Journal of Geophysical Research: Biogeosciences最新文献

{"title":"Quantifying the Effect of Petrogenic Carbon on SOC Turnover for Two Rocky Mountain Soils: When Are Petrogenic Carbon Corrections Required?","authors":"Elizabeth Williams,&nbsp;Corey Lawrence","doi":"10.1029/2023JG007838","DOIUrl":"https://doi.org/10.1029/2023JG007838","url":null,"abstract":"<p>Petrogenic organic carbon (OC_petro), derived from sedimentary rocks, is an often overlooked and poorly quantified source of soil organic carbon (SOC), which may influence measured or modeled SOC composition, age, and stability. In this study, we exploited differences in thermochemical stability between OC_petro and biogenic SOC (OC_bio) using stepped elemental analysis to quantify the fractional contribution of OC_petro to total SOC (f_petro), and we conducted a sensitivity analysis to estimate the effects of OC_petro on modeled SOC transit times and system ages. Specifically, we compared the effects of accounting for OC_petro inputs in SOC turnover modeling (using SoilR) for two montane meadow soils that are underlain by Cretaceous Mancos Shale. At these sites, we estimate that OC_petro comprises 7%–9% of the total SOC stock (f_petro = 0.07–0.09). However, accounting for OC_petro as a mixture of inert and passive C or as completely inert C had negligible effects on SOC transit times and system ages, suggesting that there is a threshold of OC_petro content under which there is minimal effect on calculated SOC turnover. Based on our sensitivity analysis, we estimate this threshold to be f_petro = 0.125, further supporting that the accurate calculation of OC_petro remains an important factor in estimating SOC turnover.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JG007838","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121454","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":"Depth-Distribution Patterns of Soil Organic Matter in the Tidal Marshes of the Venice Lagoon (Italy): Signatures of Depositional and Environmental Conditions","authors":"A. Puppin,&nbsp;D. Tognin,&nbsp;M. Ghinassi,&nbsp;E. Franceschinis,&nbsp;N. Realdon,&nbsp;M. Marani,&nbsp;A. D’Alpaos","doi":"10.1029/2024JG008327","DOIUrl":"https://doi.org/10.1029/2024JG008327","url":null,"abstract":"<p>Salt marshes are depositional landforms lying at the upper margin of intertidal environments. They provide a diverse range of valuable ecosystem services and yet are exceptionally vulnerable to climate change and human pressure. Salt marshes are intrinsically dynamic environments, shaped by complex feedback between hydrodynamic, morphological, and biological processes. Soil Organic Matter (SOM) has a crucial role within salt marsh environments, as on the one hand, its accumulation contributes to the build-up of marsh elevation which is necessary for marshes to keep pace with sea-level rise, and on the other it supports the high carbon sink potential of wetlands. To better understand variations in SOM depth distribution and further comprehend SOM drivers, we analyzed soil organic content in 10 salt marshes of the microtidal Venice Lagoon from 60 sediment cores to the depth of 1 m, relating SOM spatial and vertical patterns to the temporal and spatial variability of depositional sub-environments recorded in the study deposits. Our results suggest that changes in the depositional environment are of primary importance in determining organic matter depth distribution and caution is needed in SOM prediction at unsampled soil depths. We observed relationships between SOM vertical patterns and factors such as autochthonous and allochthonous organic inputs, sediment properties, relative sea level rise, fluvial inputs and wave action. Our findings emphasize the considerable carbon storage potential of marshes in intertidal environments and provide a conceptual framework for understanding the dynamics of SOM and their drivers, which can inform and enhance coastal management strategies.