Study On Community Structure Of Phytoplankton And Water Quality In Jinhai Reservoir

Jinhai Reservoir is located in the south of Hohhot, it is one of the most important water source in Hohhot,and it is the water source of Yellow River Diversion Project.To understand the Jinhai Reservoir’s water quality and phytoplankton community structure,the physical and chemical indicators and phytoplankton community structure of the reservoir were monitored monthly from June2012to May2013. In the paper, the main conclusions are as follows:(1) Total7phylum33genera45species of phytoplankton were identified. Among them,Chlorophyta was the dominant phylum,a total of24species of15genera.The second domination was Bacillariophyta,11species of8genera.The next dominations were followed by Cyanophyta (4genera4species),Euglenophyta (2genera2species),Pyrrhophyta (2genera2species),Cryptophyt (1genera1species),Chrysophyt(genera1species). The analysis result of the predominance index showed that there were31predominant species including Chlorella vulgaris,Kirchneriella obsea,Fragilaria intermedia,Chroococcus minutus in Jinhai Reservoir.(2) The phytoplankton number ranged from2.01×105个/L to3.35×106个/L in Jinhai Reservoir,the highest value appeared in summer and the lowest value appeared in spring, Correlation analysis of phytoplankton quantity and environmental factors indicated that total phosphorus and temperature influenced on the phytoplankton quantity.The Jinhai Reservoir has been dominated with Chlorophyta and Bacillariophyta, including with Cyanophyta, Pyrrhophyta, Euglenophyta, Chrysophyt and Cryptophyt.(3) The diversity index ranged from1.29to3.52, abundance index ranged from0.67to2.42and uniformity index from0.38to0.82. It could be concluded that the phytoplankton community structure in Jinhai Reservoir was stable and complete in the ecosystem. Water quality assessment was calculated by predominant species and community structure biodiversity,overall evaluation result of water quality was the β-type of moderately polluted type.According to the method of synthetical nutrition analysis methods, the result showed that the water quality was mesotrophers. The water quality of Jinhai Reservoir was the best in summer,and the next was in autumu and in spring,and the worest was in winter in a year.