Journal of Geophysical Research: Biogeosciences最新文献

{"title":"Carbon Burial (in)Efficiency: Tracking the Molecular Fingerprint of In Situ Organic Matter Burial Using a 30-Year Freeze-Core Series From a Northern Boreal Lake (Nylandssjön, Sweden)","authors":"Richard Bindler,&nbsp;Julie Tolu,&nbsp;Christian Bigler,&nbsp;Johan Rydberg,&nbsp;Antonio Martínez Cortizas","doi":"10.1029/2024JG008397","DOIUrl":"https://doi.org/10.1029/2024JG008397","url":null,"abstract":"<p>Organic carbon (OC) burial rates in northern lakes are estimated to have increased by 2–3 fold over the past 150 years. However, assessing OC burial efficiency is challenging because (a) long-term (decadal) process are difficult to study in situ, and (b) sediment organic matter (OM) consists of thousands of different compounds from both terrestrial and aquatic sources, which are subject to different degrees of degradation, transformation, or preservation. Here, we used pyrolysis–gas chromatography/mass spectrometry to track changes in the organic molecular composition of individual varve years in a series of sediment freeze cores collected during 1979–2010, allowing us to assess diagenetic changes over ≤31 years (or 12.5 cm depth). As predicted from previous work, the greatest losses over time/depth (18–19 years; 8.5 cm) are for compounds indicative of fresh OM, both terrestrial (e.g., levosugars with 58%–77% lost) and particularly aquatic origin (e.g., phytadiene and phytene amongst chlorophylls with 40%–82% lost). This high variability in degradation of specific compounds has implications for interpreting past changes in C and N. Although OM composition changes only slightly beyond 20 years (8.5 cm), the chlorophyll:lignin ratio (fresh vs. degraded compounds) continues to decline to 31 years (12.5 cm) and is predicted to continue up to 100 years (37 cm depth). In most northern lakes, indications of OM degradation to these depths correspond to sediment ages of 50 to &gt;150 years, suggesting that much of the recent increase in OC burial in northern lakes does not represent permanent sequestration of C.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008397","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530540","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 Deep Learning Approach of Artificial Neural Network With Attention Mechanism to Predicting Marine Biogeochemistry Data","authors":"Mingzhi Liu,&nbsp;Yipeng Wang,&nbsp;Guoqiang Zhong,&nbsp;Yongxin Liu,&nbsp;Xiaoqing Liu,&nbsp;Jifan Shi,&nbsp;Yangli Che,&nbsp;Rui Bao","doi":"10.1029/2024JG008386","DOIUrl":"https://doi.org/10.1029/2024JG008386","url":null,"abstract":"<p>Predicting marine biogeochemical data is an effective method to solve the problem of marine data-scarcity and provides data support for fundamental research in marine science. Machine learning techniques are commonly used to improve the stability and accuracy of predicting biogeochemistry data. However, current methods based on Random Forest (RF) and Artificial Neural network (ANN) often struggle to effectively capture the intricate features of ocean data, resulting in suboptimal prediction accuracy. In this study, we develop a novel deep learning method called artificial neural network with attention mechanism (ANN-att) for predicting marine biogeochemistry data. We compare and evaluate the performance of RF, ANN, and ANN-att based on two widely used ocean data sets in marine biogeochemistry: GLODAP v2.2022 and MOSAIC 2.0. Our results show that the prediction accuracy of the ANN-att method is higher than other methods by 6% for GLODAP v2.2022 and 30% for MOSAIC v.2.0. Additionally, the prediction maps of surface ocean dissolved oxygen and Δ¹⁴C in the West Pacific demonstrate that ANN-att has a significant advantage in predicting marine biogeochemistry data with stronger nonlinear characteristics.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530044","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":"In Situ Reduction of Fe(III) (Hydr)oxides-Bound As(V) via Electron Shuttling in the Presence of Organic Matter","authors":"Zhengqi Su,&nbsp;Huaming Guo,&nbsp;Zhipeng Gao,&nbsp;Tiantian Ke,&nbsp;Xiaojun Feng,&nbsp;Lingzhi Zhang","doi":"10.1029/2024JG008675","DOIUrl":"https://doi.org/10.1029/2024JG008675","url":null,"abstract":"<p>Although the reduction of pentavalent arsenic (As(V)) bound to Fe(III) (hydr)oxides (As(V)-containing FeOOH) coupled with organic matter (OM) degradation has received extensive attention, little is known about in situ reduction of FeOOH mineral-bound As(V) (As(V)_(s)) via electron shuttling in the presence of As(V)-reducing bacteria (AsRB). Here, anthraquinone-2,6-disulfonate (AQDS), Suwannee River humic acid (SRHA), and fulvic acid (SRFA) were used to establish an agar electron shuttle system with ferrihydrite-As(V)/goethite-As(V) and AsRB, which was isolated from high-As groundwater as the candidate strain (RA-1). We found that AQDS was more efficient in shuttling electrons to reduce As(V)_(s) and Fe(III) than SRHA and SRFA. High contents of quinone moieties in AQDS indicated that quinone moieties were conducive to As(V)_(s) and Fe(III) reduction. The reduction kinetic rates (<i>K</i>_red) of As(V)_(s) were higher than those of Fe(III), indicating the occurrence of in situ As(V)_(s) reduction