Geoderma最新文献

{"title":"The interplay of aboveground and belowground biodiversity drives the soil multifunctionality of hummock wetlands","authors":"Xiaoai Cao ,&nbsp;Huamin Liu ,&nbsp;Rui Zhang ,&nbsp;Yunhao Wen ,&nbsp;Linqian Ma ,&nbsp;Zhichao Xu ,&nbsp;Lu Wen ,&nbsp;Yi Zhuo ,&nbsp;Dongwei Liu ,&nbsp;Lixin Wang","doi":"10.1016/j.geoderma.2026.117708","DOIUrl":"10.1016/j.geoderma.2026.117708","url":null,"abstract":"<div><div>Hummock wetlands are important ecosystem components for maintaining biogeochemical cycles and biodiversity. Currently, there remains a lack of systematic understanding of how hummock microtopography regulates soil multifunctionality (SMF). This study investigated 11 hummock wetlands in the Inner Mongolia Plateau. By comparing and analyzing the influence of hummocks (vs. hollows) on SMF and its nutrient cycling function, the synergistic regulatory mechanism of aboveground and underground biodiversity was revealed. The results showed that hummock significantly increased key single functional indicators such as SOC, URE, β-GC, aboveground biomass (AB), and underground biomass (UB) (<em>P</em> &lt; 0.05), thereby significantly enhancing SMF. Especially in the functions of the carbon cycling, plant growth, and microbial activity (<em>P</em> &lt; 0.05). Linear fitting analysis indicated that plant species richness was significantly positively correlated with SMF (<em>P</em> = 0.031), while microbial diversity, especially fungal diversity (Sob index, Shannon index, and ACE index), had a higher explanatory power for SMF (<em>P</em> &lt; 0.05). The structural equation model showed that microtopography drives SMF by altering soil water content and, at the same time, by influencing soil pH and thereby affecting plant diversity. Furthermore, given the high explanatory power of fungal diversity for SMF, it was further identified that saprophytic fungi (such as Titaea, Dactylonectria, and Collarina) play key ecological functions in the process of organic matter decomposition and nutrient turnover. This study emphasizes the significance of protecting the heterogeneity of microtopography and the diversity of plants for the maintenance and restoration of wetland functions, providing a theoretical basis for the management of high-latitude wetlands.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117708"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074599","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":"Experimental study of rainfall and inflow characteristics effects on gully head erosion on the Loess Plateau","authors":"Chengcheng Jiang ,&nbsp;Zhao Jin ,&nbsp;Wen Fan ,&nbsp;Ningyu Yu ,&nbsp;Enlong Liu","doi":"10.1016/j.geoderma.2026.117682","DOIUrl":"10.1016/j.geoderma.2026.117682","url":null,"abstract":"<div><div>Gully head erosion is considered a major form of soil degradation on the Loess Plateau, where distinctive topographic conditions promote runoff convergence during rainfall events and consequently intensify gully head retreat. However, systematic monitoring approaches and mitigation mechanisms under the combined effects of rainfall and inflow remain insufficiently understood. The objectives of this study are to reveal the synergistic mechanisms of rainfall and inflow driving gully head erosion through field experiments, and to establish hydrodynamic critical thresholds governing gully head erosion, thereby providing new insights for predicting erosion at the gully head by integrating topographic and hydraulic conditions. Through systematic field experiments, it was revealed that soil loss increased proportionally with both the rainfall intensity and the inflow rate. Moreover, catchment characteristics are the dominant factors influencing erosion dynamics at gully heads, with inflow playing a more significant role than rainfall in triggering gully wall expansion and collapse. Specifically, stream power is the optimal hydrodynamic parameter for predicting erosion rates, with a critical threshold of 2.33 N m⁻¹ s⁻¹ to distinguish stable and erosive conditions. Based on these findings, a dimensionless model was developed to predict gully head erosion under combined rainfall and inflow conditions, integrating both topographic and hydraulic parameters, and the model achieved high predictive accuracy (<span><math><mrow><msup><mrow><mi>R</mi></mrow><mn>2</mn></msup><mo>=</mo><mn>0.843</mn></mrow></math></span>, <span><math><mrow><msub><mi>N</mi><mrow><mi>SE</mi></mrow></msub><mo>=</mo><mn>0.788</mn></mrow></math></span>) for erosion initiation of gully head under complex rainfall-inflow interactions. This study establishes a simple and effective method for predicting erosion initiation and progression. These advances provide not only a mechanistic understanding of erosion drivers but also valuable scientific insights for rational engineering and management of the Loess Plateau.