Distinctive Patterns of Soil Microbial Community During Forest Ecosystem Restoration in Southwestern China

Microorganisms are essential in soil biogeochemical processes and vegetation establishment. Nonetheless, investigating predictable patterns in the microbial structure during forest restoration damaged by natural or human factors in southwestern China is still limited. Hence, the study intended to explore the effects of forest restoration damaged by illegal construction, abandoned mines, and meteorological disasters on the microbial structure and its consequence on ecosystem functioning. The results uncovered that soil and plant attributes in the restoration forests damaged by illegal construction were similar to the natural community. Furthermore, the alpha diversity indexes were higher in the restoration forests damaged by human factors than in the natural community. Co-occurrence network analysis identified hub bacterial (e.g., Roseiarcus and Comamonas) and fungal (e.g., Exophiala and Botryotrichum) taxa, proving densely connected interactions with other microorganisms. Restoration forests damaged by illegal construction harbored beneficial genera belonging to Proteobacteria (Nordella, Xanthobacteraceae, and Sphingomonas) and Basidiomycota (Panaeolus, Psilocybe, and Sebacina), whereas restoration forests damaged by abandoned mines presented specialized bacteria involved in dark sulfur oxidation and ureolysis. Correlation analysis showed that soil properties, especially water content and pH, were the dominant factors affecting the microbial communities. Tree and shrub alpha diversities were significantly related to Chloroflexi in the natural community, and herbaceous richness was remarkably related to Proteobacteria and Mortierellomycota in the restoration forest damaged by human factors. Collectively, this comprehensive analysis generates novel insights to explore the contrasting responses of microbial communities during the process of restoration and provides essential microbial indicators for habitat restoration in southwestern China.