Global Biogeochemical Cycles最新文献

Methane Uptake by Inland Waters: Fact or Fiction? 内陆水域对甲烷的吸收：事实还是虚构？

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-17 DOI: 10.1029/2026GB009212

Mike Peacock, Jackie Webb

{"title":"Methane Uptake by Inland Waters: Fact or Fiction?","authors":"Mike Peacock, Jackie Webb","doi":"10.1029/2026GB009212","DOIUrl":"https://doi.org/10.1029/2026GB009212","url":null,"abstract":"Inland waters are widely known as net emitters of methane (CH4) to the atmosphere, contributing ∼15% of global CH4 emissions. CH4 is produced by anaerobic methanogens in aquatic sediments, but net CH4 emissions at the water–air interface are modulated by CH4 oxidation by methanotrophs in the water column. However, the prevailing paradigm is that CH4 production outweighs oxidation, and that freshwaters are ubiquitously net emitters. Here, via data collation and solicitation of expert opinion, we show that diffusive CH4 uptake (i.e., net CH4 consumption) is reported across a diverse range of freshwater types, although fluxes are generally small (median = −2.2 mg CH4 m−2 d−1). Although some reports of freshwater CH4 uptake can be attributed to errors in data collection and analysis, others are harder to dismiss. Uptake is potentially driven by biological processes such as high rates of methanotrophy, or by physical processes such as mixing-induced introduction of low-CH4 water from other layers or inflows. Our results question the paradigm that freshwaters are always sources of CH4. We call for targeted field and lab work programs to more fully detect and understand this elusive but intriguing natural phenomenon.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GB009212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206209","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}

引用次数: 0

Throughfall Gained More Ammonium From Particulates and Mineralization Than Precipitation Ammonium Retention in Forest Canopy 森林冠层中穿透雨从颗粒和矿化中获得的铵态氮多于降水保留的铵态氮

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-15 DOI: 10.1029/2025GB009042

Ke-Tong Yang, Xue-Yan Liu

{"title":"Throughfall Gained More Ammonium From Particulates and Mineralization Than Precipitation Ammonium Retention in Forest Canopy","authors":"Ke-Tong Yang, Xue-Yan Liu","doi":"10.1029/2025GB009042","DOIUrl":"https://doi.org/10.1029/2025GB009042","url":null,"abstract":"Canopy is a critical interface influencing atmospheric nitrogen (N) inputs into forest soils. Ammonium (NH4+) is a major chemical form of N deposition. However, the fluxes of precipitation-canopy NH4+ exchange processes and their environmental responses remain unclear, which impairs the assessment of N deposition effects on forest biodiversity and functions. By collecting and synthesizing the flux and N isotope (δ15N) data, we quantified the actual input of NH4+ by comparing the differences in bulk precipitation and throughfall NH4+ fluxes. We then constructed a novel model based on δ15N to identify the sources contributing to elevated throughfall NH4+ fluxes and to elucidate the NH4+ interactions between atmosphere and canopy. Results showed that throughfall had generally higher NH4+ fluxes (by 26% and 74%) and δ15N values than bulk precipitation. Throughfall gained total 67% of NH4+ (5.6 ± 6.5 and 6.0 ± 8.4 kg-N/ha/yr) from canopy particulates and mineralization, while canopy retained 59% and 41% of precipitation NH4+ (4.1 ± 4.4 and 2.2 ± 4.0 kg-N/ha/yr) in broadleaved and coniferous forests, respectively. In addition, we identified that the fluxes of precipitation-canopy NH4+ exchange processes increased with NH4+ deposition levels. These results revealed that dry deposition and microbial mineralization in canopy are important NH4+ replenishment to throughfall and atmospheric NH4+ loading would stimulate precipitation-canopy NH4+ exchanges. Our findings enrich the knowledge of forest N biogeochemistry and are useful for evaluating forest N deposition effects.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205878","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}

引用次数: 0

Dissolved Total Mercury and Methylmercury Fluxes to the Coastal Ocean via Non-Hydrothermal Submarine Groundwater Discharge 通过非热液海底地下水排放到沿海海洋的溶解总汞和甲基汞通量

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-13 DOI: 10.1029/2026GB009303

Zhijia Ci, Xiong Tang, Bochao Xu, Michael S. Bank, Wenjie Shen, Baowei Chen, Tiangang Luan, Yongguang Yin, Yong Cai

