Soil Biology & Biochemistry最新文献_第9页

Increased drought intensity stimulates the extracellular polymeric substance accumulation and their contribution to soil organic carbon rather than microbial necromass 增加的干旱强度刺激细胞外聚合物质积累及其对土壤有机碳的贡献，而不是微生物坏死

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-26 DOI: 10.1016/j.soilbio.2025.110044

Huijun Li , Baorong Wang , Haoning Chen , Na Li , Yue Zhou , Zhaolong Zhu , Jinshi Jian , Gurpal S. Toor , Shaoshan An

Beyond the recognized role of microbial cell wall residues in soil organic carbon (SOC), microbes under drought stress appear to strategically divert C toward the production of extracellular polymers (EPS), positioning them as a dynamic C pool. Their contrasting environmental behavior and turnover create a fundamental uncertainty in predicting SOC dynamics in drying ecosystems. Despite their importance, the dynamics of EPS and microbial necromass (indicated by amino sugars) under prolonged drought, their relative contributions to SOC accumulation, and the factors regulating them remain poorly constrained. We hypothesized that intensified drought would preferentially stimulate EPS accumulation over microbial necromass, as microbes divert more C toward EPS synthesis to mitigate water stress. To test this, a 9-year drought experiment was conducted with four treatments (control and 20 %, 40 %, and 60 % reductions). We found that under prolonged drought, the contents of both EPS and microbial necromass declined, with the former decreasing by 30.2 % and the latter more sharply by 76.0 % under extreme conditions, indicating their asynchronous formation and accumulation. However, increasing drought intensity enhanced the EPS accumulation coefficient rather than that of microbial necromass, indicating a greater microbial C investment in EPS production and higher formation efficiency under water stress. Long-term drought also restructured the microbial community, shifting C allocation from biomass growth and necromass formation (associated with taxa like Proteobacteria and Ascomycota) toward EPS production (e.g., Bacteroidota, Basidiomycota and Glomeromycota). In parallel, abiotic variables such as Olsen phosphorus, nitrate, and ammonium were tightly coupled to EPS accumulation, underscoring EPS role in sustaining bioavailable nutrient pools as soil moisture declines. Collectively, these findings provide direct evidence that EPS contributes more actively to SOC than microbial necromass. The strategic shift in microbial carbon from necromass to EPS buffers SOC pools, with important implications for ecosystem C cycling and climate feedbacks under drought.

除了已知的微生物细胞壁残留物在土壤有机碳（SOC）中的作用外，干旱胁迫下的微生物似乎会有策略地将C转移到细胞外聚合物（EPS）的生产中，将其定位为一个动态的C库。它们截然不同的环境行为和循环造成了预测干旱生态系统有机碳动态的根本不确定性。尽管它们很重要，但在长期干旱条件下，EPS和微生物坏死团块（由氨基糖表示）的动态、它们对有机碳积累的相对贡献以及调节它们的因素仍然知之甚少。我们假设，干旱加剧会优先刺激EPS积累，而不是微生物坏死团，因为微生物会将更多的碳转向EPS合成，以减轻水分胁迫。为了验证这一点，进行了为期9年的4个处理（对照和减少20%、40%和60%）的干旱试验。结果表明，在长期干旱条件下，EPS和微生物坏死团的含量均呈下降趋势，在极端条件下，EPS和微生物坏死团的含量分别下降30.2%和76.0%，表明它们的形成和积累是不同步的。然而，增加干旱强度增加了EPS积累系数，而不是微生物坏死块，这表明在水分胁迫下，微生物C对EPS生产的投入更大，地层效率更高。长期干旱也重组了微生物群落，将C的分配从生物量生长和坏死团块形成（与变形菌门和子囊菌门等分类群有关）转移到EPS的产生（如拟杆菌门、担子菌门和肾小球菌门）。同时，奥尔森磷、硝酸盐和铵等非生物变量与EPS积累密切相关，强调了EPS在土壤湿度下降时维持生物可利用养分库的作用。总的来说，这些发现提供了直接证据，证明EPS对SOC的贡献比微生物坏死团块更积极。微生物碳从死体到EPS的战略性转变缓冲了有机碳库，对干旱条件下生态系统C循环和气候反馈具有重要意义。

