Journal of Geophysical Research: Biogeosciences最新文献

{"title":"A Decade of Biogeochemical Monitoring in the Tropical Urban Saigon-Dong Nai River-Estuary Continuum, Vietnam","authors":"Thi-Minh-Tam Le,&nbsp;Truong-An Nguyen,&nbsp;Trung-Tin Nguyen,&nbsp;Thi-Ngoc-Tuyet Nguyen,&nbsp;Emilie Strady,&nbsp;Nicolas Gratiot,&nbsp;Christine Baduel,&nbsp;Julien Némery","doi":"10.1029/2026JG010092","DOIUrl":"https://doi.org/10.1029/2026JG010092","url":null,"abstract":"<p>Tropical Southeast Asian estuaries remain underrepresented in global water quality archives, limiting regional comparisons and the development of predictive biogeochemical models for monsoon-driven coastal systems. To address this observational gap, this paper presents a quality-controlled, 10-year (2015–2025) biogeochemical data set for the Saigon-Dong Nai River-estuary continuum in southern Vietnam. The observing program couples a biweekly time series at four fixed stations with seven seasonal longitudinal transect campaigns across 27 sites along a 140 km gradient from freshwater to marine conditions, encompassing over 19,800 observations of physical parameters, nutrients, dissolved and particulate organic carbon, and chlorophyll-<i>a</i>. Technical validation confirms high internal consistency, including stoichiometric mass balance pass rates (&gt;97%), stable certified reference material recovery (98%), and cross-instrument analytical continuity. The temporal scope and tidal phase synchronization of these observations allow for the statistical partitioning of short-term monsoonal variability from chronic, multiyear anthropogenic baseline shifts. This openly accessible data set provides an empirical foundation for investigating how extreme hydrological forcing and rapid urban wastewater loading may interact to shape estuarine hypoxia, organic matter transformation, and nutrient cycling in dynamic tropical estuaries.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG010092","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146562","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":"Uneven Responses of Regional Terrestrial Ecosystem Carbon Turnover Time to Stratospheric Aerosol Injection","authors":"Sung-Bin Park,&nbsp;Chang-Eui Park,&nbsp;Hanna Lee,&nbsp;Jin-Soo Kim","doi":"10.1029/2026JG009885","DOIUrl":"https://doi.org/10.1029/2026JG009885","url":null,"abstract":"<p>Stratospheric Aerosol Injection (SAI) is one of the alternative approaches to counteract anthropogenic warming by introducing reflective aerosols into the stratosphere. SAI-induced surface cooling and altered hydrological cycle have been widely investigated. However, the impact of SAI on terrestrial carbon retention, as represented by terrestrial ecosystem carbon turnover time (<i>τ</i>), remains unknown. Here, we quantify regional responses of <i>τ</i> to SAI, along with the relative importance of variables inducing <i>τ</i> variability, using simulations from four Earth System Models (ESMs) under the G6sulfur scenario. This scenario reduces the radiative forcing of Shared Socioeconomic Pathway 5-8.5 (SSP5-8.5) to SSP2-4.5 levels via stratospheric SO₂ injection from 2020 to 2100. Results show that global <i>τ</i> generally increased under G6sulfur relative to SSP5-8.5 throughout the injection period, indicating an increase in ecosystem carbon retention. The largest regional increase in <i>τ</i> occurred in the northern high-latitudes, reaching up to about 6 years across all four ESMs during 2081–2100. In some tropical regions, such as Africa, the projected <i>τ</i> responses to SAI showed large inter-model spread, including opposing signs of change. These regional and model-dependent differences in <i>τ</i> responses mainly stem from variations in ecosystem carbon fluxes, specifically net primary production. The divergent regional impacts of SAI on <i>τ</i> highlight the need to account for regional differences in carbon retention capacity when evaluating the overall effectiveness of geoengineering strategies.