密云水库的浮游生物群落

Study on plankton community in Miyun reservoir

2002年4～10月对密云水库浮游生物群落的调查结果显示:浮游植物有6门,58属,122种,细胞密度为565.30×104cells/L;4月份硅藻 Bacillariophyta 占优势,6～10月蓝藻 Cyanophyta 占绝对优势.浮游植物优势种群有水华微囊藻 Microcystisflos-aquae 、颗粒直链藻 Melosiragranulata 、梅尼小环藻 Cyclotellameneghiniana 、角甲藻 Ceratiumhirundinella 等.浮游动物有36种,密度为4761ind./L;浮游动物具有原生动物在数量上占绝对优势,轮虫次之,枝角类与桡足类数量较少的特点.浮游动物的优势种群有弹跳虫 Halteriagrandinella 、急游虫 Strombidiumuiride 、针簇多肢轮虫 Polyarthratrigla 、螺形龟甲轮虫 Keratellacochlearis 、广布中剑水蚤 Mesocyclopsleuckarti 、长额象鼻蚤 Bosminalongirostris 等.与1980年监测结果相比,密云水库浮游生物总密度上升较快,群落结构和优势种群也发生了明显变化.浮游生物优势种群的指示作用显示,在植物生长季节,库区水体已进入富营养状态.

The plankton composition and distribution were investigated in Miyun reservoir from April to October in 2002.122 species of phytoplankton and 36 species of zooplankton were observed in the reservoir.Phytoplankton was predominated numerically by Bacillariophyta in April and Cyanophyta from June to October.The predominant species of Phytoplankton were Microcystis flos-aquae,Melosira granulate,Cyclotella meneghiniana and Ceratium hirundinella.Zooplankton was primarily predominated by Halteria grandinella,Stronmibidium uiride,Polyarthra trigla,Keratella cochlearis,Mesocyclops leuckarti and Bosmina longirostris.Compared with the results in 1980,the cell density of plankton increased in 2002.And the community and predominated species of plankton have changed,which indicated that the water body of Miyun reservoir came into eutrophication.