{"title":"Dissolved Total Mercury and Methylmercury Fluxes to the Coastal Ocean via Non-Hydrothermal Submarine Groundwater Discharge","authors":"Zhijia Ci, Xiong Tang, Bochao Xu, Michael S. Bank, Wenjie Shen, Baowei Chen, Tiangang Luan, Yongguang Yin, Yong Cai","doi":"10.1029/2026GB009303","DOIUrl":"https://doi.org/10.1029/2026GB009303","url":null,"abstract":"Coastal ecosystems are hotspots for biogeochemical cycling of mercury (Hg) and human exposure to neurotoxic methylmercury (MMHg). However, coastal aquifer Hg biogeochemistry remains understudied at a global scale, and the contribution of submarine groundwater discharge (SGD) to global coastal Hg budgets has long been overlooked. In this study, based on a compilation of 44 new observations in the coastline of China and 20 existing observations from around the world, we investigate the distribution and transformation of Hg within global coastal aquifers and estimate non-hydrothermal SGD-derived dissolved total Hg (DTHg) and MMHg (DMMHg) flux to the global coastal ocean. We find that almost all coastal aquifers are identified as non-conservative for both DTHg and DMMHg, and the productive behavior is the most prevalent. We estimate that non-hydrothermal SGD-derived DTHg (Monte Carlo mean = 901.8; median = 339.0; interquartile range = 46.6–1005.3 Mg yr−1) rivals riverine discharge, and is ∼3 times and 14 times greater than atmospheric deposition and porewater diffusion from coastal sediments to the global coastal ocean. Notably, non-hydrothermal SGD is identified as the known largest external source of DMMHg (mean = 77.3; median = 43.4; interquartile range = 14.4–97.7 Mg yr−1) to the global coastal ocean. Hydrothermal SGD systems with elevated Hg concentrations constitute important sources of Hg to specific coastal environments, but their contribution to the global coastal Hg budgets represents a critical knowledge gap. We highlight that SGD-derived Hg discharge exerts broader and a more direct toxicological pressure on global coastal ecosystems under global change.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205532","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}

引用次数: 0

Global Anthropogenic Methane Emissions: Bottom-Up Simulations of Current Trends and Scope for Future Mitigation 全球人为甲烷排放：当前趋势和未来减缓范围的自下而上模拟

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-13 DOI: 10.1029/2026GB009471

Lena Höglund-Isaksson, Adriana Gómez-Sanabria, Lovisa Kuehnle-Nelson, Flora Brocza-Pflügl, Scarlett Quinn-Savory, Florian Lindl, Chen Huang, Shaohui Zhang

{"title":"Global Anthropogenic Methane Emissions: Bottom-Up Simulations of Current Trends and Scope for Future Mitigation","authors":"Lena Höglund-Isaksson, Adriana Gómez-Sanabria, Lovisa Kuehnle-Nelson, Flora Brocza-Pflügl, Scarlett Quinn-Savory, Florian Lindl, Chen Huang, Shaohui Zhang","doi":"10.1029/2026GB009471","DOIUrl":"https://doi.org/10.1029/2026GB009471","url":null,"abstract":"A technology-resolved bottom-up model is used to quantify the current state of global anthropogenic methane emissions and the scope for limiting them in a 2030 to 2050 timeframe. Findings show that with current legislation and “middle-of-the-road” developments in global energy and agricultural systems, anthropogenic methane emissions continue on an upward trend in the next decades. With full implementation of current national plans for methane mitigation, emissions will decline between 2020 and 2030, but not enough to meet the Global Methane Pledge target of a joint global reduction by 30%. The pledge target can be met through full implementation of existing technology, with 70% of mitigation potential in the energy sector. Maintaining low methane emissions beyond 2030 also requires investments into improved waste and wastewater systems and measures to control emissions from livestock and rice cultivation, combined with demand-side measures to phase-down fossil fuels and shifts to more sustainable consumption patterns.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GB009471","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205326","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}

引用次数: 0

Microbial Carbon Use Efficiency in Soils Exhibits a Unimodal Relationship With Temperature Across the Agroecosystem 土壤微生物碳利用效率与整个农业生态系统温度呈单峰关系

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-12 DOI: 10.1029/2026GB009352

Ziyi Li, Di Lin, Waseem Hassan, Zhenghu Zhou, Xiaobo Qin, Naijie Chang, Andong Cai

