Soil Biology & Biochemistry最新文献

{"title":"Evaluating soil dissolved organic matter as a proxy for soil organic matter properties across diverse ecosystems","authors":"Shanyi Tian ,&nbsp;Songbo Yao ,&nbsp;Sihua Zhu ,&nbsp;Peng Li ,&nbsp;Tongwen Zhang ,&nbsp;Xiaolei Su ,&nbsp;Rong Huang ,&nbsp;Yongguang Yin ,&nbsp;Jitao Lv ,&nbsp;Tao Jiang ,&nbsp;Dingyong Wang","doi":"10.1016/j.soilbio.2025.109752","DOIUrl":"10.1016/j.soilbio.2025.109752","url":null,"abstract":"<div><div>Soil organic matter (SOM) includes the soil dissolved organic matter (SDOM), an active pool in carbon biogeochemistry that contributes to vital ecosystem services such as carbon sequestration. Although SDOM properties could be related to SOM bioavailability and persistence, it needs to be confirmed that SDOM properties are related to SOM dynamics in diverse ecosystems. We collected and analyzed 31 soil samples from three ecosystems (12 croplands, 8 grasslands, and 11 forests) in western China to assess the characteristics of SOM and SDOM using multiple methods, including optical, isotopic, biomarker, and wet chemical extraction methods. Three independent multifunctionality statistical methods were used to evaluate the measured SOM or SDOM properties, and to derive a quantitative metric of the SOM persistence, defined as the organic matter persistence index (PI). The influencial SOM and SDOM properties were further confirmed by feature selection algorithms. We evaluated the relationship between the PI derived from SOM (PI_SOM) and that of the SDOM (PI_SDOM). Generally, forest soil had the highest SOM persistence, followed by grasslands and then croplands. In forests and grasslands, PI_SDOM was highly positively related to PI_SOM, indicating that it is reasonable to evaluate SOM persistence using SDOM properties as proxies in those two ecosystems. In croplands, the SOM persistence was not strongly related to the SDOM properties. We conclude that SDOM properties can be assessed rapidly and conveniently as a surrogate for SOM bioavailability and persistence, the SDOM metrics should be used cautiously because the SDOM-SOM relationship is ecosystem-dependent. Overall, this work advances the application of multi-property statistical methods for better understanding of SOM properties.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"204 ","pages":"Article 109752"},"PeriodicalIF":9.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of death and lysis of microbial and plant cells in the formation of soil organic matter","authors":"Paolo Nannipieri ,&nbsp;Gerrit Angst ,&nbsp;Carsten Mueller ,&nbsp;Giacomo Pietramellara","doi":"10.1016/j.soilbio.2025.109750","DOIUrl":"10.1016/j.soilbio.2025.109750","url":null,"abstract":"<div><div>Processes occurring in soil after microbial and plant cell death and release, adsorption, or degradation of cell molecules and organelles after cell lysis are poorly understood despite their contribution to the formation of soil organic matter (SOM). In this review, we discuss the many knowledge gaps with respect to processes occurring after death and lysis of plant and microbial cells and propose directions for future research to fill these gaps. We specifically highlight that while model studies using surface-reactive particles, such as clay minerals, have studied adsorption and binding of important biological molecules, such as proteins (including enzymes) and DNA, these processes have not been studied for entire cell organelles. These can contribute to the formation of SOM via preservation of their contents by microbial processing and subsequent adsorption on surface-reactive soil particles or occlusion in soil aggregates as microbial necromass. Moreover, active enzymes can persist after cell death and contribute to the formation of necromass in a disorganized cell environment. However, the persistence of active enzymes in soil after cell death is poorly studied. We argue that high resolution imaging techniques, for instance nano-scale secondary ion mass spectrometry (NanoSIMS), can aid in closing the related research gaps by resolving the distribution of soil organic carbon at the micro and nanometer scales, at which the above processes occur. Finally, the quantification of microbial- and plant-derived SOM is still challenging because the most commonly used marker for microbial necromass (amino sugars) only represents a part of microbial cells. The risk of overestimation is high, and we propose combining amino sugar and extracellular DNA determination to confirm necromass origin and reduce this risk. Better knowledge of the processes occurring after death and lysis of plant and microbial cells and improved quantification of plant and microbial necromass will provide more detailed insights into the formation of SOM and allow for a more efficient management of soil organic C.