Journal of Geophysical Research: Biogeosciences最新文献

{"title":"Spatiotemporal Characteristics of Drought Events in Africa's Great Green Wall Region During 1950–2022","authors":"Kidane Welde Reda,&nbsp;Wang Yongdong,&nbsp;You Yuan,&nbsp;Zhou Na,&nbsp;Zinabu Bora,&nbsp;Gebremedhin Gebremeskel Haile,&nbsp;Yikunoamlak Gebrewahid","doi":"10.1029/2024JG008313","DOIUrl":"https://doi.org/10.1029/2024JG008313","url":null,"abstract":"<p>Understanding historical spatiotemporal drought patterns is crucial for effective drought adaptation and mitigation strategies. Despite the launch of Africa's Great Green Wall (AGGW) initiative by the African Union to combat desertification in the semi-arid Sahel region, there remains a limited comprehensive long-term spatiotemporal assessment of drought patterns. In this study, we analyzed the drought spatiotemporal characteristics in the AGGW region using the Standardized Precipitation-Evapotranspiration Index (SPEI) at multiple timescales (1-month, 3-month, 6-month, 9-month, and 12-month) from 1950 to 2022. Despite regional variations, the results showed an overall increasing drought trend across the AGGW during the past 73 years. Trends of drought change per year were −0.012, −0.015, −0.018, −0.009, and −0.021 for SPEI01, SPEI03, SPEI06, SPEI09, and SPEI12, respectively. Significant spatial variability in drought duration, frequency, intensity, and trend were observed, mainly larger values concentrated in the northern and central areas of AGGW. Two significant turning points were detected, occurring in 1973 and 1996 that indicated the periods of 1950–1972 and 1973–1995 non-significant drought increase while significant severe drought occurred in the late periods (1996–2022), with widespread spatial coverage. Seasonal drought variation demonstrates an increasing trend in autumn, spring, summer, and winter across all SPEI time scales, with notably larger rates during autumn and winter. Finally, these findings provide important insights into the characteristics and mechanisms of droughts across the AGGW region and have a significant implication for drought adaptation and mitigation strategies to meet the core objectives of the AGGW regional initiative.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143822173","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":"A Coupled O2-CO2 Model for Joint Estimation of Stream Metabolism, O-C Stoichiometry, and Inorganic Carbon Fluxes","authors":"Jacob S. Diamond,&nbsp;E. Bertuzzo","doi":"10.1029/2024JG008401","DOIUrl":"https://doi.org/10.1029/2024JG008401","url":null,"abstract":"&lt;p&gt;We determine where stream carbon dioxide (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) comes from by developing a model for the joint estimation of stream metabolism, oxygen-carbon (O-C) stoichiometry, and fluxes of dissolved inorganic carbon (DIC), based on observations of stream oxygen (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{O}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; concentrations. The model is based on a stream reach mass balance of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{O}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, DIC, and total alkalinity, and it accounts for the carbonate system and the contribution of lateral flow. &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{O}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;DIC&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $text{DIC}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; mass balances are coupled through stoichiometric coefficients for photosynthesis and combined autotrophic and heterotrophic respiration. Under the assumption of constant alkalinity and circumneutral pH, the model simplifies and includes 8 parameters, which are estimated through a Bayesian hierarchical framework. The model accurately reproduced time series of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{O}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 ","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008401","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143818356","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":"Patterns and Potential Consequences of a Changing Sulfur Cycle in High Elevation Wetlands","authors":"Laura T. Rea,&nbsp;Molly E. Huber,&nbsp;Hannah R. Miller,&nbsp;Clifford Adamchak,&nbsp;Eve-Lyn S. Hinckley","doi":"10.1029/2024JG008616","DOIUrl":"https://doi.org/10.1029/2024JG008616","url":null,"abstract":"<p>Ice thaw and enhanced bedrock weathering are increasing sulfate export in alpine streams, which may change sulfur (S) and other biogeochemical cycles in adjacent wetlands. We compared S and carbon (C) concentrations and sulfate reduction rates (SRRs) across three wetland types in the Colorado Rocky Mountains, USA: snowmelt-fed wetlands (SFWs), periglacial solifluction lobes (PSLs), and subalpine wetlands (SAWs). We found that each wetland type had unique biogeochemical characteristics. Subalpine wetlands had the highest soil C (37.2 ± 8.7%C) and SRRs (29.3 ± 21 nmol mL⁻¹ soil day ⁻¹) compared with SFWs and PSLs, which had lower %C and moderate to low SRRs, respectively. Subalpine wetlands accumulated little sulfate, whereas PSLs had high