Journal of Geophysical Research: Biogeosciences最新文献

{"title":"Process-Specific Effects of Sulfide on Nitrogen Cycling in Marine Oxygen Minimum Zones","authors":"Weiyi Tang,&nbsp;Claudia Frey,&nbsp;Bess B. Ward","doi":"10.1029/2026JG009762","DOIUrl":"https://doi.org/10.1029/2026JG009762","url":null,"abstract":"<p>Marine oxygen minimum zones (OMZs) harbor a variety of nitrogen cycling processes and act as hotspots of fixed nitrogen loss and nitrous oxide (N₂O) emissions, thereby influencing nitrogen availability and the Earth's climate system. Sulfide occasionally accumulates in OMZs due to in situ production or release from the sediments, but its impact on nitrogen cycling is not fully understood. Using nitrogen tracer incubations in the Eastern Tropical South Pacific OMZ and meta-analysis of previous observations in other low oxygen environments, we found that sulfide addition generally inhibited nitrification and anammox while enhancing denitrification. These results illustrated the role of sulfide in determining the importance of different nitrogen cycling processes and changing the fate of nitrogen species, for example, increasing the contribution of denitrification to nitrogen loss compared to anammox and causing a stronger N₂O accumulation in OMZs. Improved understanding of sulfide impacts on nitrogen cycling in marine OMZs strengthens our capacity to predict changes in nitrogen availability and N₂O emissions during sulfidic events, whose frequency, duration and spatial extent are expected to change under future climate scenarios.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942070","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":"Disentangling Sources of Uncertainty in CLM5 Model Predictions: Water, Energy, and Carbon Fluxes at European Observation Sites","authors":"Fernand B. Eloundou,&nbsp;Lukas Strebel,&nbsp;Bibi S. Naz,&nbsp;Christian Poppe Terán,&nbsp;Harry Vereecken,&nbsp;Harrie-Jan Hendricks Franssen","doi":"10.1029/2026JG009768","DOIUrl":"https://doi.org/10.1029/2026JG009768","url":null,"abstract":"<p>Land surface models (LSMs) such as the Community Land Model version 5 (CLM5) are central to climate–carbon assessments but exhibit persistent biases relative to site-level observations. It remains unclear to what extent model-data mismatches arise from uncertainty in meteorological forcing, soil properties, or vegetation traits, and to what extent they instead reflect structural deficiencies. We evaluated surface and root-zone soil moisture (SM, SMr), evapotranspiration (ET), sensible heat flux (H), net ecosystem exchange (NEE), and gross primary production (GPP) at 14 European eddy-covariance sites using 128-member CLM5 ensembles in which (a) atmospheric inputs, (b) soil parameters, and (c) vegetation parameters were perturbed. Soil parameters dominate ensemble spread in SM/SMr, whereas vegetation parameters dominate spread in ET, H, NEE, and GPP. Despite this, substantial mean biases remained (0.18 cm³ cm⁻³ for SM, −0.22 mm d⁻¹ for ET, −19.7 W m⁻² for H, −1.83 gC m⁻² d⁻¹ for GPP, and 1.16 gC m⁻² d⁻¹ for NEE), and the 99% ensemble envelopes failed to cover many observations. Coverage percentage (CP; fraction of observations within the 99% ensemble envelope) was 74.3% (SM), 74.6% (SMr), 68.8% (ET), 47.7% (H), 65.1% (NEE), and 70.1% (GPP). A companion CLM5-SP (Satellite Phenology) experiment with prescribed ICOS leaf area index (LAI) confirmed that prognostic LAI errors in CLM5-BGC (Biogeochemistry) are the primary structural driver of SM/SMr and GPP coverage deficits, while BGC's carbon–nitrogen coupling better captures ET and H variability. CP diagnostics delineate parametric from structural error regimes across variables and plant functional types.