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117682"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001486","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":"Interactions between soil environmental factors and microbial communities consistently predict plant health","authors":"Hao Su ,&nbsp;Yuanyuan Yan ,&nbsp;Qiqi He ,&nbsp;Ya Li ,&nbsp;Ruimin Li ,&nbsp;Yi Ren ,&nbsp;Xing Zhou ,&nbsp;Liangliang Liu ,&nbsp;Zucong Cai ,&nbsp;Xinqi Huang","doi":"10.1016/j.geoderma.2026.117709","DOIUrl":"10.1016/j.geoderma.2026.117709","url":null,"abstract":"<div><div>Intensive agricultural practices cause dysbiosis in soil nutrient levels and microbial communities, significantly affecting plant health and productivity. However, the mechanisms underlying the interactions between soil environmental factors and microbial communities, and their role in determining and predicting plant health, remain poorly understood. In this study, we collected soils planted with tomato in different health conditions, including healthy and bacterial wilt, <em>Fusarium</em> wilt, and nematode diseases, to identify key abiotic and biotic factors influencing plant health. Additionally, We fitted machine learning models using multidimensional data to classify plant health status. Our results revealed that diseased soils (bacterial wilt, <em>Fusarium</em> wilt, and nematode disease) exhibited significantly higher AP levels compared to healthy soils. Moreover, increased Amplicon Sequence Variants (ASVs) in diseased soils had lower network connectivity and were positively correlated with soil nutrient contents, pathogen abundance, and pathogen-supportive soil microbial functions, while being negatively correlated with plant defense-associated soil microbial functions. Both soil nutrient levels and the increased ASVs in diseased soil were stronger correlates of disease occurrence than other soil indicators. Optimal classification performance was observed when both soil environmental factors and microbial communities were considered, with AP emerging as the most influential indicator. In conclusion, excessive accumulation of AP was associated with disrupted microbial community structures, destabilized microbial networks, enhanced pathogen abundance, and impaired microbial functions, which collectively correlated with higher disease occurrence. These findings highlight the potential importance of optimizing soil nutrient management for supporting plant health.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117709"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134164","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":"Climate-dependent variations in plant and nematode functional traits following shrub encroachment","authors":"Anning Zhang ,&nbsp;Ziyang Liu ,&nbsp;Jingwei Chen ,&nbsp;Hongxian Song ,&nbsp;Jiajia Wang ,&nbsp;Hanwen Cui ,&nbsp;Zi Yang ,&nbsp;Shuyan Chen ,&nbsp;Lizhe An ,&nbsp;Sa Xiao ,&nbsp;Pedro Cardoso","doi":"10.1016/j.geoderma.2026.117694","DOIUrl":"10.1016/j.geoderma.2026.117694","url":null,"abstract":"<div><div>Current climate change and anthropogenic activities are causing shrub encroachment, affecting biodiversity and ecosystem functioning. Shrub and their associated herbaceous plants and soil organisms will asynchronously colonize the new range, shaping different above and belowground relationships along climate gradients. With this work we quantify the functional linkage of plant and nematode communities in functional diversity and traits between shrubs and open spaces at 63 sites spanning broad climatic gradients on the Qinghai-Tibet Plateau. Shrub and climate interaction reshuffles herbaceous plant and nematode diversity and their function. Shrubs increased nematode taxonomic and functional diversity with increasing precipitation and temperature, but such shrub effects on plant diversity were independent of the climatic gradient. Shrub, precipitation, and temperature jointly modulate nematode traits, but have little effects on herbaceous plant traits. Shrubs increased nematodes with longer generation time, larger body mass, and at higher trophic levels, enhancing the metabolic footprint of soil communities; stronger modification on soil food webs and enrichment footprints amplified with increasing precipitation and temperature. Shifts in plant traits were associated with nematode C-P value and trophic structure, while Shrubs reduced the linkage between plants and nematodes in functional traits. Our study demonstrates that climate modulates the facilitative shrub effects on biodiversity and its functions, but points to the functional decoupling of plants and nematodes to environment shifts that may delay nutrient cycle and impact ecosystem functioning.