Abstract: An investigation was conducted on the spatiotemporal distribution of metazoan zooplankton (including Rotifers, Cladocera, and Copepoda) in the Qingcaosha Reservoir of Shanghai in January and April-December, 2011, with the relationships between the distribution pattern of the metazoan zooplankton and environmental factors analyzed. A total of 62 metazoan zooplankton species were observed, consisting of 38 Rotifers, 11 Cladocera, and 13 Copepoda. The yearly density of the zooplankton was averagely 469.1 ind·^-1, and the biomass averaged 3.23 mg·L^-1. Based on the dominant species composition of metazoan zooplankton and the Q_B/T value of Rotifers biological index (Q_B/T =1), the water quality of the Reservoir was at mesotrophic state. According to the Shannon and Margalef biodiversity indices of Rotifers, the water quality of the Reservoir was of βpollution pattern. Both the GAM and the CCA analyses showed that water temperature had considerable effects on the Rotifers density, being the key factor affecting the distribution discrepancies of the Rotifers. The GAM analysis also showed that the Cladocera density had nonlinear relationships with the water transparency and dissolved oxygen.

Key words: Yinchuan Basin, landscape pattern, vulnerability, land use change, ternary diagram.