Soil Biology & Biochemistry最新文献

{"title":"Post-drought organic carbon mineralization leads to high productivity and nutrient uptake efficiency of perennial grassland after rewetting","authors":"Marie-Louise Schärer ,&nbsp;Lucia Fuchslueger ,&nbsp;Alberto Canarini ,&nbsp;Andreas Richter ,&nbsp;Andreas Lüscher ,&nbsp;Ansgar Kahmen","doi":"10.1016/j.soilbio.2025.109744","DOIUrl":"10.1016/j.soilbio.2025.109744","url":null,"abstract":"<div><div>Grasslands often recover well from drought, with some even surpassing non-drought-stressed controls in productivity long after drought release. However, the mechanisms responsible for such post-drought productivity outperformance remain unclear. In this study we examine how rewetting after drought influences important short- and longer-term soil microbial processes (i.e. nitrogen mineralization, potential enzyme activities) and consequent plant nutrient availability and uptake. For this, a field experiment was set up where an established perennial ryegrass sward under different N-fertilization levels was subjected to either a 2-month experimental summer drought followed by rewetting or to rainfed control conditions.</div><div>Rewetting after drought led to an immediate pulse in gross N-mineralization and NH₄-consumption rates. Both rates increased by &gt;230% and &gt;430% in formerly drought-stressed subplots compared to controls in plots not N-fertilized and N-fertilized during drought, respectively. Importantly, gross N mineralization rates correlated significantly with extractable soil organic carbon contents at the end of drought. Concurrently, drought and rewetting significantly increased NO₃–N, P, K, S, Fe, Zn, and Mn availability during the 1st but not the 2nd month after rewetting, except for K. Aboveground productivity of perennial ryegrass responded positively to NO₃–N availabilities during the 1st month after rewetting, leading to productivity outperformance of formerly drought-stressed plots compared to controls. These results suggest that short-term productivity outperformance of perennial grasslands in the 1st month after rewetting is driven by an increase in NO₃–N availability caused by a rewetting-induced pulse in N-mineralization of organic substrates accumulated during drought. Although effects of drought and rewetting on nutrient availability were only observed in the 1st month after rewetting, grassland productivity outperformance persisted in the 2nd month after rewetting. This indicates that soil drought legacy increased plant nutrient uptake efficiency, explaining longer-term outperformance effects when effects of drought and rewetting on nutrient availability were no longer apparent.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"204 ","pages":"Article 109744"},"PeriodicalIF":9.8,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grazing exclusion enhanced the capability of soil microorganisms to access photosynthetic carbon in Loess Plateau grassland","authors":"Yao Li ,&nbsp;Kate Buckeridge ,&nbsp;Baorong Wang ,&nbsp;Qian Huang ,&nbsp;Chunhui Liu ,&nbsp;Yuanjia Chen ,&nbsp;Alberto Vinicius S. Rocha ,&nbsp;Shaoshan An","doi":"10.1016/j.soilbio.2025.109743","DOIUrl":"10.1016/j.soilbio.2025.109743","url":null,"abstract":"<div><div>Photosynthetic carbon (C) has a pivotal role in the C cycle of the plant-soil system, contributing significantly to soil organic C (SOC) accrual. Grassland soils have a large capacity to store organic C and grazing is an important factor influencing the C cycle, but few studies have quantitatively how grazing exclusion affects the transfer of photosynthetic C in a plant-soil-microbial system. We used <em>in situ</em> isotope pulse-chase methodology to study photosynthetic C allocation patterns in the grazed and grazing-excluded grassland soil of the Loess Plateau, China. Grazing exclusion increased the total assimilated ¹³C by 46% compared with the grazed grassland, but did not significantly change the ¹³C allocated to the aboveground (75%) and belowground (25%) plant biomass. The ¹³C transferred faster to soil via root exudates in the grazed soil with lower aboveground biomass, suggesting that removal of aboveground biomass by grazing animals influences the rate of C transfer. Most (79%) the SOC gained from grazing exclusion accumulated in the mineral associated organic C (MAOC) pool, which is a stronger predictor of SOC accrual than particulate organic C (POC). Grazing exclusion increased the transformation of POC to MAOC, mainly through the accumulation of microbial necromass. Grazing exclusion significantly reduced the G+/G- ratio and the fungal/bacteria ratio, indicating a shift in soil microbial community composition in favor of bacteria over fungi under grazing exclusion. Grazing exclusion increased the microbial biomass by 48% and significantly enhanced the capability of soil fungi and G- bacteria to access photosynthetic C. In summary, grazing exclusion increases the magnitude of C transfer from the atmosphere to soil microbial biomass, and the gradual conversion of POC to MAOC.