Study On Restoration And Rehabilitation Of The Damaged Riparian Ecosystem

The study taken part of the spillway of Jingyue Lake reservoir in Jingyue campus of Northeast Normal University as a case applies the ecological principle to the traditional hydraulic engineering planning and takes the purpose of supplying the living space for animals and plants. Based on the ecological succession theory and design theory of restoration ecology, it uses engineering and plant measures to rehabilitate primal riparian ecosystem. The paper stresses on analysis dynamics of ecosystem and quantitative evaluation indexes in the process of the restoration from 2002 to 2004. The results show as follow: (1) Soil microbes number,biochemical intensity,peroxidase,urease and O.M indexes have reached significant level in the area of experiment A1 and A2 compared with the area of comparison B1 and B2 under manual control. The results show that primal riparian ecosystem is making for development of healthiness. (2) Eight Species zoobenthos are collected in the habitat patch of manual restoration, therein two species oligochaeta, two species nollusca,three species aquatic insecta and one species other animal. The number of Limnodrilus sp. and Branchiura sowerbyi occupy 97 per cent of zoobenthos, which are absolutely dominant species in the research area. The results show that the water body is seriously eutrophication in the research area. Meanwhile, species,density,biomass and biodversity index of zoobenthos in different squares are in follow order: Square A>Square B>Square C. The results also show that habitat patch of manual restoration provides a good propagation and habitat site for zoobenthos. (3) The mechanisms of soil-reinforcement by roots have been researched through the tests for the pull-resistance of roots of Salix chaenomeloides ,Amorpha fruticosa L.,Phragmites communis Trin.,Acorus calamus L..The results show that the pull-resistance of roots increases with average diameter of roots and displays power function,and significant positive relation exists closely between pull-resistance of roots and average diameter of roots. Pull-resistance of roots will greatly enchance when average diameter of roots reaches limit point because the properties of roots changes from elasticity deformation to plastic deformation and the deformation is not reversible during roots are pulled. Meanwhile, the thin roots have good deformation ratio. The results also show that root pull-resistances and ratio of the most deformation are important indexes reflecting root coast- resistances. (4)As shown in the three-years longitudinal study on the ecosystem restoration and rebuilding carried out on the degraded riparian zone in the Jingyue campus of Northeast Normal University,the ecological diversity and stability in the degraded riparian zone increase and bank slope is safeguarded effectively after the restoration and rebuilding.