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG009768","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942048","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":"Oxide-Occluded to Calcium-Bound: Urbanization Increases Soil Phosphorus Stocks and Diversifies Pools in a Tropical West African Agroecosystem","authors":"Stephen B. Asabere,&nbsp;Daniela Sauer","doi":"10.1029/2026JG009815","DOIUrl":"https://doi.org/10.1029/2026JG009815","url":null,"abstract":"<p>Urban agriculture is widespread across tropical West African cities. Yet, the dynamics of phosphorus (P) pools in strongly weathered soils of these urban agroecosystems remain poorly constrained. We quantified, for the first time, the effect of urbanization on soil P stocks and partitioning in rainfed arable fields on Ferric Acrisols in Kumasi, Ghana. We hypothesized that inputs of P-rich household and construction waste increase soil P stocks, and that accompanying calcium (Ca) enrichment weakens the soil organic matter (SOM) control on plant-available P. We analyzed 225 topsoil samples (0–10 cm), classified into four groups representing a gradient of urbanization influence. We applied a tailored sequential P extraction, separating four operational fractions: plant-available P (P_Pa), SOM-bound P (P_SOM), Ca-bound P (P_Ca), and P occluded in pedogenic oxides (P_OCC). Total P stocks increased from 28.0 ± 1.7 to 68.8 ± 6.7 g m⁻² with urbanization influence. Stocks of all extracted soil P fractions consistently increased, with the greatest in P_Ca (2.5 ± 0.6 to 14.2 ± 2.5 g m⁻²) and P_Pa (1.4 ± 0.1 to 5.4 ± 0.8 g m⁻²). P_OCC stocks also increased in absolute terms but declined in relative contribution from 79% to 53%. Urbanization did not weaken SOM control on P_Pa as initially hypothesized. Instead, P_Ca became increasingly relevant in explaining P_Pa, suggesting an additional inorganic control on P_Pa. We conclude that tropical urban arable soils can act as inadvertent sinks for P-rich urban wastes, suggesting the potential for a deliberate waste management strategy that could enhance soil P supply.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG009815","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823327","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":"Microbial Ethane and Propane Production and Ethanogenic Enrichment of Methanogens in Coastal Sediments","authors":"Jinyan Wang,&nbsp;Yuan Yuan,&nbsp;Xue Wang,&nbsp;Kuzyakov Yakov,&nbsp;Zhen Zhou,&nbsp;Xianbiao Lin,&nbsp;Guang-Chao Zhuang","doi":"10.1029/2025JG009421","DOIUrl":"https://doi.org/10.1029/2025JG009421","url":null,"abstract":"<p>Ethane and propane are short-chain alkanes that are ubiquitous in marine environments, while the biological formation of ethane and propane remains largely unconstrained in coastal subsurface sediments. Here, we detected nanomolar concentrations of ethane and propane along 2.7–5.7 m sediment cores with different geochemical gradients at coastal sites of the East China Sea. We further conducted sediment incubation experiments and demonstrated that diethyl sulfide, bromoethane, ethanethiol, ethanol, and acetate were potential precursors for ethane biosynthesis, while propane could be produced from propanol and propanethiol. Ethane production was influenced by the change in temperature, substrate concentration, and H₂ partial pressure. Particularly, the addition of 80% H₂ in the headspace resulted in a 75-fold increase in ethane production, suggesting the involvement of H₂ in ethanogenesis. The addition of methanogenesis inhibitor, 2-bromoethanesulfonate, completely terminated the activity of methanogens and also inhibited ethane production. Taxonomic profiling of the ethane-producing enrichment suggested that methanogens, primarily from the orders <i>Methanomicrobiales</i>, <i>Methanosarcinales</i>, and <i>Methanococcales</i>, might be involved in the formation of trace amounts of ethane, which was probably achieved via the proposed intermediate of CH₃CH₂-S-CoM in a similar pathway for methane production. These results reveal the potential role of methanogens in ethane production and provide insights into the biogeochemical cycling of hydrocarbons in coastal sediments.