博斯腾湖浮游植物群落结构特征及其影响因子分析

PHYTOPLANKTON IN BOSTEN LAKE: COMMUNITY CHARACTERISTICS AND DRIVING FACTORS

2011年对博斯腾湖大湖区17个采样站位的浮游植物及水体主要理化因子进行了4次系统调查。结果表明,在17个站位共鉴定出浮游植物127种(属),其中优势种(属)9种。浮游植物群落全年均以硅藻为主导,冬、春季节,浮游植物组成呈硅藻-甲藻型,优势类群主要为贫-中营养型浮游藻类,到夏、秋季节逐渐形成硅藻-绿藻型,以富营养型的浮游藻类为优势类群。浮游植物总平均生物量为(2.51±2.95)mg/L,生物量季节变动显著,峰值出现在夏季,冬季最低。基于Canoco的多变量分析表明:环境变量共解释了浮游植物群落总变异的54.5%,水温是影响浮游植物分布最重要的环境因子,其次为枝角类丰度。水中氮含量是影响浮游植物丰度的主要因子,同时浮游植物对水体有机物含量也有较大的影响。

In order to study the community characteristics and their driving factors in the great region of Bosten Lake, four investigations on phytoplankton and physiochemical factors were carried out in 2011. We identified 127 species, 9 species out of which once formed dominant populations. Diatom was predominant in the phytoplankton community all over the year. In winter and spring the phytoplankton community mainly consisted of diatom and dinoflagellate, floating algae being predominant in dys-mesotrophic lakes. However in summer and fall the major composition of phytoplankton were diatom and green alga, eutrophic type being the dominant in the population. The total mean biomass of phyto-plankton was (2.51±2.95) mg/L. The peak of the mean biomass was reached in summer and the lowest in winter. Canoco multivariate analysis indicated that 54.5%of the total variance in the phytoplankton community could be explained with environment variables. The water temperature and the abundance of Cladocera were found to be the most and the second most important factors affecting the distribution of phytoplankton. The phytoplankton abundances were largely affected by the variations of nitrogen contents. Moreover, phytoplankton had profound effects on the concentrations of organism in Bosten Lake.