{"title":"Microbial Carbon Use Efficiency in Soils Exhibits a Unimodal Relationship With Temperature Across the Agroecosystem","authors":"Ziyi Li, Di Lin, Waseem Hassan, Zhenghu Zhou, Xiaobo Qin, Naijie Chang, Andong Cai","doi":"10.1029/2026GB009352","DOIUrl":"https://doi.org/10.1029/2026GB009352","url":null,"abstract":"Microbial carbon use efficiency (CUE), defined as the proportion of assimilated carbon allocated to microbial growth rather than respiration, is an important physiological trait influencing soil carbon cycling. However, the quantitative relationship between temperature and microbial CUE remains poorly constrained, particularly in agricultural ecosystems. Here, we conducted a large-scale sampling survey spanning approximately 28° of latitude across Chinese croplands and quantified microbial CUE using the substrate-independent 18O-H2O method to investigate the response patterns of microbial CUE to temperature and its implications for soil organic carbon (SOC) pools. Microbial CUE exhibited substantial spatial heterogeneity, ranging from 0.20 to 0.60. Across China's north-south climatic gradient, microbial CUE increased from colder regions, peaked at 0.44 in the warm-temperate zone, and declined toward warmer regions. In contrast to the commonly proposed negative temperature dependence of microbial CUE, microbial CUE exhibited a unimodal relationship with mean annual temperature across the observed range of 2.28–25.05°C, increasing below 13.67°C and declining above this threshold. Soil total phosphorus was the most important predictor of microbial CUE, whereas the unimodal temperature–CUE relationship remained significant after accounting for variation in soil total phosphorus. Furthermore, under warmer conditions (≥13.67°C), microbial CUE showed a negative statistical association with SOC through mineral-associated organic carbon, suggesting that higher microbial CUE was not necessarily associated with greater SOC stabilization in cropland soils. This large-scale empirical study advances our understanding of temperature-related variation in microbial CUE and provides an empirical basis for improving the representation of microbial physiology in cropland carbon models.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205318","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}

引用次数: 0

Global Asymmetric Temperature Responses of Soil Respiration During Warming and Cooling Phases 增温和降温阶段土壤呼吸的全球不对称温度响应

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-12 DOI: 10.1029/2026GB009547

Tao Feng, Mingming Wang, Zhongkui Luo

{"title":"Global Asymmetric Temperature Responses of Soil Respiration During Warming and Cooling Phases","authors":"Tao Feng, Mingming Wang, Zhongkui Luo","doi":"10.1029/2026GB009547","DOIUrl":"https://doi.org/10.1029/2026GB009547","url":null,"abstract":"Soil respiration is highly sensitive to temperature, and its responses to warming and cooling are commonly assumed to be symmetric in Earth system models. However, this symmetry has rarely been explicitly tested, particularly across different temporal scales. Using two global data sets spanning multiple ecosystems and temporal scales, we show that soil respiration exhibits scale-dependent asymmetry in apparent temperature sensitivity (Q10) between warming and cooling phases. Q10 was markedly higher during cooling at the daily scale, with the asymmetry weakened under the monthly scale. At the hourly scale, asymmetry was also detectable but varied in direction across ecosystem types. Machine-learning analyses revealed strong scale dependence in the drivers of Q10, with short-term variability dominated by diurnal temperature cycles and soil moisture dynamics, and longer-term patterns shaped by climatic and vegetation properties. Nonlinear responses to soil temperature and moisture suggest that temperature sensitivity may be associated with microbial metabolic demand, substrate accessibility and their interactions. Despite phase-specific Q10, fitting phase-specific model did not find significant difference in controls between warming and cooling phases. Consistently, incorporating soil temperature-moisture interactions significantly improves model performance, particularly at fine temporal scales. These results highlight the importance of testing Earth system models for their ability to capture phase- and timescale-dependent apparent temperature sensitivity, and provide opportunities to reduce uncertainties in the prediction of soil carbon–climate feedback.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205453","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}

引用次数: 0

Rapid Increase in Geogenic CO2 Emissions from Antarctic Permafrost 南极永久冻土带地源性二氧化碳排放的快速增加

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-10 DOI: 10.1029/2026GB009134

