Soil Biology & Biochemistry最新文献_第2页

The ultimate fraction – Chemical characterization of humins from forest vs grassland soils 森林与草地土壤中人类物质的最终组分化学特征

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-08 DOI: 10.1016/j.soilbio.2026.110118

Pere Rovira , Beatrice Giannetta , Joeri Kaal , Agustín Merino , César Plaza , Claudio Zaccone

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 <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 >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 O-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.

腐殖质被定义为碱法提取后土壤有机质的残余部分，几个世纪以来一直被认为是矿物土壤中最主要和最稳定的有机质形式。因此，必须在现代仪器水平上重新考虑这一点，因为目前关于其组成的证据主要受到所应用的分析方法的影响。本研究对森林和草地表层土壤的20 μm有机-矿物μm组分进行穷尽顺序提取，得到了人类素。在草地土壤的有机-矿物复合体中，人类平均占总有机碳(C)的36%，在森林土壤中占50%。然后通过13C-NMR、热解-气相色谱-质谱、thm -气相色谱-质谱、酸水解、单糖检测和定量以及热分析（DTG和DSC）对所得人源蛋白进行研究。研究的人源化合物由多种C类型组成，包括烷基C（~ 34%）和o -烷基C(~ 30%)，而羧基C非常缺乏，这可能解释了它们在碱溶液中的不溶性。总体而言，来自森林土壤的人类似乎比来自草原土壤的人类更容易发生微生物转化。特别是，碳水化合物主要是微生物来源，脂质保留了其原始前体（木质素，表皮蜡质）的特征，而木质素的保存程度尚不清楚。通过酸水解测定，森林人类的碳顽固性（40%）高于草地人类（34%）。与此同时，来自森林的人类表现出较低的热稳定性，但具有较高的能量密度。与人类主要由芳香族、烷基或多烷基组成的观点相反，我们的研究表明，人类具有高度的化学多样性，含有广泛的有机化合物，没有一种是主要的。它们的微生物改造程度随植被类型和相应的植物输入而变化；在更大的范围内，它可能随气候和母体物质而变化，这一假设将在未来的研究中得到验证。

{"title":"The ultimate fraction – Chemical characterization of humins from forest vs grassland soils","authors":"Pere Rovira , Beatrice Giannetta , Joeri Kaal , Agustín Merino , César Plaza , 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 <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 >50 % in forest soils. Obtained humins were then investigated by <sup>13</sup>C-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":"2026-02-08","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}

引用次数: 0

Long-term soil warming decreases fungal biomass and alters fungal but not bacterial communities in a temperate forest 在温带森林中，长期的土壤变暖减少了真菌生物量，改变了真菌而不是细菌群落

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-08 DOI: 10.1016/j.soilbio.2026.110120

Mohammad Rahmat Ullah , Steve Kwatcho Kengdo , Derek Peršoh , Ye Tian , Jakob Heinzle , Carolina Urbina Malo , Chupei Shi , Tillmann Lueders , Christian Poll , Wolfgang Wanek , Andreas Schindlbacher , Werner Borken

Long-term soil warming may alter microbial community structure and functioning in forest soils, thereby affecting carbon and nutrient cycling processes. We examined the effects of >14 years of soil warming (+4 °C during snow-free seasons) on the fungal biomass marker ergosterol, and on fungal and bacterial communities in a spruce dominated mountain forest in the Austrian Alps. Soil warming decreased ergosterol, and the ergosterol-to-microbial biomass carbon (MBC) ratio at 0-10 and 10-20 cm soil depth, with a stronger decline in ergosterol, indicating a higher sensitivity of fungi than bacteria to long-term warming. Warming also shifted the fungal community at both soil depths, favoring Boletus luridus, an ectomycorrhizal (ECM) fungus, which emerged as the dominant OTU in warmed plots. The dominance of ECM over saprotrophic fungi (SAP) under warming at topsoil likely resulted from increased fine root production and enhanced competition for substrates and nutrients. Bacterial abundance and community composition remained mostly unaffected at both depths, likely due to their greater resilience to elevated temperatures and their high taxonomic diversity. Our findings therefore suggest that long-term warming primarily affects fungal community composition and functional traits, thereby enhancing the contribution of ECM with fine roots to the carbon cycle in the calcareous forest soil.