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008327","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121251","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":"Seasonal Variation and Key Controls of Groundwater Ammonium Concentrations in Hypoxic/Anoxic Riparian Sediments","authors":"Matthew G. Sena,&nbsp;Marc Peipoch,&nbsp;Bisesh Joshi,&nbsp;Md. Moklesur Rahman,&nbsp;Erin Peck,&nbsp;Arthur J. Gold,&nbsp;Jinjun Kan,&nbsp;Shreeram Inamdar","doi":"10.1029/2023JG007900","DOIUrl":"https://doi.org/10.1029/2023JG007900","url":null,"abstract":"<p>The seasonal controls of hydrology, temperature, hypoxia, and biogeochemical conditions for groundwater ammonium–N (NH₄⁺) concentrations are not well understood. Here we investigated these controls for riparian groundwaters located upstream of two milldams over a period of 4 years. Groundwater chemistry was sampled monthly while groundwater elevations, hydraulic gradients, and temperatures were recorded sub-hourly. Distinct seasonal patterns for NH₄⁺ were observed which differed among the wells. For wells that displayed a strong seasonal pattern, NH₄⁺ concentrations increased through the summer and peaked in October–November. These elevated concentrations were attributed to ammonification, suppression of nitrification, and/or dissimilatory nitrate reduction to ammonium (DNRA). These processes were driven by high groundwater temperatures, low hydraulic gradients (or long residence times), hypoxic/anoxic groundwater conditions, and increased availability of dissolved organic carbon as an electron donor. In contrast, NH₄⁺ concentrations decreased in the riparian groundwater from January to April during cool and wet conditions. A groundwater well with elevated total dissolved iron (TdFe) concentrations had elevated NH₄⁺ concentrations but displayed a muted seasonal response. In addition to hydrologic controls, we attributed this response to additional NH₄⁺ contribution from Fe-driven autotrophic DNRA and/or ammonification linked to dissimilatory Fe reduction. Understanding the temporal patterns and factors controlling NH₄⁺ in riparian groundwaters is important for making appropriate watershed management decisions and implementing appropriate best management practices.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143121254","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":"Biofilm Development, Senescence, and Benthic Substrate Influence Hyporheic Transport in Streams","authors":"Sabrina N. Volponi,&nbsp;Jennifer L. Tank,&nbsp;Anna E. S. Vincent,&nbsp;Elise D. Snyder,&nbsp;Abagael N. Pruitt,&nbsp;Diogo Bolster","doi":"10.1029/2024JG008225","DOIUrl":"https://doi.org/10.1029/2024JG008225","url":null,"abstract":"<p>Understanding fate and transport within fluvial systems requires accurate modeling of breakthrough curve (BTC) tails, which often display non-Fickian behaviors. However, it is unclear how anomalous processes relate to the physical and biological characteristics of the stream ecosystem. We use the Stochastic Mobile Immobile model (SMIM) to determine the impact of biofilm colonization among different substrate types on reach-scale transport velocity (V) and dispersion (D), rate of delivery to the subsurface (Λ), and retention within the subsurface (reflected by power law slope; <i>β</i>). During the summers of 2020 and 2021, we conducted a total of <i>n</i> = 42 Rhodamine-WT releases in four experimental streams lined with contrasting substrata (sand, pea gravel, cobble, and a three-way mix) at the Notre Dame Linked Experimental Ecosystem Facility (ND-LEEF) in Indiana (USA). To explore the effect of biofilm colonization, we conducted releases under artificially shaded, early and late biofilm development, and senescent biofilm conditions. We found that replicated releases under constant conditions consistently reproduced stream BTCs and modeled transport parameters. Biofilm abundance, biofilm status (living vs. dead), and substrate type produced significant variations in BTC shape and transport parameterizations. We found a non-linear relationship between algal biomass and V, where increases in biomass produced decreases in V at low biomass and increases in V at high biomass. Substrate type also predicted patterns in transport, with sand producing higher V, Λ, and <i>β</i> than larger substrata. These results suggest that substrate type acts as the primary driver and biofilm development the secondary control on transport in these stream systems.