长江干流宜昌段浮游植物群落结构初步研究

为探索长江干流宜昌断面浮游植物群落结构分布状况和生物多样性特征及其与水文要素等环境因子的关系,2015年对长江干流宜昌段浮游植物群落结构进行了月度监测。结果共鉴定出浮游植物8门41属,其中蓝藻门7属,隐藻门1属、甲藻门2属,金藻门、黄藻门各1属,硅藻门14属,裸藻门2属,绿藻门13属。春季优势种为绿藻,夏季为蓝藻和硅藻,秋季为硅藻,冬季为绿藻和硅藻。Shannon-Weaver多样性指数和Pielou均匀性指数显示宜昌断面主要为中污染和轻污染状态,该结果与水体综合营养状态评价结果基本一致。通过环境因子间的相关关系分析可知,在三峡水库调度影响下,水动力学条件的变化成为影响现阶段宜昌段浮游植物群落结构特征与水质的主要因素。

Preliminary research on phytoplankton community in Yichang reach of Yangtze River

In order to explore the community structure and biodiversity characteristics of phytoplankton in Yichang reach of Yangtze River and its relationship with environmental factors, we monthly monitored the phytoplankton community in Yichang reach of Yangtze River in 2015. The results identified phytoplankton of 41 genera in 8 phyla in the reach, of which 7 genera of Cyanophyta, 1 genus of Cryptophyta , 2 genera of Pyrrophyta, 1 genus of Chrysophyta, 1 genus of Xanthopyta, 14 genera of Bacillariophyta, 2 genera of Euglenopyta, 13 genera of Chlorophyta. Chlorophyta in spring, Cyanophyta and Bacillariophyta in summer, Bacillariophyta in autumn, Chlorophyta and Bacillariophyta in winter were the dominant algae species. The Shannon-Weaver diversity indexes and Pielou evenness indexes showed that Yichang reach were moderately and lightly polluted. The results were basically consistent with the results of the comprehensively evaluated nutrition status of the water body. The correlation analysis between environmental factors showed that, under the influence of the Three Gorges reservoir operation, the change of hydrodynamic condition is the main influential factors to the community structure of phytoplankton and water quality in Yichang reach.