Potential changes in phytoplankton community structure in shallow lakes due to land use could pose a serious threat to ecosystem sustainability and functioning. Nevertheless, this effect has not been analyzed in detail. In this study, we chose two adjacent lakes, the main land use types around them are farmland and forest, respectively. We investigated the spatial differences in the phytoplankton community structure, water quality physicochemical parameters, and land use patterns in the two lakes. The results indicated that the annual average cell density and biomass of phytoplankton in the former were 1.84 times and 2.38 times that of the latter, respectively. The results of Pearson correlation and Redundancy analysis showed that total nitrogen (TN), total phosphorus (TP), water depth (WD), and water temperature (WT) were the main environmental factors influencing the structural changes of phytoplankton communities in the two lakes. The results indicated that different land use patterns, such as farmland and towns around the lake, increase the nitrogen (N) and phosphorus (P) content of the lake, while the forests distributed around the lake can reduce the N and P entering the lake, which is probably the main reason for the spatial difference in the characteristics of phytoplankton communities in the two lakes. Our results highlight that land use significantly affects the community structure of phytoplankton by influencing physicochemical factors in water bodies. Our study can provide guidance for pollution control and water quality management of shallow lakes.

The zooplankton community composition in shallow lakes is influenced by numerous factors, such as environmental factors and the land use patterns around the lake. To investigate the interaction between the spatial differences in the zooplankton community structure, aquatic parameters, and land use patterns in the Lake Chen Yao complex (Lake Chen Yao and Lake Feng Sha), we assessed them in four seasons from October 2020 to August 2021. The results showed that the zooplankton density and biomass of Lake Chen Yao were higher than the latter. The results of Pearson correlation and RDA analysis revealed that electrical conductivity (EC), Chlorophyll a (Chl.a), dissolved oxygen (DO), and pH were the main environmental factors affecting the zooplankton community structure in the two lakes. The nutrient content of nitrogen (N) and phosphorus (P) were significantly higher in Lake Chen Yao, and there was a considerable relationship with the distribution of land use patterns around the two lakes. The land use patterns were the main reason for the difference in water quality and thus the spatial variation in the characteristics of the zooplankton communities in the two lakes.