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引用次数: 0

Contrasting methanotrophic communities between upland and polygonal tundra and their link to nitrogen metabolism and methane uptake in the Western Canadian Arctic 加拿大西部北极地区高地和多面体苔原间甲烷营养群落的对比及其与氮代谢和甲烷吸收的联系

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-11 DOI: 10.1016/j.soilbio.2025.110038

Carolina Voigt , Henri M.P. Siljanen , Carlos Palacin-Lizarbe , Kathryn A. Bennett , Charles Chevrier-Dion , Claudia Fiencke , Christian Knoblauch , Charlotte Marquis , Maija E. Marushchak , Taija Saarela , Evan J. Wilcox , Oliver Sonnentag

Atmospheric methane (CH₄) uptake by arctic soils is widespread in dry tundra ecosystems. However, the environmental controls regulating CH₄ uptake are poorly understood, particularly such as soil nutrient availability or microbial community composition. Here, we analyzed the relative abundance and community structure of functional gene markers associated with CH₄ and mineral nitrogen (N) cycling in two contrasting tundra types in the Western Canadian Arctic using a targeted metagenomics approach. Microbial data were compared to soil properties, macro- and micronutrient concentrations, and CH₄ fluxes during an entire growing season (May–August). We find that soil pH was the most important control on gene distribution between the studied microsites. Methanotrophs associated with the upland soil cluster α (USCα) dominated in polygonal tundra (low pH), while USCγ dominated in upland tundra (high pH). Methane uptake rates ranged from −15 to −27 μg CH₄–C m⁻² h⁻¹ (growing season mean) and increased with higher relative abundances of USCα and USCγ. Although CH₄ uptake rates were similar between microsites, our microbial data indicate different mechanisms to cope with N limitation in these nutrient-limited tundra environments: upland tundra was characterized by genes involved in denitrification and N retention, while polygonal tundra contained genes associated with biological N fixation. Our study highlights the need for an integrated view on interactions between CH₄ oxidation and N availability for methanotrophs in arctic tundra soils.

北极土壤对大气甲烷（CH4）的吸收在干冻土带生态系统中广泛存在。然而，调节CH4吸收的环境控制知之甚少，特别是土壤养分有效性或微生物群落组成。在这里，我们使用目标宏基因组学方法分析了加拿大西部北极两种不同类型冻土带中与CH4和矿物氮(N)循环相关的功能基因标记的相对丰度和群落结构。在整个生长季节（5 - 8月），将微生物数据与土壤性质、宏量和微量营养素浓度以及CH4通量进行了比较。结果表明，土壤pH值是影响基因分布的最重要因素。在多边形冻土带（低pH）中，与陆地土壤簇α (USCα)相关的甲烷氧化菌占主导地位，而在旱地冻土带（高pH）中，与USCγ相关的甲烷氧化菌占主导地位。甲烷吸收率为-15 ~ -27 μg CH4-C m-2 h-1（生长期平均值），随USCα和USCγ相对丰度的增加而增加。尽管CH4吸收率在不同的微生物位点之间相似，但我们的微生物数据表明，在这些营养受限的冻土带环境中，应对氮限制的机制不同：旱地冻土带的特征是参与反硝化和氮保留的基因，而多角冻土带则包含与生物固氮相关的基因。我们的研究强调了对北极苔原土壤甲烷氧化菌CH4氧化与N有效性之间相互作用的综合看法的必要性。

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引用次数: 0

Spatio-temporal distribution of enzyme activities in cowpea rhizosphere – the role of plant growth stages and nodule senescence 豇豆根际酶活性的时空分布——植物生长阶段和根瘤衰老的作用

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-20 DOI: 10.1016/j.soilbio.2025.110042

