长春南湖水生生态系统中浮游动物群落特征

Characteristics of Zooplankton Community in the Aquatic Ecosystem of Nanhu Lake of Changchun

研究了2001～2002年长春南湖生态系统中的浮游动物群落特征．发现浮游动物94种，其中51种为轮虫．浮游动物优势种存在明显的季节变化，浮游动物的个体数量在夏季和秋季各出现一次高峰．浮游动物年净产量为704．45kJ·m^-2，年总产量为1642．50kJ·m^-2；全年浮游动物群落的P／B系数为41．4（以年净产量计）或96．4（以年总产量计）．浮游动物群落对水柱原位浮游植物和浮游细菌的牧食力分别为2．57kJ·m^-2·h^-1和1．47μgC·L^-1·h^-1，是浮游植物和细菌同期净生产力的51．7％和32．9％．形成浮游动物净生产力的碳量是浮游植物总碳固定的8．2％．浮游动物群落在一定程度上体现了南湖为温带富营养化湖泊的特征．

The zooplankton community characteristics were studied in the Nanhu Lake ecosystem of Changchun in 2001 - 2002. 94 Species of zooplankton were found, including 51 species of Rotifera. The seasonal changes of dominant zooplankton species were obvious. Twice peaks of zooplankton individual number were found in summer and autumn. The annual net and gross productions of zooplankton were 704.45 kJ·m^-2 and 1 642.50 kJ·m^-2, respectively. The annual gross production of zooplankton was 13.9% of annual net production of phytoplankton. The P/B index of zooplankton community was 41.4 （ calculated by P, ） or 96.4 （ calculated by Pg）. Based on the determination result of in situ experiment, the grazing abilities of zooplankton community on phytoplankton and bacteriaplankton were 2.57 kJ·m^-2· h^-1 and 1.47 μg C· L^-1· h^-1 respectively, which were 51,7% of phytoplankton net productivity and 32. 9% of bacteriaplankton net productivity in the same period. The carbon amount forming zooplankton net productivity was 8.2% of the total carbon amount fixed by phytoplankton. The zooplankton community indicates, to some extent, the feature of the Nanhu Lake as an eutrophicated lake in temperate zone.