Responses of Soil Microbial Community to Rocky Desertification Succession and Their Relationships With Plant Functional Diversity in Southwest China Karst Ecosystem

Soil microorganisms play a critical regulatory role in various ecosystem functions, making them essential for maintaining ecosystem stability. Plant functional diversity influences soil physicochemical properties and shapes the structure and function of soil microbial communities. However, the response patterns of soil microorganisms to karst rocky desertification (KRD) succession remain poorly understood, particularly the relationship between microbial community dynamics and aboveground plant functional diversity. Here, the present study focuses on four typical succession KRD stages in a representative karst area of southwest China. By analyzing the diversity and community composition of soil microorganisms (bacteria and fungi), measuring soil physicochemical properties, and assessing aboveground plant functional diversity, the study aims to clarify the response patterns of soil microbial communities to KRD and their relationships with plant functional diversity in the KRD ecosystem of southwest China. The following main results and conclusions were obtained: (1) The composition of soil microbial communities and diversity varied significantly across different rocky desertification degrees. Functional diversity of aboveground plants also exhibited significant differences across varying rocky desertification degrees. (2) Both taxonomic composition and diversity indices of soil microorganisms (bacteria and fungi) showed significant (<i>p</i> < 0.05) or highly significant (<i>p</i> < 0.01) correlations with soil physicochemical properties and plant functional diversity across the four rocky desertification degrees. (3) During the karst rocky desertification succession, soil bacterial diversity was directly influenced by plant functional diversity and soil physicochemical properties. While, soil fungal diversity exhibited direct regulation by soil physicochemical properties and indirect effects from plant functional diversity mediated through soil properties. During the rocky desertification succession process, there are very complex interactions present among plants, soils, and microorganisms. Elucidating these relationships is of great significance for vegetation restoration and rocky desertification control in karst regions.