Changes in the phytoplankton community structure of the Backshore Wetland of Expo Garden, Shanghai from 2009 to 2010

Phytoplankton community structure, abundance, and species' spatial and temporal distributions were examined for the Backshore Wetland of Expo Garden in Shanghai from September 2009 to August 2010. A total of 371 phytoplankton species were identified from 109 genera 8 phyla. There were 18 dominant species in total, and Phormidium tenue was dominant during four seasons. The mean annual abundance and biomass were 711.11 × 104 cells/L and 5.70 mg/L, respectively. The seasonal changing trend of existing stocks was bimodal, with main peaks of density and biomass occurring in the winter and a secondary peaks occurring in the summer. The Shannon–Wiener diversity index (H′), the Margalef species richness index (D), and Pielou's species evenness index (J) showed a clear seasonal trend. All of the indices showed a changing pattern, with the highest recorded values from the summer to autumn and the lowest recorded values from the winter to spring. The canonical correspondence analysis (CCA) showed that environmental factors, including water temperature, nitrate nitrogen, and pH were the main influencing factors to the change of phytoplankton community structure in the Backshore Wetland of Expo Garden in Shanghai.