Changes in Bacterial Community Structure in Reservoir Sediments before and after the Flood Season

Abstract

Bacterial communities are important components of reservoir ecosystems, participating in and determining the material–energy transformations within reservoirs. The intense material–energy transport during the flood season can cause perturbations to the stratified environment and material distribution within the reservoir, with the bacterial community being the most sensitive indicator of these changes. In this study, we analyzed sediments from four representative sampling sites before and after the flood season in a seasonally stratified reservoir and compared the diversity and composition of bacterial communities before and after the flood season using 16S rRNA high-throughput sequencing technology. The results showed that the bacterial community structure was different before and after flood season, and the bacterial abundance and α diversity were slightly higher before flood season than after flood season, and the relative abundance of bacteria was relatively low, and the dominant genera were not obvious. After flood season, the dominant genera were mainly Acinetobacter, Flavobacterium, Pseudomonas, Arthrobacter, and Massilia, all of which were aerobic denitrifying bacteria with strong denitrification ability. It is clear that the reservoir bacterial community structure changes significantly between flood seasons and plays a key role in later stages of aquatic ecology restoration. These results provide a new way of interpreting the dynamic changes in reservoir aquatic ecology.