The Study On The Functional Value Calculation System And Its Degraded Loss Evaluation For Chinese Grassland

The grassland ecosystem, one of the most important terrestrial ecosystems in China, plays an important role on the structure, function and processes of the natural ecosystem. However, in some regions, the ecological problem is getting worse because of grassland degradation. This article, mainly on the degraded grassland ecosystem, through the selection of evaluation indicators and accounting formulas as well as the classification of ecosystem degradation degree, finally established an operational grassland functional value calculation system, and further evaluated the lost value of degraded grassland. To sum up, the four main conclusions were as follows:First, through the establishment of indicators' selecting scope by Frequency Aanlysis, the assessment of indicators' importance by Expert Advice Method, and the construction of indicators' weight mathematical model by Analytical Hierarchy, calculated the weight and sorting of the grassland ecological functional indicators. Then, chose the ecological functional indicators in order of significance, it consisted of nine evaluation factors, including water holding, soil conservation, windbreak and sand-fixing, carbon fixation and oxygen release, biological diversity maintaining, air cleaning, eco-tourism, waste degradation, and nutrient recycling.Second, constructed the functional value calculation system of grassland.This system was divided into three categories, including the production function, ecological function and ecological loss. The value of production value corned from its TND; the ecological function value corned from the value of water holding, soil conservation, and so on; the ecological loss had a related coefficient which was from classification indicators of degradation.Third, put forward the evaluation model of value calculation of degraded grassland. That is V=MC+V'-SH,(?).Of which,(?),SH=λ'×V' (λ'≥0.1) . Forth, set the eighteen types of grassland in China as an example, the result indicated that the total value of non-degraded grassland was 424.2 billion yuan, the ecological function value accounted for 70.5 percent; the value of grassland which was caused by mild, moderate, severe and extreme degradation respectively were 356.33, 266.64, 178.16, 66.81 billion yuan; and the total loss respectively accounted for 16 , 37.1, 58, 84.2 percent of the total value. The statistics showed that compared with lost forage value, the ecological loss is more. Therefore, the lost would be great while neglecting the important environmental value.