College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, Beijing, China.
State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
Environ Microbiol. 2022 Dec;24(12):5630-5642. doi: 10.1111/1462-2920.16127. Epub 2022 Jul 26.
To feed the growing human population, natural grasslands are being converted to agricultural use at a massive scale. This conversion may have negative consequences for soil biodiversity, but its impact on the community assembly of differentially microbial groups remains largely unknown. Here, we investigated the diversity and community compositions of bacteria, archaea, fungi and protists, using a paired sampling of grassland and cropland soils across the agro-pastoral ecotone of northern China. Land-use conversion decreased α diversity of bacteria, fungi and protists, and altered the structures of the entire soil microbial community (archaea, bacteria, fungi and protists). The community assembly of archaea and bacteria was dominated by stochastic processes, and that of protists dominated by deterministic processes in both land-use types. By contrast, the fungal community was governed more strongly by stochastic processes in grassland soil, than by deterministic processes in cropland soil. Our findings support the 'size-plasticity' hypothesis that smaller body-sized microorganisms (archaea and bacteria) are more structured by stochastic processes, and larger one (protist) is more influenced by deterministic processes. Our study demonstrates that distinct ecological processes govern microbial community assembly, and land-use change regulates the balance between determinism and stochasticity.
为了养活不断增长的人口，天然草原正在大规模地被转化为农业用地。这种转化可能对土壤生物多样性产生负面影响，但它对不同微生物群体群落组装的影响在很大程度上仍不清楚。在这里，我们通过对中国北方农牧交错带的草地和耕地土壤进行配对采样，调查了细菌、古菌、真菌和原生动物的多样性和群落组成。土地利用方式的转变降低了细菌、真菌和原生动物的 α 多样性，并改变了整个土壤微生物群落（古菌、细菌、真菌和原生动物）的结构。古菌和细菌群落的组装主要由随机过程主导，而在两种土地利用类型中，原生动物群落的组装主要由确定性过程主导。相比之下，真菌群落受随机性过程的控制在草地土壤中比在耕地土壤中受确定性过程的控制更强。我们的研究结果支持“大小可塑性”假说，即较小体型的微生物（古菌和细菌）受随机性过程的影响更大，而较大体型的微生物（原生动物）受确定性过程的影响更大。我们的研究表明，不同的生态过程控制着微生物群落的组装，而土地利用变化调节着确定性和随机性之间的平衡。