Elisa Karina Albrecht , Maire Holz , Joscha N. Becker

Legume-soil interactions are well recognised for their role in ecosystem nutrient cycling, yet specific mechanisms such as nodule senescence effects on soil nitrogen (N) and carbon (C) cycling remain poorly understood. Here, we investigated the effect of nodule senescence on soil enzyme activity and soil biochemical properties in the rhizospheres of cowpea (Vigna unguiculata) during plant growth. We conducted a rhizobox experiment using soil from the Kavango (loamy sand) and Omusati (sandy soil) regions in Northern Namibia under controlled temperature and optimum water conditions. To investigate spatial and temporal C and N release, in-situ zymography was conducted at early vegetative, flowering, and maturity stage (i.e. one day after the start of nodule senescence) with six replicates per soil. Three enzymes, representing the C (β-glucosidase, chitinase) and N (chitinase, leucine-aminopeptidase) cycle, were investigated. At each plant growth stage, three additional plants per soil were harvested to identify changes in soil properties, including soil organic carbon, total N, mineral N, and pH. Our results showed that enzyme activities did not vary significantly during plant growth in rhizospheres and at nodule and root surfaces. In contrast, enzyme activities significantly increased with plant growth in bulk soil, especially β-glucosidase and chitinase, with a peak at maturity stage. Particularly in the sandy soil, nodule senescence significantly increased enzyme activities. This indicates enhanced organic matter decomposition and nutrient release mainly from the nodule-influenced rhizosphere to the bulk soil and might be attributed to rhizodeposition and microbial responses to substrate availability. We conclude that nodule senescence of legumes is an important driver of enzyme activity and can be a crucial factor for managing soil properties in low-nutrient soils.

豆科植物-土壤相互作用在生态系统养分循环中的作用已得到广泛认可，但具体机制如根瘤衰老对土壤氮(N)和碳(C)循环的影响尚不清楚。本文研究了豇豆根瘤衰老对植物生长过程中根际土壤酶活性和土壤生化特性的影响。我们在控制温度和最佳水分条件下，利用纳米比亚北部Kavango（壤土）和Omusati（沙土）地区的土壤进行了根箱试验。在营养早期、开花期和成熟期（即结瘤开始衰老后1天）进行了6个重复的原位酶谱分析，研究了碳氮释放的时空变化。研究了代表C （β-葡萄糖苷酶，几丁质酶）和N（几丁质酶，亮氨酸-氨基肽酶）循环的三种酶。在每个植物生长阶段，每个土壤额外收获3株植物，以确定土壤性质的变化，包括土壤有机碳、全氮、矿质氮和ph。我们的研究结果表明，在植物生长过程中，根际、根瘤和根表面的酶活性没有显著变化。在散装土壤中，随着植株的生长，酶活性显著增加，尤其是β-葡萄糖苷酶和几丁质酶，并在成熟期达到峰值。特别是在沙质土壤中，根瘤衰老显著提高了酶的活性。这表明有机质分解和养分释放的增强主要是由受根瘤影响的根际向大块土壤的释放，这可能归因于根沉积和微生物对基质有效性的响应。我们得出结论，豆科植物的根瘤衰老是酶活性的重要驱动因素，可能是低营养土壤管理土壤性质的关键因素。

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引用次数: 0

Biological invasions of three different alien tree species has comparable influence in soil mycobiome: increase the abundance of pathogens, and decomposers, but decrease root-associated endophytic symbionts 三种不同外来树种的生物入侵对土壤真菌群落的影响相当：增加病原体和分解者的丰度，但减少与根相关的内生共生体

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-20 DOI: 10.1016/j.soilbio.2025.110041

Robin Wilgan, Marta Brygida Kujawska, Tomasz Leski

Invasive trees can significantly transform habitats, modify nutrient cycles, and change microbial community composition and assembly processes. Therefore, they pose significant threat to nature conservation and sustainable management. However, the impacts of invasive trees on the trophy and taxonomy of soil mycobiomes in forest ecosystems remain unclear. In this study, we investigated how the invasive tree species – Robinia pseudoacacia, Prunus serotina, and Quercus rubra – influence soil mycobiomes in forest ecosystems. We analysed soil samples taken from an invasive tree density gradient, using 81 study stands in Poland, Central Europe. The soil mycobiome was identified using Next-Generation Sequencing of the ITS2 rDNA barcode region for fungi.

The three invasive tree species had a similar impact on the soil mycobiome. Each invasive tree reduced the relative abundance of root endophytes and increased the relative abundance of pathogens in soil. The response of saprotrophs varied, but they generally showed no negative response to invasive trees. The mycobial community composition and abundance of trophic guilds changed substantially, but taxa richness and diversity indices were weak predictors of disturbances. Robinia pseudoacacia had the most significant impact on the soil mycobiome, and Robinia-invaded stands had significantly higher N–NO3, potassium, and calcium content in soil. It is a major concern given that Robinia is probably the most common invasive tree in Europe. We recommend further investigation of the impact of R. pseudoacacia on soil microbiomes in various types of ecosystems to determine the habitats in which Robinia is most detrimental. This will inform targeted invasive species management.