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117694"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033235","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 “Optimization of soil hydraulic parameters within a constrained sampling space” [Geoderma 455 (2025) 117210]","authors":"Meijun Li ,&nbsp;Wei Shao ,&nbsp;Wenjun Yu ,&nbsp;Ye Su ,&nbsp;Qinghai Song ,&nbsp;Yiping Zhang ,&nbsp;Hongkai Gao ,&nbsp;Yonggen Zhang ,&nbsp;Jianzhi Dong","doi":"10.1016/j.geoderma.2026.117701","DOIUrl":"10.1016/j.geoderma.2026.117701","url":null,"abstract":"","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117701"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072097","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":"Dissolved organic matter and high precipitation drive in-situ transition from silandic to aluandic properties","authors":"Antonia Zieger ,&nbsp;Klaus Kaiser ,&nbsp;Martin Kaupenjohann","doi":"10.1016/j.geoderma.2026.117689","DOIUrl":"10.1016/j.geoderma.2026.117689","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Andosols are commonly subdivided according to silandic and aluandic features. Silandic Andosols are characterised by organic matter (OM) strongly bound to short-range ordered aluminosilicates (SROAS), while aluandic Andosols mainly consist of aluminium-OM complexes (Al-OM complexes). Two theories exist concerning their pedogenesis. One theory argues, that silandic and aluandic properties are direct results of the weathering, assuming two separate lines of genesis. The other theory argues that silandic horizons transform into aluandic over time as parts of a continuous soil forming process. The latter could be caused by dissolved organic matter (DOM) entering the silandic subsoil with the percolating soil solution and promoting the dissolution of SROAS phases by complexing Al. Increasing the loading of DOM with Al will finally result in the formation of insoluble Al-OM complexes.&lt;/div&gt;&lt;div&gt;To test the hypothesis of in-situ transition from silandic to aluandic properties in a controlled experiment, we conducted a 20-month percolation experiment with soil material of an Ecuadorian Andosol formed in a homogeneous tephra deposit and now featuring aluandic properties in the top- and silandic properties in the subsoil. Six columns were packed with aluandic material on top of silandic material, water saturated and percolated with litter DOM-solution continuously (percolation rate 8&lt;!--&gt; &lt;!--&gt;mm&lt;span&gt;&lt;math&gt;&lt;mi&gt;⋅&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;h&lt;sup&gt;−1&lt;/sup&gt;, except for a 9-week flow stop at the beginning of the experiment). In addition, three columns were packed only with aluandic material to gain additional information on the solution entering the silandic material. Among others, silicon (Si) and Al, pH, and dissolved organic carbon (DOC) in the feed and eluate solutions were monitored over a period of 20 months. We modelled the percolation experiment with the convection–dispersion equation as implemented in HYDRUS-1D to estimate the amount of retained DOC in the silandic material. Changes in OC concentration and mineral phases were tracked by analysing the column materials after 0, 8, and 20 months for OC concentrations, oxalate-extractable Al, Si, and iron (Fe) concentrations, and by X-ray diffraction.&lt;/div&gt;&lt;div&gt;Our results show that percolation had little to no effect on the aluandic material. However, for the silandic eluate the molar Al:Si ratio was well below the oxalate-extractable Alox:Siox molar ratio of the silandic material itself. This hints at desilification, while Al and OC are retained relative to Si and hence supporting the hypothesis of SROAS dissolution and neo-formation of Al-OM complexes. The latter explained up to 70&lt;!--&gt; &lt;!--&gt;% of the massive OC accumulation of 14&lt;!--&gt; &lt;!--&gt;mg&lt;span&gt;&lt;math&gt;&lt;mi&gt;⋅&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;g&lt;sup&gt;−1&lt;/sup&gt; in the silandic material, while vertical Al-OM transport and sorption played a minor role. This was supported by the HYDRUS-1D modelling, suggesting that sorption of DOM to the silandic material only dominates in ","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117689"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072101","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":"Horizontal gene transfer between bacteriophages and their hosts is a key factor in the bloom of antibiotic resistance genes in Metaphire californica","authors":"Hong-Xia Cui ,&nbsp;Qing-Fang Bi ,&nbsp;Jun Ye ,&nbsp;Yu-Chen Li ,&nbsp;Hu Liao ,&nbsp;Jian-Qiang Su","doi":"10.1016/j.geoderma.2026.117676","DOIUrl":"10.1016/j.geoderma.2026.117676","url":null,"abstract":"<div><div>Earthworm guts are a reservoir for antibiotic resistance genes (ARGs). However, the role of horizontal gene transfer (HGT) between bacteriophages and their hosts in amplifying ARG proliferation within this niche remains limited. To address this knowledge gap, we analyzed paired metagenomes from <em>Metaphire californica</em> guts and surrounding soil collected from farmland in Zhejiang, China. Earthworm guts harbored greater ARG diversity than soil (323 vs 303 subtypes), with significantly elevated abundances of macrolide-lincosamide-streptogramin (MLS), novobiocin, rifamycin, and tetracycline resistance determinants. Consistent with this, viral diversity was also higher in the earthworm gut comparing with soil. We recovered 67 microbial metagenome-assembled genomes (MAGs) and 5,703 viral operational taxonomic units (vOTUs), which enabled us to evaluate the contribution of viruses to ARG dissemination across different environments.