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109743"},"PeriodicalIF":9.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy and matter dynamics in an estuarine soil are more sensitive to warming than salinization","authors":"Shang Wang ,&nbsp;Bahar S. Razavi ,&nbsp;Sandra Spielvogel ,&nbsp;Evgenia Blagodatskaya","doi":"10.1016/j.soilbio.2025.109742","DOIUrl":"10.1016/j.soilbio.2025.109742","url":null,"abstract":"<div><div>Rising salinization of extended river-sides and estuary areas due to climate warming might alter microbial metabolic activity and cause unpredictable consequences for matter and energy turnover in soil. Therefore, we investigated the combined effects of salinization and warming on microbial activity and growth, examining CO₂ emissions (matter loss) and heat production (energy loss) during glucose metabolism. Soil from Elbe estuary was artificially salinized to medium (2.06 mS cm⁻¹) and high (3.45 mS cm⁻¹) levels, and ambient low salinity soil (0.93 mS cm⁻¹) served as the control. We examined the influence of a comprehensive +2 °C climate warming (20 vs. 22 °C) on soil respiration (CO₂ emission), heat release, enzyme kinetics (cellobiohydrolase, β-glucosidase, acid phosphomonoesterase and leucine-aminopeptidase) and microbial carbon use efficiency (CUE) across the microbial growth.</div><div>Increasing salinity did not impact respiration, heat release, microbial C and N content without glucose addition. However, activation of microorganisms with glucose brought force to the effect of salinity, and increasing salinity consistently retarded substrate uptake and growth. 2 °C warming affected substrate uptake and growth much more than increasing salinity. The calorespirometric ratio increased by 81–124% under high salinity compared to low salinity, with most of this increase occurring during the growth retardation stage. Enzyme activities increased by 68%–871% during the lag phase and remained relatively high throughout both the growth and retardation stages, regardless of salinity and temperature levels, suggesting the resistance of soil hydrolytic enzymes. The CUE gradually decreased and stabilized only at the very end of microbial growth, emphasizing the importance of considering the growth retardation for CUE estimation. Remarkably, disregarding the growth retardation stage resulted in a strong overestimation of the CUE accounting for 70%–98%. Our results highlight the importance of estimating the carbon budget of microbial growth by considering its dynamics when modeling carbon sequestration under global climate change.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"204 ","pages":"Article 109742"},"PeriodicalIF":9.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial carbon use efficiency of mineral-associated organic matter is related to its desorbability","authors":"Alexander Konrad ,&nbsp;Diana Hofmann ,&nbsp;Jan Siemens ,&nbsp;Kenton P. Stutz ,&nbsp;Friederike Lang ,&nbsp;Ines Mulder","doi":"10.1016/j.soilbio.2025.109740","DOIUrl":"10.1016/j.soilbio.2025.109740","url":null,"abstract":"<div><div>Interactions between organic substances, minerals, and microorganisms are crucial for organic carbon (OC) stabilization in soil. We hypothesized that thresholds of sorption strength (described by the sorption coefficient of the Freundlich isotherms) and desorbability (i.e., the ratio of the amount desorbed to the amount sorbed) of organic monomers control the extent of their microbial processing.</div><div>Freundlich sorption isotherms and desorbability of uniformly ¹⁴C-labeled glucose, acetylglucosamine, phenylalanine, salicylic acid, and citric acid onto goethite, kaolinite, and illite were studied in batch experiments. Monomers adsorbed to minerals were mixed with loamy and sandy arable topsoil and incubated at 25 °C. Mineralization of mineral-adsorbed monomers was observed over three weeks, after which the assimilation into microbial biomass, and the ¹⁴C remaining in soil were quantified. Subsequently, the mineralization of incubated soils was observed for additional three weeks after glucose priming.