入侵树木可以显著改变生境，改变养分循环，改变微生物群落组成和组装过程。因此，它们对自然保护和可持续管理构成了重大威胁。然而，入侵树木对森林生态系统土壤真菌群落形态和分类的影响尚不清楚。本文研究了入侵树种刺槐（Robinia pseudoacacia）、桃李（Prunus serotina）和黑栎（Quercus rubra）对森林生态系统土壤真菌群落的影响。我们分析了从入侵树木密度梯度中提取的土壤样本，使用了中欧波兰的81个研究林。利用真菌ITS2 rDNA条形码区域的下一代测序技术对土壤真菌群落进行了鉴定。三种入侵树种对土壤真菌群落的影响相似。每棵入侵树都降低了土壤中根内生菌的相对丰度，增加了土壤中病原菌的相对丰度。腐养菌对入侵树木的反应各不相同，但总体上没有负面反应。营养行会真菌群落组成和丰度发生显著变化，但类群丰富度和多样性指数对干扰的预测能力较弱。刺槐对土壤真菌群落的影响最为显著，刺槐入侵林分土壤中N-NO3、钾、钙含量显著高于刺槐林分。考虑到Robinia可能是欧洲最常见的入侵树种，这是一个主要的问题。我们建议进一步研究刺槐对不同类型生态系统土壤微生物组的影响，以确定刺槐在哪些生境中最有害。这将为有针对性的入侵物种管理提供信息。

{"title":"Biological invasions of three different alien tree species has comparable influence in soil mycobiome: increase the abundance of pathogens, and decomposers, but decrease root-associated endophytic symbionts","authors":"Robin Wilgan, Marta Brygida Kujawska, Tomasz Leski","doi":"10.1016/j.soilbio.2025.110041","DOIUrl":"10.1016/j.soilbio.2025.110041","url":null,"abstract":"<div><div>Invasive trees can significantly transform habitats, modify nutrient cycles, and change microbial community composition and assembly processes. Therefore, they pose significant threat to nature conservation and sustainable management. However, the impacts of invasive trees on the trophy and taxonomy of soil mycobiomes in forest ecosystems remain unclear. In this study, we investigated how the invasive tree species – <em>Robinia pseudoacacia</em>, <em>Prunus serotina</em>, and <em>Quercus rubra</em> – influence soil mycobiomes in forest ecosystems. We analysed soil samples taken from an invasive tree density gradient, using 81 study stands in Poland, Central Europe. The soil mycobiome was identified using Next-Generation Sequencing of the ITS2 rDNA barcode region for fungi.</div><div>The three invasive tree species had a similar impact on the soil mycobiome. Each invasive tree reduced the relative abundance of root endophytes and increased the relative abundance of pathogens in soil. The response of saprotrophs varied, but they generally showed no negative response to invasive trees. The mycobial community composition and abundance of trophic guilds changed substantially, but taxa richness and diversity indices were weak predictors of disturbances. <em>Robinia pseudoacacia</em> had the most significant impact on the soil mycobiome, and <em>Robinia</em>-invaded stands had significantly higher N–NO3, potassium, and calcium content in soil. It is a major concern given that <em>Robinia</em> is probably the most common invasive tree in Europe. We recommend further investigation of the impact of <em>R. pseudoacacia</em> on soil microbiomes in various types of ecosystems to determine the habitats in which <em>Robinia</em> is most detrimental. This will inform targeted invasive species management.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"213 ","pages":"Article 110041"},"PeriodicalIF":10.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145554828","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}

引用次数: 0

Earthworms enhance soil phosphorus cycling but plant responses differ among earthworm ecological categories: a meta-analysis 蚯蚓促进土壤磷循环，但不同生态类型蚯蚓对土壤磷循环的响应不同

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-10-31 DOI: 10.1016/j.soilbio.2025.110025

Ziyue Wang , Man Liu , Wenli Ding , Zhihui Chang , Benjamin L. Turner , Hans Lambers

