Soil Biology & Biochemistry最新文献

{"title":"Plant species specific effects of root exudates on the formation and destabilization of soil organic matter","authors":"Fangbin Hou,&nbsp;Leonardo Hinojosa,&nbsp;Boris Jansen,&nbsp;Elly Morriën,&nbsp;Franciska T. de Vries","doi":"10.1016/j.soilbio.2026.110125","DOIUrl":"10.1016/j.soilbio.2026.110125","url":null,"abstract":"<div><div>Root exudates are labile organic carbon (C) compounds released by plants into soil that can stimulate both the decomposition and formation of soil organic matter (SOM) through enhancing microbial activity. Drought alters root exudation, potentially shifting the balance between the loss and formation of SOM fractions of particulate organic matter (POM), which often turns over faster in soil, and mineral-associated organic matter (MAOM), with a comparatively slower turnover. Here, we tested how root exudates from three grassland species, <em>Lolium perenne</em>, <em>Ranunculus acris</em>, and <em>Trifolium pratense</em>, grown under drought and well-watered conditions, affect soil microbial activity, community composition, and SOM distribution over POM and MAOM. We collected and repeatedly applied exudates to unconditioned soils over five months. We found that root exudates from <em>R. acris</em> and <em>T. pratense</em> promoted the decomposition of POM and concomitantly increased MAOM formation. Root exudates from drought-stressed <em>R. acris</em> and <em>T. pratense</em> did not affect POM and MAOM pools but enhanced microbial respiration, potentially through increased microbial nitrogen (N) limitation, as evidenced by an increased C/N ratio in POM, or through reduced microbial C use efficiency. These findings advance our understanding of the dual role of root exudates in the loss and formation of SOM pools and the potential effect of drought on these processes.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110125"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160812","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":"Glucose input limits microbial-mediated sulfur release from soil minerals","authors":"Min Zhang ,&nbsp;Zhuzhong Yin ,&nbsp;Yu Liu ,&nbsp;Yanyu Liu ,&nbsp;Zhenghua Liu ,&nbsp;Zhaoyue Yang ,&nbsp;Zhengqi Xu ,&nbsp;Ibrahim Ahmed Ibrahim ,&nbsp;Fenliang Fan ,&nbsp;Ye Deng ,&nbsp;Xueduan Liu ,&nbsp;Chengying Jiang ,&nbsp;Huaqun Yin ,&nbsp;Delong Meng","doi":"10.1016/j.soilbio.2026.110109","DOIUrl":"10.1016/j.soilbio.2026.110109","url":null,"abstract":"<div><div>Sulfur-bearing minerals are key reservoirs in the global sulfur cycle, and microorganisms mediate sulfur release from these minerals. Labile carbon inputs may modify microbial sulfur metabolism, but their net effects on sulfide mineral oxidation remain unclear. Here, we conducted a 56-day soil incubation with glucose input and combined geochemical measurements, mineralogical characterization, qPCR, metagenomics, 16S rRNA amplicon sequencing, and DNA-stable isotope probing (DNA-SIP) to identify glucose-assimilating microorganisms and their roles in regulating sulfide mineral oxidation. Glucose significantly suppressed sulfide mineral oxidation, resulting in 60.00% lower sulfate (SO₄²⁻) and a 33.23% higher pH than the control by day 56. Glucose also reshaped microbial community and functions potentials. Sulfur-oxidizing bacteria (SOB) decreased, sulfate-reducing bacteria (SRB) increased, and genes annotated in sulfur oxidation (<em>soxB</em>, <em>soxX</em>, <em>soxY</em>, <em>soxZ</em>) were depleted before day 42. This inhibition was reversed after glucose depletion, with sulfur oxidation genes becoming enriched. DNA-SIP using ¹³C-glucose linked <em>Frateuria</em> and <em>Dyella</em> to glucose assimilation and to the inhibitory phase of sulfur release. Glucose-amended microcosms maintained a lower redox potential and showed a delayed rise relative to the control, consistent with oxygen competition that may constrain sulfur oxidizers such as <em>Bradyrhizobium</em>. Notably, <em>Dyella</em> harbored a complete assimilatory sulfate reduction pathway, driven by ATP and NADPH produced through the central carbon metabolism (CCM). This metabolic coupling reduced oxygen availability for terminal sulfur oxidation, suggesting a dual mechanism of sulfur release suppression via both assimilatory reduction and respiratory competition. Our findings highlight a previously underappreciated link between labile carbon metabolism and sulfur cycling in soil. This mechanism offers insights into microbial controls over sulfur fluxes and presents implications for managing soil acidification and sulfur-driven water pollution in mineral-rich environments.