Relationships among rhizosphere microbial co-occurrence patterns, core microbiota, and soil multinutrient cycling in Robinia pseudoacacia plantations of different ages

Vegetation restoration alters soil biotic and abiotic factors. Plants have evolved multiple strategies to adapt to nutrient limitation by reshaping and recruiting nutrient cycling-associated microbial communities in the rhizosphere. However, our understanding of the co-occurrence patterns of rhizosphere microbial communities and their role in soil multinutrient cycling during vegetation restoration remains limited. The present study explored the co-occurrence patterns of rhizosphere microbial communities along a chronosequence (15–45 years old) in Robinia pseudoacacia plantations in China’s Loess Plateau region, the associations between core microbiota and multinutrient cycling under spatiotemporal changes. Our results indicate that soil multifunctionality influences microbial co-occurrence patterns in the R. pseudoacacia rhizosphere, resulting in a more stable bacterial network than fungal network, forest age was a major driver of modularized distribution of nodes in bacterial and fungal networks, and forest age-sensitive microbes were taxonomically diverse at the phylum level. Meanwhile, we found that core microbiota play essential role in rhizosphere soil multinutrient cycling under R. pseudoacacia afforestation.