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823206","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":"Sources, Degradation, and Bacterial Transformation of Organic Matter in a Sediment Core From the East China Sea: A Multi-Proxy Molecular and Isotopic Investigation","authors":"Yan Chen,&nbsp;Yi Yang,&nbsp;Li-Ze Huangfu,&nbsp;Hong-Hai Zhang","doi":"10.1029/2026JG010022","DOIUrl":"https://doi.org/10.1029/2026JG010022","url":null,"abstract":"<p>Organic matter (OM) burial in continental margin sediments contributes to long-term carbon sequestration, but preserved OM is often altered during transport and early diagenesis. We analyzed a 246 cm sediment core from the Zhe-Min Mud Belt in the East China Sea using bulk geochemical, isotopic, and molecular proxies to assess OM sources, degradation, and bacterial transformation. Total organic carbon and total nitrogen ranged from 0.13% to 0.69% and 0.02% to 0.10%, respectively, and were generally higher in finer grained sediments. Bulk δ¹³C values (−24.76‰ to −20.55‰) indicate mixed terrestrial and marine OM, with stronger marine influence in the upper core and greater terrestrial and/or reworked input at depth. Depleted radiocarbon values (Δ¹⁴C = −765.07‰ to −856.02‰), corresponding to conventional bulk sedimentary organic matter ¹⁴C ages of approximately 11,570–15,500 years BP, indicate a substantial contribution of pre-aged and reworked carbon. Total hydrolyzable amino acids (THAA), carbon-normalized yields THAA (THAA-C%), and the degradation index all decreased with depth, indicating progressive OM degradation. In contrast, muramic acid (Mur), and D-amino acids occurred throughout the core, indicating pervasive bacterial transformation and preservation of bacterial residues. These results show that OM in the Zhe-Min Mud Belt is a mixed, pre-aged, and extensively microbially reworked carbon pool shaped by hydrodynamic sorting, bacterial processing, and mineral-associated preservation.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148849080","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":"Estimating Global Site-Level Net Ecosystem Exchange With a Geographically Weighted XGBoost Framework","authors":"Yicong Shi,&nbsp;Ni Huang,&nbsp;Xiaoyu Lin,&nbsp;Jie Liu,&nbsp;Yuting Shi,&nbsp;Zheng Niu,&nbsp;Li Wang","doi":"10.1029/2026JG009713","DOIUrl":"https://doi.org/10.1029/2026JG009713","url":null,"abstract":"<p>Net ecosystem exchange (NEE), a critical indicator of terrestrial carbon source-sink dynamics, remains difficult to estimate across global flux sites due to spatial heterogeneity and sparse flux observations. Existing models overlook local variability, limiting accuracy in site-level NEE estimation. Geographically Weighted Regression (GWR) captures spatial non-stationarity in environmental variables on NEE by enabling spatially varying model parameters. This study develops a Geographically Weighted eXtreme Gradient Boosting (GWXGBoost) framework coupling XGBoost's strength in modeling complex nonlinear relationships with GWR's spatial explicitness. Using 8-day data from 387 global flux sites and remote sensing predictor variables, we optimize model parameters locally per site to account for spatial heterogeneity in NEE drivers. Our results show water-related variables dominate explanatory power in GWXGBoost at 36% of sites, particularly in arid regions. The GWXGBoost framework outperforms traditional global models, achieving <i>R</i>² = 0.63 and RMSE = 1.21 g C m⁻² day⁻¹ at the 8-day scale—with ∼40% higher <i>R</i>² and ∼20% lower RMSE than global modeling. Model accuracy is enhanced at the site scale (<i>R</i>² = 0.84) and remains robust across most plant functional types, with the highest value in deciduous broadleaf forests (<i>R</i>² = 0.80) and the lowest in grasslands (<i>R</i>² = 0.37). Independent validation across 140 flux sites (<i>R</i>² = 0.61) demonstrated the model's robustness and multi-scale generalizability. Moreover, local modeling produces NEE estimates more consistent with observations and better captures site-specific NEE controls than global models. Our study demonstrates that modeling spatial heterogeneity with localized models improves NEE prediction and supports carbon budget assessments.