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143120701","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 2020 Heatwave Led to a Larger Enhancement in Annual Gross Primary Production in West Siberia Than in East Siberia","authors":"Sung-Bin Park,&nbsp;Chang-Eui Park,&nbsp;Jin-Soo Kim,&nbsp;Jingfeng Xiao,&nbsp;Eun-Ji Song,&nbsp;Damwon Seo,&nbsp;Sang Seo Park","doi":"10.1029/2024JG008487","DOIUrl":"https://doi.org/10.1029/2024JG008487","url":null,"abstract":"<p>Spring and summer vegetation productivity in Siberia shows opposing responses to warmer spring. Spring warming causes excessive vegetation growth and earlier start of photosynthesis, enhancing productivity in spring. However, this leads to reduced productivity in the following season (i.e., summer) through soil moisture depletion. To understand how an exceptional spring heatwave (HW) affected ecosystem carbon uptake, we investigated the spatiotemporal cascade of gross primary production (GPP) and multiple climate variables over Siberia in 2020, using a satellite-retrieved GPP product (GOSIF-GPP) and the ERA5-Land reanalysis data set for 2001–2020. Results showed a positive impact of anomalous spring warming on annual GPP (GPP_ann). GPP_ann from GOSIF-GPP in West Siberia (55°–70°N, 50°–90°E) was enhanced by up to 10% above the 2001–2019 average despite continued dry conditions from May to August. In East Siberia (55–70°N, 90–130°E), the GPP increases for May and June were sufficient to compensate for marked reduction of GPP in July due to negative anomaly in radiation. In addition, the higher sensitivity of GPP_ann to spring temperature in West Siberia than in East Siberia suggests that GPP increase coupled with strong warming and respective excessive vegetation growth might be more pronounced in the western region, as observed in 2020. Our results indicate that the warming trend in spring, combined with possible extreme heat events, could elevate annual carbon uptake in Siberia, particularly in West Siberia. Further, this case study for the extreme HW event that occurred in 2020 can provide useful insight for understanding future change in carbon uptake over Siberia.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143120700","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":"Sensitivity of Chlorophyll Vertical Structure to Model Parameters in the Biogeochemical Southern Ocean State Estimate (B-SOSE)","authors":"Angela M. Kuhn,&nbsp;Matthew R. Mazloff,&nbsp;Sarah T. Gille,&nbsp;Ariane Verdy","doi":"10.1029/2024JG008300","DOIUrl":"https://doi.org/10.1029/2024JG008300","url":null,"abstract":"<p>The Southern Ocean is a region of intense air–sea exchange that plays a critical role for ocean circulation, global carbon cycling, and climate. Subsurface chlorophyll-a maxima, annually recurrent features throughout the Southern Ocean, may increase the energy flux to higher trophic levels and facilitate downward carbon export. It is important that model parameterizations appropriately represent the chlorophyll vertical structure in the Southern Ocean. Using BGC-Argo chlorophyll profiles and the Biogeochemical Southern Ocean State Estimate (B-SOSE), we investigate the sensitivity of chlorophyll vertical structure to model parameters. Based on the sensitivity analysis results, we estimate optimized parameters, which efficiently improve the model consistency with observations. We characterize chlorophyll vertical structure in terms of Empirical Orthogonal Functions and define metrics to compare model results and observations in a series of parameter perturbation experiments. We show that chlorophyll magnitudes are likely to respond quasi-symmetrically to perturbations in the analyzed parameters, while depth and thickness of the subsurface chlorophyll maximum show an asymmetric response. Perturbing the phytoplankton growth tends to generate more symmetric responses than perturbations in the grazing rate. We identify parameters that affect chlorophyll magnitude, subsurface chlorophyll or both and discuss insights into the processes that determine chlorophyll vertical structure in B-SOSE. We highlight turbulence, differences in phytoplankton traits, and grazing parameterizations as key areas for improvement in models of the Southern Ocean.