[Effects of Different Land Use Types on Microbial Community Diversity in the Shizishan Mining Area]

Soil microorganisms play an important role in ecosystem function. Soil microbial community structure can be used to feed back the status of heavy metal pollution in soil at different functional areas of mines related to mining activities. Samples of four different land use types (vegetable garden, tailings reservoir, heap mining area, and dressing area) were collected in the Shizishan mining area, Tongling, Anhui Province, to determine the effect of heavy metal pollution on microbial community structure. Soil physical and chemical properties and heavy metal contents of the four different land use types were measured, and soil microbial community abundance and structure diversity were analyzed by Illumina MiSeq high-throughput sequencing technology. The results show that there are significant differences in physical and chemical properties between different regions. The comprehensive pollution index of Nemerow is heap mining area (7.28) > dressing area (6.99) > tailings reservoir (6.55) > vegetable garden (5.92). The distribution of microbial community abundance and structure diversity was tailings reservoir > dressing area > vegetable garden > heap mining area. In addition, principal coordinates analysis (PCoA), canonical correspondence analysis (CCA), and correlation analysis showed that land use type, soil pH and heavy metal content had significant effects on the microbial community. The dominant soil microbial communities at the phylum level were Proteobacteria, Bacteroidetes, Acidobacteria, and Actinobacteria, at the class level were β-Proteobacteria, α-Proteobacteria, and γ-Proteobacteria, and at the genus level were Flavobacterium, Kaistobacter, and Ramlibacter. The bacteria that are more tolerant to heavy metals are Proteobacteria, Firmicutes, β-Proteobacteria, and Kaistobacter. These results have deepened our understanding of microbial changes and aggregation patterns in soils of heavy-metal-contaminated mining areas. This study can provide bacterial species and theoretical basis for bioremediation of heavy metal mining areas.