长期的土壤变暖可能改变森林土壤微生物群落结构和功能，从而影响碳和养分循环过程。我们研究了14年土壤变暖（无雪季节+4°C）对真菌生物量标志物麦角甾醇的影响，以及对奥地利阿尔卑斯山云杉为主的山林真菌和细菌群落的影响。土壤增温降低了0 ~ 10 cm和10 ~ 20 cm土壤深度麦角甾醇与微生物生物量碳（MBC）之比，且麦角甾醇下降幅度更大，表明真菌对长期增温的敏感性高于细菌。变暖还改变了两种土壤深度的真菌群落，有利于外菌根真菌（ECM） Boletus luridus，它在变暖地块中成为主要的OTU。表层土壤变暖条件下，ECM对腐养真菌（SAP）的优势可能是由于细根产量增加，对基质和养分的竞争加剧。细菌丰度和群落组成在两个深度基本未受影响，可能是由于它们对高温的适应能力更强，分类多样性也更高。因此，长期变暖主要影响真菌群落组成和功能性状，从而增强细根ECM对钙质森林土壤碳循环的贡献。

{"title":"Long-term soil warming decreases fungal biomass and alters fungal but not bacterial communities in a temperate forest","authors":"Mohammad Rahmat Ullah , Steve Kwatcho Kengdo , Derek Peršoh , Ye Tian , Jakob Heinzle , Carolina Urbina Malo , Chupei Shi , Tillmann Lueders , Christian Poll , Wolfgang Wanek , Andreas Schindlbacher , Werner Borken","doi":"10.1016/j.soilbio.2026.110120","DOIUrl":"10.1016/j.soilbio.2026.110120","url":null,"abstract":"<div><div>Long-term soil warming may alter microbial community structure and functioning in forest soils, thereby affecting carbon and nutrient cycling processes. We examined the effects of >14 years of soil warming (+4 °C during snow-free seasons) on the fungal biomass marker ergosterol, and on fungal and bacterial communities in a spruce dominated mountain forest in the Austrian Alps. Soil warming decreased ergosterol, and the ergosterol-to-microbial biomass carbon (MBC) ratio at 0-10 and 10-20 cm soil depth, with a stronger decline in ergosterol, indicating a higher sensitivity of fungi than bacteria to long-term warming. Warming also shifted the fungal community at both soil depths, favoring <em>Boletus luridus</em>, an ectomycorrhizal (ECM) fungus, which emerged as the dominant OTU in warmed plots. The dominance of ECM over saprotrophic fungi (SAP) under warming at topsoil likely resulted from increased fine root production and enhanced competition for substrates and nutrients. Bacterial abundance and community composition remained mostly unaffected at both depths, likely due to their greater resilience to elevated temperatures and their high taxonomic diversity. Our findings therefore suggest that long-term warming primarily affects fungal community composition and functional traits, thereby enhancing the contribution of ECM with fine roots to the carbon cycle in the calcareous forest soil.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110120"},"PeriodicalIF":10.3,"publicationDate":"2026-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134150","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

Diversity and activity of group 5/1h high-affinity H2 oxidizing bacteria is non-responsive to pH 5/1h组高亲和H2氧化菌的多样性和活性对pH无响应

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-05 DOI: 10.1016/j.soilbio.2026.110111

Lijun Hou , Philippe Constant , Joann K. Whalen

Biological high-affinity H₂ uptake in soil is the largest global sink for atmospheric H₂. Soil pH often influences soil biological activity but the impact of pH on high-affinity H₂ oxidizing bacteria (HOB) was not confirmed. We compared the activity and diversity of group 5/1h HOB in agricultural and forest soils across a gradient from pH 4 to pH 8. The potential H₂ uptake activity was approximately 2 times higher in agricultural soil than in forest soil across the pH gradient. Both H₂ oxidizing activity and HOB community structure were non-responsive to pH adjustment in these soils, and no pH optima was observed. Greater H₂ oxidizing activity was associated with higher iron content and lower carbon and nitrogen concentrations in soil. Catabolic repression of HOB was likely triggered when more organic carbon was present, due to the mixotrophic metabolism in the HOB community. A few hhyL genotypes (5%) responded to pH manipulation, but preference for acidic or alkaline pH was not consistent at the HOB taxonomic level. We conclude that pH preference is not an ecological trait that predicts group 5/1h HOB distribution in soil.

土壤生物高亲和H2吸收是全球最大的大气H2汇。土壤pH经常影响土壤生物活性，但pH对高亲和H2氧化菌（HOB）的影响尚未得到证实。我们比较了在pH 4 ~ pH 8梯度下农业和森林土壤中5/1h群HOB的活性和多样性。在不同的pH梯度下，农业土壤的潜在H2吸收活性大约是森林土壤的2倍。H2氧化活性和HOB群落结构均不受pH调节的影响，不存在最优pH值。土壤H2氧化活性越强，铁含量越高，碳氮浓度越低。由于HOB群落的混合营养代谢，当存在更多有机碳时，可能会触发HOB的分解代谢抑制。少数hhyL基因型（5%）对pH操纵有反应，但在HOB分类水平上对酸性或碱性pH的偏好并不一致。因此，pH偏好并不是预测5/1h HOB在土壤中分布的生态性状。

