Plant functional diversity regulates the composition and diversity of soil microbial communities in temperate grasslands of northern China

Plant communities can influence the structure of soil microbial communities by affecting the quality and quantity of plant-derived resources available to soil microorganisms. However, the specific mechanisms underlying these effects remain unclear. We sampled soil bacterial and fungal communities, as well as plant biomass and functional traits, across nine temperate grassland sites in northern China. We explored how plant community characteristics, including biomass and functional diversity along conservation and collaboration gradients, shape the growth strategies, diversity, and composition of soil microbial communities. Our results revealed a coupling of strategies between plant and soil fungal communities, where plant communities dominated by ‘fast’ or ‘do-it-yourself’ strategy species were associated with soil fungal communities dominated by copiotrophic taxa following similar ‘fast’ strategies. Soil fungal richness was positively influenced by functional divergence along the collaboration gradient, primarily through increased biomass. Plant functional composition on the conservation gradient had a stronger influence on the composition of soil fungal communities than on bacterial communities. These findings underscore the importance of different aspects of plant functional diversity, including functional divergence and community-weighted mean associated with plant resource acquisition strategies, in shaping soil microbial communities and provide a novel perspective for exploring plant-microbe interactions at the community level.