Soil bacterial communities of alpine shrubs

Soil bacteria are critical to ecosystem function, and plant species influence fragile alpine ecosystem processes by affecting soil microbial communities. This study examined the bacterial community composition and diversity in soils from three shrub ecosystems on the eastern edge of Qinghai-Tibetan Plateau. We sampled 40 sites, collecting 0-20 cm surface soil, and analyzed DNA from these samples using high-throughput sequencing. Our research revealed that plant species can regulate the composition, diversity, stability, and assembly processes of soil bacterial communities. Altitude and pH showed opposite trends in their impact on different bacterial alpha diversity indices, with rare microorganisms may play a crucial role in it. Soil nutrient or geographical factors exerted differential effects on the bacterial community structure of different shrub species. Geographical factors directly and indirectly regulated bacterial community alpha and beta diversity by influencing soil properties. Bacterial community assembly was dominated by stochastic processes which was particularly dispersal limitation, while species replacement served as the primary driver of beta diversity in alpine shrubs. This study underscores the importance of plant species in influencing microbial diversity, stability and assembly processes, contributing to a better understanding of how shrub expansion affects the landscape heterogeneity and biogeochemical cycles of alpine ecosystems.