{"title":"Diversity and activity of group 5/1h high-affinity H2 oxidizing bacteria is non-responsive to pH","authors":"Lijun Hou , Philippe Constant , Joann K. Whalen","doi":"10.1016/j.soilbio.2026.110111","DOIUrl":"10.1016/j.soilbio.2026.110111","url":null,"abstract":"<div><div>Biological high-affinity H<sub>2</sub> uptake in soil is the largest global sink for atmospheric H<sub>2</sub>. Soil pH often influences soil biological activity but the impact of pH on high-affinity H<sub>2</sub> oxidizing bacteria (HOB) was not confirmed. We compared the activity and diversity of group 5/1h HOB in agricultural and forest soils across a gradient from pH 4 to pH 8. The potential H<sub>2</sub> uptake activity was approximately 2 times higher in agricultural soil than in forest soil across the pH gradient. Both H<sub>2</sub> oxidizing activity and HOB community structure were non-responsive to pH adjustment in these soils, and no pH optima was observed. Greater H<sub>2</sub> oxidizing activity was associated with higher iron content and lower carbon and nitrogen concentrations in soil. Catabolic repression of HOB was likely triggered when more organic carbon was present, due to the mixotrophic metabolism in the HOB community. A few <em>hhyL</em> genotypes (5%) responded to pH manipulation, but preference for acidic or alkaline pH was not consistent at the HOB taxonomic level. We conclude that pH preference is not an ecological trait that predicts group 5/1h HOB distribution in soil.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110111"},"PeriodicalIF":10.3,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146134151","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

Root exudate-induced priming of CO2 and CH4 in a thawing permafrost peatland 冻土融化中根系分泌物诱导CO2和CH4的启动

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-05 DOI: 10.1016/j.soilbio.2026.110110

Marie Mollenkopf , Sylvain Monteux , Ellen Dorrepaal , Birgit Wild , Joachim Kilian , Mark Stahl , Andreas Kappler , E. Marie Muehe

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.

由于气候变暖，北极永久冻土面临着融化、排水和植被转移等多种相互作用的变化。解冻引起的内涝可以将植被从灌木转变为禾草，从而改变温室气体排放。本研究旨在量化和机械地解释在解冻和排水过渡期间，特定植被的根系分泌物如何放大或抑制北极永久冻土的温室气体排放。通过实地观察和土壤培养，我们发现，从特定解冻阶段的植物中获得的根有机渗出物（占溶解有机碳的15%）的环境相关浓度，在现场真实的氧化还原条件下改变了温室气体通量。禾本科植物分泌物中糖和羧酸含量较高，而灌木植物分泌物中氨基酸含量较高。在解冻的、缺氧的永久冻土土壤培养中，与没有渗出物相比，禾禾类渗出物刺激了51%的CO2和83%的CH4的排放。在完整、排水的永久冻土中，与未处理的土壤相比，灌木渗出物增加了14%的CO2和可忽略不计的CH4。地球化学和微生物分析表明，土壤（包括其水文）和渗出物的差异驱动了渗出物和土壤有机质的分解。这些土壤孵化结果得到了实地测量的支持：每个土壤栖息地的裸露地点提供了与每种土壤的水分和地球化学性质有关的温室气体通量基线。禾本科植被显著增加了冻融土壤的温室气体排放，而灌木对冻融土壤的温室气体排放几乎没有影响。总的来说，这项研究表明，特定于融化的植被塑造了温室气体通量，表明植被的变化可以加剧辐射强迫，超出了已知的永久冻土融化和相关水文转变的直接影响。澄清这些独特的渗出物效应背后的环境依赖性和机制可能会改善北极陆地气候反馈的预估。

{"title":"Root exudate-induced priming of CO2 and CH4 in a thawing permafrost peatland","authors":"Marie Mollenkopf , Sylvain Monteux , Ellen Dorrepaal , Birgit Wild , Joachim Kilian , Mark Stahl , Andreas Kappler , 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 CO<sub>2</sub> and 83% more CH<sub>4</sub> compared to the absence of exudates. In intact, drained permafrost soil, shrub exudates stimulated 14% more CO<sub>2</sub> and negligible CH<sub>4</sub> 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":"2026-02-05","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}

引用次数: 0

Glucose input limits microbial-mediated sulfur release from soil minerals 葡萄糖输入限制土壤矿物质中微生物介导的硫释放

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-02-04 DOI: 10.1016/j.soilbio.2026.110109

Min Zhang , Zhuzhong Yin , Yu Liu , Yanyu Liu , Zhenghua Liu , Zhaoyue Yang , Zhengqi Xu , Ibrahim Ahmed Ibrahim , Fenliang Fan , Ye Deng , Xueduan Liu , Chengying Jiang , Huaqun Yin , Delong Meng

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 (soxB, soxX, soxY, soxZ) were depleted before day 42. This inhibition was reversed after glucose depletion, with sulfur oxidation genes becoming enriched. DNA-SIP using ¹³C-glucose linked Frateuria and Dyella 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 Bradyrhizobium. Notably, Dyella 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.

