Disturbances consistently restrain the role of random migration in grassland soil microbial community assembly

Abstract

Random migration often plays important roles in soil microbial community assembly. However, it remains unexplored that whether its role is affected by anthropogenic disturbances, and whether the effects of different disturbances are consistent. Here, we report a novel and general pattern that different disturbances consistently restrain the role of migration in soil bacterial community assembly. We mimicked 16 types of anthropogenic disturbances relevant to a Eurasian steppe ecosystem, including removing different number of plant functional groups, mowing, adding nitrogen, adding phosphorus, watering, warming, and some of their combinations. The estimated migration rates in soil bacterial community assembly with Stephen Hubbell’s neutral model decreased by 0.19–6.29% under these disturbances. The relative change in migration rate was correlated with the deterministic change in community composition and the relative change in soil pH. Our results suggested that the intensifying anthropogenic disturbances may restrain the random dispersal, colonization and distribution of soil microorganisms.