<!--> <!-->Notably, virus-encoded ARGs were distributed across 43 Resfams families (RFs), with 32 detected in earthworm gut and only 23 in soil. Crucially, 1,568 potential HGT events between vOTUs and MAGs were identified, with a significantly higher frequency observed in the earthworm gut (1,110 events) compared to soil (458 events). Interestingly, the potential HGT regions against the Resfams database revealed that 32 gut-associated HGT events involved 11 RFs, whereas only 12 events associated with 5 RFs were detected in soil. These findings reveal the earthworm gut’s role in accelerating antibiotic resistance proliferation within agricultural ecosystems, highlighting the interconnected health risks emphasized by the One Health framework.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117676"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001553","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":"Comparative adsorption mechanism and transport behaviors of 2,4-D and 4-CPA in soil column with addition of Mg-Al layered double hydroxides","authors":"Sitong Pan ,&nbsp;Wenqing Wang ,&nbsp;Miaoyue Zhang ,&nbsp;Ying Li ,&nbsp;Ning Wang ,&nbsp;Jingna Liu ,&nbsp;Xiaoqian Jiang","doi":"10.1016/j.geoderma.2026.117691","DOIUrl":"10.1016/j.geoderma.2026.117691","url":null,"abstract":"<div><div>2,4-Dichlorophenoxyacetic acid (2,4-D) and 4-chlorophenoxyacetic acid (4-CPA) exhibit high water solubility and mobility, leading to low utilization efficiency and environmental contamination. Research into controlling the migration and leaching of multiple pesticides in complex soil environments remains relatively limited. This study employed Mg-Al layered double hydroxides (LDHs) to control the loss of 2,4-D and 4-CPA simultaneously. Here, adsorption kinetics experiments, density functional theory (DFT) calculations, column experiments and numerical models were conducted to investigate the adsorption mechanisms of the two herbicides onto LDHs, the co-/transport and co-/release behaviors of the herbicides in soil with the addition of LDHs. Outer-sphere complexation was the predominant adsorption mechanism for 4-CPA with LDHs, while outer-sphere and inner-sphere complexation occurred between 2,4-D and LDHs. DFT calculations indicated lower adsorption energy and greater adsorption strength between LDHs and 2,4-D compared to that between LDHs and 4-CPA. The retention of two herbicides in the soil increased by 8.99–22.46 % with 0.5 wt% LDHs and increased with the decrease of pH values and ionic strength (IS) of soil solution. The release amounts of 4-CPA and 2,4-D from LDHs in soil columns increased by 9.06 % and 12.05 % when the IS of K⁺ decreased from 100 to 0 mM, and increased by 11.12 % and 15.49 % in the presence of 25 mM carbonate. LDHs exerted a greater loss control effect on the simultaneous application of both herbicides. Either 2,4-D or 4-CPA would lead to the release of each other with the addition of LDHs. Pot experiment results further verified that the addition of LDHs in soil could reduce the loss of the herbicides by up to 77.29 %, which brought greater germination control of <em>Abutilon theophrasti</em>. This study provides novel mechanistic insights into the differential adsorption and transport of coexisting herbicides controlled by LDH_S under complex environmental conditions, offering promising strategies for enhancing herbicide efficacy and mitigating environmental risks in sustainable agriculture.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117691"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014530","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":"Effects of shrub expansion on methane emissions from temperate wetlands and their regulatory mechanisms","authors":"Shenzheng Wang ,&nbsp;Xin Sui ,&nbsp;Haixiu Zhong ,&nbsp;Xiaoyu Fu ,&nbsp;Rongtao Zhang ,&nbsp;Yingnan Liu","doi":"10.1016/j.geoderma.2026.117693","DOIUrl":"10.1016/j.geoderma.2026.117693","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Climate warming and human activities have led to widespread expansion of shrubs in many wetlands, altering the distribution patterns of native vegetation and disrupting C cycling. Although the effects of shrub expansion on soil microbial communities and methane (CH&lt;sub&gt;4&lt;/sub&gt;) emissions have been extensively studied, the specific microbial-mediated pathways involved in methane cycling remain unexplored. The static chamber method was used to investigate the characteristics of CH&lt;sub&gt;4&lt;/sub&gt; emission flux changes under different levels of shrub expansion. Additionally, metagenomics technology was employed to assess the effects of different shrub expansion levels on soil microbial community composition, function, and diversity (bacteria and fungi), as well as the methane metabolic pathways mediated by these communities. Shrub expansion in wetlands was categorized into four classes based on shrub coverage. We found that methane flux decreased significantly