via electron shuttling. Furthermore, <i>K</i>_red of As(V)_(s) for ferrihydrite-As(V) systems was greater than that of goethite-As(V) systems, demonstrating that As(V) bound to ferrihydrite via monodentate was more easily reduced than that bound to goethite via bidentate. The relative expression levels of As metabolic genes (<i>ars</i>C, <i>arr</i>A, and <i>ars</i>B) initially increased and then decreased in the late stage of experiments. High As concentrations in suspension inhibited the transcriptional activity of As metabolic genes in the late stage, reducing the electron production efficiency of RA-1 and subsequently slowing in situ reduction of As(V)_(s). This study highlights the importance of OM electron shuttling in the reduction of As(V)_(s), offering new perspectives in As enrichment in groundwater.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513845","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":"Novel Field Experiment on Alkalinity Enhancement in Intertidal Environments—A Trailblazer for Natural Climate Solutions","authors":"I. Mendes,&nbsp;J. Lübbers,&nbsp;J. Schönfeld,&nbsp;A. Baldermann,&nbsp;A. R. Carrasco,&nbsp;A. Cravo,&nbsp;A. Gomes,&nbsp;P. Grasse,&nbsp;F. M. Stamm","doi":"10.1029/2024JG008591","DOIUrl":"https://doi.org/10.1029/2024JG008591","url":null,"abstract":"<p>One recently proposed approach to reduce atmospheric CO₂ concentrations is marine alkalinity enhancement. This technique increases the CO₂ uptake capacity of seawater through weathering of fine-grained (mafic) rocks and minerals in marine environments. The weathering process has been extensively tested in laboratory studies and verified by numerical models. Field experiments scaling the CO₂ uptake under natural conditions are still lacking. In a methodological approach, a novel in situ experiment was designed and installed in a salt marsh at Ria Formosa coastal lagoon, southern Portugal. The experiment comprised deployments of different sizes of olivine and basalt substrates, and a control site, which were tidally submerged twice a day. A monthly monitoring scheme of supernatant and porewater properties from each deployment and control site was established, and procedures for temperature, salinity, oxygen, pH, total alkalinity, nutrient, and trace metal analyses were defined. This paper is devoted to the methods and describes the design, a protocol for the analyses, and an evaluation of experimental performance and reliability. Data from the first 6 months are presented for validation of the experiment. They demonstrated elevated total alkalinity in water samples, mostly in porewater after the deployments, while salinity, oxygen, and pH reflect the control conditions. Significant alkalinity differences were observed between the treatments and the natural background conditions monitored at the control site, during the 6 months of the experiment. The methodological approach is presented with strengths, limitations, and recommendations for an upscaling as CO₂ removal measure, servicing, and subsequent investigations.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008591","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513600","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":"Interplay of Seasonal Hydrology and Landscape Topography Drives Black Carbon Export in the Fraser River","authors":"Emily Brown,&nbsp;Sasha Wagner,&nbsp;Brian P. V. Hunt","doi":"10.1029/2024JG008627","DOIUrl":"https://doi.org/10.1029/2024JG008627","url":null,"abstract":"<p>Fire is an important driver of carbon cycling across terrestrial and aquatic ecosystems, but global fire regimes are changing. Black carbon (BC), a product of biomass burning, is more environmentally persistent than its parent biomass carbon and cycles differently than bulk organic carbon. This study aims to refine understanding of the environmental drivers of BC flux from land to ocean through year-long measurement of BC in the Fraser River in British Columbia, Canada. The Fraser River’s environmental context is distinct from systems that currently form the basis of understanding of BC export, characterized by highly seasonally variable hydrology, and with its basin spanning diverse ecosystems from glaciated mountainous regions to dry flatlands. We found that the Fraser River exported 18,765 ± 2,734 Mg yr⁻¹ of BC, with dissolved black carbon (DBC) comprising 3.3 ± 0.9% of annual dissolved organic carbon (DOC) flux, both lower than previous estimates would suggest. Strong seasonal variation in the DBC content of DOC and BC aromaticity were measured in the Fraser River. This reveals the importance of seasonal hydrology in the export of different pools of BC and indicates that seasonality and hydrologic regime should be given more consideration in future estimations of global riverine BC flux. These findings bring to light the importance of seasonality, hydrology, and basin topography in BC transport, with implications for global carbon cycles in a changing climate.