Earthworms are integral to soil processes and influence plant growth and phosphorus (P) nutrition. We investigated the role of earthworms in the P cycle by synthesizing data from 181 studies, of which 22 % were field observations and 78 % were from pot or mesocosm experiments. Earthworms increase the concentration of soil Olsen P and microbial P, phosphatase activity, and plant biomass. Deep-dwelling epi-anecic and anecic earthworms are more effective than other ecological groups at increasing the soil available P, although surface-dwelling earthworms (epigeic and endogeic) contribute more effectively to plant P uptake. The increase of plant biomass by earthworms decreases with increasing organic matter content, but Olsen P concentration and plant P uptake show the opposite trend. Moreover, the impact of endogeic earthworms on P is sensitive to soil organic matter content. The positive effects of earthworms on P cycling are more pronounced under acidic and alkaline conditions than under neutral conditions (6.5–7.5). Finally, the increased available P concentration due to earthworms directly stimulates microbial P uptake, while all three main ecological categories of earthworms indirectly stimulate root growth and increase plant P uptake. Overall, earthworms can effectively promote P cycling in ecosystems, with a more significant effect in nutrient-poor soils.

蚯蚓是土壤过程中不可或缺的一部分，影响植物生长和磷(P)营养。通过综合181项研究资料，研究了蚯蚓在磷循环中的作用，其中22%为田间观测，78%为盆栽或中生态试验。蚯蚓增加了土壤奥尔森磷和微生物磷浓度、磷酸酶活性和植物生物量。深层蚯蚓和内生蚯蚓在增加土壤速效磷方面比其他生态类群更有效，尽管表层蚯蚓（表层蚯蚓和内源蚯蚓）对植物磷素吸收的贡献更有效。蚯蚓对植物生物量的增加随有机质含量的增加而减小，而奥尔森磷浓度和植物磷素吸收量呈相反趋势。此外，内源蚯蚓对磷的影响对土壤有机质含量敏感。蚯蚓对磷循环的积极作用在酸性和碱性条件下比在中性条件下更为明显（6.5-7.5）。最后，蚯蚓增加的有效磷浓度直接刺激微生物对磷的吸收，而蚯蚓的三个主要生态类别都间接刺激根系生长，增加植物对磷的吸收。总体而言，蚯蚓能有效促进生态系统中磷的循环，在养分贫乏的土壤中效果更为显著。

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引用次数: 0

Nitrogen fertilization does not affect non-symbiotic N2 fixation in northern forest soils despite its negative impacts on diazotroph communities 氮肥对北方森林土壤的非共生固氮作用没有影响，但对重氮营养型群落有负面影响

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-13 DOI: 10.1016/j.soilbio.2025.110037

Eduardo Vázquez , Jaanis Juhanson , Sara Hallin , Marie Spohn

Tree productivity in northern regions is limited by low soil nitrogen (N) availability, and biological N₂ fixation is a crucial N input to these forests. To enhance forest productivity, N fertilization has been proposed as a strategy although it may negatively affect N₂ fixation and the abundance of diazotrophic microorganisms. In contrast to N₂ fixation by the cyanobacteria-moss associations, there is limited understanding of non-symbiotic N₂ fixation in northern forest soils and the free-living diazotrophs involved. To assess the impact of N fertilization on non-symbiotic N₂ fixation and the diazotrophic community in soil, we sampled 15 forest sites along a latitudinal gradient in Sweden that are part of a fertilization experiment. Fertilization started between 41 and 55 years ago, using ammonium nitrate at 100–150 kg N ha⁻¹ every 5th year for the first 25 years and thereafter every 7th year. We measured non-symbiotic N₂ fixation in the soil organic layer in laboratory incubations and analyzed the diazotrophic community. Both the abundance and diversity of diazotrophs decreased in response to N fertilization. However, this decline did not translate into significant changes in non-symbiotic N₂ fixation rates (22.4 ± 4.2 and 22.5 ± 5.7 ng N g⁻¹ dry weight soil h⁻¹ in the control and N treatments, respectively). Yet, N₂ fixation per area increased by 24 % in fertilized plots because of the increase in the organic layer stock caused by higher primary production. Additionally, we observed an influence of fertilization and mean annual temperature on diazotroph community composition across the gradient. Our findings indicate that N fertilization in northern forests strongly affects diazotrophs, the organic layer stock, and N₂ fixation. Although N fertilization positively affected the N₂ fixation rate per area in this experiment, its negative effect on diazotroph diversity might reduce N₂ fixation in the long run.