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143120521","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":"Regulation Mechanisms of CO2 Fluxes in Subtropical Mountain Peatlands Based on Long-Term In Situ Observations at the Dajiuhu Peatland","authors":"Shiyu Yang,&nbsp;Jiwen Ge,&nbsp;Xiangnan Xu,&nbsp;Ziwei Liu,&nbsp;Jiumei Wang,&nbsp;Yuehuan Wang","doi":"10.1029/2024JG008328","DOIUrl":"https://doi.org/10.1029/2024JG008328","url":null,"abstract":"<p>The Dajiuhu peatland in Shennongjia, China, is a highly representative subalpine peatland, emblematic of subtropical mountainous peatlands. Due to the lack of long-term in situ continuous observations and in-depth studies on CO₂ absorption and emission patterns, the regulation mechanisms of CO₂ flux in subtropical peatlands remain unclear. Since July 2015, we have conducted over five years of continuous in situ observations of CO₂ fluxes and major environmental factors in the Dajiuhu peatland ecosystem. We calculated the annual average net ecosystem carbon exchange (NEE) of CO₂ and decomposed NEE into gross primary productivity (GPP) and ecosystem respiration (Reco), thus examining the peatland ecosystem's absorption and emission of CO₂ separately. The results indicate that the annual average NEE from 2016 to 2020 was −283.6 g C m⁻² yr⁻¹, reflecting a strong CO₂ sink. Our study indicates the regulation mechanisms of CO₂ flux in the peatland. Temperature is the most direct factor affecting CO₂ absorption and emission, serving as the most important driver of CO₂ flux on short time scales. Precipitation only affects CO₂ absorption but has a significant impact on NEE, being a key factor in maintaining the peatland's CO₂ sink function. Variations in annual precipitation also led to differences in net CO₂ absorption between years. Our results illustrate an important role of sub-tropical mountain peatlands in mitigating the greenhouse effect and maintaining moisture conditions is crucial for protecting its ecological functions.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143119660","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":"Quantifying Dust Nutrient Mobility Through an Alpine Watershed","authors":"Jeffrey R. Nielson,&nbsp;Janice Brahney","doi":"10.1029/2024JG008175","DOIUrl":"https://doi.org/10.1029/2024JG008175","url":null,"abstract":"<p>Dust has the potential to play a significant role in the nutrient dynamics of alpine watersheds with important ecological implications. However, little is known about how dust nutrients circulate through the environment and which watershed characteristics facilitate dust impacts on water quality. This study explored the contribution of dust-deposited nutrients, focusing on a high-elevation Long Term Ecological Research site, where dust samples have been continuously collected since 2017. We incorporated observed dust nutrient compositions, including fractions of inorganic and organic nitrogen and phosphorus, into a popular hydrological model, the Soil and Water Assessment Tool, and ran simulations for 2019–2021. By comparing simulations with and without dust nutrient inputs, we estimated the impact of dust-deposited nutrients on individual watershed processes. Results revealed a significant contribution of dust-deposited nutrients, particularly soluble reactive phosphorus (SRP), to several nutrient cycling and transport pathways. Notably, dust contributed up to 19.3% of the SRP load in annual streamflow (increasing monthly streamflow concentration by up to 10.9 μg <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>L</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${mathrm{L}}^{-1}$</annotation>\u0000 </semantics></math> ). Spatial analysis of model estimates demonstrated a relationship between topography, soil type, and the cycling and transport of dust nutrients. The largest dust nutrient contributions were found in catchment areas with lower slope and less hydric soils, where other natural mobilization processes may be limited. This comparative modeling approach stresses the importance of including dust nutrients in watershed models, especially in oligotrophic systems, and has potential to validate these findings elsewhere and identify how watershed characteristics may either mollify or accentuate the impacts of dust deposition on mountain freshwater systems.