微型生态系统中鲢、鳙下行影响的实验研究——1.浮游生物群落和初级生产力  

EXPERIMENTAL STUDIES ON THE TOP-DOWN EFFECTS OF SILVER CARP AND BIGHEAD CARP IN FRESHWATER MICROCOSMS (Ⅰ) : PLANKTON COMMUNITY AND PRIMARY PRODUCTIVITY

作　　者：阮景荣[1] 戎克文[1] 王少梅[1] 

机构地区：[1]中国科学院水生生物研究所,武汉430072

出　　处：《湖泊科学》1995年第3期226-234,共9页Journal of Lake Sciences

基　　金：国家自然科学基金(3870344)

摘　　要：在营养物供给量较大的实验条件下,鲢、鳙放养明显地改变了微型生态系统的群落结构、代谢和理化环境,以致实验后期鳙单养和鲢、鳙混养系统出现不同程度的富营养化。微型生态系统中浮游植物密度的增长不完全由营养级联效应所致,但初级生产力的组间差异可大致依据营养级联假说来解释。实验结果认为,以提高鱼产量为目标的鲢、鳙高密度放养,对加速营养物来源丰富的天然水域的富营养化起着重要的作用。Experimental studies were carried out on the top-down effects of silver carp (Hypophlhalmichthys molitrix) and bighead carp (Arstichthys nobilis) at a stocking level of 15g/m3 in freshwater microcosms under relatively high nutrient loading (average P loading = 0. 0061 g P/(m3 ?day)). The results indicate that the community structure, metabolism and physico-chemical conditions of the microcosms stocked with fishes changed obviously ; the microcosms containing bighead carp alone (monoculture) or both species of fish (mixed culture) became more or less eutrophic at the end of the experiment. It is found that primary production was correlated positively with phytoplankton density but negatively with zooplankton density in the microcosms, so the differences in productivity among various groups of microcosms could be on the whole explained by the trophic cascade hypothesis. However, the dynamics of plankton community show both top-down and bottom-up effects between zooplankton and phytoplankton, and the increase in algal density did not entirely result from the trophic cascade effects. It is considered that dense stocking of silver carp and bighead carp for the purpose of increasing fish yield played an important role in accelerating the eutrophication processes of natural waters with rich nutrient sources.

关 键 词：微型生态系统 鲢 鳙 浮游生物群落 初级生产力 

分 类 号：Q959.468[生物学—动物学]