北方地区的树木生产力受到土壤氮有效性低的限制，而生物固氮是这些森林至关重要的氮输入。为了提高森林生产力，尽管氮肥可能会对固氮和重氮营养微生物的丰度产生负面影响，但仍被提出作为一种策略。与蓝藻-苔藓联合固氮相反，对北方森林土壤中非共生固氮和自由生活重氮营养菌的了解有限。为了评估氮肥对土壤非共生固氮和重氮营养群落的影响，我们在瑞典沿纬度梯度取样了15个森林样地，作为施肥试验的一部分。在41 - 55年前开始施肥，前25年每5年施用100-150 kg N hm -1硝酸铵，此后每7年施用一次。在实验室培养条件下测定了土壤有机层非共生固氮量，并对重氮营养化群落进行了分析。重氮营养体的丰度和多样性随施氮量的增加而降低。然而，这种下降并未转化为非共生固氮率的显著变化（对照和施氮处理分别为22.4±4.2和22.5±5.7 ng N g-1干重土壤h-1）。然而，施肥地块的单位面积固氮量增加了24%，这是由于初级产量增加导致有机层储量增加。此外，我们还观察了施肥和年平均温度对重氮营养菌群落组成的影响。研究结果表明，氮肥对北方森林重氮营养物、有机层储量和氮固定有显著影响。虽然在本试验中，施氮对单位面积固氮率有积极影响，但从长期来看，施氮对重氮养分多样性的负面影响可能会降低氮素的固定。

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引用次数: 0

Morphological traits comparable to molecular approaches for soil nematode community analysis: a meta-analysis and field experiment 土壤线虫群落分析的形态特征与分子方法：荟萃分析和田间试验

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-24 DOI: 10.1016/j.soilbio.2025.110046

Yali Zhang , Jiayao Han , Joann K. Whalen , Mingsen Qin , Chenyu Li , Yongjun Liu

High-throughput sequencing (HTS) has become the most widely applied molecular approach for analyzing soil nematode communities, but its consistency with traditional morphology-based methods remains insufficiently validated. Here, we compared molecular (HTS-based) and morphological approaches in characterizing nematode communities, using data from a controlled field experiment with tillage and fertilization treatments (n = 36) and 146 additional datapoints from a systematic meta-analysis. Most community-level metrics, including trophic groups, diversity indices, ecological indicators, overall community structure, and their responses to tillage and fertilization, were consistent between the two approaches, indicating that molecular data can yield reliable ecological insights comparable to those derived from morphological analysis. Nonetheless, the molecular approach detected higher genus richness but lower Shannon and evenness indices, and it tended to over-estimate omnivores-predators while under-estimating herbivores, thereby causing discrepancies in maturity and structure indices. These inconsistencies highlight methodological biases that must be carefully considered when interpreting molecular data. By integrating empirical and meta-analytical evidence, our study provides one of the most comprehensive evaluations to date of the alignment between molecular and morphological assessments of soil nematode communities. Future efforts should focus on refining molecular approaches, including improving primer coverage, expanding reference databases, and linking DNA sequences with functional traits, to further enhance the accuracy and ecological utility of HTS in nematode diversity monitoring and soil ecosystem assessment.

高通量测序（High-throughput sequencing， HTS）已成为土壤线虫群落分析中应用最广泛的分子方法，但其与传统的基于形态的方法的一致性仍未得到充分验证。在这里，我们比较了分子（基于hts的）和形态学方法表征线虫群落，使用来自耕作和施肥处理的对照田间试验数据（n = 36）和来自系统荟萃分析的146个附加数据点。两种方法的大多数群落水平指标，包括营养类群、多样性指数、生态指标、群落整体结构及其对耕作和施肥的响应，都是一致的，这表明分子数据可以获得与形态学分析相当的可靠的生态见解。然而，分子方法的属丰富度较高，Shannon指数和均匀度指数较低，且倾向于高估杂食-捕食动物而低估草食动物，从而导致成熟度和结构指数的差异。这些不一致突出了在解释分子数据时必须仔细考虑的方法偏差。通过整合经验和元分析证据，我们的研究提供了迄今为止最全面的土壤线虫群落的分子和形态评估之间的一致性评估之一。未来应进一步完善分子方法，包括提高引物覆盖率、扩大参考数据库、将DNA序列与功能性状联系起来，以进一步提高HTS在线虫多样性监测和土壤生态系统评价中的准确性和生态效用。

