Community Structure and Diversity Index of Phytoplankton in Songacha River in Spring

Community structure and diversity index of phytoplankton were surveyed in seven sampling sites in Songacha River in May2013.A total of 111 species was observed including 59 in Chlorophyta,24 in Bacillariophyta,14 in Cyanophyta,6 in Chrysophyta,5in Euglenophyta,2 in Cryptophyta and 1 in Pyrroophyta.Abundance of phytoplankton was changes significantly in different sampling sites,the minimum 50.4 ×104/L,the maximum 416.4 ×104/L.Canonical correspondence analysis(CCA)was applied to explore the relationship between phytoplankton composition,and the Shannon-weaver phytoplankton diversity index and Pielou index were used to evaluate diversity of phytoplankton and water quality.It was found that 7 sampling sites were under different level of pollution,light pollution or non-pollution.The main factors affecting the distribution of phytoplankton community were total phosphorus,turbidity,temperature,total nitrogen and chemical oxygen demand(COD).