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148849079","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":"Hydrologically-Driven Microbial Assembly Shapes DOM Biodegradability in an Alpine Permafrost Catchment","authors":"Jing Xiong,&nbsp;Rui Ma,&nbsp;Beibei Chen,&nbsp;Ziyong Sun,&nbsp;Hongchen Jiang,&nbsp;Qinglong Fu,&nbsp;Zhao Pan,&nbsp;Changjian Zou,&nbsp;Yanhe Wang,&nbsp;Qiong Wu,&nbsp;Huili Gong,&nbsp;Yanxin Wang","doi":"10.1029/2026JG009919","DOIUrl":"https://doi.org/10.1029/2026JG009919","url":null,"abstract":"<p>Permafrost degradation on the Qinghai–Tibet Plateau (QTP) fundamentally alters the hydrological regime, with profound implications for microbially mediated carbon cycling. However, the mechanistic links between changing flow paths, microbial community assembly, and dissolved organic matter (DOM) characteristics at the catchment scale remain poorly understood. This study integrated hydrological monitoring, hydrochemical analyses, 16S rRNA gene sequencing, and ultrahigh-resolution mass spectrometry to investigate these interactions in an alpine catchment of the QTP. We found that contrasting hydrological processes create environmental heterogeneity that critically governs microbial community assembly. Deep groundwater under stable hydrological conditions hosted more complex and stable microbial networks dominated by deterministic processes and was associated with DOM characterized by higher aliphatic content and lower aromaticity, suggesting higher potential lability. In contrast, strong hydrological fluctuations in shallow groundwater result in simpler microbial networks shaped by stochasticity, associated with more aromatic, terrestrially derived DOM. Hydrochemical gradients mediate these divergent assembly patterns. Our results further show that enhanced hydrological connectivity from permafrost degradation is projected to transport shallow DOM into deeper groundwater, accelerating its microbial processing. This functional convergence of microbial communities is predicted to increase the overall biodegradability potential of DOM, amplifying carbon emissions to surface waters. Our findings underscore hydrological dynamics as a key regulator of microbial spatial organization and DOM processing in permafrost regions, providing a mechanistic basis for improved predictions of the permafrost carbon–climate feedback.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148785194","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":"Landscape and Storm Characteristics Influence DOC and Nitrate Mobility and Riverine Export Magnitude in Two Arctic Catchments","authors":"Abigail F. Rec,&nbsp;Arial J. Shogren,&nbsp;Jay P. Zarnetske,&nbsp;Jonathan A. O’Donnell,&nbsp;Amelia L. Grose,&nbsp;Benjamin W. Abbott,&nbsp;William B. Bowden","doi":"10.1029/2025JG009594","DOIUrl":"https://doi.org/10.1029/2025JG009594","url":null,"abstract":"<p>Intensifying Arctic hydrological cycles and permafrost thaw alter the magnitude and timing of lateral solute fluxes to rivers, yet interactions among hydrological, biogeochemical, and landscape controls on carbon and nutrient export remain unclear. We calculated yields of dissolved organic carbon (DOC) and nitrate (NO₃⁻) and storm hysteresis (HI) and flushing indices (FI) across six thaw seasons of high-frequency monitoring to examine solute export dynamics across timescales (daily, storm-event, monthly, annual) and flow conditions in two headwater catchments (River-dominated tundra vs. Lake-influenced tundra). High-flow conditions comprising less than 40% of the study period dominated annual thaw-season solute yields in both catchments, accounting for 75%–80% of annual thaw-season DOC and 55%–65% of NO₃⁻ yields. Storm-events reflected abundant DOC sources (+FI) and limited NO₃⁻ supply (−FI) in catchment soils. In the River-dominated catchment, storm HI and solute yields were related to storm intensity (as storm rising limb duration and peak storm discharge), while responses in the Lake-influenced catchment were more variable. Flow-weighted concentrations at daily and monthly timescales revealed patterns not detectable during individual storms, including a late-season increase in DOC in the Lake-influenced catchment that may indicate a seasonal shift in DOC source. Overall, our analysis suggests that catchment storage components such as in-network lakes introduce variability in solute export behaviors and may decouple concentration-discharge relationships at high flows. This study provides a mechanistic framework to connect disparate temporal scales of hydrochemical observation and offers a clearer understanding of catchment-specific processes that regulate the timing and magnitude of solute export in Arctic headwaters.