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引用次数: 0

Locating enzyme activities and nutrients in the rhizosphere: Combining zymography and DET methods 定位根际酶活性和营养成分：结合酶谱法和DET方法

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-14 DOI: 10.1016/j.soilbio.2025.110039

L. Paillat , P. Cannavo , A. Mouret , E. Metzger , L. Huché-Thélier , F. Barraud , A.S. Azimi , J. Cardenas , C. Banfield , Y. Kuzyakov , M. Dippold , R. Guénon

Organic fertilization is a recognized sustainable practice in agriculture and represents a major nutrient source for microbes and plants in these systems. Microbes produce hydrolytic enzymes to mineralize nutrients from organic forms into mineral forms to satisfy their own needs, and thus can compete with plants for these mineralized nutrients. Thus, interactions between plants and microbes in the rhizosphere determine nutrient availability and flows. We investigated these relations, using a spatial approach that combined zymography with the method of diffusive equilibrium in thin films (DET) to localize enzyme activity and N and P availabilities simultaneously. Basil (Ocimum basilicum L.) was grown in rhizoboxes filled with an organo-mineral crop soil (MS) or 100 % organic peat soil (OS) that was unfertilized or fertilized locally with horn meal for 20 days. In general, enzyme activities were higher in MS than in OS, but the stimulation of leucine aminopeptidase (LAP) activity and associated decrease in nutrient availability was 2 times as strong in OS as in MS. A rhizosphere effect, in which rhizodeposits stimulated enzyme activity, was clearly observed in OS. Fertilization increased LAP activity and nutrient availability near the location of fertilization, which increased basil growth in OS but not in MS. β-glucosidase, acid phosphatase and N-acetyl-glucosaminidase activities responded weakly to fertilization and the rhizosphere. By relating enzyme activities mapped by zymography to nutrient availability mapped by DET, we identified microbial hotspots in the rhizosphere where most nutrient mobilization processes and competition between plants and microbes occurred.

有机施肥是公认的农业可持续做法，是这些系统中微生物和植物的主要营养来源。微生物产生水解酶，将有机形式的营养物质矿化为矿物质，以满足自身的需要，因此可以与植物竞争这些矿化的营养物质。因此，植物和根际微生物之间的相互作用决定了养分的可利用性和流动。我们利用结合酶谱法和薄膜扩散平衡法（DET）的空间方法来研究这些关系，同时定位酶活性和氮磷有效性。罗勒（Ocimum basilicum L.）在根箱中生长，根箱中填充有机-矿物作物土壤（MS）或100%有机泥炭土壤（OS），未施肥或局部用角粕施肥20天。总的来说，MS的酶活性高于MS，但对亮氨酸氨基肽酶（LAP）活性的刺激和相关的养分有效性的降低是MS的2倍。在MS中，可以明显观察到根际效应，即根沉积物刺激酶活性。施肥提高了施肥地附近的LAP活性和养分有效性，这促进了罗勒植株的生长，而对ms植株无促进作用。通过将酶谱图绘制的酶活性与DET绘制的养分有效性相关联，我们确定了根际微生物热点，其中大多数养分动员过程和植物与微生物之间的竞争发生在根际。

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引用次数: 0

The influence of iron plaque and root traits on organic carbon turnover in the rice root detritusphere 铁膜和根系性状对水稻根腐殖层有机碳周转的影响

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-05 DOI: 10.1016/j.soilbio.2025.110036

Alexine Ehlinger , Sara Martinengo , Maria Sofia Lasagna , Fulvia Tambone , Maria Martin , Luisella Celi , Daniel Said-Pullicino

