Impact of the South-to-North water diversion on the soil microbial community structure in the Miyun Reservoir riparian zone

Abstract

In order to clarify the effect of the South-to-North Water Diversion Project on the microbial community structure in the reservoir riparian zone, the differences of microbial community structure and diversity before and after water transfer were investigated using the Miseq high-throughput sequencing methods. The results showed that pH and TN content increased after water transfer, but not significantly (p> 0.05). However, TP and TOC contents were significantly lower than those before water transfer (p <0.05). Proteobacteria, Chloroflexi, Acidobacteria, Nitrospirae and Bacteroidetes were the dominant soil microbes before water transfer. The main phylum species after water diversion were Proteobacteria, Bacteroidestes, Chloroflexi, Verrucomicrobia and Actinobacteria. The relative abundance of Proteobacteria, Bacteroidetes, Actinobacteria, Verrucomicrobia, Cyanobacteria and Chlorobi were significantly increased after water diversion (p <0.05), indicating that water diversion had a significant effect on microbial community structure. The communities Cyanobacteria, Verrucomicrobia, Actinobacteria and Bacteroidetes have a strong positive correlation with pH and TN. Planctomycetes and Nitrospirae are closely related to TOC. Our results showed that the TOC content decreased obviously after water diversion (p <0.05), which caused the soil nitrification bacteria abundance decreased. This indicates that impoundment had a significant impact on the eco-physiological process of soil nitrifying microorganisms in the early stage of water diversion.