Establishment And Application Of The Synthetic Assessment System Of Forest Ecosystem Health In Beijing Area

The evaluation of ecosystem health has been one of the main researches in the ecosystem domain these years. Acturally, the attention people pay to ecosystem health is more about what the social functions the ecosystem affords, which depends on the integrity and maintenance of the structures and functions inside ecosystem and disturbances outside the ecosystem. According to that, this research, from the structure, the functions inside the ecosystem and the disturbance outside, established the Synthetic Assessment System of Forest Ecosystem Health in Beijing area(SAS-FEHB), which compounded the propoties of nature, economy and society of Beijing. Thenwith the mathod of the Analytical Hierarchy Process(AHP), the health comprehensive index(HCI) which represented the health state of the forest ecosystem, could be obtained. In the end, the forest ecosystem health state was divided into such four grades as excellent, healthy, sub-healthy and morbid, which made the foundation of case study next step of themoumtain forest ecosystem in the northwesten Beijing.The result showed that the HCI of Badaling forest center ranged from 4.9～8.8. The natrual forests were in a healthy state. As to the plantation, the HCI of the two Pinus tabulaeformis forests were 7.9 and 7.7, achieving to the healthy state, while the others were relative worse. From that, it proved the reforestation by closing the land was an wise action.The health comprehensive indexes of Miaofengshan forest center ranged from 4.9～8.8, and the health state of plantation of Quercus variabilis and plantation of Robinia pseucdoacacia were at the same level to the broad leaved community.Compared the two forest centers, it showed that the health state of the artificial forest ecosystem in Miaofengshan forest center was better than that in Badaling forest center. The Pinus.armandii forests both introduceed were in a sub-healthy state and the Lanix pninapis-rupprechlii forests both planted were also in a sub-healthy state.In the end, some advices were given: the natural forests should be kept in its original state, unless do some thinning if necessary; as to the plantations growing well, the native species regeneration should be promoted; while the the plantations growing bad, artificial improvement should be taken to make them grow in a correct way.