含硫矿物是全球硫循环的关键储集层，微生物介导了这些矿物中硫的释放。不稳定碳输入可能改变微生物硫代谢，但其对硫化物矿物氧化的净效应尚不清楚。在这里，我们进行了为期56天的葡萄糖输入土壤培养，并结合地球化学测量、矿物学表征、qPCR、宏基因组学、16S rRNA扩增子测序和dna稳定同位素探测（DNA-SIP）来鉴定葡萄糖同化微生物及其在调节硫化物矿物氧化中的作用。葡萄糖显著抑制了硫化物矿物的氧化，使第56天的硫酸盐（SO42-）比对照降低了60.00%，pH比对照提高了33.23%。葡萄糖也重塑了微生物群落和功能电位。硫氧化细菌（SOB）数量减少，硫酸盐还原细菌（SRB）数量增加，与硫氧化有关的基因（soxB、soxX、soxY、soxZ）在第42天前被耗尽。这种抑制在葡萄糖消耗后被逆转，硫氧化基因变得丰富。DNA-SIP利用13c -葡萄糖将兄弟姐妹菌和痢疾菌连接到葡萄糖同化和硫释放抑制阶段。葡萄糖修饰的微生物保持较低的氧化还原电位，并表现出相对于对照的延迟上升，这与氧气竞争可能抑制硫氧化剂（如慢生根瘤菌）一致。值得注意的是，Dyella拥有一个完整的同化硫酸盐还原途径，由ATP和NADPH驱动，通过中心碳代谢（CCM）产生。这种代谢偶联降低了末端硫氧化的氧利用率，表明硫释放抑制的双重机制通过同化还原和呼吸竞争来实现。我们的研究结果强调了土壤中不稳定的碳代谢和硫循环之间以前未被重视的联系。这一机制为微生物对硫通量的控制提供了见解，并为在富含矿物质的环境中管理土壤酸化和硫驱动的水污染提供了启示。

{"title":"Glucose input limits microbial-mediated sulfur release from soil minerals","authors":"Min Zhang , Zhuzhong Yin , Yu Liu , Yanyu Liu , Zhenghua Liu , Zhaoyue Yang , Zhengqi Xu , Ibrahim Ahmed Ibrahim , Fenliang Fan , Ye Deng , Xueduan Liu , Chengying Jiang , Huaqun Yin , 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 (SO<sub>4</sub><sup>2−</sup>) 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 <sup>13</sup>C-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":"2026-02-04","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}

引用次数: 0

Meta-analysis reveals contrasting effects of biodegradable and conventional microplastics on earthworm fitness, physiology, and gut microbiota 荟萃分析揭示了可生物降解微塑料和常规微塑料对蚯蚓健康、生理和肠道微生物群的不同影响

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-01-31 DOI: 10.1016/j.soilbio.2026.110108

Hesen Zhong , Jerome Mathieu , Chengshuai Liu , Patrick Lavelle , Jun Dai , Ying Lu , Chi Zhang

Microplastics (MPs) have become widespread contaminants in terrestrial ecosystems and may pose risks to soil fauna, particularly earthworms, a key group of soil ecosystem engineers. Because laboratory ecotoxicological studies have demonstrated that MPs disrupt earthworm physiological and cellular functions, then we must establish whether earthworms respond consistently to the conventional MPs and newer types of biodegradable MPs. Here, we conducted a quantitative meta-analysis of peer-reviewed studies published from database inception to 8 December 2025 to assess the effects of conventional and biodegradable MPs on earthworm fitness, physiology, and gut microbiota. A total of 2124 observations extracted from 102 articles were evaluated for the effect of MPs on 15 indicators of earthworm. Overall, MPs exposure reduced survival and growth rates, increased oxidative stress and oxidative DNA damage, and inhibited gut bacterial diversity and richness. Meta-regression analysis indicated that conventional MPs exhibited stronger dose-dependent toxicity patterns, characterized by increased catalase (CAT), and peroxidase (POD) activities, elevated malondialdehyde (MDA), and decreased survival and growth at higher doses. In contrast, biodegradable MPs primarily affected reproduction, CAT activity and glutathione (GSH) level in a size-dependent manner. Among the MPs and experiment features, the MP shape, dose, and exposure duration were most likely to cause earthworm responses, with MDA, 8-hydroxy-2′-deoxyguanosine (8-OHdG), and reactive oxygen species (ROS) consistently acting as sensitive physiological indicators of MPs exposure in earthworms. Overall, MP pollution poses substantial risks to earthworms and gut microbial communities, and biodegradable MPs do not eliminate the earthworm biological responses. This suggests that substituting biodegradable MPs for conventional MPs might not improve earthworm survival, growth and reproduction, which has implications for earthworm populations and community ecology.

