Journal of Geophysical Research: Biogeosciences最新文献

{"title":"Different Mechanisms Underlie Plant-Mediated Methane Transport in a Tidal Salt Marsh Versus an Impounded Brackish Wetland","authors":"Georgia S. Seyfried,&nbsp;Barbara J. Campbell,&nbsp;Nichole Giani,&nbsp;Dustin G. Gannon,&nbsp;Thomas L. O’Halloran","doi":"10.1029/2025JG008987","DOIUrl":"https://doi.org/10.1029/2025JG008987","url":null,"abstract":"<p>Wetlands are a significant source of methane (CH₄), but their contributions to the global CH₄ budget remain uncertain. Wetland CH₄ production may be better constrained by addressing uncertainty in plant-mediated CH₄ transport, which is highly variable, motivating the current work. We measured whole-plant, plant-adjacent and non-vegetated carbon dioxide (CO₂) and CH₄ fluxes throughout the day approximately monthly for 1 yr in a euhaline tidal salt marsh and a mesohaline, non-tidal impounded wetland. To assess mechanisms, gas fluxes were accompanied by measurements of environmental variables and soil chemical and biological properties. We found that plants facilitated greater CH₄ fluxes across diurnal and seasonal scales but via distinct mechanisms at our two study sites. We observed daytime peaks in whole-plant and plant-adjacent CH₄ fluxes at the salt marsh, but no diurnal patterns in any CH₄ fluxes at the impounded wetland. Daytime peaks could indicate more efficient pressurized flow of CH₄ through plant biomass or greater sensitivity of aboveground fluxes to temperature or plant productivity. At the annual scale, peak whole-plant CH₄ fluxes were greater at the impounded wetland than at the salt marsh, while peak plant-adjacent CH₄ fluxes were greater at the salt marsh than at the impounded wetland. Differences between sites were attributed to plant-soil-microbe interactions and abiotic conditions such as temperature, water column depth and salinity that determine root-adjacent porewater CH₄ concentrations and the potential for plant-mediated CH₄ transport. These results increase our understanding of plant-mediated CH₄ transport and the mechanisms underlying high variability in these fluxes across coastal wetlands.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563907","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}

{"title":"Self- and Electrodic-Potential Response to Hydrological and Biogeochemical Processes in the Soil-Tree Continuum","authors":"M. Dumont,&nbsp;X. Takver,&nbsp;K. M. Jarecke,&nbsp;R. Yilangai,&nbsp;L. Slater,&nbsp;E. B. Graham,&nbsp;H. R. Barnard,&nbsp;P. L. Sullivan,&nbsp;K. Singha","doi":"10.1029/2025JG009375","DOIUrl":"10.1029/2025JG009375","url":null,"abstract":"<p>Forest sustainability is regulated by the interplay between water and biochemical fluxes within the soil–tree continuum. However, capturing the daily to seasonal interplay of these ecohydrological and biological processes remains a major challenge. Instrumentation is typically compartmentalized—soil, roots, or trunk—hindering a unified understanding of the continuum. Here, we explore the potential of passive electrical methods to concurrently track water and biochemical fluxes across the soil–tree interface. Self and electrodic potential, depending on electrode type, respond to water flow, chemical and thermal diffusion, and redox gradients. We propose an electro-hydro-biogeochemical conceptual model linking electrical potential generation to tree transpiration, water uptake, hydraulic redistribution, and soil respiration. Using electrical potential monitored within the soil and across the soil-root-trunk continuum at the H.J. Andrews Experimental Forest, Oregon, USA, during summer 2023, we tested this model via daily correlations with sap flow, soil moisture, and carbon dioxide. Despite disturbances caused by wildfire smoke, electrical signals revealed strong correlations with daily patterns and event-driven perturbations (e.g., wildfire smoke) of hydrological fluxes and biological activity in both trees and soil. Water fluxes emerge as the primary driver of self and electrodic potentials, with redox gradients also playing a significant role across the soil–tree continuum. This study presents a framework for using passive electrical methods as proxies for monitoring forest ecohydrological resilience.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009375","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563791","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}