concentrations (0.04 ± 0.04 vs. 0.6 ± 1.4 mg S g⁻¹ dry soil respectively); SFWs had low sulfate concentrations (0.02 ± 0.01 mg S g⁻¹ dry soil). Sulfate-S stable isotope data suggest different sources of S in the SFWs and PSLs: atmospheric and geologic, respectively. The data indicate that high C supports high SRRs in SAWs, whereas SRRs may be C-limited and co-limited by C and S in PSLs and SFWs, respectively. With climate warming, SAWs have the greatest potential to release more C to the atmosphere, SFWs will likely decrease in size and experience changes in plant community composition, and PSLs may be sources of acid rock drainage. These data demonstrate different biogeochemical fates of S and C in three wetland types present across alpine landscapes, and notable consequences for biogeochemical cycling as warming continues.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143818355","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":"Widespread Advances in Corn and Soybean Phenology in Response to Future Climate Change Across the United States","authors":"Yanjun Yang,&nbsp;Bo Tao,&nbsp;Alex C. Ruane,&nbsp;Chaopeng Shen,&nbsp;David S. Matteson,&nbsp;Rémi Cousin,&nbsp;Wei Ren","doi":"10.1029/2024JG008266","DOIUrl":"https://doi.org/10.1029/2024JG008266","url":null,"abstract":"<p>Crop phenology regulates seasonal carbon and water fluxes between croplands and the atmosphere and provides essential information for monitoring and predicting crop growth dynamics and productivity. However, under rapid climate change and more frequent extreme events, future changes in crop phenological shifts have not been well investigated and fully considered in earth system modeling and regional climate assessments. Here, we propose an innovative approach combining remote sensing imagery and machine learning (ML) with climate and survey data to predict future crop phenological shifts across the US corn and soybean systems. Specifically, our projected findings demonstrate distinct acceleration patterns—under the RCP 4.5/RCP 8.5 scenarios, corn planting, silking, maturity, and harvesting stages would significantly advance by 0.94/1.66, 1.13/2.45, 0.89/2.68, and 1.04/2.16 days/decade during 2021–2099, respectively. Soybeans exhibit more muted responses with phenological stages showing relatively smaller negative trends (0.59, 1.08, 0.07, and 0.64 days/decade under the RCP 4.5 vs. 1.24, 1.53, 0.92, and 1.04 days/decade under the RCP 8.5). These spatially explicit projections illustrate how crop phenology would respond to future climate change, highlighting widespread and progressively earlier phenological timing. Based on these findings, we call for a specific effort to quantify the cascading effects of future phenology shifts on crop yield and carbon, water, and energy balances and, accordingly, craft targeted adaptive strategies.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770184","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":"Nitrate-Driven Eutrophication Supports High Nitrous Oxide Production and Emission in Coastal Lagoons","authors":"Henry L. S. Cheung,&nbsp;Mindaugas Zilius,&nbsp;Tobia Politi,&nbsp;Elise Lorre,&nbsp;Irma Vybernaite-Lubiene,&nbsp;Isaac R. Santos,&nbsp;Stefano Bonaglia","doi":"10.1029/2024JG008510","DOIUrl":"https://doi.org/10.1029/2024JG008510","url":null,"abstract":"<p>Under current circumstances, coastal lagoons are net emitters of nitrous oxide (N₂O) to the atmosphere. We hypothesize that widespread nitrogen-driven coastal eutrophication will enhance N₂O production and emissions from coastal lagoons. Here, we quantified spatial and temporal patterns of sediment-water and water-air N₂O fluxes in three large eutrophic lagoons in Europe. Annual sediment N₂O fluxes ranged between −0.3 ± 0.3 (summer) and 10.6 ± 2.0 μmol m⁻² d⁻¹ (spring). In spring, conspicuous sediment effluxes were mainly supported by high nitrate concentrations (89–202 μM) and incomplete denitrification. In summer, a small sediment influx was related to nitrate limitation (0–9 μM), potentially leading to N₂O demand for denitrification. The water-air N₂O fluxes were comparable with benthic fluxes, indicating that sediment was the main source of N₂O to the atmosphere. The hypereutrophic Curonian Lagoon had the largest N₂O emission at 4.9 ± 2.1 μmol m⁻² d⁻¹, while the less eutrophic Oder and Vistula lagoons emitted 2.5 ± 1.0 and 2.0 ± 0.7 μmol m⁻² d⁻¹, respectively. Our observations, combined with earlier measurements in coastal lagoons worldwide, revealed a lagoon median (Q1–Q3) N₂O emission of 14.2 (2.7–29.8) Gg yr⁻¹, which is about 48% higher than previous estimates. Eutrophication driven by large nitrogen inputs is thus a significant driver of coastal N₂O emissions globally.