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110109"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146116259","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":"Subsoil rhizosphere carbon enrichment and depletion: processes and scaling in tree-based systems","authors":"Gabin Piton ,&nbsp;Elisa Taschen ,&nbsp;Clara Ducrocq ,&nbsp;Soline Martin-Blangy ,&nbsp;Laurie Amenc ,&nbsp;Pauline Castel ,&nbsp;Damien Dezette ,&nbsp;Rémi Dugué ,&nbsp;Marion Forest ,&nbsp;Philippe Hinsinger ,&nbsp;Benoit Marie ,&nbsp;Aline Personne ,&nbsp;Manoël Seignon ,&nbsp;Jerôme Ngao ,&nbsp;Christophe Jourdan ,&nbsp;Isabelle Bertrand","doi":"10.1016/j.soilbio.2026.110103","DOIUrl":"10.1016/j.soilbio.2026.110103","url":null,"abstract":"<div><div>Tree roots have the potential to release carbon into deep soil layers, where this carbon is generally considered to exhibit greater stability. However, field studies that investigate the drivers of the soil organic carbon (SOC) balance in the rhizosphere of trees across soil depths and that upscale this balance to the whole soil profile are lacking. This study presents an innovative approach integrating normalized rhizosphere sampling and root density mapping to a depth of 1.5 m under trees from Mediterranean agroforestry and a tree plantation. The estimated SOC balance in the rhizosphere of the <em>Robinia pseudoacacia</em> trees varied from −38 kg C ha⁻¹ to +53 kg C ha⁻¹ at the different soil horizons, with a neutral balance at 0–0.3 m, a negative balance at 0.3–0.5 m and a positive balance at 0.5–1.0 m and 1.0–1.5 m of soil depth. When scaled up to the whole profile, the value was +50.6 kg C ha⁻¹ for the tree plantation and +72.4 kg C ha⁻¹ for the tree row for the agroforestry system, with no significant difference between these two estimates. The balance between hydrolytic and oxidative enzyme activities and between fungal guilds indicated increasing nutritional constraints for microbial saprotrophs at depth. In the subsoil, these nutritional constraints were locally attenuated in the rhizosphere, inducing a substantial increase in microbial abundance and triggering a pronounced shift from oligotrophic to copiotrophic communities, which in turn supported SOC enrichment. In the topsoil, the lower chemical complexity of substrates available to microorganisms increases susceptibility to saprotrophic activity, which likely underlies the observed neutral or negative SOC balances in the rhizosphere. This field study presents a scalable approach for quantifying the rhizosphere SOC balance in deep soil horizons and disentangling its biogeochemical drivers.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110103"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146057101","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":"Stand age and fire return interval shape soil microbial communities in young, postfire lodgepole pine stands","authors":"Arielle C. Link ,&nbsp;Thea Whitman ,&nbsp;Monica G. Turner","doi":"10.1016/j.soilbio.2026.110102","DOIUrl":"10.1016/j.soilbio.2026.110102","url":null,"abstract":"<div><div>As wildfire activity increases globally, understanding how soil microbial communities vary in young postfire forests and the effect of short fire-return intervals on these communities becomes increasingly important for anticipating postfire ecosystem function. We asked how soil bacterial and fungal communities varied during early postfire stand development in lodgepole pine (<em>Pinus contorta</em> var. <em>latifolia</em>) forests, and whether a short-interval (16 yr) reburn altered those trajectories. We sampled soils in 6-, 22-, and 34-year-old stands in Grand Teton National Park (Wyoming, USA) and used high-throughput sequencing to assess community composition, environmental drivers, and fire responsive taxa. Bacterial and fungal community composition shifted with stand age under typical fire return intervals. For fungi, Ascomycetes declined in relative abundance with stand age whereas Basidiomycetes increased, consistent with the expected increase in ectomycorrhizal fungi associated with lodgepole pine. Litter mass and soil nutrient properties explained 28.6 % and 23.9 % of variance in bacterial and fungal community composition, respectively. Following the short-interval stand-replacing fire, bacterial communities in 6-year-old stands closely resembled nearby stands (22-year-old) that did not reburn, whereas fungal communities more closely resembled nearby 6-year-old stands that burned in the historical long (&gt;100 yr) fire-return interval. These results suggest that microbial recovery during early stand development in postfire forests is shaped by changes in resource availability, and that short fire-return intervals may have greater effects on fungi than on bacteria.