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG009885","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048072","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":"Summer Heat Stress Downregulates Photochemistry in Coast Redwoods","authors":"Lily Klinek,&nbsp;Jessie Au,&nbsp;Milagros Rodriguez-Caton,&nbsp;Mukund Palat Rao,&nbsp;Lauren Fety,&nbsp;George W. Koch,&nbsp;Troy S. Magney","doi":"10.1029/2026JG010052","DOIUrl":"https://doi.org/10.1029/2026JG010052","url":null,"abstract":"<p>Coast redwood (<i>Sequoia sempervirens</i>) forests are among the most carbon-dense ecosystems on Earth, yet parts of their range are increasingly exposed to extreme summer heat and water scarcity. Under these conditions, redwood leaves may face reduced photochemical efficiency or potential damage to photosynthetic systems if needles surpass critical temperature thresholds. To evaluate redwood responses to changing climate conditions, leaf-level physiological data were collected sub-monthly over a 2-year span from coast redwoods in the greater Mendocino County area of California. During periods of increased heat, leaf temperatures consistently exceeded air temperatures, with leaf-to-air differences (ΔT) reaching 10°C. Summer increases in ΔT corresponded to elevated non-photochemical quenching and reduced photosynthetic efficiency. Temperature response curves were measured at four dates throughout the 2024 growing season, and consistently showed a reduction in photosynthesis at temperatures above 30°C, while internal CO₂ concentrations remained high. This indicates that heat imposes direct, non-stomatal (i.e., biochemical) limitations on redwood photosynthetic capacity as opposed to indirectly decreasing capacity by causing stomatal closure. These findings suggest that intensifying drought-heat events may decrease the carbon sequestration ability of iconic but already vulnerable coastal redwood ecosystems.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG010052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048295","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":"Heterogeneity in Permafrost Organic Matter Molecular Composition With Depth and Ramifications Upon Thaw in the Western Siberian Lowlands","authors":"James M. Anderson,&nbsp;Martin R. Kurek,&nbsp;Artem G. Lim,&nbsp;Sergey V. Loiko,&nbsp;Oleg S. Pokrovsky,&nbsp;Jean-Jacques Braun,&nbsp;Robert G. M. Spencer","doi":"10.1029/2026JG010169","DOIUrl":"https://doi.org/10.1029/2026JG010169","url":null,"abstract":"<p>Northern circumpolar permafrost represents a globally significant soil organic carbon (C) reservoir. The reintroduction of this previously frozen C into the contemporary C cycle with accelerated northern climate change has raised concerns over a potential permafrost C warming feedback. Additionally, the chemically distinct molecular composition of permafrost organic C has previously been linked to its high biolability upon thaw. Despite this, few studies to date have characterized trends in the molecular composition and hence potential reactivity of this frozen C with depth in permafrost, limiting understanding of potential feedback evolution with forecast 21st century thaw trajectories. Here, we examine depth-dependent trends in dissolved organic matter (DOM) molecular composition within frozen peat cores collected from the Western Siberian Lowlands (WSL), the largest permafrost peatland system in the world. We observe a strong positive correlation between dissolved organic C (DOC) concentration and high-energy aliphatic compound relative abundance within WSL permafrost peat (<i>ρ</i> = 0.81, <i>p</i> &lt; 0.01), with distinct “zones of enrichment” containing between 1.5-4x higher DOC concentrations and ∼10 percentage point higher aliphatic DOM contribution versus surrounding permafrost peat horizons found to be present within core depth profiles. These observations, coupled with previous regional findings documenting nutrient and trace element enrichment within these depth ranges, suggest that these localized zones of enrichment may act as biogeochemical hotspots within the depth profile of WSL permafrost peat. As such, solute mobilization from these zones may drive non-linear trajectories (specifically hot moments) of regional and global thaw impacts from WSL permafrost peatlands with continued warming.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146605","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":"Low Denitrification, Anammox, and Dissimilatory Nitrate Reduction to Ammonium Rates in a Low Disturbance Mangrove-Saltmarsh System Using an in Situ Intact Chamber Method","authors":"Britte C. van Haastregt,&nbsp;Dirk V. Erler,&nbsp;Jacob Z.