Eutrophication Evaluation Of Greenbelt And Park Lakes In Shanghai

In order to envaluate the entrophication of greenbelt and park lakes in Shanghai and know the water quality,we did a phytoplankton community survey from July 2008 to March 2009.Based on the basic character of distribution,establish time,squares and so on,we chosed 15 greenbelt and park lakes in Shanghai.The seasonal ecological features of phytoplankton community including its species compositon,population size,and domimant species were studied in the 15 greenbelt and park lakes in Shanghai.Trophic State Index(TSI),Margalef's diversity index,Shannon- weaver's diversity index,Pielou index,National standard of surface water were used to value the trophic state of greenbelt and park lakes.Pearson Diversity index and CCA were adopted to analyse the relation to the species of phytoplankton with environments. The main findings are as follows:1.Analysis of environmental factorsThe transparency of the range is 22～100cm.Dissolved oxygen range is 1.45～17.90 mg/L,a more significant change.Ammonium nitrogen ranged from 0.099～3.204 mg/L.Total nitrogen ranged from 0.073～8.930 mg/L.TP range of 0.016～1.114 mg/L.COD range from 0.71～27.04 mg/L.During the investigation we found a total of 136 species of zooplankton.Among them,55 kinds of Protozoa, 65 kinds of Rotifers,7 kinds of Cladocera,9 kinds of Copepoda.Zooplankton Shannon-Weaver diversity index H,Margalef species richness index D and the Pielou evenness index J average are 0.71,1.41,0.76 respectively.2.Phytoplankton:8 phylum 109 genera 498 species of phytoplankton were collected.They were maily belonged to Chlorophyceae,53 genera 198 species and Bacillariophyceae, 21 genera 136 species.The phytoplankton had an abundance ranging from 2.01×10⁵～57.60×10⁵ cells·L^-1.Highest density of phytoplankton in the Xinzhuang park 156.38×10⁵cells·L^-1 the minimum value is Dapaifang greenbelts 0.60×10⁵cells·L^-1. 3.Phytoplankton diversityThe annual mean of Shannon-weaver's diversity index of Xinzhuang Park was maximum which was 1.48,followed by Xujiahui Park(1.43),Binjiang Forest Park(1.35),Botanical Park(1.32),Caoxi Park(1.27),Zhongshan Park(1.26), Dapaifang greenbelt,Zoo and Yanzhong greenbelt(1.22),Lujiazui central greenbelt(1.15),Baoshan greenbelt(1.13),People's Park(1.10),Caoyang Park (1.08),Yangpu Park(0.94),Century Park(0.89).The Pielou eveness index and Margalef's diversity index were obviously related to the species of phytoplankton. Therefore,the complexity of phytoplankton community can be evaluated with these meteods.4.Relationship of phytoplankton and environmental factorsPhytoplankton species,phytoplankton density,phytoplankton Margalef richness index,Pielou evenness index were related to temperature,total phosphorus, zooplankton volume was highly significant positive correlation,and significantly negative correlation with transparency and significant positive correlation with dissolved oxygen.Phytoplankton Shannon-Weaver diversity index and temperature were highly significant positive correlation,with the amount of zooplankton was significantly positively correlated with transparency was negatively correlated.Shannon-Weaver diversity of phytoplankton and zooplankton volume index,the relevance of transparency than the number of species of phytoplankton,phytoplankton density,phytoplankton Margalef richness index,Pielou evenness index of phytoplankton decreased dissolved oxygen and total phosphorus and no significant relations.Through the CCA analysis,the year by a variety of phytoplankton species distribution of the combined effect of environmental factors.Among them,the water temperature, pH,the amount of zooplankton,dissolved oxygen,chemical oxygen demand, nutrient concentrations on the seasonal distribution of phytoplankton have a significant impact.Of these,the greatest impact on the distribution of phytoplankton is the water temperature,nutrients and zooplankton volume.5.Water quality evaluation of greenbelt and park lakes in Shanghai Comprehensive assessments of phytoplankton density,zooplankton evaluation, evaluation of the dominant species,amendments to the nutritional status of Carson's index,Shannon-Weaver diversity index H,Margalef species richness index D,Pielou evenness index J of 15 greenbelt and park lakes.The classification of water bodies is:the first level:Xujiahui Park,Dapaifang greenbelt,Baoshan greenbelt;second level:Caoxi Park,Yanzhong greenbelt, Botanical Garden;the third level:Zhongshan Park,the People's Park,Yangpu Park,Binjiang Forest Park,Xinzhuang Park;Fourth level:Century Park,Lujiazui central greenbelt,Caoyang Park,Zoo.With the increased level,water quality deteriorate.