{"title":"Self- and Electrodic-Potential Response to Hydrological and Biogeochemical Processes in the Soil-Tree Continuum","authors":"M. Dumont,&nbsp;X. Takver,&nbsp;K. M. Jarecke,&nbsp;R. Yilangai,&nbsp;L. Slater,&nbsp;E. B. Graham,&nbsp;H. R. Barnard,&nbsp;P. L. Sullivan,&nbsp;K. Singha","doi":"10.1029/2025JG009375","DOIUrl":"https://doi.org/10.1029/2025JG009375","url":null,"abstract":"<p>Forest sustainability is regulated by the interplay between water and biochemical fluxes within the soil–tree continuum. However, capturing the daily to seasonal interplay of these ecohydrological and biological processes remains a major challenge. Instrumentation is typically compartmentalized—soil, roots, or trunk—hindering a unified understanding of the continuum. Here, we explore the potential of passive electrical methods to concurrently track water and biochemical fluxes across the soil–tree interface. Self and electrodic potential, depending on electrode type, respond to water flow, chemical and thermal diffusion, and redox gradients. We propose an electro-hydro-biogeochemical conceptual model linking electrical potential generation to tree transpiration, water uptake, hydraulic redistribution, and soil respiration. Using electrical potential monitored within the soil and across the soil-root-trunk continuum at the H.J. Andrews Experimental Forest, Oregon, USA, during summer 2023, we tested this model via daily correlations with sap flow, soil moisture, and carbon dioxide. Despite disturbances caused by wildfire smoke, electrical signals revealed strong correlations with daily patterns and event-driven perturbations (e.g., wildfire smoke) of hydrological fluxes and biological activity in both trees and soil. Water fluxes emerge as the primary driver of self and electrodic potentials, with redox gradients also playing a significant role across the soil–tree continuum. This study presents a framework for using passive electrical methods as proxies for monitoring forest ecohydrological resilience.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009375","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563599","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}

{"title":"A Temporally Consistent Spatial Gradient in Methane Ebullition From a Eutrophic Lake","authors":"S. Moras,&nbsp;J. R. Paranaíba,&nbsp;E. Hiltunen,&nbsp;S. Sobek","doi":"10.1029/2024JG008256","DOIUrl":"10.1029/2024JG008256","url":null,"abstract":"<p>Gas bubble emission (ebullition) from lake sediment is a prominent source of the greenhouse gas methane (CH₄) to the atmosphere, but the stochastic nature of bubble release and thus high variability in space and time makes the estimation of lake CH₄ ebullition challenging. Several studies have identified major drivers of CH₄ ebullition variability over time, while fewer studies have identified what modulates CH₄ ebullition spatially. Here, we measured CH₄ ebullition in a Swedish eutrophic lake for 2 years over a longitudinal gradient between the main inlet and outlet, hypothesizing that differences in sediment properties across the lake are related to CH₄ ebullition. We found that CH₄ ebullition decreased with increasing distance from the main inlet. Elevated CH₄ ebullition was observed in areas with high sediment organic carbon density. These regions experience temporary sediment deposition but are not sites of long-term sediment accumulation due to their proximity to the inlet and susceptibility to erosion during high discharge events. Major CH₄ ebullition events were synchronous across sites and related to water level changes, indicating that changes in hydrostatic pressure regulate the timing of CH₄ ebullition. Even though the timing of major CH₄ ebullition events was very different between years, the spatial variability pattern in CH₄ ebullition was very similar both within and between years, further indicating that site-specific sediment characteristics drive CH₄ ebullition. The links between sediment properties and the spatial variability of CH₄ ebullition shown here can contribute to reducing the uncertainty in estimates of CH₄ emission from lakes.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008256","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563131","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}