L. Ruggiero, A. Sciarra, F. Florindo, L. Davidson, J. Beagley, C. Berquist, G. Wilson

{"title":"Rapid Increase in Geogenic CO2 Emissions from Antarctic Permafrost","authors":"L. Ruggiero, A. Sciarra, F. Florindo, L. Davidson, J. Beagley, C. Berquist, G. Wilson","doi":"10.1029/2026GB009134","DOIUrl":"https://doi.org/10.1029/2026GB009134","url":null,"abstract":"Thawing permafrost can amplify climate change by releasing previously stored carbon, but observations of this feedback come mainly from the Arctic. Ice-free Antarctic terrains are generally regarded as minor CO2 sources, although sub-permafrost brines and deep carbon reservoirs may support localized geogenic degassing. We report repeated soil CO2 flux and soil-gas surveys in the Taylor Valley in 2020, 2023, and 2025. The mean flux increased from 1.73 to 9.49 g CO2 m−2 d−1, the median from 1.20 to 6.70 g CO2 m−2 d−1, the 90th percentile from 4.11 to 20.62 g CO2 m−2 d−1, and the maximum from 11.36 to 72.99 g CO2 m−2 d−1. Carbon isotope ratios of CO2 and CH4 are consistent with a substantial deep geogenic contribution and thermogenic or mixed signatures, with limited microbial influence at the highest flux sites. Geological and electrical-resistivity observations identify heterogeneous permafrost, brine-bearing horizons, and potential permeable pathways, but the available data do not establish whether permafrost thaw or subglacial drainage caused the temporal increase. Conditional scaling of the campaign-specific areal emission densities to the 4,500 km2 ice-free area of the McMurdo Dry Valleys yields 1.14–15.90 Mt CO2 yr−1, whereas scaling to 21,745 km2 of mapped Antarctic ice-free terrain yields 5.51–76.84 Mt CO2 yr−1, equivalent to a maximum of approximately 0.021 Pg C yr−1. These calculations represent illustrative spatial-scaling scenarios rather than regional emission inventories or temporal forecasts. The observations demonstrate substantial, spatially focused geogenic degassing and motivate co-located thermal, hydrological, and geophysical monitoring.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GB009134","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146125","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}

引用次数: 0

Tropical Sources Dominate the Ocean Carbonyl Sulfide Budget 热带来源主导海洋羰基硫化物收支

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-08 DOI: 10.1029/2026GB009439

Wu Sun, Julian Merder, Gang Zhao, Sinikka T. Lennartz, Anna M. Michalak

{"title":"Tropical Sources Dominate the Ocean Carbonyl Sulfide Budget","authors":"Wu Sun, Julian Merder, Gang Zhao, Sinikka T. Lennartz, Anna M. Michalak","doi":"10.1029/2026GB009439","DOIUrl":"https://doi.org/10.1029/2026GB009439","url":null,"abstract":"Carbonyl sulfide (OCS) regulates stratospheric aerosol–climate interactions and helps to track terrestrial photosynthesis. Using OCS to infer drivers of stratospheric aerosol loading or biospheric productivity requires understanding its largest and most uncertain natural source—ocean emissions. Top-down ocean OCS budget estimates inferred from atmospheric observations range from 230 to 1,083 Gg S yr−1 (median: 677 Gg S yr−1), with most estimates far beyond bottom-up estimates informed by process understanding and ship-based observations, which range from 182 to 313 Gg S yr−1 (median: 280 Gg S yr−1). While ship-based observations suggest that direct OCS emissions are unlikely to account for this gap, limited understanding of the marine cycling of carbon disulfide (CS2), a key OCS precursor, hampers the assessment of CS2-derived OCS emissions. Here, we construct a data-driven model to predict OCS and CS2 fluxes from ship-based observations and reanalysis and remotely sensed environmental covariates. We estimate an ocean OCS budget of 270 ± 28 Gg S yr−1, half of which results from CS2 emissions. Of the portion of OCS emissions resulting from direct and CS2-derived emissions (217 Gg S yr−1), more than half come from tropical (23.5°S–23.5°N) oceans, contrasting with process-based models that show stronger high-latitude contributions. Our new data-driven ocean OCS budget estimate remains substantially lower than most top-down estimates and implies a weaker land OCS sink. Our findings suggest that the OCS budget imbalance could have resulted from an overestimated land sink rather than the commonly presumed missing ocean source, with major implications for tracking terrestrial photosynthesis.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GB009439","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146289","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}

引用次数: 0

Amazon River Plume Control on Carbonate Chemistry in the Western Tropical Atlantic 热带大西洋西部亚马孙河羽流对碳酸盐化学的控制

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-06 DOI: 10.1029/2026GB009389

