Climate regulates the effect of land-use change on the diversity of soil microbial functional groups and soil multifunctionality

Although studies have explored how soil microbial diversity and soil multifunctionality respond to land-use change at local scales, they have rarely been explored at larger scales and across different climatic and soil environmental conditions.

By sampling 40 paired sites of land-use change from natural forests to agricultural lands (including croplands and orchards) along the middle and lower Yangtze River, combined with a global meta-analysis, we investigated the effects of land-use change and climate on the alpha and beta diversity of soil bacterial and fungal functional groups (FGs) and their associated soil multifunctionality at a regional scale.

Our results showed that land-use change strongly changed the diversity of soil bacterial and fungal FGs and decreased multifunctionality, which was supported by our meta-analysis at a global scale. Direct effects of land-use change and climate and their interaction, together with changes in soil environmental variables, were the main determinants of the land-use change-induced changes in the diversity of soil bacterial or fungal FGs. The land-use change-induced decrease in multifunctionality was mainly associated with the direct effect of forest conversion, soil fertility, and diversity of fungal FGs. Furthermore, climate also regulated the effects of land-use change on multifunctionality by affecting soil fertility and fungal FGs diversity along the Yangtze River.

Synthesis and applications. Taken together, our findings highlight the important effects of land-use change, climate, and their interactions on microbial diversity and multifunctionality, and suggest that effective land-use management and climate change mitigation strategies should be adopted to protect biodiversity and ecosystem function in the Yangtze River Basin.