Studies On Indicator System For Napahai Wetland Ecosystem Degradation Degree Evaluation

Evaluations of degradation wetland are the important basis of the works of wetland restoration.Currently,most studies of the evaluations of degradation wetland are at the qualitative leve and single factors .It is an urgent and key issue in the field of restoration ecology theory and ecological practice to ascertain the degradation degree of wetland ecosystem quantitatively by multifold factors.Napahai,lying between 99°37′~99°43′E,27°49′~27°55′N,at 3,260m above sea level, is a Karst wetland of Yunnan plateau. Situated in the middle part of Hengduan Mountain, upstream of Yangtze River, Napahai plays an important role in adjusting the water flow and the water level of the downstreams, regulating local climate and provides a habitat for rare and endangered species,such as Grus nigricollis. However,since 1970,s, the wetland has continuously suffered from disturbance of human activities around it .Wetland environment has deteriorated due to unreasonable utilization of wetland resources such as wetland reclamation, over pasture,destroying the vegetation and unordered touring etc. It is urgently to restore degradation wetland ecosystem.Based on the studies on the wetland soil, water environment, wetland vegetation, wetland ecological funcations, wetland landscape and driving factors,21 indexs were selected to establish an indicator system of Napahai degradation wetland ecosystem according to the mode of PSR(Pressure State Response ).At the same time,a theoretic indicator system was established by historical literature, research methods of ecology and national environment standard.Using the method of APH(Analytic Hierarchy Process), the weights of indexs were calculated. Indexs were standardized by contrast value of indexs with theoretic indicator system.The results of evaluations of degradation wetland ecosystem were calculated by the method of synthesis index .The results of evaluations indicates that the pressures of disturbance of human activities have overstepped the limit of wetland ecosystem. Wetland environment ,wetland...