长江流域镇江段浮游植物群落结构特征

于2004年5月至2005年4月对长江镇江段浮游植物群落结构进行了调查.结果表明:长江镇江段浮游植物共计7门59属, 以绿藻、硅藻和蓝藻为主,分别占33.90%、30.51%和22.03%.内江浮游植物平均密度为4.94×10~4个·L~(-1), 绿藻密度最大为7.95×10~4个·L~(-1).浮游植物密度季节变化秋季最大(2.71×10~5个·L~(-1)) ,春季最小(4.65×10~4个·L~(-1)).水平分布密度塔影湖站最大,为1.39×106个·L~(-1).调查显示长江镇江段浮游植物中小环藻、针杆藻、小球藻、丝藻、颤藻等为优势属种.浮游植物Shannon-Wiener多样性指数在2.30～3.98之间.指数变化由高到低分别为冬季、秋季、春季.

Community Structure of Phytoplankton in Zhenjiang Branch,Yangtze River

A survey was conducted to study the structure of phytoplankton community in Zhenjiang Branch, Yangtze River from May 2004 to April 2005. A total of fifty-nine genera in 7 phylum of phytoplankton were recorded. The dominant algae were Chlorophyceae, Bacillariophyta and Chlorophyta, accounting for 33.90%, 30.51% and 22.03%, respectively. The average density of phytoplankton was 4.94×10~4 individuals per liter, among which Chlorophyceae exhibited the highest density of 7.95×10~4 individuals per liter. The maximum density of 2.71×10~5 individuals per liter was observed in autumn and the minimum of 0.47×10~5 individuals per liter was in summer. The horizontal density distribution of phytoplankton in the station of Tayinghu was the highest among all the six stations, with 1.39×10~6 individuals per liter. The survey showed that Cyclotella, Synedra, Chlorella, Ulothrix, and Ocsillatoria were dominant genus. Shannon-Wiener diversity index of phytoplankton ranged from 2.30 to 3.98, and, the index was the highest in winter and the lowest in spring.