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"204 ","pages":"Article 109750"},"PeriodicalIF":9.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417447","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":"Microbial scents: Soil microbial Volatile Organic Compounds (mVOCs) as biomarkers for grasslands across a land use gradient","authors":"Rosa W.C. Boone ,&nbsp;Joris Meurs ,&nbsp;Riikka Rinnan ,&nbsp;Hannie de Caluwe ,&nbsp;Anouk A. Wakely ,&nbsp;Jan-Willem C. Takke ,&nbsp;Simona M. Cristescu ,&nbsp;Wim H. van der Putten ,&nbsp;Hans de Kroon ,&nbsp;Bjorn J.M. Robroek","doi":"10.1016/j.soilbio.2025.109749","DOIUrl":"10.1016/j.soilbio.2025.109749","url":null,"abstract":"<div><div>Extensifying land use practices – i.e. decreasing management intensity – is pivotal to facilitate the transition towards sustainable agriculture in productive grasslands, as it promotes the enhancement of soil biotic communities that support important ecosystem services. To monitor these transitions effectively, improved inventories are needed to track changes in microbial communities. Microbial Volatile Organic Compounds (mVOCs) are potential biomarkers that can link soil community change to land use extensification (i.e. reducing land use intensity) and may provide important information on changes in soil processes in transitional productive grasslands. We investigated how land use extensification affects mVOC profiles in grassland soils through both abiotic and biotic factors and whether mVOCs can be linked to bacterial (16S) and fungal (ITS2) community composition. We measured mVOCs (GC-MS), microbial communities, and abiotic soil parameters (SOM, SOC, pH, bulk density, and nutrients) across eighteen grasslands with varying land use intensity. A total of 75 mVOCs were identified using the mVOC 4.0 library. Furthermore, we show that mVOC profiles and chemical classes differ across land use types – conventional, extensive, and semi-natural grasslands. Within these grasslands, only fungi showed distinct community compositions between land use intensity types, whereas there were no compositional differences of bacteria. Using Taxon Indicator Threshold Analysis (TITAN), we identified sixteen mVOC compounds that varied significantly along a land use intensification gradient. These findings suggest that mVOCs can serve as biomarkers linking changes in land use intensity and soil microbial communities, although these relationships are complex in field conditions. We identified a set of mVOCs tied to changes in land-use extensification and highlighted their potential as indicators of soil microbial community turnover. mVOCs offer a valuable tool for monitoring land use transitions, and our results emphasize their role in integrating microbial community metrics and soil health indicators into land management strategies.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"204 ","pages":"Article 109749"},"PeriodicalIF":9.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioavailable carbon additions to soil promote free-living nitrogen fixation and microbial biomass growth with N-free lipids","authors":"Georg Dittmann ,&nbsp;Su Ding ,&nbsp;Ellen C. Hopmans ,&nbsp;Simon A. Schröter ,&nbsp;Alice M. Orme ,&nbsp;Erika Kothe ,&nbsp;Markus Lange ,&nbsp;Gerd Gleixner","doi":"10.1016/j.soilbio.2025.109748","DOIUrl":"10.1016/j.soilbio.2025.109748","url":null,"abstract":"<div><div>Globally, the process of atmospheric nitrogen (N₂) fixation by free-living diazotrophs in soils contributes significantly to the soil N supply, yet the understanding of its driving factors, particularly the role of energy availability, is limited. In this study, we explored how two different energy sources, an artificial carbon input, simulating highly bioavailable root exudates, and a natural gradient in soil organic matter that requires decomposition, affect N₂ fixation by free-living diazotrophs and soil microbial community