Bacterial Composition and Influencing Factors in Surface and Bottom Waters of Three Major Drinking Water Reservoirs in Guiyang,Southwestern China
Reservoirs are one of the main forms of utilizing surface water resources. As the construction time of a reservoir increases, it begins to exhibit limnological responses or processes similar to those of natural lakes, including thermal stratification, light stratification, redox stratification, and dissolved oxygen stratification . Bacteria play a crucial role in various biogeochemical reactions in reservoirs (such as sulfate dissimilatory reduction, sulfide oxidation, iron and manganese cycling, organic matter degradation, methane production, and nitrate removal), functioning as "source element pumps." Changes in the physical and chemical environment of a reservoir affect the bacterial composition at different depths, and conversely, changes in bacterial composition impact the migration and transformation of elements and their compounds in the water, which can influence short-term microhabitat changes and long-term environmental evolution. Assuming that the reservoir ecosystem is in a steady state over a period, the bacterial composition and the corresponding migration and transformation of elements and compounds in the water may have characteristic fixed relationships. Understanding and clarifying this intrinsic connection could provide accurate assessments of short-term and long-term environmental evolution processes and directions, thereby aiding in the refined management of reservoir water quality.