微塑料（MPs）已成为陆地生态系统中广泛存在的污染物，并可能对土壤动物，特别是土壤生态系统工程师的关键群体蚯蚓构成威胁。由于实验室生态毒理学研究表明，MPs会破坏蚯蚓的生理和细胞功能，因此我们必须确定蚯蚓对传统MPs和新型可生物降解MPs的反应是否一致。在这里，我们对从数据库建立到2025年12月8日发表的同行评议研究进行了定量荟萃分析，以评估常规和可生物降解MPs对蚯蚓健康、生理和肠道微生物群的影响。从102篇文献中提取了2124条观察结果，评估了MPs对蚯蚓15项指标的影响。总体而言，MPs暴露降低了存活和生长速度，增加了氧化应激和氧化DNA损伤，抑制了肠道细菌的多样性和丰富度。荟萃回归分析表明，传统MPs表现出更强的剂量依赖性毒性模式，其特征是过氧化氢酶（CAT）和过氧化物酶（POD）活性增加，丙二醛（MDA）升高，高剂量下存活和生长降低。相比之下，可生物降解的MPs主要影响生殖，CAT活性和谷胱甘肽（GSH）水平的大小依赖的方式。在MPs和实验特征中，MP的形状、剂量和暴露时间最容易引起蚯蚓的反应，其中MDA、8-羟基-2 ' -脱氧鸟苷（8-OHdG）和活性氧（ROS）一直是蚯蚓MPs暴露的敏感生理指标。总的来说，MP污染对蚯蚓和肠道微生物群落构成了巨大的风险，可生物降解的MP并不能消除蚯蚓的生物反应。这表明用可生物降解的MPs代替传统的MPs可能不会提高蚯蚓的生存、生长和繁殖，这对蚯蚓种群和群落生态有影响。

{"title":"Meta-analysis reveals contrasting effects of biodegradable and conventional microplastics on earthworm fitness, physiology, and gut microbiota","authors":"Hesen Zhong , Jerome Mathieu , Chengshuai Liu , Patrick Lavelle , Jun Dai , Ying Lu , Chi Zhang","doi":"10.1016/j.soilbio.2026.110108","DOIUrl":"10.1016/j.soilbio.2026.110108","url":null,"abstract":"<div><div>Microplastics (MPs) have become widespread contaminants in terrestrial ecosystems and may pose risks to soil fauna, particularly earthworms, a key group of soil ecosystem engineers. Because laboratory ecotoxicological studies have demonstrated that MPs disrupt earthworm physiological and cellular functions, then we must establish whether earthworms respond consistently to the conventional MPs and newer types of biodegradable MPs. Here, we conducted a quantitative meta-analysis of peer-reviewed studies published from database inception to 8 December 2025 to assess the effects of conventional and biodegradable MPs on earthworm fitness, physiology, and gut microbiota. A total of 2124 observations extracted from 102 articles were evaluated for the effect of MPs on 15 indicators of earthworm. Overall, MPs exposure reduced survival and growth rates, increased oxidative stress and oxidative DNA damage, and inhibited gut bacterial diversity and richness. Meta-regression analysis indicated that conventional MPs exhibited stronger dose-dependent toxicity patterns, characterized by increased catalase (CAT), and peroxidase (POD) activities, elevated malondialdehyde (MDA), and decreased survival and growth at higher doses. In contrast, biodegradable MPs primarily affected reproduction, CAT activity and glutathione (GSH) level in a size-dependent manner. Among the MPs and experiment features, the MP shape, dose, and exposure duration were most likely to cause earthworm responses, with MDA, 8-hydroxy-2′-deoxyguanosine (8-OHdG), and reactive oxygen species (ROS) consistently acting as sensitive physiological indicators of MPs exposure in earthworms. Overall, MP pollution poses substantial risks to earthworms and gut microbial communities, and biodegradable MPs do not eliminate the earthworm biological responses. This suggests that substituting biodegradable MPs for conventional MPs might not improve earthworm survival, growth and reproduction, which has implications for earthworm populations and community ecology.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"216 ","pages":"Article 110108"},"PeriodicalIF":10.3,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095786","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

Optimal soil storage methods for enzyme activity assays: a meta-analysis 酶活性测定的最佳土壤储存方法：荟萃分析

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-01-30 DOI: 10.1016/j.soilbio.2026.110107

