武汉东湖浮游植物群落结构的时空变化与环境因子的关系

 研究了武汉东湖浮游植物群落结构的时空变化。东湖3个采样点的TN和TP含量存在显著差异。东湖Ⅰ、Ⅱ站浮游植物生物量的最高值出现在冬季和春季，Ⅲ站生物量的最高值则出现在夏季。相对于东湖较高的营养盐含量，其浮游植物生物量相对较低。这一方面是因为东湖较高密度的滤食性鲢鳙鱼的摄食作用抑制了浮游植物生物量的升高，另一方面是由于东湖较低的透明度使浮游植物的生长受到光照的限制。由于受到滤食性鱼类摄食、较高的营养水平以及较低的透明度的影响，东湖的浮游植物主要由隐藻、真蓝裸甲藻、小环藻和直链藻以及小型的绿球藻和蓝藻所组成。

Temporal and Spatial Variation of Phytoplankton Structure and its Relationship with Environmental Factors in Lake Donghu

Temporal and spatial variation of phytoplankton structure in the lake was studied. TN and TP concentrations were significantly different among three stations. Phytoplankton biomass peaked in winter and spring at station I and Ⅱ, while it peaked in summer at station Ⅲ. Compared with many other eutrophic lakes with similar or even lower nutrient concentrations, phytoplankton biomass in Lake Donghu was much lower. It was probably due to both high grazing pressures from filter feeding fishes and light limitation. Phytoplankton in Lake Donghu is mainly composed of flagellated Cryptomonas and Gymnodinium eucyaneum, centric Cylotella spp and Melosira ambigua, small sized cyanobacteria and chlorococcales,most of which were typical species in condition of high grazing and high nutrient level.