拉市海浮游生物群落特征及其初级生产力和鱼产力的估算

研究拉市海湖泊生态系统中浮游生物群落特征，包括浮游生物的种类组成、种类密度及生物量，对于评价该湖泊的水质现状及对其的保护工作都具有十分重要的意义。这次调查共发现133种浮游植物及62种浮游动物，定量结果表明浮游植物和浮游动物平均密度分别为758000cells／L和29500ind／L总生物量分别为13．36mg／L和2．24mg／L。其中硅藻、绿藻和轮虫，无论是种类数量还是种群个体数均占有绝对优势，说明拉市海水体属于寡污染型。此外，文章还测定拉市海水体初级生产力，同时对鱼产潜力进行估算。得到该水体浮游植物平均总产氧量为1．02mg／（m^2·d），湖泊总鱼总产力为390．39kg／hm^2。虽然该浮游植物产氧量较低，但从整体角度上看却是适宜的，即浮游生物在该水体中的种类和数量与其水体自身维持生态平衡。

Plankton Community Characteristics in Lake Lashi,and Estimation on its Primary Productivity and Fish Productivity

The survey on plankton community characteristics in Lake Lashi,including the species composition,density and biomass,is significant in the assessment of lake water quality and its protection.Totally,133 species of phytoplankton and 62 species of zooplankton were found in Lake Lashi.The average density of phytoplankton and zooplankton was 758 000 cells/ L and 29 500ind/L separately,and their biomass was 13.36mg/L and 2.24mg/L individually.Bacillariophyta,Chlorophyta and Rotatoria are dominant species among them,indicating that Lake Lashi is still few polluted.Meanwhile,the primary productive force and fish productivity in Lake Lashi are also estimated.The total output of oxygen dissolved in this water by phytoplankton was 1.02mg/(m3·d)and the fish productivity was 390.39 kg/hm2.Though the total output of oxygen by phytoplankton is lower than other advanced plant’s,it suggest that the variety and the quantity of plankton in the Lake Lashi keep ecological balance with the water.