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 3","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008627","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497371","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":"SOMnmR: An R Package for Analyzing CP MAS 13C NMR Spectra of Environmental Samples","authors":"Luis Carlos Colocho Hurtarte,&nbsp;Noelia Garcia-Franco,&nbsp;Gabriela Villalba Ayala,&nbsp;Joerg Prietzel,&nbsp;Ingrid Koegel-Knabner","doi":"10.1029/2024JG008288","DOIUrl":"https://doi.org/10.1029/2024JG008288","url":null,"abstract":"<p>Cross-polarization (CP) magic angle spinning (MAS) ¹³C NMR spectroscopy is a versatile tool for studying organic matter (OM) in soils. Despite its versatility, the extensive post-processing required—including spinning-sidebands (SSB) correction and integration—limits its broader use. We present a new open-source R package, “SOMnmR” (accessible on CRAN and GitHub), designed to quickly process a large number of spectra, correcting for SSBs if required. The package computes the relative abundance of functional groups and can also model organic matter composition using end-member compounds. We describe the package's installation and functionalities and provide examples that (a) compare the results of two different spectrometers and (b) model the results of a large CP MAS ¹³C NMR data set. Overall, the presented package is a valuable tool for the fast analysis of ¹³C NMR data sets.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475545","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":"Peatland Plant Community Changes in Annual Production and Composition Through 8 Years of Warming Manipulations Under Ambient and Elevated CO2 Atmospheres","authors":"P. J. Hanson,&nbsp;N. A. Griffiths,&nbsp;V. G. Salmon,&nbsp;J. M. Birkebak,&nbsp;J. M. Warren,&nbsp;J. R. Phillips,&nbsp;M. P. Guilliams,&nbsp;K. C. Oleheiser,&nbsp;M. W. Jones,&nbsp;N. J. Jones,&nbsp;J. Enterkine,&nbsp;N. F. Glenn,&nbsp;K. J. Pearson","doi":"10.1029/2024JG008511","DOIUrl":"https://doi.org/10.1029/2024JG008511","url":null,"abstract":"<p>The Spruce and Peatland Responses Under Changing Environments (SPRUCE) experiment has operated five whole-ecosystem warming manipulations (+0, +2.25, +4.5, +6.75, and +9°C) with paired ambient and elevated CO₂ atmospheres (eCO₂, +500 ppm) for 8 full calendar years (since August 2015). We tracked shrub-layer vegetation responses to the treatments using annual destructive plot sampling. Tree (<i>Picea</i> and <i>Larix</i>) responses were assessed annually using nondestructive dimensional analyses and allometric conversions. Shrub community changes were assessed for key ericaceous shrubs (<i>Rhododendron, Chamaedaphne,</i> and <i>Kalmia</i>), two <i>Vaccinium</i> species (<i>V. angustifolium, V. oxycoccos</i>), graminoid species (mostly <i>Eriophorum</i>), and one common forb (<i>Maianthemum trifolium</i>), plus minor understory species. We tracked annual aboveground net primary production (ANPP) for vascular plant species in gC m⁻² y⁻¹ and overall stand contribution in dry mass. We observed a linear increase in shrub-layer aboveground biomass accumulation with warming over time due primarily to an increase in ericaceous shrub abundance. Cumulative biomass increases across the shrub community showed overall positive responses to eCO₂ after 8 years. Community composition also changed with warming, with increases in woody shrub density, and the reduction or loss of forbs. The tree community showed minimal initial responses to warming early in the treatments, but since 2020, has shown significant increases in ANPP and individual tree growth with warming. The main driver of change in the vascular plant community was temperature, with less pronounced effects of eCO₂ evident. These results indicate an overall increase in ANPP with warming from both the tree and shrub layers of peatland vegetation.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008511","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446957","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":"Monitoring Peatland Condition and Restoration Sites Using Vertical Surface Motion Data From the European Ground Motion Service","authors":"M. P. Wilson","doi":"10.1029/2024JG008670","DOIUrl":"https://doi.org/10.1029/2024JG008670","url":null,"abstract":"<p>Vertical displacement data from satellite interferometric synthetic aperture radar (InSAR) can indicate peatland condition and can therefore be used for restoration site identification or monitoring programs. However, many peatland scientists and restoration practitioners lack InSAR expertise and do not have the financial resources available to purchase data processed by commercial third parties. Conversely, the European Ground Motion Service (EGMS) freely provides pre-processed vertical displacement data derived from the Sentinel-1 satellites. Using data covering the North Pennines National Landscape, England, this study is the first to investigate the potential for using EGMS Level 3 Ortho products to monitor landscape-scale peatland condition and the impacts of site-scale restoration. Linear regression analysis showed that, despite site restoration being considered successful based on visually extensive re-vegetation and water retention, the peatland is still subsiding at rates of −1.3 to −4.4 mm/year, likely because more time is needed for peat-forming <i>Sphagnum</i> spp. to re-colonize the site and exceed degradation rates. Nevertheless, there were indications that restoration interventions may be slowing subsidence in some areas and seasonally linked bog breathing may be returning to the site, which was absent prior to restoration efforts. The largest drawback of the EGMS Ortho products is their limited spatial coverage in rural vegetated locations, meaning peatlands are unlikely to receive the near-full coverage possible using advanced InSAR techniques. Nonetheless, where EGMS Ortho product coverage does exist, vertical displacement data can offer useful insight into the dynamic functionality of peatlands which cannot be obtained through monitoring programs based on visual observations.