The Assessment On Health Of In Qinghai-tibet Plateau Alpine Meadow Ecosystem

In recent years, there have been different degrees of degradation in Qinghai-Tibet Plateau alpine meadow ecosystem, such as change of plant community structure, decline of biodiversity and NPP, more serious soil erosion. All these lead to decline of ecosystem function and recovery. Three rivers area is one of distinctive and typical areas in Qinghai-Tibet Plateau, with rich water resources. The area plays an important role in ecological regulation. However, in order to utilize grassland reasonably, it is necessary to understand its situation, especially the health situation. This will help managers and researchers understand the whole situation.By reading relevant references and consulting experts, the essay use plant-soil-interference index system, and employs 20 indicators:biomass,proportion of good grass,vegetation cover,low biomass,soil organic matter and so on. These indicators can reflect the health situation of alpine meadow ecosystem.Used AHP to determine weights of indexes.Constructed two-two comparison matrix though the relative importance of various criteria of the same level and the previous level elements in index system. Compared to the corresponding matrix, get the solution of the comparison matrix to determine the index weight by inviting experts to evaluate the two-two importance of each matrix elements.Using composite Index model to evaluate the ecosystem's health condition of alpine meadow, analysis the spatial pattern of the regional ecosystem health of Chengduo county in 2009.The result shows that: Cheng-duo county's alpine meadow ecosystem H₁ (very healthy) level area is 40831.2hm², the proportion is 3.35%;ecosystem H₂ (health) level area is 322021.1hm², the proportion is 29.07%; ecosystem H₃ (sub-health) level area is 431286.4hm², the proportion is 38.94%; ecological systems H₄ (poor) level area is 276374.0hm², the proportion is 24.95%; ecosystems H₅ (very poor) level area is 37048.3hm², the proportion is 3.35%.The overall index of ecosystem health in Cheng-duo county is 63.95, whose ecosystems in the sub-health condition and have been biased in favor of early-warning level. This should lead to government authorities and the people's attention.