[Analysis of River Zooplankton Community Characteristics in Autumn in Beijing]

To clarify the spatial distribution characteristics of zooplankton communities and the relationship between zooplankton and water environmental factors, 81 samples from 28 rivers and lakes in Beijing were collected in September 2017. A total of 68 species of zooplankton were identified, including 17 species of protozoa (25%), 36 species of rotifers (53%), 13 species of cladocera (19%), and copepods (3%, which were mainly copepodids and nauplii). Among 15 dominant species, 12 were copepods and rotifers. Zooplankton communities varied between the different rivers:The zooplankton in rivers in mountainous areas were mainly protozoa and copepods; in suburban areas, communities were dominated by copepods; and in urban areas, rotifers were dominant. A comprehensive water quality index, the Shannon-Wiener index, the Pielou evenness index, and the Margalef richness index were also calculated. Results showed that the water quality of the rivers in mountainous areas was generally better than in urban areas, which was better than in suburban areas. TN was found to be the main form of pollution using the single factor water quality index. Principal component analysis (PCA) and canonical correspondence analysis (CCA) identified that NH₄⁺-N, BOD₅, and COD had a significant effect on zooplankton community characteristics.