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008510","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761920","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":"The Impact of Turfgrass on Urban Carbon Dioxide Fluxes in Indianapolis, Indiana, USA","authors":"Jason P. Horne,&nbsp;Claire Jin,&nbsp;Natasha L. Miles,&nbsp;Scott J. Richardson,&nbsp;Samantha L. Murphy,&nbsp;Kai Wu,&nbsp;Kenneth J. Davis","doi":"10.1029/2024JG008477","DOIUrl":"https://doi.org/10.1029/2024JG008477","url":null,"abstract":"<p>Evaluating the efficacy of climate mitigation measures requires quantifying urban greenhouse gas (GHG) emissions. Both anthropogenic and biogenic GHG fluxes are important in urban systems, and disaggregation is necessary to understand urban GHG fluxes. In urban environments one common source of biogenic carbon dioxide (CO₂) fluxes is turfgrass. We use CO₂ fluxes measured using eddy covariance over a cemetery (less managed) and golf course (more managed) to investigate the contribution of turfgrass lawns to biogenic CO₂ fluxes in Indianapolis, IN. We assess the ability of a simple light-use efficiency model, the Vegetation Photosynthesis and Respiration Model (VPRM), commonly used to create prior fluxes necessary for determining urban carbon dioxide (CO₂) fluxes via inversion modeling, to represent daily and seasonal patterns in turfgrass CO₂ fluxes. Our results show that the existing VPRM Plant Functional Types (PFTs) cannot capture observed daily and seasonal fluxes at either location. We then use data from these sites to create a new turfgrass PFT for the VPRM. We find that less-managed lawns like cemeteries are best represented by different parameters than heavily managed lawns like golf courses, and seasonally changing parameters best match the observed fluxes. We then use the new turfgrass PFT within the VPRM to explore daily and seasonal variability in turfgrass fluxes and their impact, integrated across the city, on urban ecosystem CO₂ fluxes. This study illustrates the importance of representing turfgrass as a unique PFT when quantifying urban GHG fluxes and the biases resulting from misrepresentation.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761919","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":"Hydrologic Management Convolutes Expected Spatiotemporal Patterns of Dissolved Organic Matter in the Hudson River","authors":"Alex C. Collins,&nbsp;Julia Hubbard,&nbsp;Sasha Wagner","doi":"10.1029/2024JG008131","DOIUrl":"https://doi.org/10.1029/2024JG008131","url":null,"abstract":"<p>Riverine dissolved organic matter (DOM) is a vector for nutrient cycling and elemental exchange between terrestrial and oceanic reservoirs. The quality and quantity of DOM transported in rivers are determined by a complex interplay of watershed-specific conditions (e.g., land use and discharge). In many temperate rivers, the frequency and intensity of hydrologic events are expected to increase with continued climate change, which would result in an overall increased export of terrestrial DOM. However, the presence of dams and other impoundments increase water residence time and could dampen these effects. Here, we examine DOM biogeochemistry in the Hudson River (New York, USA), which experiences intermittent periods of elevated discharge and receives a seasonally varied series of inputs from urban, agricultural, and forested landscapes. DOM was quantified and characterized using optical spectroscopic techniques, including parallel factor analysis (PARAFAC) modeling of fluorescent DOM components. Our findings indicate that the influence of land cover on DOM composition is secondary to that of hydrologic management. We also found DOM pulse-shunt effects to be more muted in the upper Hudson River watershed, where more water is retained by dams and reservoirs than in the Mohawk River watershed. Regardless of hydrologic management, discharge events consistently enhanced aromatic DOM export in the Hudson River and its subbasins, which suggests climate change and increased rainfall will enhance the delivery of humic-like DOM to the estuary and coastal margins.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761921","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":"Exploring the Signature of Lipid Biomolecules Influenced by Soil Aggregates Across Terrestrial Ecosystems","authors":"Biswajit Roy,&nbsp;Twismary Kharphuli,&nbsp;Disha Baidya,&nbsp;Prasanta Sanyal","doi":"10.1029/2024JG008424","DOIUrl":"https://doi.org/10.1029/2024JG008424","url":null,"abstract":"<p>Soils across terrestrial ecosystems comprise aggregates with varying biological and physicochemical properties that impact plant lipid distribution. This study examines the role of aggregates characteristics in the distribution of <i>n-</i>alkyl lipids (<i>n</i>-alkanes and <i>n-</i>alkanoic acids) in forest, grassland, and mixed (shrubs and grasses) ecosystems across five different particle size fractions (PSF) in the lower Ganga region (India). Fresh plant-derived <i>n-</i>alkyl lipid signature, similar to the bulk soil, mostly associates sand PSF (&gt;63 μm), which constitutes larger aggregates formed by extensive biological (fungal hyphae and roots) and physical (clay coating) components. Fragmented soil aggregates comprise mostly the silt PSF, which allowed restricted storage of plant <i>n-</i>alkyl lipids and increased microbial contribution. Stable clay-rich microaggregates in finer PSF (&lt;20 μm) vary across ecosystems, influencing the storage and modification of plant-derived <i>n</i>-alkyl lipid signatures. Principle component analysis showed that the <i>n</i>-alkyl lipid signature across PSF in forest soil is distinct and more variable than other two ecosystems. In grassland and mixed PSF, extensive belowground root processes fragments and reduces soil aggregates, which limits the modification of plant <i>n</i>-alkyl lipids when compared to physically stable aggregates found in forest ecosystems. The susceptibility of <i>n</i>-alkanoic acids to microbial decomposition resulted in consistent replacement and a stable profile across soil fractions, while <i>n</i>-alkanes exhibit greater variability due to differences in aggregate protection. Such difference in biochemical response between <i>n</i>-alkyl lipids highlights the crucial role of aggregate characteristics in mineral protection and/or microbial decomposition of OM, which contributes to microscale carbon dynamics across ecosystems.