-Q. Yeo,&nbsp;Bradley D. Eyre","doi":"10.1029/2026JG009861","DOIUrl":"https://doi.org/10.1029/2026JG009861","url":null,"abstract":"<p>Mangroves and saltmarshes can remove anthropogenic nitrogen (N) moving from the land to the ocean, but many previous N cycling measurements used destructive sampling procedures that excluded important habitats such as crab burrows, pneumatophores, and saltmarsh vegetation. In this study, a new intact chamber method using ¹⁵NO₃⁻ labeling was developed to quantify in situ denitrification, anammox, and DNRA rates in different habitats across a low disturbance mangrove-saltmarsh system. No anammox was detected, likely due to the low nutrient concentrations. Denitrification rates were 0.4–36 times higher than DNRA rates. The highest denitrification rates were measured in crab burrows (36.4 μmol N m⁻² h⁻¹) and saltmarsh (26.6 μmol N m⁻² h⁻¹), while DNRA rates were highest in saltmarsh (7.4 μmol N m⁻² h⁻¹) and pneumatophores (2.1 μmol N m⁻² h⁻¹). Rates were scaled using a detailed habitat map, giving a total of 17.1 kg N ha⁻¹ yr⁻¹ being removed via denitrification in the mangrove system, 17.0 in the saltmarsh system, 17.5 in the open water system, and 17.1 in the mangrove-saltmarsh-open water system. Furthermore, 2.5 kg N ha⁻¹ yr⁻¹ was recycled by DNRA in the mangrove system, 2.9 in the saltmarsh system, 1.9 in the open water system, and 2.5 in the saltmarsh-mangrove-open water system. The low denitrification and DNRA rates compared to previous studies likely reflect minimal anthropogenic disturbance and associated low nitrogen availability at the study site, but this needs to be confirmed with replicated measurements using the new intact chamber method at a high nutrient concentration mangrove-saltmarsh site.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG009861","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048296","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":"Moisture-Driven Phenology Regulates Seasonal Canopy Dynamics and Carbon Uptake in a Tropical Deciduous Forest","authors":"A. Jaya Prakash,&nbsp;Mukunda Dev Behera,&nbsp;Chandra Prakash Singh,&nbsp;C. Jeganathan","doi":"10.1029/2026JG009704","DOIUrl":"https://doi.org/10.1029/2026JG009704","url":null,"abstract":"<p>Phenology sets the seasonal window over which terrestrial ecosystems take up carbon, and in drought-deciduous tropical forests this window is governed by rapid canopy transitions difficult to capture from satellites alone. We address this gap using daily near-surface imagery from a PhenoCam co-located with an automatic weather station in the Similipal Biosphere Reserve, eastern India, from January 2023 to May 2024. Daily Green Chromatic Coordinate (GCC) was analyzed with co-located meteorology and surface (5 cm) and subsurface (20 cm) soil moisture and temperature. Interannual comparison focused on the leaf-off (LP1), leaf-initiation (LP2), and leaf-growth (LP3) phases common to both years. In 2023, the start of season (SOS) fell on day-of-year (DOY) 82, peak greenness on DOY 154, and senescence onset on DOY 211. In 2024, SOS advanced to DOY 61, yet greening was slower and weaker: the leaf-off minimum occurred about 12 days later and GCC remained below 2023 for most of the window. The two years were compared over their shared DOY 1–150 window. Machine-learning models identified subsurface soil moisture as the dominant control on LP1 (<i>R</i>² ≈ 0.67), subsurface temperature and moisture as joint drivers of LP2 (<i>R</i>² ≈ 0.88), and atmospheric humidity as an increasing constraint on LP3. Granger-precedence analysis revealed rapid (≤6-day) responses to moisture and radiation superimposed on a ∼25-day subsurface thermal memory. The Sentinel-2 enhanced vegetation index, trained on 2023, reproduced the 2024 GCC trajectory (<i>R</i>² ≈ 0.88). These results imply that 10–15-day phenological shifts can substantially alter the seasonal carbon-uptake window and pre-monsoon fire risk.