Study On The Photosynthetic Characteristics Of The Dominant Plants And Human-induced Restoration Technology In The Mount Beigu Wetland

It is the current situation that the Mount Beigu wetland has been destroyed seriously, and the function of the wetland has been weakened, the sight has been demolished. According to the national "863" project of the "Ecological bank-waterfront-wetland system restoration and pollution-controlling technology and demonstration", the author studies the physiological and ecological characteristics of the wetland plants. The objective is to provide the theoretic and technical bases for the wetland human-induced restoration. The major results are as follows:(1) According to the data collection and site investigation, the author analyzes the ecological characteristics of the local species and plant diversity. The author analyzes the existing problems that the Phragmites communis coverage is very low, thus accounting for the necessity of the human-induced restoration.(2) The author analyzes the diurnal variation of photosynthesis and transpiration of the dominant plants Phragmites communis and Phalaris arundinacea L., and the effect of the environmental factors upon the two wetland dominant plants, as well as the correlativity among them. Studies are also made on the light response, photon use efficiency and water use efficiency. The Pn of Phragmites communis is higher than that of Phalaris arundinacea L, meanwhile Phragmites communis has the higher diurnal photosynthetic capacity, which shows that the Phragmites communis could grow more rapidly, and have higher biomass, so the Phragmites communis could be one of the priority implemental plant.(3) By introducing the various restoration methods in wetland, the studies of human-induced ecological engineering are conducted. It can show through the comparisons that the Phragmites communis's seedlings are appropriately chosen as being transplanted before the middle of the April. Phragmites communis grows in the mixed-cropping section less than that does in the single-cropping section, so the Phalaris arundinacea L. restrains the growth of Phragmites communis. The natural Phragmites communis grow more rapidly than that of the artificial cultivation, but the former expand very slowly, so the Phragmites communis in the wetland vacancy are artificially cultivated, thus accelerating the restoration velocity.(4) The effect of artificial cultivation upon the expansion of Phragmites communis species is studied; the two cultivating patterns are adopted on the Phragmites communis. The results show that the Phragmites communis planted by using the rhizome propagation method grow more rapidly than those planted by seedling propagation method. However, the rhizome propagation method has the demerits with consuming labors and large destruction to soil. Therefore, the cultivating patterns must be chosen according to the actual conditions.(5) In the biological diversity experimentation, Zizania caduciflora, Typha orientalis and Acorus calamus are chosen, and the results show that Acorus calamus are not adaptable to the wetland environment, the variation of the other lengths is near to the sigmoid curve.