利用生态工程降低湖体含磷量的研究

Study on Decreasing Phosphorus Content in Lake by Ecological Engineering

在长春南湖实施了生态工程以降低湖体含磷量。 1 996年 ,通过收获水生高等植物和鱼产品带出湖体的磷量分别为 1 49 6kg和 1 89 9kg ,蚌体生长固定的磷量为 1 53 4kg ,三者合计 4 92 9kg ,与湖体每年纳磷量大体持平。实施生态工程后 ,水质明显好转 ,湖水中的总磷浓度逐年下降 ,浮游植物个体密度减小、种类数增加。

Ecological engineering has been conducted to decrease phosphorus content in the Nanhu Lake of Changchun.In 1996,removal contents of phosphorus from lake by harvesting aquatic macrophytes and fishes were 149 6kg and 189 9kg,phosphorus fixed mussels was 153 4kg,the total was 492 9kg,which approximately equals to the phosphorus accommodated in the lake.Through ecological engineering,water quality turns better,TP concentration in lake water decreased,phytoplankton density reduced and the number of phytoplankton species increased.The roles of mussels and fish in controlling lake eutrophication should be further studied.