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438986","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":"Species-By-Species Pattern Analysis of Coastal Dune Vegetation","authors":"D. Demichele,&nbsp;E. Belcore,&nbsp;M. Piras,&nbsp;C. Camporeale","doi":"10.1029/2024JG008419","DOIUrl":"https://doi.org/10.1029/2024JG008419","url":null,"abstract":"<p>Vegetation is crucial for stabilizing and developing coastal dunes. Different plant species exhibit different spatial distributions which reflect their environmental role and adaptation strategy. This study aims to provide a fine-scale species-by-species analysis of vegetation spatial patterns on coastal dunes within the San Rossore–Migliarino–Massacciuccoli Regional Park (Tuscany, Italy). A comprehensive vegetation data set generated by an Object-Based Image Analysis (OBIA) algorithm applied to high-resolution ortho-images has been utilized. A Digital Terrain Model (DTM) of the study area was created to assess the impact of dune morphology on plant distribution. Moreover, a wave runup analysis was also conducted to understand the interaction between vegetation and hydrodynamic forces. The research highlights how the vegetation threshold distance from the coastline, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>L</mi>\u0000 <mi>veg</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${L}_{mathit{veg}}$</annotation>\u0000 </semantics></math>, is superimposed by the reaching distance of wave runup during extreme events. Terrain morphology significantly affects the vegetation zonation: on taller and undisturbed dunefields, species zonation is clearer and more defined, whereas, on flatter and disturbed ones, spatial distribution is significantly fuzzier. A positive correlation emerges between the abundance of a species and its degree of spatial clustering, indicating how less abundant species form more tightly clustered spatial patterns. Modified Ripley's L-function analysis revealed a multi-scale clustered pattern for most species under examination. The present results may provide a solid benchmark in coastal ecology research for supporting natural-based conservation plans and eco-morphodynamic modeling.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JG008419","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431173","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":"N2O Emission From a Subtropical Forest Is Dominantly Regulated by Soil Denitrifiers Under Exogenous N Enrichment and Seasonal Precipitation Distribution Change","authors":"Xiaoge Han,&nbsp;Changchao Xu,&nbsp;Xiangping Tan,&nbsp;Yanxia Nie,&nbsp;Jinhong He,&nbsp;Qi Deng,&nbsp;Weijun Shen","doi":"10.1029/2024JG008206","DOIUrl":"https://doi.org/10.1029/2024JG008206","url":null,"abstract":"<p>Nitrogen-rich tropical/subtropical forest soil acts as a terrestrial source of nitrous oxide (N₂O), a greenhouse gas commonly affected by soil nitrogen availability and soil moisture. However, in tropical and subtropical regions experiencing both elevated nitrogen deposition and altered precipitation regimes, it is unclear whether nitrogen deposition and precipitation regimes have interactive effects on forest soil N₂O emissions and what roles N₂O-associated nitrifiers/denitrifiers play in these interactions. We conducted a 2 year field study in a subtropical evergreen broadleaf forest in southern China by applying four treatments: nitrogen addition (N), seasonal precipitation distribution change (PC), both nitrogen addition and seasonal precipitation distribution change (NPC) and a control (C). We found that N₂O efflux from the forest soil was significantly greater in the wet season than in the dry season, but was promoted by 77.4% by the NPC treatment only in the dry season. Soil moisture and pH decreased in the PC and N treatments, respectively. The abundance of nitrifying gene AOA-<i>amoA</i> and denitrifying gene <i>nosZ</i> in the wet season and the abundance of denitrifying gene <i>nirK</i> in the dry season differed significantly among the four treatments. A structural equation model showed that precipitation change was more important than nitrogen addition in affecting soil properties (e.g., moisture and pH) and N₂O-associated nitrifiers/denitrifiers, while soil <i>nirK</i>- and <i>nosZ</i>-denitrifiers were the dominant functional microbes in regulating N₂O emissions. The results support predictions of future nitrogen losses (N₂O) in subtropical forests in the context of interactions between elevated nitrogen deposition and altered precipitation regimes.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":"130 2","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143404500","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}