Linking Microbial Community Structure to Function Underneath Moss‐dominated Biocrusts in Rare Earth Elements Mine Areas under a Subtropical Climate

Rare earth elements (REEs) exploitation has caused large‐scale desertification. Biocrusts and their microbial community are crucial for the restoration and revegetation of abandoned mine areas. However, little is known about how microbial communities with biocrusts contribute to the sustainable function of degraded mine lands. Here, we evaluated soil nutrients, microbial community structure, and enzyme activities (involved in C, N, and P cycling) underneath moss biocrusts in REEs mine lands in Jiangxi Province, China. The results showed that the dissimilarities in the diversity, and structure of bacteria/fungi community with and without moss biocrusts were significant. Nevertheless, the effects of moss biocrusts on the abundant fractions of bacterial/fungal communities depend on land use types. Moreover, network hubs affiliated with Gammaproteobacteria (OTU7263) and Geodermatophilus sp. (OTU7087) were identified from moss networks, but no hub was found in bare soil. More importantly, the microbial communities underneath moss biocrusts mainly had direct effects on enzyme activities, while the microbial communities in bare soils had a relatively weak direct influence on enzyme activities, and most effects were indirectly driven via soil abiotic properties. Our results contribute to a better understanding of microbial community and corresponding ecological functions with moss biocrusts in degraded mine lands.