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110102"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072096","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":"Virus-inclusive microbial network relationships align with the stress gradient hypothesis in saline-alkali agroecosystems","authors":"Fang Li ,&nbsp;Linwei Wu ,&nbsp;Changlin Xu ,&nbsp;Shuwen Guo ,&nbsp;Jinhua Zhao ,&nbsp;Yi Wang ,&nbsp;Peipei Li ,&nbsp;Biao Zhu","doi":"10.1016/j.soilbio.2026.110123","DOIUrl":"10.1016/j.soilbio.2026.110123","url":null,"abstract":"<div><div>Salinization-alkalization is increasing globally, yet its impact on cross-kingdom microbial correlations remains poorly understood. Herein, cross-kingdom correlations among rhizosphere archaea, bacteria, fungi, and viruses in farmland subjected to gradient saline-alkali stress were investigated. By analyzing changes in the structure and network of rhizosphere soil microbiomes in the typical saline-alkali region of Northeast China, we demonstrated that: (1) Rhizospheric archaeal and viral α-diversity increased significantly with saline-alkali stress intensity. Beta-diversity of all four kingdoms (archaea, bacteria, fungi, and viruses) was strongly influenced by both stress intensity and crop genotype, with community divergence primarily shaped by plant sodium concentration. (2) The composition of rhizosphere viral communities varied across crop types and stress levels, with dominant viruses belonging to Cressdnaviricota (infecting eukaryotes), Phixviricota and Uroviricota (both infecting prokaryotes). (3) Under increasing saline-alkali stress, co-occurrence networks exhibited a rise in both overall and cross-kingdom positive correlations, supporting the Stress Gradient Hypothesis (SGH). Notably, significant increases in positive correlations were observed between viruses and fungi, viruses and bacteria. In addition, the proportion of within-kingdom positive correlations declined, suggesting intensified intra-kingdom competition. These findings refine the traditional SGH at the microbial scale by incorporating viral communities, providing critical theoretical guidance for identifying key microbial species in ecological networks. This advances the design of targeted microbial inoculants to enhance saline-alkali soil remediation and broader ecosystem restoration.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110123"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146152894","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":"Nitrogen partitioning between plant species and soil microbes in alpine heath","authors":"Ellen L. Fry ,&nbsp;Jonathan R. De Long ,&nbsp;Edward Ayres ,&nbsp;René van der Wal ,&nbsp;Richard D. Bardgett","doi":"10.1016/j.soilbio.2026.110127","DOIUrl":"10.1016/j.soilbio.2026.110127","url":null,"abstract":"<div><div>Nitrogen is rapidly taken up by plants and microbes, but questions remain as to which forms are preferred. Using <em>in situ</em> stable isotope labelling (¹³C and ¹⁵N), we show that co-existing plant species of alpine heath mainly take up ammonium and nitrate, passing ¹⁵N from root to shoot over time, leading to accumulated nitrogen in the shoots (over 10-fold increase compared with roots), with more complex organic nitrogen forms such as amino acids taken up to a lesser extent. Conversely, soil microbes preferred amino acids, potentially as a side-effect of satisfying their carbon requirements to build cellular structures. We show that competition for nitrogen can be alleviated by differing growth rates in plants and varying microbial preference of nitrogen forms.