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Soil organic carbon (SOC) persistence is predominantly governed by mineral protection, consequently, soil mineral-associated (MAOC) and particulate organic carbon (POC) turnovers have different impacts on the vulnerability of SOC to climate change. Here, we generate the global MAOC and POC maps using 8341 observations and then infer the turnover times of MAOC and POC by a data-model integration approach. Global MAOC and POC storages are 975 964 987 Pg C (mean with 5% and 95% quantiles) and 330 323 337 Pg C, while global mean MAOC and POC turnover times are 129 45 383 yr and 23 5 82 yr in the top meter, respectively. Climate warming-induced acceleration of MAOC and POC decomposition is greater in subsoil than that in topsoil. Overall, the global atlas of MAOC and POC turnover, together with the global distributions of MAOC and POC stocks, provide a benchmark for Earth system models to diagnose SOC-climate change feedback. Separating soil organic carbon into mineral-associated and particulate organic carbon enables a more accurate prediction of soil vulnerability to climate change. The authors generate the global atlas of stocks and turnover times of these two fractions. [ABSTRACT FROM AUTHOR]

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Across ecology, and particularly within microbial ecology, there is limited understanding how the generation and maintenance of diversity. Although recent work has shown that both local assembly processes and species pools are important in structuring microbial communities, the relative contributions of these mechanisms remain an important question. Moreover, the roles of local assembly processes and species pools are drastically different when explicitly considering the potential for saturation or unsaturation, yet this issue is rarely addressed. Thus, we established a conceptual model that incorporated saturation theory into the microbiological domain to advance the understanding of mechanisms controlling soil bacterial diversity during forest secondary succession. Conceptual model hypotheses were tested by coupling soil bacterial diversity, local assembly processes and species pools using six different forest successional chronosequences distributed across multiple climate zones. Consistent with the unsaturated case proposed in our conceptual framework, we found that species pool consistently affected α‐diversity, even while local assembly processes on local richness operate. In contrast, the effects of species pool on β‐diversity disappeared once local assembly processes were taken into account, and changes in environmental conditions during secondary succession led to shifts in β‐diversity through mediation of the strength of heterogeneous selection. Overall, this study represents one of the first to demonstrate that most local bacterial communities might be unsaturated, where the effect of species pool on α‐diversity is robust to the consideration of multiple environmental influences, but β‐diversity is constrained by environmental selection. [ABSTRACT FROM AUTHOR]

Studying the functional heterogeneity of soil microorganisms at different spatial scales and linking it to soil carbon mineralization is crucial for predicting the response of soil carbon stability to environmental changes and human disturbance. Here, a total of 429 soil samples were collected from typical paddy fields in China, and the bacterial and fungal communities as well as functional genes related to carbon mineralization in the soil were analysed using MiSeq sequencing and GeoChip gene microarray technology. We postulate that CO2 emissions resulting from bacterial and fungal carbon mineralization are contingent upon their respective carbon consumption strategies, which rely on the regulation of interactions between biodiversity and functional genes. Our results showed that the spatial turnover of the fungal community was 2–4 times that of the bacterial community from hundreds of meters to thousands of kilometres. The effect of spatial scale exerted a greater impact on the composition rather than the functional characteristics of the microbial community. Furthermore, based on the establishment of functional networks at different spatial scales, we observed that both bacteria and fungi within the top 10 taxa associated with carbon mineralization exhibited a prevalence of generalist species at the regional scale. This study emphasizes the significance of spatial scaling patterns in soil bacterial and fungal carbon degradation functions, deepening our understanding of how the relationship between microbial decomposers and soil heterogeneity impacts carbon mineralization and subsequent greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Microbes inhabiting deep soil layers are known to be different from their counterpart in topsoil yet remain under investigation in terms of their structure, function, and how their diversity is shaped. The microbiome of deep soils (>1 m) is expected to be relatively stable and highly independent from climatic conditions. Much less is known, however, on how these microbial communities vary along climate gradients. Here, we used amplicon sequencing to investigate bacteria, archaea, and fungi along fifteen 18‐m depth profiles at 20–50‐cm intervals across contrasting aridity conditions in semi‐arid forest ecosystems of China's Loess Plateau. Our results showed that bacterial and fungal α diversity and bacterial and archaeal community similarity declined dramatically in topsoil and remained relatively stable in deep soil. Nevertheless, deep soil microbiome still showed the functional potential of N cycling, plant‐derived organic matter degradation, resource exchange, and water coordination. The deep soil microbiome had closer taxa–taxa and bacteria–fungi associations and more influence of dispersal limitation than topsoil microbiome. Geographic distance was more influential in deep soil bacteria and archaea than in topsoil. We further showed that aridity was negatively correlated with deep‐soil archaeal and fungal richness, archaeal community similarity, relative abundance of plant saprotroph, and bacteria–fungi associations, but increased the relative abundance of aerobic ammonia oxidation, manganese oxidation, and arbuscular mycorrhizal in the deep soils. Root depth, complexity, soil volumetric moisture, and clay play bridging roles in the indirect effects of aridity on microbes in deep soils. Our work indicates that, even microbial communities and nutrient cycling in deep soil are susceptible to changes in water availability, with consequences for understanding the sustainability of dryland ecosystems and the whole‐soil in response to aridification. Moreover, we propose that neglecting soil depth may underestimate the role of soil moisture in dryland ecosystems under future climate scenarios. [ABSTRACT FROM AUTHOR]

