The restoration of aquatic macrophytes for improving water quality in a hypertrophic shallow lake inHubei Province, China

摘要

This paper deals with a case study of the restorationof submerged macrophytes for improving water quality in a hypertrophic shallow lake, lake Donghu of Wuhan,Hubei Province, China. Macrophyte restoration experiments were conducted in large-scale enclosures established in three sublakes of different rophic status, and the effectiveness for water quality improvement was tested by using the enclosure experiment in the hypertrophic sublake. Water quality was remarkably improved after the reestablishment of aquatic macrophytes. It is suggested that the submerged vegetation of less polluted sublakes could be capable of recovering spontaneously once the stockingof herbivorous fishes has been ceased, andthe K-selectedplants such as Potamogeton maackianus should be introduced into these sublakes to enhance the staility of aquatic vegetation. However, it may not be possible and economical to restore the submerged macrophytes in severely polluted basins unless external pollution has been cut off and internal nutrient loadings considerably reduced. in this case, the r-selected submerged plants should be used as the pioneer species for macrophyte recovery.