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110127"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146209546","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":"The ultimate fraction – Chemical characterization of humins from forest vs grassland soils","authors":"Pere Rovira ,&nbsp;Beatrice Giannetta ,&nbsp;Joeri Kaal ,&nbsp;Agustín Merino ,&nbsp;César Plaza ,&nbsp;Claudio Zaccone","doi":"10.1016/j.soilbio.2026.110118","DOIUrl":"10.1016/j.soilbio.2026.110118","url":null,"abstract":"<div><div>Humin, defined as the residual fraction of soil organic matter remaining after alkaline extraction, has been recognized as the predominant and most stable form of organic matter in mineral soils for centuries. Consequently, it is imperative to reconsider this at the modern instrumental level, as the current evidence about its composition is primarily influenced by the analytical methods applied. Here, humin was recovered from the &lt;20 μm organo-mineral fraction of forest and grassland topsoils after exhaustive sequential extractions. On average, humin accounted for ∼36 % of the total organic carbon (C) in the organo-mineral complex in grassland soils, and for &gt;50 % in forest soils. Obtained humins were then investigated by ¹³C-NMR, Pyrolysis-GC-MS, THM-GC-MS, acid hydrolysis followed by monosaccharide detection and quantification, and thermal analyses (DTG and DSC). The studied humins consisted of a broad mixture of C types, including alkyl C (∼34 %) and <em>O</em>-alkyl C (∼30 %), while they were remarkably poor in carboxyl C, which may explain their insolubility in alkali solutions. Overall, humins from forest soils seemed more microbially transformed than those from grassland soils. In particular, carbohydrates were mainly of microbial origin, lipids preserved the features of their original precursors (suberin, epicuticular waxes), whereas the degree of preservation of lignins was unclear. Carbon recalcitrance, measured by acid hydrolysis, was higher in forest humins (40 %) than in grassland humins (34 %). At the same time, humins from forests showed a lower thermal stability than those from grasslands, but were characterized by a higher energy density. Contrary to views that propose a humin composition predominantly aromatic, alkyl or poly-alkyl in nature, our study showed that humins are highly chemodiverse, containing a wide range of organic compounds, none of them being predominant. Their degree of microbial reworking varied with vegetation type and, thus, with corresponding plant inputs; on a larger scale, it probably varies with climate and parent material, a hypothesis to verify in future research.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110118"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138618","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":"Microsites support microbial sulfate reduction in upland soils","authors":"Laura T. Rea ,&nbsp;Clifford Adamchak ,&nbsp;Jacqueline R. Gerson ,&nbsp;Magdalena A. Franchois ,&nbsp;Hans Røy ,&nbsp;Eve-Lyn S. Hinckley","doi":"10.1016/j.soilbio.2026.110121","DOIUrl":"10.1016/j.soilbio.2026.110121","url":null,"abstract":"<div><div>Agricultural sulfur (S) inputs are a primary source of anthropogenic S to the environment, often stimulating microbial sulfate reduction (MSR) in downstream environments and driving multiple ecosystem consequences. Because it is assumed that bulk oxygenated soils do not support reduction processes, MSR is typically only studied in saturated environments like downstream wetlands. Here, we investigated MSR activity and its spatial distribution within soil profiles experiencing different hydrologic conditions (dry, moist, saturated) across Napa Valley, California, USA, where elemental S is added to vineyards as a fungicide. Using a combination of ³⁵S-sulfate radioisotope tracer methods and silver film imaging, we observed the highest sulfate reduction rates (SRRs) (22.10 ± 61.02 nmol cm⁻³ soil day⁻¹) in small microsites during moist conditions, and lower SRRs (0.90 ± 2.05 nmol cm⁻³ soil day⁻¹) in diffuse zones during saturated conditions. Our findings suggest that MSR activity within upland soils shifts between microsites with high SRRs during moist conditions, and diffuse zones with lower SRRs during saturated conditions. Remarkably, we also found evidence that microsites with MSR persisted during dry conditions, further challenging the conventional view that MSR is restricted to bulk anoxic environments. Our findings highlight the potential for upland soils to be important areas of S transformations within the human-altered S cycle.