Plantation vegetation restoration enhances the relationship between rhizosphere microbial diversity and soil multifunctionality

Abstract Many studies have demonstrated the importance of rhizosphere microorganisms to soil nutrient cycling and plant stress resistance. However, we still lack a comprehensive understanding of the potential relationship between rhizosphere microbial diversity and soil multifunctionality during forest vegetation restoration. In this study, the diversity, assembly processes, and co‐occurrence patterns of rhizosphere microbial communities were explored along a 45‐year chronosequence of Robinia pseudoacacia plantations in China's Loess Plateau region. Soil multifunction index was calculated based on 11 measured available nutrient properties. The results showed that both α‐ and β‐diversities of rhizosphere microbial communities were significantly correlated with the soil multifunction index. Stochastic processes dominated rhizosphere microbial community assembly. Correlations between the abundances of sensitive operational taxonomic units for different forest ages (i.e. 15, 25, 35, and 45 years old) and soil multifunctional index varied in distinct network modules, being positive in module 1 and negative in module 2. There was a positive correlation between microbial network complexity (e.g. degree) and soil multifunctional index. The contribution of rhizosphere core microbiota to soil multifunctional index was higher than that of non‐core microbiota. To sum up, plantation vegetation restoration enhances the relationship between microbial diversity and soil multifunctionality, while affecting microbial co‐occurrence patterns in the rhizosphere.