Function of Submersed and Floating-Leaved Macrophytes in the Shallow Lake Ecological System-A Case Study of Taihu Lake

The submersed and floating-leaved macrophytes,macrozoobenthos,water quality,and sediments in the Taihu Lake have bee investigated. The results show that the existence of submersed and floating-leaved macrophytes have a significant effect on water quality,sediments’ characteristics and the index of biodiversity of the macrozoobenthos. Through the comparison of the area with macrophytes and the area without macrophytes,it is found that water transparency improve 1.12 (May) and 1.99 (Sept.) times,TN reduce 1.84 (May) and 0.70 (Sept.) times,TP reduce 0.99 (May) and 1.58 (Sept.) times,the content of chlorophyll reduce 2.17 (May) and 1.54 (Sept.) times; the biodiversity of macrozoobenthos (75 species) in the area with macrophytes is higher than that in the area without macrophytes (53 species). The Analysis of Variance shows that the difference reached significant level (P0.05) or extremely significant level (P0.01). The research reveals that Taihu Lake’s submersed and floating-leaved macrophytes is an important part to maintain the healthy shallow lake ecological system.