Study On The Phytoplankton Species Diversity And The Evaluation Of Water Quality In Several Downtown Parks Of Shanghai City

Phytoplankton is a relatively sensitively and effective kind of biological indicator to the environmental changes due to its structure and life histroy. Based on the analysis of investigation data from March 2005 to January 2006, the seasonal ecological features of phytoplankton community including its species composition, population size, and dominant species were studied in the ten downtown parks of Shanghai. Grade-marking approach, Trophic State Index (TSI), Margalef s diversity index, Shannon-weaver ' s diversity index, National standard of surface water were used to value the trophic state of water body .Pearson Diversity Index and CCA were adopted to analyse the relation to the species of Phytoplankton with environments. The main conclusions as follows:1. Phytoplankton:8 phylum 93 genera 385 species of phytoplankton (include mutant) were collected in these parks. They are: green algae, 50 genera 233 species; Euglenophyta, 7 genera 60 species; Cyanophyta, 11 genera 42 species. Chrysophytax, 14 genera 28 species; Cryptophyta, 2 genera 3 species; Pyrrhophyta, 4 genera 8 species; Chrysophyta, 3 genera 7 species; Xanthophyta, 2 genera 3 species. The average individuals number of phytoplankton are Changfeng Park, 3.93×10~7ind/L, Yuyun,3×10~7ind/L;Heping Park, 2.26×10~7ind/L; Gongqing Forest Park, 7.96×10~6 ind/L; Century Park, 6.61 ×10~6 ind/L; Luxun Park, 5.26×10~6 ind/L; Kangjian Park, 4.76×10~6 ind/L; Botany Garden, 4.34×10~6 ind/L; Renmin Park, 1.96×10~6 ind/L; Jing'an Park, 3.41×10~6 ind/L.2. Evaluation of water quality.The evaluation of the water quality were obtained seasonally by use of Gradeapproach method. The results showed all these parks were entrophication. The annual average grades of these parks was larger than 60 which indicated the trophic status was worse than phication, and the grades of Heping Park, Yuyuan park and Century...