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.

The submerged plant Vallisneria natans can provide an attachment matrix and habitat for diverse microorganisms and plays an important role in maintaining the structure and function of the shallow lake ecosystem. However, little is known about how V. natans-related microorganism components, especially bacteria, adapt to specific plant compartments. In this study, we investigated the assembly and network of bacterial communities living in different plant compartments (sediment, rhizosphere, rhizoplane, root endosphere, and leaf endosphere) associated with V. natans by 16S rRNA gene sequencing. The results showed that the diversity and network complexity of the bacterial community in the sediment was significantly higher than that in other plant compartments. The bacterial community composition showed that the dominant phyla were Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Desulfobacterota, and Chloroflexi, among which Proteobacteria were extremely abundant in all samples, and there were notable differences in bacterial community composition related to plant compartments. Different networks based on sediment and plant compartments showed distinct co-occurrence patterns and exhibited distinct topological features. Additionally, functional predictions from FAPROTAX indicate that the predominant biogeochemical cycle function of the V. natans-related bacterial community is to participate in the carbon and nitrogen cycle. These results strongly suggested how the microbial community adapted to different plant compartments and provided theoretical and technical data for isolating beneficial bacteria from macrophytes in the future.

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.