A central aim of community ecology is to understand how local species diversity is shaped. Agricultural activities are reshaping and filtering soil biodiversity and communities; however, ecological processes that structure agricultural communities have often overlooked the role of the regional species pool, mainly owing to the lack of large datasets across several regions. Here, we conducted a soil survey of 941 plots of agricultural and adjacent natural ecosystems (e.g., forest, wetland, grassland, and desert) in 38 regions across diverse climatic and soil gradients to evaluate whether the regional species pool of soil microbes from adjacent natural ecosystems is important in shaping agricultural soil microbial diversity and completeness. Using a framework of multiscales community assembly, we revealed that the regional species pool was an important predictor of agricultural bacterial diversity and explained a unique variation that cannot be predicted by historical legacy, large‐scale environmental factors, and local community assembly processes. Moreover, the species pool effects were associated with microbial dormancy potential, where taxa with higher dormancy potential exhibited stronger species pool effects. Bacterial diversity in regions with higher agricultural intensity was more influenced by species pool effects than that in regions with low intensity, indicating that the maintenance of agricultural biodiversity in high‐intensity regions strongly depends on species present in the surrounding landscape. Models for community completeness indicated the positive effect of regional species pool, further implying the community unsaturation and increased potential in bacterial diversity of agricultural ecosystems. Overall, our study reveals the indubitable role of regional species pool from adjacent natural ecosystems in predicting bacterial diversity, which has useful implication for biodiversity management and conservation in agricultural systems. [ABSTRACT FROM AUTHOR]

Aim Location Time period Major taxa studied Methods Results Main conclusions Revealing the role of regional species pool size in community assembly rules is essential for extending the species‐pool framework to large‐scale community ecology, and thus for more comprehensive understanding of biodiversity formation. However, little has been done to couple the regional species‐pool effect into local ecological processes in soil fungal communities, which play essential roles in ecosystems worldwide. Here, we performed large‐scale soil surveys of fungal communities to examine the linkage between regional species pool size and Dispersal–Selection Relationships (DSRs), and their relations to community structure.China.July–August 2019.Fungal communities.By conducting the nationwide soil survey of ~1200 samples from various ecosystems across China, including agricultural, forest, grassland, and wetland soils, we examined the linkage between regional species pool size and DSRs, and their relationship to fungal community structure.We found that selection was negatively related to dispersal, which was consistent with the general view that the strength of selection is weakened by dispersal homogenization, and that this relationship was stronger in regions with larger species pools. Moreover, an increase in community dispersion was correlated with stronger effect size of DSRs, implying greater heterogeneity among fungal communities under larger species pools.Our study clearly illustrates the association of regional species pool size with local assembly rules and community formation of soil fungi across terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Cover cropping is a sustainable agricultural practice that profoundly influences soil microbial communities and ecosystem functions. However, the responses of soil ecosystem functions and microbial communities to cover cropping under the projected changes in precipitation, remain largely unexplored. To address this gap, a field experiment with cover cropping (control, hairy vetch, ryegrass, and hairy vetch plus ryegrass) and precipitation reduction (ambient precipitation and 50 % reduction in ambient precipitation) treatments was conducted from 2018 to 2020 in an agroecosystem located in the Guanzhong Plain of China. Soil ecosystem functions related to nutrient storage, nutrient cycling, and organic matter decomposition were measured to assess the soil multifunctionality index and bacterial and fungal communities were determined by Illumina NovaSeq sequencing. The results indicated that cover cropping enhanced soil multifunctionality index, and reduced precipitation strengthened this effect. Microbial community composition, rather than microbial diversity, was significantly altered by cover cropping regardless of precipitation reduction. Cover cropping increased the microbial network complexity and stability, but this effect was dampened by reduced precipitation. The microbial community composition and network complexity significantly and positively correlated with soil multifunctionality index under ambient and reduced precipitation conditions. Linear regression analyses and structural equation models collectively demonstrated that the increase in soil multifunctionality index was attributed to cover cropping-induced changes in microbial community composition and network complexity, irrespective of precipitation reduction. This study highlights the crucial role of microbial communities in driving the response of soil multifunctionality to cover cropping in the context of reduced precipitation, which has important implications for agricultural management and sustainability under future climate change scenarios., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The Microbiome Protocols eBook (MPB) serves as a crucial bridge, filling gaps in microbiome protocols for both wet experiments and data analysis. The first edition, launched in 2020, featured 152 meticulously curated protocols, garnering widespread acclaim. We now extend a sincere invitation to researchers to participate in the upcoming 2nd version of MPB, contributing their valuable protocols to advance microbiome research., Competing Interests: The authors declare no conflict of interest., (© 2024 The Authors. iMeta published by John Wiley & Sons Australia, Ltd on behalf of iMeta Science.)