Effects of Ecological Spur Dikes on Spring Phytoplankton in Wangyu River

摘要

In order to study the effects of the newly-built ecological spur dikes on spring phytoplankton in Wangyu River, a river way of water diversion project from Yangtze River to Taihu Lake, triple samplings were carried out in eleven sites from the near and upper water around the ecological spur dikes in April and May, 2011. The samples were collected to investigate the species and density of phytoplankton. Meanwhile, some environmental factors, such as temperature, pH, total nitrogen (TN), total phosphorus (TP) were determined. Indices of Simpson (D), Shannon-Wiener (H), Pielou (J) and Margalef (D_m) were used to analyze the change regulations of phytoplankton diversity. H, J, D_m were also used to evaluated the water quality, and they were 2.873, 0.532, 3.037. The results indicated that the composition of phytoplankton species was similar to the typical character of large or medium rivers. Based on the diversity indices, higher biological plankton diversity and better water quality emerged near the dikes. Results of this research supplied a theory for building ecological spur dikes to improve water quality of large or medium rivers and also provided a basis of using phytoplankton to monitor changes of water quality.