Soil nutrient loss and soil erosion have led to significant soil degradation, hindering the sustainable development of ecosystems. The response relationship between artificial vegetation restoration models and soil microorganisms holds crucial significance in enhancing the ecological environment and establishing a comprehensive understanding of soil health status. This study, based on soil physicochemical parameter determination and high-throughput sequencing of 16S rDNA amplicons, compares three study sites: severely eroded land with no treatment (SA), a managed model of mixed forests consisting of trees, shrubs, and grasses (RA), and a control site with the dominant local community (UA). It aims to explore the effects of different vegetation construction models on soil physicochemical parameters, microbial diversity, and community structure in inefficient Pinus massoniana forests. The results demonstrated that compared to SA, the RA site significantly altered soil pH, increased the content of alkali-hydrolyzable nitrogen (AN), available phosphorus (AP), available potassium (AK), and organic carbon (OC), as well as enhanced soil microbial diversity and abundance. Dominant bacterial phyla in the soil included Proteobacteria, Chloroflexi, Acidobacteria, Actinobacteria, and GAL15, while dominant fungal phyla were Ascomycota, Basidiomycota, and Kickxellomycota. At the genus level, dominant bacterial genera were Acidobacteriia, Alphaproteobacteria, AD3, Actinobacteria, and GAL15, and dominant fungal genera included Talaromyces, Archaeorhizomyces, and Russula. Correlation analysis revealed that pH and soil bulk density (SBD) were the primary physicochemical factors influencing soil microbial community structure. The forest-grassland mixed restoration model promoted soil fertility and significantly improved microbial diversity and community structure in inefficient Masson pine forests. The findings of this study provide guidance and reference for the demonstration and promotion of this restoration model.

Pinus massoniana inefficient forest; vegetation restoration; Soil fertility; Soil microorganism