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749348","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":"Using a Plant Hydrodynamic Model, FETCH4, to Supplement Measurements and Characterize Hydraulic Traits in a Mixed Temperate Forest","authors":"Justine E. C. Missik,&nbsp;Gil Bohrer,&nbsp;Madeline E. Scyphers,&nbsp;Ashley M. Matheny,&nbsp;Ana Maria Restrepo Acevedo,&nbsp;Marcela Silva,&nbsp;Golnazalsadat Mirfenderesgi,&nbsp;Yair Mau","doi":"10.1029/2024JG008198","DOIUrl":"https://doi.org/10.1029/2024JG008198","url":null,"abstract":"<p>Species-specific hydraulic traits play an important role in ecosystem response to water stress; however, representation of biodiverse forest canopies remains a challenge in land surface models. We introduce FETCH4, a multispecies, canopy-level, hydrodynamic model, which builds upon previous versions of the finite-difference ecosystem-scale tree crown hydrodynamics model (FETCH). FETCH4 simulates water transport through the soil, roots, and stem as porous media flow. Stomatal conductance is controlled by xylem water potential, which is resolved along the vertical dimension. A key feature of FETCH4 is a multispecies canopy formulation, which uses crown and stem dimensional characteristics to allow the model to produce both tree-level and plot-level outputs and improves the representation of hydraulic traits and their variation among trees and species. We demonstrate the model's performance in a mixed temperate forest in Michigan with species of contrasting hydraulic strategies. We optimize species-specific hydraulic parameters using a Bayesian optimization framework incorporating sapflow measurements. FETCH4 performed well in simulating sapflow of species with contrasting hydraulic strategies under conditions of water stress. In addition, the model was able to capture higher-level emergent traits, such as drought sensitivity. Using FETCH4 in combination with available observations can provide unique insights about difficult to measure hydraulic traits and plant hydrodynamics.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008198","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741353","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":"On the Relationship Between Methane Production in Anaerobic Incubations of Peat Material and In Situ Methane Emissions","authors":"Alexandra B. Cory,&nbsp;Rachel M. Wilson,&nbsp;Olivia C. Ogles,&nbsp;Patrick M. Crill,&nbsp;Zhen Li,&nbsp;Kuang-Yu Chang,&nbsp;Samantha H. Bosman,&nbsp;Virginia I. Rich,&nbsp;Jeffrey P. Chanton,&nbsp;EMERGE Project Coordinators,&nbsp;Moira Hough,&nbsp;Sky Dominguez,&nbsp;Nicole Irwin-Raab,&nbsp;Gareth Trubl,&nbsp;Robert M. Jones,&nbsp;Darya Anderson,&nbsp;Isogenie Field Team","doi":"10.1029/2024JG008371","DOIUrl":"https://doi.org/10.1029/2024JG008371","url":null,"abstract":"<p>Anaerobic incubations of peat have been widely used to explore soil processes, but this in vitro technique raises many questions as to how well it reproduces in situ conditions. To investigate this, we conducted 60–100 days (+25 days pre-incubation) anaerobic, temperature-controlled incubation experiments across a temperature range of 1–26°C on samples from bog and fen habitats, at two different depths (9–19and 25–35 cm). We observed exponential increases in CO₂ and methane production with temperature in all conditions. We then compared field-based measurements of methane emission with modeled expectations by extrapolating incubation-determined methane production rates based on (a) soil temperature profiles, (b) the observed incubation temperature-methane production relationship, and (c) seasonal thaw depth from each site. The resulting incubation-extrapolated methane production agreed with measured emission rates within a factor of two at both sites and corresponded to 182 ± 54% and 59 ± 14% of the measured average yearly fluxes from the field for the bog and fen, respectively. The underestimation of fen methane fluxes may be due to the lack of living plant root-derived dissolved organic carbon inputs in incubations, a key process in fens. Conversely, the overestimation in bogs could be attributed to methane oxidation in the field, which is absent in anaerobic incubation conditions. Nonetheless incubations predicted greenhouse gas emissions from a northern peatland within a factor of two.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 4","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726777","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}