</div><div>The adsorption of carboxylic acids onto minerals exceeded that of (amino) sugars and phenylalanine, with the overall highest amounts both adsorbed and retained after desorption with water for goethite. Assimilation of monomer ¹⁴C into microbial biomass and the microbial carbon use efficiency (CUE) of mineral-adsorbed monomers in both soils increased linearly with the monomer desorbability from mineral phases. Furthermore, the CUEs of monomers adsorbed to goethite were lower than those of the same monomers adsorbed to clay minerals. In terms of total amount of carbon retained in the soil, carboxylic acids adsorbed on goethite showed highest values, emphasizing the significance of oxides for the stabilization of OC within soils. Priming of incubated soil with non-labeled glucose caused an additional mineralization of monomer-C, with the priming effect decreasing from goethite to clay minerals.</div><div>We conclude that sorption strength and desorbability shape microbial utilization of mineral-bound organic compounds, but no universal thresholds determine bio-accessibility of sorbed organic compounds.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109740"},"PeriodicalIF":9.8,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143371532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interactions between earthworm species and soil type influence the porosity of earthworm casts","authors":"Issifou Amadou ,&nbsp;Arnaud Mazurier ,&nbsp;Laurent Caner ,&nbsp;Yacouba Zi ,&nbsp;Cornelia Rumpel ,&nbsp;Nicolas Bottinelli","doi":"10.1016/j.soilbio.2025.109739","DOIUrl":"10.1016/j.soilbio.2025.109739","url":null,"abstract":"<div><div>Earthworms significantly influence soil structure and associated ecosystem services, but the effect of different earthworm species and soil types on the physical organization of casts remains poorly understood. This study aims to shed light on the importance of earthworm species, soil type and their interactions in shaping cast microstructure. Using a microcosm experiment and X-ray microtomography image analysis, we examined the porosity and pore connectivity of casts produced by nine different temperate earthworm species in two contrasting soil types (Alluviosol and Cambisol). Our results showed that generally casts were characterized by lower overall porosity (reduced by 39–86% in Cambisol and 14–64% in Alluviosol) and pore connectivity (up to 76% lower in Cambisol) than control aggregates formed without earthworm activity, but they showed higher bioporosity (up to 50%). Both, earthworm species and soil type influenced pore properties, and the interaction of both explained most of the variability. In addition, we found no clear link between ecological categories of earthworms and the cast pore characteristics, highlighting the difficulty of generalizing species effects on cast microstructural properties. These results call for more nuanced approaches in future research to better predict earthworm effects on physical soil properties and resulting ecosystem services, considering both species-specific traits and their interactions with different soil environments.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109739"},"PeriodicalIF":9.8,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143257888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preferential use of organic acids over sugars by soil microbes in simulated root exudation","authors":"Julia Wiesenbauer ,&nbsp;Stefan Gorka ,&nbsp;Kian Jenab ,&nbsp;Raphael Schuster ,&nbsp;Naresh Kumar ,&nbsp;Cornelia Rottensteiner ,&nbsp;Alexander König ,&nbsp;Stephan Kraemer ,&nbsp;Erich Inselsbacher ,&nbsp;Christina Kaiser","doi":"10.1016/j.soilbio.2025.109738","DOIUrl":"10.1016/j.soilbio.2025.109738","url":null,"abstract":"<div><div>Sugars and organic acids, primary components in plant root exudates, are thought to enhance microbial decomposition of organic matter in the rhizosphere. However, their specific impacts on microbial activity and nutrient mobilisation remain poorly understood. Here, we simulated passive root exudation to investigate the distinct effects of sugars and organic acids on microbial metabolism in the rhizosphere. We released ¹³C-labelled sugars and/or organic acids via reverse microdialysis into intact meadow and forest soils over 6-h. We measured substrate-induced microbial