Response Analysis of Microbial Community Structures and Functions Under Water and Sediment Changes in the Middle and Lower Yellow River

This is the authors' abstract. We don't add key points for this paper.

Safety and ecological health are restricted by the high amount of suspended sediment in the Yellow River. To solve the problems of the high sediment content and siltation in the Yellow River, the Xiaolangdi Reservoir (XLDR) has been carrying out water–sediment regulation (WSR) since 2002. To clarify the effects of the water and sediment changes caused by WSR on microbial communities, we analysed the composition of the microbial communities and functional groups in surface water and sediments before and after WSR using high-throughput sequencing and microbial functional annotation. Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were detected as the main microbial communities in the Yellow River’s middle and lower reaches. The water temperature (WT), dissolved oxygen (DO), total nitrogen (TN), total phosphorus (TP), and evolution of the microbial communities were all correlated (p < 0.05). The biodiversity indices of the surface water and sediment microbes, respectively, greatly declined. The WSR programme broke down nutrients that had been adsorbed on the sediments, which diminished microbial metabolic activity and impaired the water bodies’ capacity to purify themselves. In summary, this study provides the biological information needed for the ecological conservation of the Yellow River basin, as well as insights into the changes in and response characteristics of microorganisms following severe disturbances in rivers with high sediment concentrations.