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994640","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":"Inwelling Versus Outwelling: Controls on Dissolved Organic Carbon Exchange in a Mesotidal Saltmarsh Estuary","authors":"Mohammed Mezied,&nbsp;Cédric G. Fichot,&nbsp;Sergio Fagherazzi","doi":"10.1029/2026JG009790","DOIUrl":"https://doi.org/10.1029/2026JG009790","url":null,"abstract":"<p>Saltmarsh estuaries influence land-ocean carbon exchange, yet inlet carbon fluxes remain poorly constrained by tidal variability and limited high-frequency observations. This study quantifies dissolved organic carbon (DOC) fluxes in a mesotidal saltmarsh estuary in the northeastern USA by integrating high-frequency field data with a two-dimensional hydrodynamic model. DOC concentrations were estimated from fluorescent dissolved organic matter and ancillary water-quality measurements collected by moored sondes during summers 2023 and 2024. DOC fluxes were computed by coupling modeled discharge with observation-derived concentrations. The tidal inlet exhibited the lowest DOC concentrations and largest DOC fluxes, indicating that tidal exchange volume exerts stronger control on carbon transport than concentration. DOC fluxes at the inlet switched from net export to the ocean in 2023 (outwelling) to net import into the estuary in 2024 (inwelling). The 2024 inwelling was associated with reduced riverine inputs and was consistent with greater relative influence of marine-derived DOC from the adjacent shelf, followed by partial degradation within the estuary. Phase analyses revealed systematic offsets between water level and DOC flux, consistent with delayed marsh drainage and tidal storage effects, especially at the inlet. Across years and cross sections, the spring-neap difference in DOC flux normalized to saltmarsh area was relatively consistent, providing a first-order proxy for marsh-associated DOC outwelling. Together, these results support a dynamic interpretation of the outwelling hypothesis, in which saltmarshes act as persistent DOC sources while the estuary alternates between net DOC export and import in response to fluvial and oceanic boundary conditions.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994641","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":"Forest Carbon Exchange Dynamics and Integrated Carbon Budget of a Subtropical Island Ecosystem","authors":"Mengjie Han,&nbsp;Lei Zhu,&nbsp;Minxuan Sun,&nbsp;Jiaxin Zhou,&nbsp;Zhixuan Guo,&nbsp;Yi Leng,&nbsp;Zhe Zhao,&nbsp;Jiaying He,&nbsp;Jian Wang,&nbsp;Chenyi Yuan,&nbsp;Yongxing Cui,&nbsp;Kang Xu,&nbsp;Ruikun Gou,&nbsp;Junqing Zheng,&nbsp;Le Yu,&nbsp;Chao Wu,&nbsp;Xuejiao Zhang,&nbsp;Qing Zhao,&nbsp;Wei Li","doi":"10.1029/2026JG010032","DOIUrl":"https://doi.org/10.1029/2026JG010032","url":null,"abstract":"<p>Island ecosystems are on the frontline of climate change, yet their terrestrial carbon exchange remains poorly quantified because direct ecosystem-scale observations are rare. Based on year-round (2024) eddy covariance measurements of net ecosystem exchange (NEE) in the forest ecosystem of a representative island (Dachen Island) in the East China Sea, we analyzed the seasonal dynamics of carbon fluxes and identified their main drivers. The annual forest carbon sink was further constrained using multiple complementary approaches and integrated into an island-scale carbon budget assessment. The island forest showed pronounced seasonal variation in NEE, with higher net carbon uptake during the wet season than in the dry season. Within both seasons, shortwave downward radiation was the dominant driver of temporal variation in NEE. The island forest functioned as a carbon sink, with estimated net carbon uptake rates ranging from 55.6 to 114.4 gC m⁻² yr⁻¹ across different approaches, while the age-biomass curve approach yielded a modeled upper bound of 262.6 ± 57.5 gC m⁻² yr⁻¹ for potential biomass accumulation. However, the total carbon sinks from forests and fishery-related blue carbon (2564.1–4060.0 t CO₂ yr⁻¹) were generally insufficient to offset total anthropogenic emissions (4363.8–5450.8 t CO₂ yr⁻¹) on Dachen Island. Our findings improve direct observational evidence that island forests can function as meaningful carbon sinks, but also show that they are unlikely to compensate for local emissions without substantial emission reductions. This study offers a framework for assessing carbon budgets on small islands, thereby informing integrated carbon dioxide removal strategies toward carbon neutrality.