以浮游植物评价百花湖水质污染及富营养化

本文利用百花湖１９９５－４ ～１９９６－６ 　１ 个水文年浮游植物的监测结果，对百花湖的水质污染及富营养化进行评价。结果表明百花湖浮游植物的群落结构为绿—蓝藻型，细胞密度年平均４７－６２ ×１０６ 个／Ｌ（ 或个体数年平均２２－５５ ×１０６ 个／Ｌ） ，浮游植物细胞密度比１９８０ 年增长２３ 倍。藻类综合指数为３－６ ～９－０ ，绿藻指数１－３ ～５－５ ，Ｒ．Ｍａｒｇｌｅｆ 多样性指数为０－９１ ～２－０６ ，Ｓｈａｎｎｏｎ －Ｗｅａｖｅｒ 多样性指数为０－５８７ ～１－２２１ ，均匀度指数为０－１９７ ～０－３７３ 。各项藻类指标均指示百花湖已受到重污染，水体属富营养型湖泊。

AN EVALUATION OF WATER POLLUTION AND EUTROPHICATION IN THE BAIHUA LAKE BY MEANS OF PHYTOPLANKTON

The seasonal ecological features of phytoplankton community including its species composition, population size, dominant species, saprobic indicostor, comprehensive index, R.Margalef index, shannon-weaver index and Evenness index were preliminarily studied at 5 sampling stations in the Baihua Lake, Guizhou Province(1995.4～1996 6)。By using population densities(individuals and cells per litre),dominant species,saprobic indicators comprehensive index, R.Margalef index, Shannon Weaver index and Evenness index as the important biological parameters, the trophic level and saprobic degree were evaluted for both the whole and subareas of the lake. In the Baihua Lake, the annual mean density of phytoplankton reached 47.62×10 6 cells per litre or 22.55×10 6 individuals per litre. the comprehensive index was 3.6～9 0,the R.Margalef index was 0.91～2 06, the Shannon-Weaver index was 0.587～1 221,the Evenness index was 0.197～0 373。In Spring, Summer, Autumn and Winter the dominant species of planktonic algae were almost entirely composed of green algae and blue-green algae, especially pediastrum, Ocystis and Microcystis. All thes features indicate that the lake has suffered from serious pollution and can be regarded as a green algae and blue-green algae eutrophic lake.