{"title":"Source Prediction and Distribution of Organic Matter Across a Land to Ocean Sediment Transect: An Integrative Biogeochemical and Multivariate Machine Learning Approach","authors":"Yeganeh Mirzaei,&nbsp;Cameron Skinner,&nbsp;Gregor Kos,&nbsp;Yves Gélinas","doi":"10.1029/2025JG009527","DOIUrl":"10.1029/2025JG009527","url":null,"abstract":"<p>Identifying organic matter (OM) distribution and origins in sediments is vital for distinguishing archival records, depositional dynamics, and extent of terrigenous inputs to marine systems. However, degradation and modification of OM before deposition can camouflage and mask its source signals in sedimentary sinks. Also, limited number of samples, matrix complexity, and multiple available tracers for single-proxy mixing models can all challenge source apportionment of sedimentary OM. To overcome these limitations and deconvolute the origins of deposited OM along a land-ocean transect, this study integrates machine learning and multivariate analyses of elemental contents (C and N), biomarker abundances (C17-C27 <i>n</i>-alkanes), and bulk and compound specific stable carbon isotope values (δ¹³C) of sediments across the St. Lawrence Estuary and Gulf (SLEG). With pronounced provenance and terrestrial-marine regimes, the most proximal and distal sedimentary endmembers of the SLEG (60 and 780 km away from outlet) retain distinct geochemical information for training Principal Component Analysis and Partial Least Squares Regression model, predicting OM distribution across in-between stations. Results reveal a gradual shift in sedimented OM composition along the continuum due to OM inputs and source-to-sink processes; with a gradient of 2% decrease in terrestrial character of sedimentary OM per each 10 km distance from river outlet, findings reflect that the inputs and signals of terrigenous OM are progressively diluted and transformed offshore. Also, isotopic and molecular signatures exert stronger predicting controls than conventional tracers such as C/N ratios, highlighting that the diagnostic strength of proxies is system-specific, particularly under dynamic conditions. Integrative multivariate approaches can hence capture the complexity and covariances of multiple biogeochemical proxies to better decode camouflaged sedimentary archives and provide more holistic estimations of OM transportation and transformation across systems with strong geo-spatial and input gradients.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009527","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563156","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}

{"title":"A Temporally Consistent Spatial Gradient in Methane Ebullition From a Eutrophic Lake","authors":"S. Moras,&nbsp;J. R. Paranaíba,&nbsp;E. Hiltunen,&nbsp;S. Sobek","doi":"10.1029/2024JG008256","DOIUrl":"https://doi.org/10.1029/2024JG008256","url":null,"abstract":"<p>Gas bubble emission (ebullition) from lake sediment is a prominent source of the greenhouse gas methane (CH₄) to the atmosphere, but the stochastic nature of bubble release and thus high variability in space and time makes the estimation of lake CH₄ ebullition challenging. Several studies have identified major drivers of CH₄ ebullition variability over time, while fewer studies have identified what modulates CH₄ ebullition spatially. Here, we measured CH₄ ebullition in a Swedish eutrophic lake for 2 years over a longitudinal gradient between the main inlet and outlet, hypothesizing that differences in sediment properties across the lake are related to CH₄ ebullition. We found that CH₄ ebullition decreased with increasing distance from the main inlet. Elevated CH₄ ebullition was observed in areas with high sediment organic carbon density. These regions experience temporary sediment deposition but are not sites of long-term sediment accumulation due to their proximity to the inlet and susceptibility to erosion during high discharge events. Major CH₄ ebullition events were synchronous across sites and related to water level changes, indicating that changes in hydrostatic pressure regulate the timing of CH₄ ebullition. Even though the timing of major CH₄ ebullition events was very different between years, the spatial variability pattern in CH₄ ebullition was very similar both within and between years, further indicating that site-specific sediment characteristics drive CH₄ ebullition. The links between sediment properties and the spatial variability of CH₄ ebullition shown here can contribute to reducing the uncertainty in estimates of CH₄ emission from lakes.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008256","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563159","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}

