[Structural Characteristics of Zooplankton and Phytoplankton Communities and Its Relationship with Environmental Factors in Different Regions of Nanhu Lake in Jiaxing City].

Nanhu Lake is a red tourist attraction in Jiaxing city and the birthplace of the "Red Boat Spirit."To identify the influence of environmental factors on the distribution of plankton communities after ecological restoration in different regions, the environmental factors and plankton community in areas A, B, C, D, and S of Nanhu Lake were investigated in January 2021 after the completion of the ecological restoration projects. The concentrations of total nitrogen(TN), dissolved total nitrogen (DTN), ammonia nitrogen (NH-N), nitrate nitrogen (NO-N), total phosphorus (TP), and dissolved total phosphorus (DTP) in the ecological restoration areas were significantly lower, and the content of dissolved oxygen (DO) was significantly higher (<0.05) than those in the non-restoration area. The main phytoplankton species in the study area belonged to Cyanophyta and Bacillariophyta, and the main zooplankton species were protozoans and rotifers. The phytoplankton biomass in the restored area was lower than that in the unrestored area, and the number of phytoplankton and zooplankton species increased. Clustering and principal coordinate analysis results showed significant differences in plankton communities among the restoration areas (<0.05), and plankton structures in regions A and B were similar. Redundancy analysis (RDA) showed that the main environmental factors affecting the distribution of phytoplankton communities were DO, NO-N, pH, and water temperature (WT). The main driving factors of zooplankton community distribution were DO, NO-N, NH-N, and TP. The results clarified the phytoplankton community characteristics and environmental correlation in different regions of Nanhu Lake, which can provide data support and reference for water ecological restoration of the lake.