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994642","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":"Temperature and Degree of Aeration Influence Membrane Fatty Acid Composition in the Soil Bacterium Pseudomonas putida","authors":"Elizabeth Trembath-Reichert,&nbsp;Chanel Vidal,&nbsp;Jordyn Robare,&nbsp;Mary Beth Wilhelm,&nbsp;Jackie Goordial,&nbsp;Katherine Dawson","doi":"10.1029/2026JG009896","DOIUrl":"https://doi.org/10.1029/2026JG009896","url":null,"abstract":"<p>Maintaining membrane function under fluctuating environmental conditions is critical for microbial survival. Bacteria maintain membrane function under changing environmental conditions through homeoviscous adaptation, a suite of physiological responses that includes the synthesis of new fatty acids and modification of existing membrane lipids. Here we investigated how the mesophilic soil bacterium <i>Pseudomonas putida</i> ATCC 17453 modifies its membrane fatty acid composition when exposed to colder temperatures and sudden temperature decreases under both shaking and static culture conditions. Cultures were grown under three constant temperatures (10°C, 20°C, and 30°C) and three cold temperature shock treatments, with membrane composition characterized using fatty acid methyl ester (FAME) analysis. Multivariate analyses showed that temperature was the dominant driver of membrane composition, explaining 38.6% of the observed variation, with additional effects of incubation movement (18.3%). We also evaluated potential membrane remodeling through metrics for unsaturation index, <i>cis</i>/<i>trans</i> isomerization, and cyclopropane fatty acid abundance. Across analyses, expected temperature-dependent membrane responses were less consistently expressed in static cultures than in shaking cultures. We highlight the importance of considering factors that limit growth beyond temperature when interpreting membrane responses in natural microbial systems and lipid signatures in present or past environments.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994390","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":"The Strength of Fuel Self-Regulation in Alaska's Wildfire Regimes","authors":"B. V. Gaglioti,&nbsp;C. A. Quinn,&nbsp;S. Z. Mark,&nbsp;W. D. Hansen,&nbsp;J. Hall,&nbsp;D. H. Mann","doi":"10.1029/2025JG009543","DOIUrl":"https://doi.org/10.1029/2025JG009543","url":null,"abstract":"<p>Fuel depletion following wildfires in the North American boreal forest can temporarily reduce the probability of a subsequent fire. Landscape-wide shifts to younger, less flammable forests may act as an important negative feedback to a warming-driven increase in biomass burning, but only if regenerating-fuel limitations remain strong during severe fire weather. We assessed the climate sensitivity of regenerating-fuel limitations within Alaska's historical fire regime by analyzing 568 examples where fires either spread into or stopped at the edge of a previously mapped burn between 1984 and 2020. We classified every 30-m pixel located along the contact perimeters of interacting fires as either reburn or limited incursion and then used logistic regression to assess the number of years since last fire (YSLF), contact perimeter length, and fire weather indices as predictor variables. Over the course of the first 30 YSLF, contact perimeters became ∼2.5x less likely to limit fire spread, and up to 2x less likely under extreme fire weather conditions. Rates of reburning by area were one to three orders of magnitude lower than rates of burning in &gt;35-year-old fuels. Using these observations to parameterize a statistical fire model, we estimate that the rates of historical burning would have been ∼4.9x greater without the negative feedback created by fuel limitations. We conclude that fuel limitation has been an important, self-regulating aspect of Alaska's wildfire regimes, and while it will weaken as climate change accelerates, this negative feedback will continue to significantly limit fire spread.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009543","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994588","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}