Study On The Structure Of Phytoplankton Community And Its Relationships With The Environmental In The WuxiGang River

1. Based on the results of all kinds of chemical and physical indexes,the average water temperature is 18.3 degrees and the average PH is 8.20,which showed the quality took on alkaline, the average TDS is 0.28mg/l, the average TDS is 22.86 mg/l.2. January, May, August, November (spring,summer,autumum,winter) in 2011, There are 133 species of phytoplankton,which belonged to 68 fenera of 8 phyla. Most of them are freshwater species;dominant species ascribing to chlorophyta accounted for 47.3 percent and the quality is 63 species belonging to 30 Genera; secondly the percentage of Euglenaphyta is 18.8 percent.3.On the issue of phytoplankton biomass, it appears that Chrysophyta is the dominant kind. Bacillariophyta,Chlorophyta, Cyanophyta are also important to the construction of biomass,the rest of the phytoplankton biomass is rare.4. There are 7 kinds of dominant species,including Melosira granulata var. angustissima Müll, Synedra acus Kützing, Cyclotella meneghiniana Kützing, Chlamydomonas globosa Snow, Merismopedia minima G..Beck, Cryptomonas erosa Ehr, Microcystis flos-aquae(Wittr.)Kirchner.5. According to the planktonic algae biomass and environment factor multiple regression analysis, PH and water temperature are obviously correlated with phytoplankton biomass.6. According to the mean evaluation of Shannon-Weavers diversity index,the diversity index in the Wuxi Gang River had a little change.one sample point number 13 on November diversity index was minimum, According to Margalef diversity index ,which is lower, is in the mean, the pollution arose 2.53, including 5 state, 7, 10, 13, 14, 17 in heavy pollution condition, other may, in August, 11 standard in light pollution state.