Phytoplankton Community Dynamics in West Lake After Drawing Water from the Qiantang River
Seventeen phytoplankton dominant species of 218 taxa were found to have contributed to more than 80% of the biomass after analysis of the January, 1955 to December, 1996 phytoplankton population at five stations in West Lake after Qiantang River water had been drawn into the lake for a decade. The seasonal fluctuations were obvious; the maximum cell density of 90.91×107-93.58×107 cells/L and biomass of 57.41-58.61 mg/L occurred mainly in summer of 1996,largely as a result of the development of Lyngbya contorta, Merismopedia tenuissima, Oscillatoria limnetica, Spirulina laxissima and Scenedesmus quadricauda, etc. at Stations 2 and 4. At Station 1 located near the inlet for drawing water from the Qiantang River, the species number, cell density, biomass, chlorophyll a concentration and physico-chemical parameters (except for total nitrogen) were obviously greater than those at the other four stations, also greater than the corresponding parameters before the drawing of water from the Qiantang River into the lake.Compared with the results of study on the phytoplankton community in 1980 before the drawing of Qiantang River into the lake, the species number and the total individual density were increased, the dominant species changed somewhat, the biomass was decreased. The water quality was improved (especially at Station 1) after the drawing of river water into the lake.Based on criteria for evaluating trophic status, the biological and chemical indicators such as species composition and dominant species, and other parameters such as annual mean value cell densities (36.06×107-51.27×107 cells/L), biomass (29.03-39.74 mg/L), chl a concentrations (41.29-67.67μg/L), total nitrigen (1.72-2.89 mg/L), total phosphorus (0.12-0.16 mg/L) obtained at Stations 2, 3, 4 and 5, showed that West Lake is still at eutrophic lake.
作 者： 魏印心 李瑾 虞左明 作者单位： 魏印心(Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan 430072, China)李瑾,虞左明(Institute of Environmental Science, Hangzhou 310007, China)
刊 名： 中国海洋湖沼学报(英文版) ISTIC SCI 英文刊名： CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY 年，卷(期)： 2004 22(2) 分类号： P7 关键词： phytoplankton community dynamics dominant species biomass West Lake