Rice roots represent an important contributor to belowground organic carbon (C) inputs in paddy soils. They have characteristic traits specifically linked to their growth in predominantly anoxic soils, such as the presence of iron plaque (IP) on the roots surfaces and the development of apoplastic barriers through the lignification/suberization of cell wall exteriors. Nevertheless, evidence on how these traits influence microbial decomposition and root C turnover in the detritusphere is still lacking. In this work we evaluated how water management practices, involving rice cropping under continuous flooding (CF) and alternate wetting and drying (AWD), affect coarse and fine root C inputs, their biochemical quality and IP contents. Moreover, by harnessing the difference in natural abundance ¹³C between C3 rice plant residues added to a C4 maize-cropped soil, we elucidated how these traits affect microbial decomposition, soil organic C (SOC) priming and the contribution of root C to different functional SOC pools over a 90-d microcosm incubation under aerobic conditions. The main findings suggest that growing rice under CF resulted in a lower abundance of fine roots and favoured the accumulation of root-associated IP compared to AWD. This, together with their greater content of aromatic and alkyl C moieties, was mainly responsible for the slower turnover of fine compared to coarse roots, and their slightly greater contribution to mineral-associated OC pools, without considerably affecting native SOC priming. We conclude that evaluating the effects of water management practices, among other parameters, on belowground C inputs and rice root traits may help decipher the root C turnover and contribution to stable SOC in rice paddies.

水稻根系是水稻土地下有机碳(C)输入的重要来源。它们具有与主要在缺氧土壤中生长有关的特征，例如根表面铁质斑块（IP）的存在以及通过细胞壁外木质素化/剥蚀而形成的外壁屏障。然而，关于这些性状如何影响腐肉层微生物分解和根C转换的证据仍然缺乏。在这项工作中，我们评估了水分管理措施，包括在连续淹水（CF）和干湿交替（AWD）条件下种植水稻，如何影响粗根和细根C输入，它们的生化品质和IP含量。此外，通过利用C3水稻残体在C4玉米土壤中天然碳丰度的差异，研究了这些性状在有氧条件下对微生物分解、土壤有机碳（SOC）启动以及根C对不同功能SOC库的贡献的影响。研究结果表明，与全旱相比，全旱条件下水稻细根丰度较低，有利于根系相关IP的积累。这一点，再加上它们的芳烃和烷基C含量较高，是细根比粗根更替速度较慢的主要原因，它们对矿物相关OC库的贡献略大，但对原生SOC启动没有明显影响。我们认为，评价水分管理措施对地下碳输入和水稻根系性状的影响可能有助于解释水稻根系碳周转及其对稳定有机碳的贡献。

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引用次数: 0

Actinobacteria, mycorrhizae, and the biology of soil aggregate stability 放线菌，菌根，和土壤团聚体稳定性的生物学

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-01 Epub Date: 2025-11-27 DOI: 10.1016/j.soilbio.2025.110048

Kinsey Reed Close , Damon LeMaster , Ronald Schartiger , Kayla Guthrie , Jennifer Kane , James Kotcon , Ember Morrissey

Soil macroaggregate stability is an essential component of soil health. Microbes can enhance macroaggregate stability; however, which microorganisms are responsible remains poorly understood. Arbuscular mycorrhizal fungi (AMF) have long been credited as the primary biological stabilizers despite conflicting information. Soil bacteria, particularly Actinobacteria, can also possess mycelial-like, filamentous growth and many bacteria produce substantial extracellular polymeric substances that may enhance soil macroaggregate stability. Using a novel combination of phospholipid fatty acid (PLFA) profiling and the SLAKES application, we evaluated microbial PLFA biomarker composition and macroaggregate stability in pasture soils across Appalachia. Here, we show the best predictors of macroaggregate stability to be Actinobacteria, gram-negative bacteria, and gram-positive bacteria. These findings challenge prevailing scientific narrative and highlight the need to further investigate bacteria as a source of macroaggregate stability in soil.

土壤大团聚体稳定性是土壤健康的重要组成部分。微生物可以增强宏观团聚体的稳定性；然而，究竟是哪些微生物造成了这种情况，人们仍然知之甚少。丛枝菌根真菌（AMF）一直被认为是主要的生物稳定剂，尽管信息相互矛盾。土壤细菌，特别是放线菌，也具有菌丝样、丝状生长，许多细菌产生大量的胞外聚合物质，可以增强土壤大团聚体的稳定性。利用磷脂脂肪酸（PLFA）分析和SLAKES应用的新组合，我们评估了阿巴拉契亚牧场土壤中微生物PLFA生物标志物组成和大团聚体稳定性。在这里，我们展示了放线菌、革兰氏阴性菌和革兰氏阳性菌是大聚集体稳定性的最佳预测因子。这些发现挑战了主流的科学叙述，并强调了进一步研究细菌作为土壤中大团聚体稳定性来源的必要性。

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引用次数: 0