respiration, soil organic matter mineralization, metabolite concentrations, and substrate incorporation into lipid-derived fatty acids. Our results reveal a pronounced microbial preference for organic acids over sugars, with organic acids being removed faster from the exudation spot and preferentially respired by microbes. Unlike sugars, organic acids increased concentrations of microbial metabolic byproducts and cations (K, Ca, Mg) near the exudation spot. Our results challenge the prevailing assumption that sugars are the most readily available and rapidly consumed substrates for soil microbes. Microbial preference for organic acids indicates a trade-off between rapid biomass growth and ATP yield. Our findings underscore the significant role of exudate composition in influencing microbial dynamics and nutrient availability, and emphasize the importance of biotic and abiotic feedback mechanisms in the rhizosphere in regulating root exudation.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109738"},"PeriodicalIF":9.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143191739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic cropping systems alter metabolic potential and carbon, nitrogen and phosphorus cycling capacity of soil microbial communities","authors":"Hans-Martin Krause ,&nbsp;Ralf C. Mueller ,&nbsp;Martina Lori ,&nbsp;Jochen Mayer ,&nbsp;Paul Mäder ,&nbsp;Martin Hartmann","doi":"10.1016/j.soilbio.2025.109737","DOIUrl":"10.1016/j.soilbio.2025.109737","url":null,"abstract":"<div><div>Intensive agriculture can impair soil quality and threaten the provision of critical soil ecosystem services. Organic cropping systems aim to ensure sustainable production by promoting soil biodiversity to enhance soil functioning and regulate nutrient cycling through microbial processes. While taxonomic changes in microbial community composition in response to agricultural management are well described, there is still a fundamental knowledge gap when it comes to the impact of cropping system on soil functional diversity. Therefore, we revisited the 42-year-old DOK field experiment and used shotgun metagenomics to assess the metabolic potential and nutrient cycling capacities in organic and conventionally managed soils. The functional annotation of 11.4 billion reads to universal (EC, SEED), as well as carbon (CAZy), nitrogen (NCycDB) and phosphorus (PCycDB) cycling gene ontologies showed that manure fertilization was the main factor altering soil metabolic potential. But also, organic management practices, such as omission of synthetic pesticides and mineral fertilization induced changes in soil metabolic potential e.g. by enriching functional genes involved in organic phosphorus acquisition, nitrate transformation, organic degradation and non-hydrolytic carbohydrate cleavage. Conventional systems, receiving mineral fertilization and chemical plant protection, enriched genes associated with inorganic nutrient acquisition and transcriptional activity. The results of this study demonstrate that cropping systems influence the functional potential of soils, affecting fundamental mechanisms of nutrient cycling and thus soil regulating capacity. Consequently, cropping systems can be utilized to steer the regulating potential of agricultural soils and to lower the environmental impact of food systems.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109737"},"PeriodicalIF":9.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143124394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Input of high-quality litter reduces soil carbon losses due to priming in a subtropical pine forest” [Soil Biology and Biochemistry 194 (2024) 109444]","authors":"Shiting Li ,&nbsp;Maokui Lyu ,&nbsp;Cui Deng ,&nbsp;Wei Deng ,&nbsp;Xiaohong Wang ,&nbsp;Anne Cao ,&nbsp;Yongmeng Jiang ,&nbsp;Jueling Liu ,&nbsp;Yuming Lu ,&nbsp;Jinsheng Xie","doi":"10.1016/j.soilbio.2024.109652","DOIUrl":"10.1016/j.soilbio.2024.109652","url":null,"abstract":"","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"201 ","pages":"Article 109652"},"PeriodicalIF":9.