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110121"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138617","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":"Functional trait diversity in overstorey and understorey increases microbial carbon use efficiency in a forest plantation soil","authors":"Renping Wan ,&nbsp;Junxi Hu ,&nbsp;Huan Xiao ,&nbsp;Zhe Li ,&nbsp;Jingnan Xu ,&nbsp;Bo He ,&nbsp;Lanlan Song ,&nbsp;Lifeng Wang ,&nbsp;Jian Peng ,&nbsp;Xiaoyan Yu ,&nbsp;Xiaolin Li ,&nbsp;Lihua Tu ,&nbsp;Yang Liu ,&nbsp;Dongyu Cao ,&nbsp;Xinglei Cui ,&nbsp;Xinhua He ,&nbsp;Congde Huang ,&nbsp;Shixing Zhou ,&nbsp;Yakov Kuzyakov","doi":"10.1016/j.soilbio.2026.110119","DOIUrl":"10.1016/j.soilbio.2026.110119","url":null,"abstract":"<div><div>Soil microbial carbon (C) use efficiency (CUE) is a critical parameter in C cycling process, but its relationship with aboveground plant communities remains largely unexplored. This study examines how vegetation composition and functional diversity influence microbial CUE_ST assessed by enzyme stoichiometry-based approach in soils across four subtropical plantation types. We hypothesized that: (i) the effects of overstorey tree and understorey plant diversity on CUE_ST are shaped by multiple community- and ecosystem-level functional dimensions: dispersions, means, variances, skewness, and kurtosis; and (ii) CUE_ST is influenced by resource limitations (mainly C and phosphorus, P) in soil. While soil microorganisms in all four plantations were co-limited by C and P, plantations with higher plant diversity have much lower C and P limitations compared to those with lower plant diversity. Across all plantations, plant community attributes, functional traits, and physico-chemical and microbial soil properties affect CUE_ST variation. Specifically, greater functional diversity in overstorey trees and understorey plants effectively reduces microbial C and P limitations and increases CUE_ST. The community-weighted contents of leaf nitrogen (N) and P affected CUE_ST variation more compared to other measures. These findings indicate that plant community composition and functions are critical to regulate CUE_ST and resource limitations. The results highlight that maintaining a functionally diverse overstorey and understorey vegetation is crucial to increasing soil C accumulation in soils of subtropical forest plantations.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110119"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146138616","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":"Root exudate-induced priming of CO2 and CH4 in a thawing permafrost peatland","authors":"Marie Mollenkopf ,&nbsp;Sylvain Monteux ,&nbsp;Ellen Dorrepaal ,&nbsp;Birgit Wild ,&nbsp;Joachim Kilian ,&nbsp;Mark Stahl ,&nbsp;Andreas Kappler ,&nbsp;E. Marie Muehe","doi":"10.1016/j.soilbio.2026.110110","DOIUrl":"10.1016/j.soilbio.2026.110110","url":null,"abstract":"<div><div>Arctic permafrost faces multiple interactive changes in thaw, drainage, and vegetation shift due to climate warming. Thaw-induced waterlogging can shift vegetation from shrubs to graminoids, altering greenhouse gas emissions. This study aims to quantify and mechanistically explain how vegetation-specific root exudates amplify or dampen greenhouse gas emissions from Arctic permafrost during thaw and drainage transitions. Using field observations and soil incubations, we show that environmentally relevant concentrations of root organic exudates (15% of dissolved organic carbon), obtained from thaw stage-specific plants, altered greenhouse gas fluxes under site-realistic redox conditions. Graminoid exudates were richer in sugars and carboxylates, whereas shrub exudates were richer in amino acids. In thawed, anoxic permafrost soil incubations, graminoid exudates stimulated the emission of 51% more CO₂ and 83% more CH₄ compared to the absence of exudates. In intact, drained permafrost soil, shrub exudates stimulated 14% more CO₂ and negligible CH₄ compared to untreated soils. Geochemical and microbial analyses revealed that soil, including their hydrology, and exudate differences drove exudate and soil organic matter decomposition. These soil incubation findings were supported by field measurements: Bare locations per soil-habitat provided baseline greenhouse gas fluxes in relation to each soil's properties of moisture and geochemistry. Vegetation by graminoids increased greenhouse gas emissions from thawed permafrost soils significantly while shrubs barely affected greenhouse gas emissions from drained permafrost soils. Collectively, this study shows that thaw-specific vegetation shapes greenhouse gas fluxes, indicating that vegetation shifts can intensify radiative forcing beyond the known direct effect of permafrost thaw and associated hydrological transitions. Clarifying the context-dependence and mechanisms underlying these distinct exudate effects may improve projections of Arctic terrestrial climate feedback.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110110"},"PeriodicalIF":10.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146115735","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}