Dredging and aquatic macrophytes reestablishment were carried out in the West Lake Wuli of Lake Taihu. Total phosphorous and total nitrogen in the water, as well as different forms of phosphorus and nitrogen in the sediment cores of different areas were investigated in different seasons to examine the effects of different restoration measures. The results showed that, the distribution of nitrogen and phosphorus in the water and sediment under different ecological restoration were different. The content of nitrogen and phosphorus in the water in dredging only area and control area was lower than other areas. Vertical distribution of different forms of phosphorus in the sediment of West Lake Wuli varied with different ecological restoration measures. Macrophytes reestablishment after dredging affected Lab-P,Al-P,Fe-P observably, other than Ca-P and Org-P. In the former-fishery area, Ca-P and org-P took up the largest proportion in the total phosphorus, followed by Fe-P. However, Fe-P and Ca-P took up the largest proportion in the dredging only area. Compared with TP, the effects of ecological restoration measures on TN were not so obviously. In dredging only area, the contents of nitrogen and phosphorus in both the water and sediments were high, the long-term effects of dredging needed further study. In the area of dredging plus macrophytes reestablishment, the content of TN and TP was the lowest, with plenty of aquatic macrophytes. It was suggested that the effective way of eutrophicated lake control may be actualizing through reestablishment of aquatic macrophytes in the dredging area by the precondition of reducing external source pollution.
Yu Haiqiao; Fang Tao (email@example.com) ; Xia Shibin; Ao Hongyi.Seasonal and vertical distribution of nitrogen and phosphorus in the sediment under different ecological restoration measures in the West Lake Wuli, Lake Taihu,Hupo Kexue,2007,19(6):683-689