{"title":"Source Prediction and Distribution of Organic Matter Across a Land to Ocean Sediment Transect: An Integrative Biogeochemical and Multivariate Machine Learning Approach","authors":"Yeganeh Mirzaei,&nbsp;Cameron Skinner,&nbsp;Gregor Kos,&nbsp;Yves Gélinas","doi":"10.1029/2025JG009527","DOIUrl":"https://doi.org/10.1029/2025JG009527","url":null,"abstract":"<p>Identifying organic matter (OM) distribution and origins in sediments is vital for distinguishing archival records, depositional dynamics, and extent of terrigenous inputs to marine systems. However, degradation and modification of OM before deposition can camouflage and mask its source signals in sedimentary sinks. Also, limited number of samples, matrix complexity, and multiple available tracers for single-proxy mixing models can all challenge source apportionment of sedimentary OM. To overcome these limitations and deconvolute the origins of deposited OM along a land-ocean transect, this study integrates machine learning and multivariate analyses of elemental contents (C and N), biomarker abundances (C17-C27 <i>n</i>-alkanes), and bulk and compound specific stable carbon isotope values (δ¹³C) of sediments across the St. Lawrence Estuary and Gulf (SLEG). With pronounced provenance and terrestrial-marine regimes, the most proximal and distal sedimentary endmembers of the SLEG (60 and 780 km away from outlet) retain distinct geochemical information for training Principal Component Analysis and Partial Least Squares Regression model, predicting OM distribution across in-between stations. Results reveal a gradual shift in sedimented OM composition along the continuum due to OM inputs and source-to-sink processes; with a gradient of 2% decrease in terrestrial character of sedimentary OM per each 10 km distance from river outlet, findings reflect that the inputs and signals of terrigenous OM are progressively diluted and transformed offshore. Also, isotopic and molecular signatures exert stronger predicting controls than conventional tracers such as C/N ratios, highlighting that the diagnostic strength of proxies is system-specific, particularly under dynamic conditions. Integrative multivariate approaches can hence capture the complexity and covariances of multiple biogeochemical proxies to better decode camouflaged sedimentary archives and provide more holistic estimations of OM transportation and transformation across systems with strong geo-spatial and input gradients.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009527","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563157","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}

{"title":"Longitudinal Riverine CH4 Emissions and the Impacts of River Damming and Urbanization","authors":"Jiao Liu,&nbsp;Xin Chen,&nbsp;Shaoda Liu,&nbsp;Lishan Ran,&nbsp;Xinghui Xia","doi":"10.1029/2025JG009184","DOIUrl":"10.1029/2025JG009184","url":null,"abstract":"<p>Urbanization and river damming represent profound anthropogenic disturbances that alter hydrological processes and watershed characteristics, thereby influencing riverine methane (CH₄) emissions. However, the mechanisms of how these activities drive CH₄ emissions within the watershed scale remain inadequately understood, especially in densely populated regions. To address this, here we measured CH₄ emissions along a 747 km transect in a populated northern China river during late summer. Our results show that CH₄ emissions were 70%–110% higher in reservoir-affected and lower reaches than in the upper reaches (3.30 and 2.64 vs. 1.58 mmol m⁻² d⁻¹, <i>p</i> &lt; 0.01). CH₄ emission hotspots were closely associated with fine sediments, which were most pronounced in urbanized and impounded reaches. Reduced flow velocity and increased water residence time in these reaches promoted fine sediments and nutrients accumulation, which enhanced organic substrate availability, created anoxic conditions, and reshaped methanogenic communities. Furthermore, urbanization and damming markedly altered carbon metabolic pathways, as evidenced by the increase in the CH₄: CO₂ ratio from 0.03 in the upperstream to 0.08 in urbanized-reaches and to 0.16 in reservoir-affected reaches, along with a higher <i>pmoA</i>/<i>mcrA</i> gene ratio in the upper reaches. Oxygen-depleted conditions and elevated organic inputs from sewage created a favorable environment for methanogens' growth and activity, ultimately contributing to more CH₄ emissions in urbanized reaches. These findings highlight the critical role of human activities in controlling riverine CH₄ emissions and shifting CH₄: CO₂ ratios along anthropogenic gradients by changing sediment and hydrological regimes as well as methanogenic communities.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147562887","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}

