千岛湖枝角类的群落结构

研究了一大型深水湖泊——千岛湖枝角类的群落结构，包括种类组成、种群动态、现存量及多样性指数等．在一周年的研究中，共发现26种枝角类，根据年平均密度和生物量，优势种为透明溞(Daphnia，hyalina)、象鼻溞(Bosmina spp．)和短尾秀体溞(Diaphanosoma brachyurum)．相关回归分析表明：采样站之间群体的密度越大，群落的多样性和均匀度显著增加，种类数也明显增多．通过比较8个湖泊、水库枝角类的种类组成发现，枝角类的种类数并不与湖泊面积大小呈明显的正相关关系，这与Dodson通过研究欧洲及北美湖泊中的枝角类得出的结论并不一致．

Community Structure of Planktonic Cladocera in Qiandao Lake

Community structure of planktonic Cladocera,including specise composition,population dynamics, standing crops and diversity indexes, was studied in a large,deep water lake,Qiandao Lake (Zhejiang).Duringa one year study,26 species were found.In terms of annual average density and biomass,the dominant Cladocera were Daphnia hyalina, Bosmina spp. and Diaphanosoma brachyurun. Analysis of regression indicated that the higher the diversity is, the gredter the evenness and species richness,and density of the Cladocera community.A comparison of species composition of cladocera in eight lakes shows that the species number of Cladocera is not proportional to the surface area of the lake,which is not consistent with Dodson's conclusion on the positive relationship of lake surface area vis a vis cladocera species number in European and North American Lakes.