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JG009594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784779","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":"Tidal and Rainfall Controls of CH4 Fluxes in a Southern Moreton Bay Mangrove-Saltmarsh","authors":"Eboni-Jane Vienna-Hallam,&nbsp;Ruth Reef,&nbsp;Judith A. Rosentreter,&nbsp;Bradley D. Eyre,&nbsp;Jacob Yeo,&nbsp;Adam J. Kessler,&nbsp;Tivanka Anandappa","doi":"10.1029/2026JG009795","DOIUrl":"https://doi.org/10.1029/2026JG009795","url":null,"abstract":"<p>Coastal wetlands play a crucial role in global carbon dynamics, acting as carbon dioxide (CO₂) sinks while also emitting methane (CH₄), a potent greenhouse gas. This study investigates CH₄ fluxes over a six-month period in a sub-tropical coastal mangrove-saltmarsh wetland in southern Moreton Bay, Queensland, Australia, using eddy covariance. The site functioned predominantly as a net CH₄ source, with a mean (±SD) half-hourly flux of 0.054 ± 0.943 μmol m⁻² s⁻¹ over the full six-month period, exceeding previous mean CH₄ estimates from coastal wetlands and reflecting high variability. Hydrological factors, particularly the extent and duration of tidal inundation and rainfall, strongly influenced coastal wetland CH₄ dynamics. Spring tides amplified emissions by promoting waterlogged anoxic conditions ideal for methanogenesis. In contrast, rainfall events disrupted typical flux patterns, enhancing both emissions and uptake, overall leading to a net CH₄ sink. Diel and seasonal variations were also evident, with elevated night-time emissions and seasonal fluxes modulated by hydrological events. These findings underscore the importance of short-term hydrological disturbances in shaping CH₄ fluxes and highlight the need for region-specific long-term monitoring in coastal wetlands. As climate change intensifies precipitation, storm frequency, and associated inundation patterns, capturing these transient, high-impact events is essential for accurate GHG accounting and climate mitigation strategies.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG009795","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784775","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":"Representativity of CO2 Exchange on Extensive Green Roofs: Scaling From Leaf to Plant, and Plant to Roof Scale","authors":"J. Gelhaus,&nbsp;N. Markolf,&nbsp;S. Weber","doi":"10.1029/2026JG009972","DOIUrl":"https://doi.org/10.1029/2026JG009972","url":null,"abstract":"<p>Urban green roofs have potential for local urban climate change mitigation, as they have been demonstrated to uptake carbon dioxide (CO₂) from the atmosphere. However, most roofs are too small to qualify for area-integrating direct surface-atmosphere exchange measurements using the eddy covariance technique (EC), resulting in sparse data on net CO₂ sequestration capacities. Small-scale methods such as leaf chambers or automated surface chambers (AC) may provide a monitoring alternative for smaller roofs. To assess whether alternative methods can produce representative data on the CO₂ sequestration capacity of an extensive green roof, simultaneous measurements at the scale of leaf, plants, and roof were conducted. The representativity of leaf scale measurements was strongly affected by spatial heterogeneity and high temperatures within the chamber. Linear regression indicated accurate scaling from plant to roof scale (slope = 0.76) at diurnal mean temperatures around 14.2°C and recurring precipitation. However, with daytime temperatures exceeding 25°C, AC more significantly underestimated the roof CO₂ assimilation capacity in comparison to EC (slope = 0.63). Data from a prolonged drought period indicated that certain small-scale responses to water stress, such as the shift to CAM photosynthesis, captured by AC are not registered by EC. A spatial upscaling based on the estimated vegetation distribution on the roof indicated a limited consistency with the EC data with slopes of 0.20 and 0.42 for the aforementioned periods. Differences between AC and EC should not necessarily be regarded as errors but as valuable insights into spatial and plant-physiological heterogeneity.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"131 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JG009972","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784786","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}