{"title":"Longitudinal Riverine CH4 Emissions and the Impacts of River Damming and Urbanization","authors":"Jiao Liu,&nbsp;Xin Chen,&nbsp;Shaoda Liu,&nbsp;Lishan Ran,&nbsp;Xinghui Xia","doi":"10.1029/2025JG009184","DOIUrl":"https://doi.org/10.1029/2025JG009184","url":null,"abstract":"<p>Urbanization and river damming represent profound anthropogenic disturbances that alter hydrological processes and watershed characteristics, thereby influencing riverine methane (CH₄) emissions. However, the mechanisms of how these activities drive CH₄ emissions within the watershed scale remain inadequately understood, especially in densely populated regions. To address this, here we measured CH₄ emissions along a 747 km transect in a populated northern China river during late summer. Our results show that CH₄ emissions were 70%–110% higher in reservoir-affected and lower reaches than in the upper reaches (3.30 and 2.64 vs. 1.58 mmol m⁻² d⁻¹, <i>p</i> &lt; 0.01). CH₄ emission hotspots were closely associated with fine sediments, which were most pronounced in urbanized and impounded reaches. Reduced flow velocity and increased water residence time in these reaches promoted fine sediments and nutrients accumulation, which enhanced organic substrate availability, created anoxic conditions, and reshaped methanogenic communities. Furthermore, urbanization and damming markedly altered carbon metabolic pathways, as evidenced by the increase in the CH₄: CO₂ ratio from 0.03 in the upperstream to 0.08 in urbanized-reaches and to 0.16 in reservoir-affected reaches, along with a higher <i>pmoA</i>/<i>mcrA</i> gene ratio in the upper reaches. Oxygen-depleted conditions and elevated organic inputs from sewage created a favorable environment for methanogens' growth and activity, ultimately contributing to more CH₄ emissions in urbanized reaches. These findings highlight the critical role of human activities in controlling riverine CH₄ emissions and shifting CH₄: CO₂ ratios along anthropogenic gradients by changing sediment and hydrological regimes as well as methanogenic communities.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147562888","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}

{"title":"Extreme Spring Drought and Extreme Summer Precipitation Weakened the Carbon Sink Strength in an Estuarine Wetland","authors":"Siyu Wei,&nbsp;Wenhe Wu,&nbsp;Xiaojing Chu,&nbsp;Xiaoshuai Zhang,&nbsp;Mingliang Zhao,&nbsp;Xiaojie Wang,&nbsp;Peiguang Li,&nbsp;Weimin Song,&nbsp;Feng Lu,&nbsp;Buli Cui,&nbsp;Guangxuan Han","doi":"10.1029/2025JG009583","DOIUrl":"https://doi.org/10.1029/2025JG009583","url":null,"abstract":"<p>Ongoing climate change is expected to increase the frequency and intensity of extreme hydrological events globally. Since the carbon sink function of wetlands is largely driven by hydrology, it is essential to comprehensively understand how these extreme events impact wetland carbon processes. However, the response of the wetland carbon cycle to extreme hydrological events under a changing climate remains uncertain. In this study, we employed the eddy covariance technique to evaluate the impact of extreme hydrological events on the carbon sink strength in an estuarine wetland in the Yellow River Delta. We selected 2 years, 2019 and 2020, with comparable annual rainfall totals but notable differences in seasonal precipitation patterns: the year 2019 was characterized by an extremely dry spring and an extreme precipitation event in summer. The results revealed a 60% decline in annual CO₂ uptake, with net ecosystem CO₂ exchange (NEE) recorded at −105 g C m⁻² yr⁻¹ in 2019, compared to −261 g C m⁻² yr⁻¹ in 2020. Both the extreme drought in spring and the extreme precipitation in summer reduced the maximum rates of photosynthesis throughout the growing season. Finally, a comparison with historical monitoring data from 2011 to 2020 at the study site revealed that the annual CO₂ sink magnitude in 2019 decreased by 54% compared to the multi-year average NEE of −228 ± 58 g C m⁻² yr⁻¹. This study provides a novel perspective on how extreme hydrological events influence the carbon budget of wetlands.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 3","pages":""},"PeriodicalIF":3.5,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147562553","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}