with increasing shrub expansion, with cumulative emissions under extensive expansion conditions being only 28 % of those under no expansion conditions. The peak emissions on August 15 under no expansion conditions were 2–3 times higher than those in shrub-expanded plots. The partial least squares path model (PLS-PM, GOF = 0.731) indicated that shrub expansion enhanced soil physicochemical properties (β = 0.865), which inhibited methanogenic genes (β = −0.617) and activated methane oxidation pathways (total effect β = 0.728). Methane-oxidizing genes contributed the most to CH&lt;sub&gt;4&lt;/sub&gt; reduction, accounting for 72.4 % of the pathway effect. This was primarily manifested as inhibition of key genes involved in the acetate pathway for methane production (comB and hdrA) and upregulation of methane-oxidizing-related genes (mmoB and DAK). Shrub expansion significantly increased soil ammonium nitrogen content while reducing soil moisture content. Although bacterial α diversity remained unchanged, the fungal Chao1 index significantly increased. Additionally, MI and HI treatments significantly altered bacterial community structure, while fungal communities remained relatively stable. The relative abundance of Verrucomicrobia initially increased with shrub expansion but decreased at higher levels, while Ascomycota, Basidiomycota, and Mucoromycota showed significant increases. The study suggests that the reduction in CH&lt;sub&gt;4&lt;/sub&gt; emissions caused by shrub expansion is primarily regulated by a synergistic pathway involving the combined effects of soil physicochemical properties and oxidative microbial genes. Furthermore, bacterial communities are more sensitive to shrub expansion than fungal communities. These results highlight the complex interactions between aboveground vegetation dynamics, soil microbial communities, greenhouse gas fluxes, and environmental factors. However, this CH&lt;sub&gt;4&lt;/sub&gt; reduction likely reflects hydrological degradation and wetland desiccation, which may increase CO&lt;su","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117693"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014829","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":"Aridity dependency of soil plant- and microbial-derived carbon in mongolia plateau in northern China","authors":"Shaoyu Li,&nbsp;Lishan Yang,&nbsp;Feng Zhang,&nbsp;Jiahua Zheng,&nbsp;Bin Zhang,&nbsp;Guodong Han,&nbsp;Mengli Zhao","doi":"10.1016/j.geoderma.2026.117706","DOIUrl":"10.1016/j.geoderma.2026.117706","url":null,"abstract":"<div><div>Soil plant-derived carbon (PDC) and microbial-derived carbon (MDC) represent the two primary sources of soil organic carbon (SOC). The relative proportions of these carbon (C) sources shape SOC composition, accumulation, stability, and turnover. Dryland ecosystems, while serving as critical C reservoirs, are particularly vulnerable to climate change. However, the influence of aridity on PDC and MDC sequestration remains understudied at the regional scale, which limits our ability to understand and predict soil C dynamics in drylands under the context of global warming. To address this knowledge gap, we measured PDC, MDC, and associated biotic and abiotic variables at 90 sampling sites along a ∼ 3000 km transect across the Mongolian Plateau. We examined the biogeographical distribution patterns of PDC and MDC along a natural aridity gradient. Our findings revealed that both PDC and MDC declined concurrently in response to increasing aridity. Based on the contributions of PDC and MDC to SOC, we identified the shifting point marking the transition in the dominance of different pathways of the microbial C pump. This shifting point was further validated using microbial C use efficiency (CUE) and soil extracellular enzyme activity. In subhumid-semiarid region (aridity = 0.37), the contribution of PDC to SOC exceeds that of MDC, coupled with higher extracellular enzyme activity, indicating the dominance of <em>ex vivo</em> modification. Here, PDC formation is primarily driven by the microbial fragmentation of abundant plant litter. High precipitation and nutrient availability in these areas further support the conversion of microbial biomass C into MDC. In contrast, in semiarid region (aridity = 0.78), the contribution of PDC to SOC is lower than that of MDC, coupled with higher microbial CUE, indicating the dominance of <em>in vivo</em> turnover. MDC accumulation is promoted by physical protection mechanisms, such as increased clay and silt content, while PDC formation is constrained by limited root C inputs. Our findings provide new insights into the mechanisms of SOC sequestration in drylands and emphasize the need to consider both PDC and MDC in strategies aimed at preserving the terrestrial C sink under current and future climate change.</div></div>","PeriodicalId":12511,"journal":{"name":"Geoderma","volume":"466 ","pages":"Article 117706"},"PeriodicalIF":6.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048416","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}