Chammi P. Attanayake , Andrew J. Margenot

The lack of standardized soil storage methods for enzyme activity assays has restricted cross-comparison of activities in the literature, but reported effects of soil sample storage on enzyme activities are often study-specific and conflicting. We conducted a systematic literature review and meta-analysis to (1) identify data gaps in evaluations of storage effects on soil enzyme activities and (2) quantify enzyme activity responses to soil sample storage method and duration. Evaluated storage methods were (i) cold (field moist soils at 2–7 °C), (ii) freeze (field moist soils at −5 to −35 °C) or (iii) air-dry (air-drying and storing at room temperature, assumed to be ≈ 24 °C) relative to activities assayed ≤24 h of soil sampling (field fresh) and/or in soils under cold storage. Twenty-two research articles evaluated 106 soils for effects of one or more three soil storage methods on activities of β-glucosidase (BG), phosphomonoesterase (PME, assayed at pH 4.0–6.5), N-acetyl-β-glucosaminidase (NAG), and urease (URE). Most soils evaluated were acidic (86 %), and were Oxisols (34 %) or Mollisols (19 %). Soil storage decreased BG (9–55 %) and PME (7–53 %) activities relative to field fresh soils least with cold storage, and decreased NAG activities (33–68 %) least with cold and freeze storage. Greatest decreases occurred with air-drying for BG, PME and NAG relative to activities in field fresh soils or under cold storage. Only under cold storage was URE activity impacted (−8 %). Changes in enzyme activities by storage method were independent of storage duration, except for continued decreases in BG activity under cold storage. The decreases in activities due to storage were largely inconsistent across soil pH, clay, OC, and USDA taxonomic order, and varied by assay method. Based on least decreases in activities that were consistent across soil properties and types, the most appropriate soil storage method appeared to be cold storage ≤3 d for chromogenically assayed BG activity and freeze storage for fluorogenically assayed BG and PME activities.

缺乏用于酶活性测定的标准化土壤储存方法限制了文献中活性的交叉比较，但报道的土壤样品储存对酶活性的影响通常是研究特异性的和相互矛盾的。我们进行了系统的文献综述和荟萃分析，以(1)找出土壤酶活性评估中的数据缺口；(2)量化酶活性对土壤样品储存方法和持续时间的响应。评估的储存方法是(i)冷（2-7°C的田间潮湿土壤），（ii）冷冻（- 5至- 35°C的田间潮湿土壤）或（iii）风干（风干并在室温下储存，假设为≈24°C）相对于≤24小时的土壤取样（田间新鲜）和/或在冷藏土壤中进行。22篇研究文章评估了106种土壤中一种或三种以上土壤储存方法对β-葡萄糖苷酶（BG）、磷酸单酯酶（PME，测定pH 4.0-6.5）、n -乙酰-β-葡萄糖苷酶（NAG）和脲酶（URE）活性的影响。大多数评价土壤为酸性（86%），氧化性（34%）和软溶质（19%）。与田间新鲜土壤相比，低温贮藏降低了BG（9 - 55%）和PME（7 - 53%）活性，低温和冷冻贮藏降低了NAG活性（33 - 68%）。与田间新鲜土壤和冷藏条件下相比，空气干燥条件下BG、PME和NAG的降低幅度最大。只有在冷藏条件下，URE活性受到影响（- 8%）。除BG活性在冷藏条件下持续下降外，不同贮藏方式下酶活性的变化与贮藏时间无关。贮藏导致的活性降低在不同的土壤pH、粘土、有机碳和USDA分类顺序上是不一致的，并且在不同的测定方法上是不同的。根据不同土壤性质和类型的活性下降最小的一致性，对于显色测定的BG活性，最合适的土壤储存方法似乎是冷藏≤3 d，对于荧光测定的BG和PME活性，冷冻储存。

