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 research studies in ecology these years. Actually, the attention people pay to ecosystem health is more about what social functions the ecosystem affords, which depend on the integrity and maintenance of the structures and functions inside the ecosystem and disturbances outside the ecosystem. Accordingly, 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). And with the method of the Analytical Hierarchy Process (AHP), the health comprehensive index (HCI) which represented the health state of the forest ecosystem could be obtained, and the health state was divided into four grades such as excellent, healthy, sub-healthy and morbid to help people better get a general idea.The researchers chose the Badaling forest farm and Xishan forest farm for case study. The result shows that the HCI of Badaling forest farm ranges from 4.9 similar to 8.8. The natural forests are in the healthy state. As to the plantations, the HCI of the two places of the Chinese pine (Pinus tabulaeformis Carr.) were 7.9 and 7.7, achieving the healthy state, while the others were relatively worse. Accordingly, it may well prove that the reforestation by closing the land is a wise action.The HCI of Xishan forest farm range from 6.8 similar to 8.8, and the health state of plantation of the oriental oak (Quercus variabilis Bl.) and plantation of the locust tree (Robinia pseudoacacia L.) are at the same level to the broad-leaved community.According to the comparison of the two forest farms, it shows that the health state of the sample plots selected in the Xishan forest farm is superior to that in the Badaling forest farm. The forests of the Armand's pine (Pinus armandii Franch.) both introduced in the two forest farms are in the sub-healthy state and the forests of the prince Rupprecht's larch (Larix principis-rupprechtii Mayr.) both planted are also in a sub-healthy state. And finally, some suggestions are put forward.