[Dynamic of phytoplankton abundance and the relationship with environmental factors in Dianshan Lake, Shanghai].

During January 2004 to December 2006, the abundance of phytoplankton and environmental factors such as the water temperature, wind speed, transparency of water (SD), TN, TP, pH, and permanganate index were monitored monthly in Dianshan Lake. The water quality of Dianshan Lake was in the mid-eutrophication state. The correlation analysis between phytoplankton community and environmental factors were performed. It indicated that the phytoplankton abundance, cyanobacteria abundance in Dianshan Lake were positively correlated with temperature (r = 0.487, r = 0.497), pH (r = 0.415, r = 0.379) and permanganate index (r = 0.460, r = 0.436), and negatively correlated with SD (r = -0.382, r = -0.394). Chlorophyta abundance in Dianshan Lake was positively correlated with PO4(3-) -P (r = 0.466). There was also a significant positive correlation between phytoplankton abundance and cyanobacteria abundance (r = 0.970). According to (CCA) ordination analysis, temperature, DO, SD and PO4(3-) -P were main factors affecting dynamic characteristics of phytoplankton community. The meteorological and hydrological factors were more important than nutrition concentration related to the water bloom in Dianshan Lake.