洱海浮游植物种类组成及多样性分析

Species Composition and Diversity of Phytoplankton in Erhai Lake

通过2014—2015年洱海浮游植物监测数据,运用Shannon-Wiener指数和Pielou均匀度指数进行分析计算,解析洱海浮游植物群落的组成、分布,以揭示洱海水体浮游植物多样性指数、均匀度指数的变化规律。分析表明洱海多样性指数值、均匀度指数值分别在2~4、0.17~0.73之间,总体评价洱海地区属于中度污染。洱海藻细胞密度变化表现为秋季高,春季低,夏冬季平的特点,冬、春季同期藻种多样性指数、均匀度指数高,物种丰富,水质良好;夏季藻细胞密度、多样性及水质变化则反之。研究还发现浮游植物藻细胞密度高,藻类多样性会降低,极易引起水华;同时,蓝藻水华爆发又容易引起浮游植物多样性指数、均匀度指数的降低,造成浮游植物藻种相对单一。

Through the phytoplankton monitoring data of Erbai Lake in 2014 - 2015, analyzed by Shannon - Wiener index and Pielou evenness index, this paper parsed the composition distribution of phytoplankton conmmnity, which revealed the variation of phytol）lank- ton diversity index and evenness index. The results showed that the diversity index was between 2 - 4, and the evenness index was be- tween 0.17 - 0.73 in the monitoring points. Tile overall evaluation of Erhai area belonged to moderate pollution. The density of algal cell was high in autumn, low in spring, steady in summer and winter. In winter and spring, there were high diversity index and evenness index with rich species and good water quality, but in summer, there was the opposite. This paper also found that phytoplankton algal cell density would be high and diversity would be reduced, which was easy to cause algal blooms. At the same time, blue - green algae blooms were easy to outbreak and cause lower diversity index and evenness index, which led to relatively single on phytoplankton species.