Response of bacterial communities to mining activity in the alpine area of the Tianshan Mountain region, China

Anthropogenic activities, such as mining, influence soil bacterial community composition and microbial distributions. In the current study, the patterns in microbial distribution and the environmental drivers shaping the soil bacterial community composition in the alpine mining area of the Tianshan Mountain region, China, were investigated, and the bacterial communities were analyzed using 16S rDNA pyrosequencing. The environmental factors and their relationships with the microbial community composition, structure, and diversity were also assessed. The soil organic carbon (SOC) concentration increased along the elevation gradient, with the highest concentration in the mining area, which increased microbial abundance and species richness. Some metals, like Ca, Cu, Pb, and Zn, accumulated significantly in the tailing area and were negatively correlated with the microbial community structure. Proteobacteria, Acidobacteria, Actinobacteria, and Verrucomicrobia were the dominant phyla; these dominant phyla were more abundant in the areas without mining than in the areas with mining at the same altitude. The relative abundance of Proteobacteria and Verrucomicrobia significantly increased along the elevation gradient, while that of Actinobacteria in the mining camp area was more than twice those in the other areas due to higher soil pH. Soil biomass was the highest in the valley. Collectively, these results elucidate the influence of anthropogenic mining activities on soil microbial communities in alpine mining soils and provide a basis for the future management of heavy metal-contaminated areas using the indigenous dominant bacterial phyla.