{"title":"Optimal soil storage methods for enzyme activity assays: a meta-analysis","authors":"Chammi P. Attanayake , Andrew J. Margenot","doi":"10.1016/j.soilbio.2026.110107","DOIUrl":"10.1016/j.soilbio.2026.110107","url":null,"abstract":"<div><div>The lack of standardized soil storage methods for enzyme activity assays has restricted cross-comparison of activities in the literature, but reported effects of soil sample storage on enzyme activities are often study-specific and conflicting. We conducted a systematic literature review and meta-analysis to (1) identify data gaps in evaluations of storage effects on soil enzyme activities and (2) quantify enzyme activity responses to soil sample storage method and duration. Evaluated storage methods were (i) cold (field moist soils at 2–7 °C), (ii) freeze (field moist soils at −5 to −35 °C) or (iii) air-dry (air-drying and storing at room temperature, assumed to be ≈ 24 °C) relative to activities assayed ≤24 h of soil sampling (field fresh) and/or in soils under cold storage. Twenty-two research articles evaluated 106 soils for effects of one or more three soil storage methods on activities of β-glucosidase (BG), phosphomonoesterase (PME, assayed at pH 4.0–6.5), <em>N</em>-acetyl-β-glucosaminidase (NAG), and urease (URE). Most soils evaluated were acidic (86 %), and were Oxisols (34 %) or Mollisols (19 %). Soil storage decreased BG (9–55 %) and PME (7–53 %) activities relative to field fresh soils least with cold storage, and decreased NAG activities (33–68 %) least with cold and freeze storage. Greatest decreases occurred with air-drying for BG, PME and NAG relative to activities in field fresh soils or under cold storage. Only under cold storage was URE activity impacted (−8 %). Changes in enzyme activities by storage method were independent of storage duration, except for continued decreases in BG activity under cold storage. The decreases in activities due to storage were largely inconsistent across soil pH, clay, OC, and USDA taxonomic order, and varied by assay method. Based on least decreases in activities that were consistent across soil properties and types, the most appropriate soil storage method appeared to be cold storage ≤3 d for chromogenically assayed BG activity and freeze storage for fluorogenically assayed BG and PME activities.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"215 ","pages":"Article 110107"},"PeriodicalIF":10.3,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089460","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

Does soil inoculation truly steer the composition of native soil communities? 土壤接种真的能控制原生土壤群落的组成吗？

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-01-29 DOI: 10.1016/j.soilbio.2026.110105

Yuhui Li , Yingbin Li , Xu Han , Qi Li , T. Martijn Bezemer

Soil inoculation is a promising tool for restoring degraded ecosystems, that is based on the assumption that introduced soil communities establish in the new environment and create positive feedback with new plant communities. However, we lack empirical evidence on the extent to which the soil community present in the relatively small amount of inoculated soil can truly alter the recipient or native soil community in the field. For the first time, we measured the soil community in both the inoculated and in the underlying soil layers in a whole-soil inoculation experiment in a restoration grassland. Within the inoculated layer, nematode and bacterial communities became increasingly similar to the donor soil community. However, in the soil layer beneath the inoculated layer, the similarity of the native bacterial and nematode communities to the donor community did not change significantly over time. Only the native fungal community gradually shifted towards the community present in the donor meadow. Our study provides conclusive field evidence that soil inoculation can restructure soil biota at the recipient site, but this effect is largely restricted to the inoculated soil layer. This challenges the commonly held assumption that soil inoculation drives changes in native soil communities through positive plant-soil feedbacks.

土壤接种是恢复退化生态系统的一种很有前景的工具，其基础假设是引入的土壤群落在新环境中建立并与新的植物群落产生正反馈。然而，我们缺乏经验证据表明，在相对少量的接种土壤中存在的土壤群落在多大程度上能够真正改变田间接受者或原生土壤群落。在恢复草地全土壤接种试验中，首次对接种层和下垫层土壤群落进行了测量。在接种层内，线虫和细菌群落与供体土壤群落越来越相似。然而，在接种层以下的土层中，原生细菌和线虫群落与供体群落的相似性没有随时间发生显著变化。只有原生真菌群落逐渐向供体草甸中存在的群落转移。我们的研究提供了确凿的田间证据，证明土壤接种可以重构受训地的土壤生物群，但这种作用主要局限于接种层。这挑战了普遍持有的假设，即土壤接种通过积极的植物-土壤反馈驱动原生土壤群落的变化。

{"title":"Does soil inoculation truly steer the composition of native soil communities?","authors":"Yuhui Li , Yingbin Li , Xu Han , Qi Li , T. Martijn Bezemer","doi":"10.1016/j.soilbio.2026.110105","DOIUrl":"10.1016/j.soilbio.2026.110105","url":null,"abstract":"<div><div>Soil inoculation is a promising tool for restoring degraded ecosystems, that is based on the assumption that introduced soil communities establish in the new environment and create positive feedback with new plant communities. However, we lack empirical evidence on the extent to which the soil community present in the relatively small amount of inoculated soil can truly alter the recipient or native soil community in the field. For the first time, we measured the soil community in both the inoculated and in the underlying soil layers in a whole-soil inoculation experiment in a restoration grassland. Within the inoculated layer, nematode and bacterial communities became increasingly similar to the donor soil community. However, in the soil layer beneath the inoculated layer, the similarity of the native bacterial and nematode communities to the donor community did not change significantly over time. Only the native fungal community gradually shifted towards the community present in the donor meadow. Our study provides conclusive field evidence that soil inoculation can restructure soil biota at the recipient site, but this effect is largely restricted to the inoculated soil layer. This challenges the commonly held assumption that soil inoculation drives changes in native soil communities through positive plant-soil feedbacks.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"215 ","pages":"Article 110105"},"PeriodicalIF":10.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072095","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

Stand age and fire return interval shape soil microbial communities in young, postfire lodgepole pine stands 林龄和还火间隔对幼龄、火后黑松林分土壤微生物群落的影响

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-01-28 DOI: 10.1016/j.soilbio.2026.110102

Arielle C. Link , Thea Whitman , Monica G. Turner

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 (Pinus contorta var. latifolia) 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 (>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.

