Effects of Stream Connectivity on Phytoplankton Diversity and Community Structure in Sunken Lakes: A Case Study from an August Survey

After the underground coal resources were exploited in the Huainan high diving mining area, the surface subsidence water formed a subsidence lake. Studying the influencing factors of the phytoplankton community structure in coal mining subsidence lakes is extremely important in enabling us to understand the nutritional status and ecological environment of the lake. In this study, we sampled phytoplankton in sunken lakes in August 2021 and analyzed the effects of the environmental factors on the phytoplankton community structure and diversity. The results showed that WT, pH, Cond, AN, NO and TP were the main environmental factors affecting phytoplankton cell density. The density and diversity of phytoplankton cells revealed obvious spatial distribution differences depending on the different drainage connectivity of sunken lakes, and the density and diversity of phytoplankton cells were higher in sunken lakes with better drainage connectivity. This study provides basic data for an in-depth understanding of sunken lakes, a special water body, and provides scientific data support for the reconstruction, restoration and sustainable development of the ecological environment in the mining area from the perspective of ecology.