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A global meta-analysis of soil respiration in response to elevated CO2","authors":"Junjie Liu ,&nbsp;Bo Fan ,&nbsp;Zhongyi Sun ,&nbsp;Abing Duan ,&nbsp;Licong Dai","doi":"10.1016/j.soilbio.2025.109734","DOIUrl":"10.1016/j.soilbio.2025.109734","url":null,"abstract":"<div><div>Soil respiration (<em>R</em>_s) is a crucial component of the terrestrial ecosystem carbon (C) cycle, which significantly regulates atmospheric CO₂ concentrations. Although previous studies have suggested potential impacts of rising atmospheric CO₂ concentrations on <em>R</em>_s, most of these studies are limited in geographic distribution and variability in CO₂ exposure techniques. Globally, particularly across climatic conditions and vegetation types, resulting in the response of <em>R</em>_s to elevated CO₂ (eCO₂) remains poorly understood. In this study, 1191 paired observations from 207 published experimental eCO₂ studies were synthesized to quantify the response of <em>R</em>_s and its related factors to eCO₂. The results showed that eCO₂ significantly increased root biomass (32%), soil organic carbon (SOC, 3.6%), and soil water content (SWC, 9.6%), leading to an overall increase in <em>R</em>_s by 23%. Moreover, the impacts of eCO₂ on <em>R</em>_s varied significantly across climate conditions and vegetation types. The positive effects of eCO₂ on <em>R</em>_s in humid regions (26%) were higher than that in arid regions (14%), primarily due to differences in climatic conditions. Furthermore, eCO₂ increased <em>R</em>_s in forest ecosystems (28%) was higher than that in grassland ecosystems (15%). Additionally, <em>R</em>_s was positively correlated with the magnitude of eCO₂. However, the response of <em>R</em>_s to eCO₂ duration exhibited a convex relationship, indicating that the positive effect of CO₂ on <em>R</em>_s may diminish when extended experimental durations. Our findings suggest that the effects of eCO₂ on <em>R</em>_s will vary significantly across ecosystems and climate regions. In summary, our study provides a scientific basis for enhancing the accuracy of soil C cycling models and informing effective climate change policies.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109734"},"PeriodicalIF":9.8,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of iron-organic carbon associations shifts net greenhouse gas release after initial permafrost thaw","authors":"Eva Voggenreiter ,&nbsp;Laurel ThomasArrigo ,&nbsp;Joachim Kilian ,&nbsp;Daniel Straub ,&nbsp;Maike Friedel ,&nbsp;Mark Stahl ,&nbsp;Andreas Kappler ,&nbsp;Prachi Joshi","doi":"10.1016/j.soilbio.2025.109735","DOIUrl":"10.1016/j.soilbio.2025.109735","url":null,"abstract":"<div><div>In thawing permafrost soils, associations between organic carbon (OC) and ferric iron (Fe(III)) (oxyhydr)oxide minerals may stabilize OC in recently thawed soil layers, thus limiting the microbially mediated release of greenhouse gases (GHGs) such as carbon dioxide (CO₂) and methane (CH₄). Conversely, the development of anoxic conditions during thaw could lead to the microbial reductive dissolution of these Fe(III)-OC associations, resulting in a mobilization of the associated OC with unknown consequences for GHG release. In this study, we investigated the role of Fe(III)-OC associations (in the form of Fe(III)-OC coprecipitates) in soil GHG release during the collapse of previously oxic permafrost soils (“palsa”) and the inundation of seasonally anoxic soils (“bog”) at Stordalen Mire (Abisko, Sweden). We performed anoxic microcosm experiments using these two soils with the addition of ⁵⁷Fe-labeled Fe(III)-OC coprecipitates. The coprecipitates were reduced entirely after 42 days, with rapid reductive dissolution of 22 ± 7% and 20 ± 7% of coprecipitates within 1 day in palsa and bog soils, respectively. Emissions of GHG varied depending on soil type: in case of the palsa soil, cumulative CO₂ emissions increased by 43 ± 16% after addition of the Fe(III)-OC coprecipitates compared to a non-amended control, due to microbial Fe(III) reduction coupled to OC oxidation and likely additional OC input due to the release of Fe-bound OC. Concurrently, we observed an increase in activity of fermenting and complex OC-degrading microorganisms. Within the bog soil, it was notable that CH₄ emissions were temporarily suppressed, likely due to inhibition of methanogenesis by microbial Fe(III) reduction of the added coprecipitates, indicated by a decrease in <em>mcrA</em> gene copies. In conclusion, our findings demonstrate that Fe(III)-OC associations do not provide protection for OC after establishment of anoxic conditions during permafrost thaw, with resulting GHG emissions controlled by previous redox status of the soils and the microbial community.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109735"},"PeriodicalIF":9.8,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}