苏州河浮游植物群落结构及其对水环境的指示作用

Phytoplankton community in Suzhou Creek and its role as water quality monitor

2004年4月至2005年2月共6次对苏州河的浮游植物进行调查,共设4个采样点。每两个月在4个样点采集浮游植物,同时测定了水体部分理化指标。采用生物指示法、香农(Shannon-Wiener)多样性指数法对苏州河的水质进行评价,结果表明,苏州河通过整治和自然恢复,水质从生物多样性极低的、劣于Ⅴ类的黑臭水体Ⅳ类水转化,依据浮游植物的种类组成、优势种的演替和生物多样性指数的结果判定:苏州河处于有机物污染的中度-乙型(β-中污)阶段．其指示浮游植物为颗粒直链藻(Melosira granulata)及其变种和二角盘星藻(Pediastrum duplex)及其变种。

This paper reports the investigation on phytoplankton community of Suzhou Creek on 4 sampling sites during Apr. 2004 to Feb. 2005, with counting the cell number and identifying the species composition of phytoplankton flora, determination of some physical ＇and chemical index of water quality. The water quality was evaluated with biological indication,Shannon - Wiener diversity index. The results illustrate that the water body of Suzhou Creek was converted to abundance of algal biodiversity from the state of darkening and stinking with sparse algal species and worse of class Ⅴ of national standard （ No. GB 3838 - 88） , and was in the progress from class Ⅴ to class Ⅳ of national standard （ No. GB 3838 - 88）. Even this, the Creek is still in β - mesosaprobic stage assessed by the analysis of succession of dominant species and species composition of phytoplankton, and the Shannon - Wiener＇s index. The indicators of β - mesosaprobic stage are the diatom of Melosira granulata and its varieties, and the green algae of Pediastrum duplex and its varieties.