随着野火活动在全球范围内的增加，了解火灾后幼林土壤微生物群落的变化以及较短的火灾返回间隔对这些群落的影响对于预测火灾后生态系统功能变得越来越重要。我们询问了在火种后早期黑松（Pinus contorta var. latifolia）森林中土壤细菌和真菌群落是如何变化的，以及短间隔（16年）的再燃烧是否改变了这些轨迹。我们对美国怀俄明州大提顿国家公园6年、22年和34年树龄林分的土壤进行了采样，并利用高通量测序技术评估了群落组成、环境驱动因素和火灾响应分类群。在典型的还火间隔下，细菌和真菌群落组成随林龄的变化而变化。对于真菌而言，子囊菌的相对丰度随着林龄的增加而下降，而担子菌的相对丰度则增加，这与预期的与黑松相关的外生菌根真菌的增加一致。凋落物质量和土壤养分特性分别解释了28.6%和23.9%的细菌和真菌群落组成变异。在短间隔林分换火之后，6年树龄林分中的细菌群落与附近未再次燃烧的林分（22年）非常相似，而真菌群落与历史上较长的（100年）回火间隔中燃烧过的6年树龄林分更相似。这些结果表明，在火灾后森林林分发育早期，微生物的恢复受资源可用性变化的影响，并且较短的还火间隔可能对真菌的影响大于对细菌的影响。

{"title":"Stand age and fire return interval shape soil microbial communities in young, postfire lodgepole pine stands","authors":"Arielle C. Link , Thea Whitman , 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 (>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":"2026-01-28","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}

引用次数: 0

Subsoil rhizosphere carbon enrichment and depletion: processes and scaling in tree-based systems 地下根际碳富集和消耗：树木系统的过程和结垢

IF 10.3 1区农林科学 Q1 SOIL SCIENCE

Soil Biology & Biochemistry

Pub Date : 2026-01-27 DOI: 10.1016/j.soilbio.2026.110103

Gabin Piton , Elisa Taschen , Clara Ducrocq , Soline Martin-Blangy , Laurie Amenc , Pauline Castel , Damien Dezette , Rémi Dugué , Marion Forest , Philippe Hinsinger , Benoit Marie , Aline Personne , Manoël Seignon , Jerôme Ngao , Christophe Jourdan , Isabelle Bertrand

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 Robinia pseudoacacia 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.

树根有可能将碳释放到深层土壤中，这些碳通常被认为在那里表现出更大的稳定性。然而，研究树木根际土壤有机碳平衡的驱动因素并将其提升到整个土壤剖面的实地研究缺乏。本研究提出了一种整合标准化根际采样和根密度测绘至1.5 m深度的地中海农林业和人工林树下的原始方法。不同土层刺槐根际有机碳平衡在-38 ~ +53 kg C ha-1之间变化，0 ~ 0.3 m处为中性平衡，0.3 ~ 0.5 m处为负平衡，0.5 ~ 1.0 m和1.0 ~ 1.5 m处为正平衡。当放大到整个剖面时，人工林的值为+50.6 kg C ha-1，农林复合系统的树行值为+72.4 kg C ha-1，两者之间没有显著差异。水解酶和氧化酶活性之间的平衡以及真菌行会之间的平衡表明，深层腐生微生物的营养限制在增加。在地下土壤中，这些营养限制在根际被局部减弱，导致微生物丰度大幅增加，并引发从贫营养群落向富营养群落的明显转变，从而支持有机碳的富集。在表层土壤中，微生物可利用的基质的化学复杂性较低，增加了对腐坏活性的敏感性，这可能是根际观察到的中性或负SOC平衡的基础。本研究提出了一种量化深层土壤根际有机碳平衡并解开其生物地球化学驱动因素的可扩展方法。

{"title":"Subsoil rhizosphere carbon enrichment and depletion: processes and scaling in tree-based systems","authors":"Gabin Piton , Elisa Taschen , Clara Ducrocq , Soline Martin-Blangy , Laurie Amenc , Pauline Castel , Damien Dezette , Rémi Dugué , Marion Forest , Philippe Hinsinger , Benoit Marie , Aline Personne , Manoël Seignon , Jerôme Ngao , Christophe Jourdan , 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<sup>−1</sup> to +53 kg C ha<sup>−1</sup> 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<sup>−1</sup> for the tree plantation and +72.4 kg C ha<sup>−1</sup> 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":"2026-01-27","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}

引用次数: 0