functions through microcosm ¹⁵N₂ incubation experiments. We analysed the incorporation of ¹⁵N into soil and used mass spectrometry to determine microbial lipids, which serve as indicators of microbial community functions, via an untargeted lipidomics approach. Our findings demonstrate a significant capacity for N₂ fixation by free-living diazotrophs, with a potential annual storage of 111 kg N per hectare. The addition of artificial exudates yielded an extra of 51 kg N ha⁻¹y⁻¹. This N₂ fixation was accompanied by a presumable N limitation in the microbial community, as biomass growth favoured N-free lipids with an equal synthesis of storage (triacylglycerols) and structural membrane lipids. While energy addition boosted N uptake particularly in soils with low organic matter, in soils rich in organic matter, N uptake was naturally higher (an extra 20 kg N ha⁻¹y⁻¹), along with increased levels of membrane-associated lipids, suggesting a larger microbial community. Our results imply that enhanced root exudation, potentially driven by more productive plant communities, could mitigate the energy constraints on free-living diazotrophic N₂ fixation as part of a vital soil microbial community. These insights support the development of sustainable agricultural practices that stimulate the capacity for N₂ fixation by free-living diazotrophs, aiming to maintain ecological balance by minimising N loss from fertilisation.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109748"},"PeriodicalIF":9.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417454","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":"Soil trenching – are microbial communities alike in experimental peatland plots measuring total and heterotrophic respiration?","authors":"Hannu Fritze ,&nbsp;Jyrki Jauhiainen ,&nbsp;Arta Bārdule ,&nbsp;Aldis Butlers ,&nbsp;Dovilė Čiuldienė ,&nbsp;Muhammad Kamil-Sardar ,&nbsp;Ain Kull ,&nbsp;Raija Laiho ,&nbsp;Andis Lazdiņš ,&nbsp;Valters Samariks ,&nbsp;Thomas Schindler ,&nbsp;Kaido Soosaar ,&nbsp;Egidijus Vigricas ,&nbsp;Krista Peltoniemi","doi":"10.1016/j.soilbio.2025.109747","DOIUrl":"10.1016/j.soilbio.2025.109747","url":null,"abstract":"<div><div>Soil trenching is a generally applied method used to differentiate heterotrophic respiration (R_HET) from total respiration in soil CO₂ flux data collection. However, the soil microbial community composition may change due to trenching and estimates of the impacts of any human-induced disturbance on R_HET might be inflated if the microbial community involved was not the same as in the ambient untrenched environment. Here, we report that the bacterial and fungal community, as measured by amplicon sequencing, of 30 different research sites in peatland forests was mostly alike in trenched and untrenched plots still four years after trenching. Soil trenching thus seems to be a feasible method to study the R_HET from peatland forest soils from the overall microbial community composition point of view as no major changes were observed.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109747"},"PeriodicalIF":9.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric nitrogen deposition has minor impacts on the abundance and diversity of arbuscular mycorrhizal fungi and their contribution to soil carbon stock in tropical forests","authors":"Andi Li ,&nbsp;Peter Meidl ,&nbsp;Senhao Wang ,&nbsp;Bo Tang ,&nbsp;Matthias C. Rillig ,&nbsp;Guangcan Yu ,&nbsp;Jing Chen ,&nbsp;Rongzhen Liu ,&nbsp;Zhiyang Lie ,&nbsp;Anchi Wu ,&nbsp;Lili Rong ,&nbsp;Cheng Peng ,&nbsp;Zhanfeng Liu ,&nbsp;Wei Zhang ,&nbsp;Xiankai Lu ,&nbsp;Juxiu Liu ,&nbsp;Qing Ye ,&nbsp;Jiangming Mo ,&nbsp;Mianhai Zheng","doi":"10.1016/j.soilbio.2025.109746","DOIUrl":"10.1016/j.soilbio.2025.109746","url":null,"abstract":"<div><div>Knowledge about arbuscular mycorrhizal fungi (AMF) is crucial for understanding nutrient limitations on primary productivity and soil organic carbon (C) storage in terrestrial ecosystems. Both theoretical models and empirical evidence hold that nitrogen (N) addition in phosphorus-limited ecosystems can either increase or decrease AMF diversity and abundance. However, many of these studies involved high-level N additions, which do not reflect realistic levels of atmospheric N deposition, thus leading to biased estimations of AMF and their role in the soil C stock. Here, we assessed AMF diversity