A Study On The Restoration Of The Higher Plant Community In The Wetland Ecosystem Of Xuanwu Lake

This thesis belongs to the program "Research on Wetland Ecosystem Restoration and Wetland Plant Community Constructional Technology in Xuanwu Lake". This program comes from Nanjing Science Commission. The thesis is the foregoing basic research of the program.The thesis is made up of two pieces, "Research on Wetland Higher Plant Community Restoration Basis in Xuanwu Lake" and "Restoration Plan of Wetland Higher Plant Community in Xuanwu Lake"."Research on Wetland Higher Plant Community Restoration Basis in Xuanwu Lake" includes the investigation of the history of Xuanwu Lake, discussion of major function of wetland ecosystem, water analysis (analysis target: pH, T, SS, TP, TN, Chla, DO, CODcr, BOD5, Cr, Cu, Cd, Pb, Zn.), evaluation of eutrophication, sediments analysis (analysis target: TP, TN, Cr, Cu, Cd, Pb, Zn.), interaction among the biology communities of wetland, relationships of water, plant and sediments. From the research results, we can see that the initial reason, which leads to the degradation of Xuanwu lake ecosystem, is pollution. Pollution makes the water and sediments hypertrphiation, increases the opacity of water, and decreases the oxygen in water, so the wetland higher plant communities decrease or disappear. The wetland ecosystem loses the balance, while the biodiversity also decreases. Because of the nutrient load both inside and outside, Xuanwu Lake became a eutrophic lake; eutrophication is going to be more serious in the future. From the change of the analysis target of the water and the sediments in these years, we can see that these measures that take place in these years only make a little improvement on the degradation problem. These measures cannot change the trend of wetland ecosystem degradation. Therefore, we must restore the lose part of the wetland ecosystem-wetland higher plant community, make the wetland construction rational, then can we achieve the aim of holding back the degradation of wetland ecosystem, solve the problem of environment pollution."Restoration Plan of Wetland Higher Plant Community in Xuanwu Lake" discusses the tenet and principle of the restoration of wetland higher plant community in Xuanwu Lake, collects the basis of choosing of the wetland higher plant communities from four angles, controlling pollution, landscape succession, beautifying environment, economic utilization. Then on the basic of the environment characteristic of the Xuanwu Lake and the characteristic of the vegetative form andthe distribution pattern of wetland plant community, we choose the suitable wetland plant population; make the plan of the topographical reformation and wetland plant community construction. At last, the thesis gives some suggestion on the future operation.