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143119424","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":"Effects of Hot Versus Dry Vapor Pressure Deficit on Ecosystem Carbon and Water Fluxes","authors":"Miriam R. Johnston,&nbsp;Mallory L. Barnes,&nbsp;Yakir Preisler,&nbsp;William K. Smith,&nbsp;Joel A. Biederman,&nbsp;Russell L. Scott,&nbsp;A. Park Williams,&nbsp;Matthew P. Dannenberg","doi":"10.1029/2024JG008146","DOIUrl":"https://doi.org/10.1029/2024JG008146","url":null,"abstract":"<p>Vapor pressure deficit (VPD) has increased and will likely continue increasing, with wide-ranging effects on ecosystems. Future VPD increases will largely be driven by warming, yet most experiments examining VPD effects on plants have done so by changing humidity. Here, we used meteorological data and carbon and water fluxes measured at 26 climatically-diverse eddy covariance sites to quantify the extent to which VPD has been driven by variation in air temperature versus humidity. We fit generalized additive models (GAMs) at each site to quantify effects of hotter (and wetter) and cooler (and drier) versus typical VPD on ecosystem-scale fluxes of carbon and water. We found that VPD has occurred under diverse combinations of temperature and humidity: &gt;50% of a site's daytime growing season temperature range and &gt;35% of its relative humidity range have often combined to define a particular VPD. We found moderate evidence that hotter versus drier VPD of the same magnitude differentially affect gross primary productivity (GPP), net ecosystem productivity (NEP), and latent heat flux (LE): Selected GPP and NEP GAMs at about half of sites and LE GAMs at about a third of sites included a VPD-temperature interaction. The magnitude of the interaction varied, but was generally 29%–57% of the effect attributable solely to VPD. The direction of the interaction also varied, but hot VPD was commonly associated with higher carbon fluxes. These effects were not strongly modified by soil moisture. Overall, results emphasize the relevance of VPD-temperature interactions at a critical time of rapid VPD increase.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008146","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143119035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Machine Learning Approach for Filling Long Gaps in Eddy Covariance Time Series Data in a Tropical Dry Forest","authors":"Mohammed Abdaki,&nbsp;Arturo Sanchez-Azofeifa,&nbsp;Hendrik F. Hamann","doi":"10.1029/2024JG008375","DOIUrl":"https://doi.org/10.1029/2024JG008375","url":null,"abstract":"<p>Long-term eddy covariance (EC) data are crucial for understanding the impact of global change on ecosystem functions. However, EC data often contain long gaps, particularly in tropical dry forests (TDF) due to seasonality and El Niño-Southern Oscillation (ENSO) phases. These factors create high variability, complex dependencies, and dynamic flux footprints. No current gap-filling method adequately addresses long gaps in TDFs. This study introduces a novel framework for addressing this issue by (a) defining gap sizes by their relative percentages, (b) training, tuning, and evaluating two machine learning (ML) models: MissForest for short gaps and Prophet for intermediate and long gaps, and (c) predicting half-hourly EC data from 2013 to 2022 for six EC variables, where actual gap data sets ranged from 26.6% to 28.4%, at TDF in Costa Rica. Results indicate that MissForest excelled at filling short gaps (≤5%, <i>R</i>² = 0.76 and Nash-Sutcliffe efficiency (NSE) = 0.71), while Prophet performed exceptionally well for gaps between 5% and 10% (<i>R</i>² = 0.72 and NSE = 0.67). However, both models struggled with gaps between 10% and 13%. Validation showed <i>R</i>² values of 0.79, 0.88, and 0.77 for CO₂ flux, sensible heat flux, and latent heat flux, respectively, with corresponding NSE values of 0.78, 0.86, and 0.72, and normalized root mean squared error (NRMSE) around 2E-4. Additionally, to validate our results, we applied our approach at three EC sites with different ecological conditions, demonstrating robust performance. This study presents a reliable ML approach for imputing long gaps in EC data, which can be applied to sites with strong variability.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143118659","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}