec (i.e., 1 km at the equator) and higher, spatial explicit global NPPpot, mainly provided by Dynamic Global Vegetation Models (DGVMs), are usually generated at 30 arcmin (i.e., 55 km at the equator). This spatial mismatch causes uncertainties in HANPP assessments. We here present a workable solution for downscaling NPPpot until global, high-resolution results, for example, from DGVMs, become feasible. This method uses a simple NPPpot model with readily available auxiliary information at higher spatial resolution to generate fine-scale patterns to downscale high-quality coarse scale NPPpot. It includes a smoothing procedure to reduce downscaling artifacts. We demonstrate this Smooth Auxiliary Data (SAD) downscaling by applying it to NPPpot results from the LPJ-GUESS DGVM model for the year 2010 to downscale from 30 arcmin to 30 arcsec resolution. This approach generates fine-scaled NPPpot patterns and aligns with alternative models for smaller geographic units while computational cost is acceptable.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009019","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144681518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Plant Community Shifts as Early Indicators of Abrupt Permafrost Thaw and Associated Carbon Release in an Interior Alaskan Peatland 植物群落变化是阿拉斯加内陆泥炭地永久冻土突然融化和相关碳释放的早期指标

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-22 DOI: 10.1029/2024JG008639

W. D. Cox, C. M. Dieleman, T. A. Douglas, E. S. Kane, R. B. Neumann, E. S. Euskirchen, M. R. Turetsky

{"title":"Plant Community Shifts as Early Indicators of Abrupt Permafrost Thaw and Associated Carbon Release in an Interior Alaskan Peatland","authors":"W. D. Cox, C. M. Dieleman, T. A. Douglas, E. S. Kane, R. B. Neumann, E. S. Euskirchen, M. R. Turetsky","doi":"10.1029/2024JG008639","DOIUrl":"https://doi.org/10.1029/2024JG008639","url":null,"abstract":"Widespread changes to near-surface permafrost in northern ecosystems are occurring through gradual top-down thaw and more abrupt localized thermokarst development. Both thaw types are associated with a loss of ecosystem services, including soil hydrothermal and mechanical stability and long-term carbon storage. Here, we analyzed relationships between the vascular understory, basal moss layer, active layer thickness (ALT), and greenhouse gas fluxes along a thaw gradient from permafrost peat plateau to thaw bog in Interior Alaska. We used ALT to define four distinct stages of thaw: Stable, Early, Intermediate, and Advanced, and we identified key plant taxa that serve as reliable indicators of each stage. Advanced thaw, with a thicker active layer and more developed thermokarst features, was associated with increased abundance of graminoids and Sphagnum mosses but decreased plant species richness and ericoid abundance, as well as a substantial increase in methane emissions. Early thaw, characterized by active layer thickening without thermokarst development, coincided with decreased ericoid cover and plant species richness and an increase in CH4 emissions. Our findings suggest that early stages of thaw, prior to the formation of thermokarst features, are associated with distinct vegetation and soil moisture changes that lead to abrupt increases in methane emissions, which then are perpetuated through ground surface subsidence and collapse scar bog formation. Current modeling of permafrost peatlands will underestimate carbon emissions from thawing permafrost unless these linkages between plant community, nonlinear active layer dynamics, and carbon fluxes of emerging thaw features are integrated into modeling frameworks.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144672003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Implications for the Missing South Asian Carbon Sink: Hydrologic Coupling of Water and Carbon Balances in a Tropical Catchment 南亚碳汇缺失的启示：热带流域水碳平衡的水文耦合

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-19 DOI: 10.1029/2025JG008839

Sachintha Senarathne, Robert van Geldern, Rohana Chandrajith, Gabriele Chiogna, Johannes A. C. Barth

{"title":"Implications for the Missing South Asian Carbon Sink: Hydrologic Coupling of Water and Carbon Balances in a Tropical Catchment","authors":"Sachintha Senarathne, Robert van Geldern, Rohana Chandrajith, Gabriele Chiogna, Johannes A. C. Barth","doi":"10.1029/2025JG008839","DOIUrl":"https://doi.org/10.1029/2025JG008839","url":null,"abstract":"This study applied stable water isotopes (δ18OH2O and δ2HH2O) and remote sensing techniques to predict basin-wide CO2 uptake in the tropical Deduru Oya River Basin (DOB) in Sri Lanka. It used the fact that water and carbon cycles are linked by transpiration. Between November 2022 and October 2023, the DOB lost 2,563 million m3 of water by evapotranspiration (ET). This number corresponds to 65.8% of the 3,895 million m3 of incoming precipitation. Based on the δ18OH2O in a revised Craig–Gordon model and normalized difference vegetation index (NDVI), our data showed that ET could be separated into its subcomponents evaporation (E), transpiration (T), and interception (I) with 10.4%, 53.9%, and 1.5% of the annual precipitation, respectively. After translation to carbon uptake via the water use efficiency (WUE), the DOB showed a net primary productivity (NPP) of 1,130 g C m−2 that corresponded to 2,808 × 109 g C for the entire basin. After subsequent subtraction of basin-wide soil respiration (1,737 × 109 g C) and surface water degassing (101 × 109 g C) back to the atmosphere, our study yielded a net ecosystem production (NEP) of 979 ± 313 × 109 g C for the entire basin. These result indicate that the DOB is a carbon sink. Our study is the first to present this technique together with error propagation and with CO2 evasions from surface waters.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG008839","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144657733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seasonal and Interannual Variability of Soil Heterotrophic Respiration and Autotrophic Respiration in Typical Grassland of Inner Mongolia 内蒙古典型草原土壤异养呼吸和自养呼吸的季节和年际变化

IF 3.7 3区环境科学与生态学

Journal of Geophysical Research: Biogeosciences Pub Date : 2025-07-19 DOI: 10.1029/2024JG008651

Bingyan Jin, Yibo Yan, Xiaowen Wang, Xiujun Wang, Xianglan Li, Haiqing Song

{"title":"Seasonal and Interannual Variability of Soil Heterotrophic Respiration and Autotrophic Respiration in Typical Grassland of Inner Mongolia","authors":"Bingyan Jin, Yibo Yan, Xiaowen Wang, Xiujun Wang, Xianglan Li, Haiqing Song","doi":"10.1029/2024JG008651","DOIUrl":"https://doi.org/10.1029/2024JG008651","url":null,"abstract":"Considerable differences exist between soil heterotrophic respiration and autotrophic respiration in terms of variation and regulating factors. However, there is still a lack of evaluation of the differences between the two components in grasslands of arid and semi-arid regions under a changing climate. We developed a semi-process model separately for heterotrophic respiration and autotrophic respiration for the Inner Mongolian grassland of China to estimate their rates over seasonal and interannual cycles from 2002 to 2021. The models were calibrated with site-specific parameters and validated against independent field measurements. Our model results show stronger seasonal and interannual variability in autotrophic respiration than in heterotrophic respiration over 2002–2021. There was a significant increasing trend in most seasons at all three sites for autotrophic respiration (with the greatest slope in summer, i.e., 2.12–3.97 g C m−2 yr−2), but only in winter for heterotrophic respiration at the southern typical grassland site (0.27 g C m−2 yr−2). Soil temperature was responsible for the seasonal and interannual variability in heterotrophic respiration but plant growth responsible for the temporal variations of autotrophic respiration. Our results highlight that distinguishing between soil heterotrophic respiration and autotrophic respiration is of importance not only for better understanding of the carbon cycle in the grasslands but also for predicting how soil respiration responds to climate change in the future.","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144657745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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