Traits of dominant species and soil properties co-regulate soil microbial communities across land restoration types in a subtropical plateau region of Southwest China

Soil microbial community is essential for maintaining and improving ecosystem functioning in ecological restoration practice and is intimately linked with the plant community. However, little is known on how soil microbial communities respond to the functional characteristics of plant communities. Here we investigated the changes in plant community functional attributes, soil properties, and soil microbial community characteristics of four land restoration (vegetation) types in a subtropical plateau region. The relative contributions of soil abiotic properties and plant community functional attributes to variation in microbial community composition and function were then assessed. We found that plant community attributes, soil properties, and the soil microbial communities differed significantly among land restoration types, and the plant functional traits of dominant species and soil properties jointly determined soil microbial community structure and functions. Specifically, soil microbial community structure was significantly linked to the community-weighted mean (CWM) of plant functional traits, soil water content, and soil organic carbon. Soil microbial carbon-metabolic functions were tightly correlated with the CWM of leaf dry matter content, specific leaf area, and specific root length. Variance partitioning also revealed that the CWM of plant functional traits and soil variables cooperatively explained 67% and 64% variation in soil microbial community structure and carbon-metabolic functions. Meanwhile, significant correlations were found between variation in microbial community composition and carbon-metabolic functions. In conclusion, our observations demonstrate that soil microbial community characteristics were governed by dominant species in plant communities across land restoration types, mainly due to differences in plant functional traits and soil resource driven by plant traits.