浮桥河水库浮游植物的多样性及其演变

SPECIES DIVERSITY AND SUCCESSION OF PHYTOPLANKTON IN FUQIAOHE RESERVOIR

1997年4月至1998年1月对浮桥河水库浮游植物状况进行了调查,结果表明:该水库常见浮游植物约189种,隶属于8门92属,其中硅藻门25属64种,绿藻门39属79种,蓝藻门17属30种,甲藻门、隐藻门、裸藻门、黄藻门及金藻门种类较少。其个体密度年平均为44.9×104ind/L;生物量年平均为6.439mg/L,其中蓝藻占33.37%,硅藻和绿藻分别占20.68%和20.16%,甲藻占16.31%。浮游植物现存量的季节变化表现为从春季开始平稳上升,至秋季达到最大值。蓝藻、硅藻、绿藻等主要种类的季节变化按生物量大小依次为:秋季夏季春季冬季。浮游植物现存量的水平分布为上游最高,中游次之,下游最低,库汊低于中游而略高于下游。群落的相似性表现为上、中游相近,下游和库汊相近。群落的物种多样性根据计算Shannon-Weiner指数为上游最大,其次为中游,下游再次,库汊最低。与1980年的调查结果相比较,浮桥河水库浮游植物种类小型化明显,生物量增加2.5倍。

The status of phytoplanktonic algae was investigated from April1997to January1998in Fuqiaohe Reservoir of Hubei Province.There were189phytoplanktonic algal species belonging to8phyla and92genera of which25genera and64species were in Bacillariophyta,39genera and79species in Chlorophyta,17genera and30species in Cyanophyta.The number of Species of Xanthophyta,Pyrrophyta,Cryptophyta,Euglenophyta and Chrysophyta were relatively less.The average annual density of planktonic algae was44.9×10 4 ind·L -1 .The average annual biomass was6.439mg·L -1 ,among which Cyanophyta accounted for33.37%,Bacillariophyta20.68%,Chlorophyta20.16%,and Pyrrophyta16.31%.The standing crop of phytoplantonic algae in Fuqiaohe Reservoir peaked in autumn by seasonal distribution and in upper reaches by horizontal distribution.The similarity index of phytoplanktonic algal taxa were similar between the upper and middle reaches,and also similar between the lower reaches and branches.The Shnnon-Weiner index was higher in the upper reaches,followed by the middle,lower,and then branches.Comparing to the investigation in1980,the biomass of phytoplanktonic algae in Fuqiaohe Reservoir increased by2.5times,with a trend of smallization in the size of species.