三峡库区典型支流浮游细菌的生态分布及其影响因素

Ecological distribution and its influencing factors of bacterioplankton in the typical tributaries of Three Gorges Reservoir

2013年夏季对三峡库区3条典型支流朱衣河、梅溪河、草堂河进行了采样调查,分析了浮游细菌丰度的分布特征及其与环境因子的关系。结果表明：浮游细菌丰度在调查的水体中存在明显空间差异,变化范围为0.53×10^5-10.55×10^5个·m L^-1,平均值为2.71×10^5个·m L^-1;平均细菌丰度从大到小依次为梅溪河、朱衣河、长江干流和草堂河;3条支流浮游细菌丰度垂向分布特征均表现为表层〉中层〉底层。相关性分析表明,溶解氧、p H、叶绿素a与浮游细菌丰度具有显著的相关性,为该水域浮游细菌丰度空间分布的主要限制因子。根据浮游细菌丰度,各调查水域均处于富营养状态。

The distribution of bacterioplankton in three typical tributaries （Zhuyi River, Meixi River and Caotang River） of Three Gorges Reservoir was investigated in summer of 2013. The correlation between the abundance of bacterioplankton and ecological factors was analyzed. The results showed that the abundances of bacterioplankton were significantly different in these rivers, ranging from 0.53×10^5 to 10.55×10^5 cells · mL^-1 with an average value of 2.71×10^5 cells · mL^-1. The average abundance values were in order of Meixi River 〉 Zhuyi River 〉 Yangtze River 〉 Caotang River. Vertical distribution of baeterioplankton biomass in three tributaries showed a similar change trend, being the highest in the surface water and the lowest on the bottom. The correlation analysis showed that DO, pH and chlorophyll-a had significant correlations with bacterioplankton abundance, indicating that these parameters are the main factors limiting the bacterioplankton abundance in this region. The waters surveyed were eutrophic according to bacterioplankton abundance.