Method for restoring lake water ecology by utilizing natural ecological botanical system

The invention relates to a method for restoring lake water ecology by utilizing a natural ecological botanical system, which comprises the following steps of: planting bulrush and Nymphoides peltatum in March; culturing zizania caduciflora seedlings in March; raising trapa seedlings in a nursery in April; arranging soft isolations and fences at the periphery of a trapa planting area from March to April, transplanting the cultured trapa seedlings behind the two ways of fences and soft isolations, and planting the cultured zizania caduciflora seedlings serving as a plant wave dissipating band from one way of soft isolation adjacent to the shoreside closely to a water body shoal band of which the depth of water is 1 meter; harvesting water chestnuts from September to October; planting eel grass in October; and removing leaf stems of the bulrush, the Nymphoides peltatum, the zizania caduciflora and the trapa from a water body in December. After the water body is restored by the method of the invention for one year, the coverage rate of aquatic plants is about 95 percent, the blue algae reduction rate of the water body is over 84 percent, the transparency of the water body is improved to between 1 and 1.2 meters, and water quality in a preventing and control area reaches III water standard from the original V water standard.