沉水植物在生态修复和水质改善中的作用——以惠州南湖生态系统的修复与构建(中试)工程为例

目的]探索改善惠州西湖水质的有效途径。方法]于2007年5~10月对惠州南湖(西湖子湖之一)生态修复中试区的水质进行调查分析。结果]工程区水体中总磷和总氮含量分别降低54.47%和52.67%,叶绿素含量也降低78.59%。水体由浑水态转变成清水态,透明度由原来的30 cm厚提高到150 cm厚。营养指数下降28.5%,营养盐含量大幅度降低,生态链的多样性提高2~3倍。沉水植物增长迅速,其覆盖率达50%~60%,其中苦草生物量为2.2 kg/m2,黑藻生物量为9.6 kg/m2,说明工程区有向原生演替的趋势。结论]沉水植物的恢复与重建是改善西湖水质的关键。恢复并建立相对复杂的水生态系统,是解决惠州西湖水体富营养化的根本途径。

Study on the Functions of Submerged Macrophytes in Ecological Restoration and Water Quality Improvement

Objective] The aim of the research was to discuss the effective approach to improve the water quality of Huizhou West Lake.Method] The water quality of middle test ecosystem restoration area in Huizhou South Lake (one sub-lake of West Lake) was investigated from May to October of 2007.Result] The contents of total phosphorus and total nitrogen in water body of the engineering area were decreased by 54.47% and 52.67% resp.,the content of chlorophyll was also decreased by 78.59%.Water body turned into clear water state from muddy water state and the diaphaneity was increased from original 30 cm to 150 cm in thickness.Nutritional index was decreased by 28.5%,the content of nutritious salt was greatly decreased and the diversity of ecological chain was increased 2～3 times.Submerged macrophytes went up rapidly and their coverage rates reached 50%～60%.And the biomass of Vallisneria natans was 2.2 kg/m2 and that of Hydrilla verticillata was 9.6 kg/m2,which indicated that the engineering area had a trend of primary succession.Conclusion] The restoration and reconstruction of submerged macrophytes was the key to improve the water quality of West Lake.It was the basic approach for solving water eutrophication in Huizhou West Lake to restore and establish relatively complex water ecosystem.