and abundance under N addition using data from five tropical forests, ranging from 88%, 31%, and 25% arbuscular mycorrhizal tree dominance to dual-mycorrhizal tree dominance, and combined it with a global synthesis of tropical/subtropical forests. Our field study showed that N addition based on realistic N deposition (≤50 kg N ha⁻¹ yr⁻¹, comparable to the actual rate of atmospheric N deposition in the studied sites) caused little change in AMF abundance and diversity, as confirmed by our meta-analysis. The responses of AMF abundance to N addition did not differ significantly across forests with varying mycorrhizal dominance. However, high-level N addition (&gt;50 kg N ha⁻¹ yr⁻¹) from a global dataset reduced AMF abundance and diversity. AMF responses were correlated with plant C, soil nutrient availability, and/or pH. Our findings further indicate that current atmospheric N deposition is unlikely to enhance soil C content via AMF. Given that N deposition has been stable or even declined in major global economies, we propose that previous studies may have overestimated AMF responses to atmospheric N deposition, which neither increased nor reduced AMF abundance and diversity as previously thought.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"204 ","pages":"Article 109746"},"PeriodicalIF":9.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401208","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":"AquaMEND: Reconciling multiple impacts of salinization on soil carbon biogeochemistry","authors":"Jianqiu Zheng ,&nbsp;Timothy D. Scheibe ,&nbsp;Melanie A. Mayes ,&nbsp;Michael N. Weintraub ,&nbsp;J. Patrick Megonigal ,&nbsp;Vanessa L. Bailey","doi":"10.1016/j.soilbio.2025.109745","DOIUrl":"10.1016/j.soilbio.2025.109745","url":null,"abstract":"<div><div>Soil salinization, exacerbated by climate change, poses a global threat to coastal ecosystems and soil function. Salinity affects soil carbon cycling by directly impacting microbial activity and indirectly altering soil physicochemical properties. Current models inadequately represent these complexities, relying on linear reduction functions that overlook specific physicochemical changes induced by salinity. AquaMEND addresses this gap by integrating microbial-explicit carbon decomposition modeling with advanced geochemical processes. Through the incorporation of equilibrium chemistry via PHREEQC, AquaMEND accurately predicts soil chemistry responses to salinization and enables detailed simulations on how salinity impacts microbial processes. To represent microbial responses to salinity, we developed salt-sensitive and slat-resistant response functions, with microbial activity inhibited by 50% at 4 ppt and 55 ppt, respectively. While the choice of salinity response functions influences model outcomes, simulations revealed that respiration responses to salinization varied depend on the underlying microbial mechanisms. Increased microbial mortality and impaired extracellular enzyme activity led to decreased respiration, while reduced carbon use efficiency could enhance respiration unless substrate uptake was also inhibited by high salinity. These microbial processes interact in a coordinated manner with multiple abiotic factors, collectively determining both the direction and magnitude of soil carbon responses. These findings highlight the need for novel experiments to disentangle the complex interactions governing microbial and geochemical responses to salinity. AquaMEND's capability to model such interactions offers a versatile tool for studying and predicting the effects of soil salinization on belowground carbon cycling.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109745"},"PeriodicalIF":9.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393921","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":"Soil viral community dynamics over seven years of heat disturbance: Spatial variation exceeds temporal in annually sampled soils","authors":"Samuel E. Barnett ,&nbsp;Ashley Shade","doi":"10.1016/j.soilbio.2025.109741","DOIUrl":"10.1016/j.soilbio.2025.109741","url":null,"abstract":"<div><div>Viruses are important components of the soil microbiome, influencing microbial population dynamics and the functions of their hosts. However, the relationships and feedbacks between virus dynamics, microbial host dynamics, and environmental disturbance are not