School of Ecology and Environment, Tibet University, Lhasa 850001, PR China; Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
Sci Total Environ. 2023 Nov 25;901:165937. doi: 10.1016/j.scitotenv.2023.165937. Epub 2023 Jul 31.
Biological soil crusts (BSCs) are an important biological component of the soil surface, covering approximately 12 % of the Earth's land surface. Although BSCs are closely related to habitats, the microbial diversity and spatial variability of BSCs in different ecosystems are still unclear, especially on the Qinghai-Tibet Plateau (QTP), where climate is changeable and habitats are complex. Here, we investigated the diversity, assembly processes, spatial distribution pattern and driving factors of prokaryotic and eukaryotic microbial communities in BSCs in four habitats on the QTP. It was found that habitat-specific environmental factors regulated the composition, diversity and spatial variability of BSC microbial communities. Soil organic carbon and soil water content were the most important factors (R = 0.9024, P = 0.001; R = 0.8004, P = 0.001) affecting the spatial differences in prokaryotes and eukaryotes, respectively. Under the specific climate of the QTP, the spatial pattern of microbial communities in BSCs was controlled by precipitation rather than temperature. In addition, ecological processes further explained the effects of habitat specificity, and environmental filtering explained microbial community differences better than dispersal limitation. The results of the neutral community model and the normalized stochastic ratio index revealed that the assembly of prokaryotic communities was determined by deterministic processes at the regional scale, and at the local scale, the assembly process was mainly determined by habitat type, while the assembly of eukaryotic communities was determined by stochastic processes at both the regional and local scales. This study provided a scientific reference for the prediction of BSC distribution and resource conservation under future climate change scenarios.
生物土壤结皮（BSCs）是土壤表面的重要生物组成部分，覆盖了地球陆地表面的约 12%。尽管 BSCs 与栖息地密切相关，但不同生态系统中 BSCs 的微生物多样性和空间变异性仍不清楚，特别是在气候变化和生境复杂的青藏高原（QTP）。在这里，我们研究了 QTP 四个生境中 BSCs 中原核生物和真核微生物群落的多样性、组装过程、空间分布模式和驱动因素。结果发现，特定的生境环境因素调节了 BSC 微生物群落的组成、多样性和空间变异性。土壤有机碳和土壤含水量分别是影响原核生物和真核生物空间差异的最重要因素（R=0.9024，P=0.001；R=0.8004，P=0.001）。在 QTP 特定的气候条件下，BSC 微生物群落的空间格局受降水而不是温度控制。此外，生态过程进一步解释了生境特异性的影响，环境过滤比扩散限制更好地解释了微生物群落差异。中性群落模型和归一化随机比指数的结果表明，原核生物群落的组装由区域尺度上的确定性过程决定，而在局部尺度上，组装过程主要由生境类型决定，而真核生物群落的组装则由区域和局部尺度上的随机过程决定。本研究为预测未来气候变化情景下 BSC 分布和资源保护提供了科学参考。