Matheus Batista, Eunice Machado, Thiago Monteiro, Nathalie Lefèvre, Rodrigo Kerr

{"title":"Amazon River Plume Control on Carbonate Chemistry in the Western Tropical Atlantic","authors":"Matheus Batista, Eunice Machado, Thiago Monteiro, Nathalie Lefèvre, Rodrigo Kerr","doi":"10.1029/2026GB009389","DOIUrl":"https://doi.org/10.1029/2026GB009389","url":null,"abstract":"The Amazon River Plume (ARP) modulates the carbonate system of the western Tropical Atlantic (WTA) through physical and biological processes, including freshwater dilution, biological carbon uptake, and circulation-driven transport; however, its basin-scale impact has not been quantitatively assessed. Here we combine climatological spatial anomalies of sea surface salinity (SSS), carbonate system variables, and biogeochemical indicators to determine the percentage contribution of offshore ARP waters to regulate carbonate chemistry during wet and dry seasons. We show that ARP-derived freshwater and nutrients drive ∼8%–10% reductions in sea surface fugacity (fCO2), total alkalinity, dissolved inorganic carbon and carbonate ion concentrations across the WTA during the wet season, closely matching a ∼9% decrease in SSS. These reductions represent a substantial perturbation to carbonate chemistry across the offshore plume-influenced WTA, strengthening the role of the ARP in modulating carbon cycling and atmospheric CO2 uptake. These findings identify physical dilution, enhanced photosynthesis and nitrogen cycle transformations, as strong first-order controls on carbonate system drawdown, supporting CO2 uptake in low-SSS waters. ARP-driven reductions in fCO2 extend far beyond the plume through offshore export by the North Brazil Current and North Equatorial Countercurrent, decreasing fCO2 by up to 20 μatm near 10°N and modulating carbonate chemistry across the equatorial Atlantic. Together, these results demonstrate that the ARP is a major regulator of sea surface carbonate chemistry in the WTA, enhancing atmospheric CO2 uptake through coupled physical–biological processes. The spatial anomaly approach provides a robust framework for quantifying river-plume impacts on basin-scale carbon cycling.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GB009389","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146026","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}

引用次数: 0

Climate-Linked Si-Fe Dynamics and Their Associations With Soil Mineral-Associated Organic Carbon 气候相关的Si-Fe动态及其与土壤矿物相关有机碳的关系

IF 6.9 2区地球科学

Global Biogeochemical Cycles Pub Date : 2026-10-05 DOI: 10.1029/2026GB009071

Aiquan Shi, Zhaoliang Song, Ji Chen, Zhongkui Luo, Chengjie Ren, Xiaomin Yang, Yidong Wang, Weiqi Wang, Chuancheng Fu, Zhihong Xu, Cong-Qiang Liu, Changxun Yu

{"title":"Climate-Linked Si-Fe Dynamics and Their Associations With Soil Mineral-Associated Organic Carbon","authors":"Aiquan Shi, Zhaoliang Song, Ji Chen, Zhongkui Luo, Chengjie Ren, Xiaomin Yang, Yidong Wang, Weiqi Wang, Chuancheng Fu, Zhihong Xu, Cong-Qiang Liu, Changxun Yu","doi":"10.1029/2026GB009071","DOIUrl":"https://doi.org/10.1029/2026GB009071","url":null,"abstract":"Iron (Fe) (hydr)oxides and silicate minerals are key controls on the formation of mineral-associated organic carbon (MAOC) in soils—a relatively persistent fraction of soil organic carbon (SOC). Silicon (Si) is essential for silicate mineral formation, and the interactions between Fe and Si are widespread in natural environments. However, the interactive effects of Fe (hydr)oxides and Si on MAOC remain poorly understood. Here, we determined Fe and Si speciation in soils across diverse ecosystems by selective extraction, and estimated their individual and interactive effects on MAOC. Our results show that pedogenic and biogenic amorphous Si are positively associated with MAOC accumulation, while more mobile Si forms (including dissolved and weakly adsorbed Si) are negatively associated with the formation of Fe-bound organic carbon (Fe-OC). Although amorphous Fe oxides serve as the dominant carriers of Fe-OC complexes, increasing metal oxide-associated Si is linked to a reduced contribution of Fe oxides to MAOC. Additionally, temperature and precipitation are associated with variations in Si and Fe speciation, likely through changes in soil weathering stage and pH, and these patterns are further linked to differences in MAOC accumulation. Our results highlight climate-linked Si-Fe dynamics and interactions as critical but previously underappreciated factors related to SOC stabilization, and we suggest that Si speciation should be integrated into land management and SOC sequestration strategies across diverse ecosystems.","PeriodicalId":12729,"journal":{"name":"Global Biogeochemical Cycles","volume":"40 10","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145978","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}

引用次数: 0