understood. Centralia, PA, USA, is the site of an underground coal seam fire that has been burning for over 60 years. As the fire moves along the coal seam, previously heated soils cool to ambient temperature, creating a gradient of heat disturbance intensity and recovery. We examined annual soil viral population dynamics over seven consecutive years in Centralia using untargeted metagenome sequencing. Viral communities changed over time and were distinct between fire-affected and reference sites. Dissimilarity in viral communities was greater across sites (space) than within a site across years (time), and cumulative viral diversity more rapidly stabilized within a site across years than within a year across sites. There also were changes in number of CRISPR arrays per genome as soils cooled, corresponding to shifts in viral diversity. Finally, there were also differences in viral-encoded auxiliary metabolic genes between fire-affected and reference sites. Thus, despite high site-to-site soil viral diversity, there was surprising viral community consistency within a site over the years and shifting host-viral interactions in soils recovering from disturbance. Overall, this work provides insights into the interannual dynamics of soil viruses and their host communities, as well as how they collectively respond to long-term warming.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109741"},"PeriodicalIF":9.8,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385132","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":"Post-drought organic carbon mineralization leads to high productivity and nutrient uptake efficiency of perennial grassland after rewetting","authors":"Marie-Louise Schärer ,&nbsp;Lucia Fuchslueger ,&nbsp;Alberto Canarini ,&nbsp;Andreas Richter ,&nbsp;Andreas Lüscher ,&nbsp;Ansgar Kahmen","doi":"10.1016/j.soilbio.2025.109744","DOIUrl":"10.1016/j.soilbio.2025.109744","url":null,"abstract":"<div><div>Grasslands often recover well from drought, with some even surpassing non-drought-stressed controls in productivity long after drought release. However, the mechanisms responsible for such post-drought productivity outperformance remain unclear. In this study we examine how rewetting after drought influences important short- and longer-term soil microbial processes (i.e. nitrogen mineralization, potential enzyme activities) and consequent plant nutrient availability and uptake. For this, a field experiment was set up where an established perennial ryegrass sward under different N-fertilization levels was subjected to either a 2-month experimental summer drought followed by rewetting or to rainfed control conditions.</div><div>Rewetting after drought led to an immediate pulse in gross N-mineralization and NH₄-consumption rates. Both rates increased by &gt;230% and &gt;430% in formerly drought-stressed subplots compared to controls in plots not N-fertilized and N-fertilized during drought, respectively. Importantly, gross N mineralization rates correlated significantly with extractable soil organic carbon contents at the end of drought. Concurrently, drought and rewetting significantly increased NO₃–N, P, K, S, Fe, Zn, and Mn availability during the 1st but not the 2nd month after rewetting, except for K. Aboveground productivity of perennial ryegrass responded positively to NO₃–N availabilities during the 1st month after rewetting, leading to productivity outperformance of formerly drought-stressed plots compared to controls. These results suggest that short-term productivity outperformance of perennial grasslands in the 1st month after rewetting is driven by an increase in NO₃–N availability caused by a rewetting-induced pulse in N-mineralization of organic substrates accumulated during drought. Although effects of drought and rewetting on nutrient availability were only observed in the 1st month after rewetting, grassland productivity outperformance persisted in the 2nd month after rewetting. This indicates that soil drought legacy increased plant nutrient uptake efficiency, explaining longer-term outperformance effects when effects of drought and rewetting on nutrient availability were no longer apparent.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"204 ","pages":"Article 109744"},"PeriodicalIF":9.8,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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