Abstract: Ecological security is the basis for regional security as well as regional socio-economic sustainable development. The situation of ecological environment and forest ecological security in Beijing,the capital of China, is not optimistic. Forest ecological security(FES)has attracted a widespread attention of the government and the public. Through four designed scenarios,this paper obtained the development trend of forest ecological security in Beijing under different control schemes,and provides an effective way for the sustainable forest ecological security in Beijing. According to the characteristics of forest ecosystems in Beijing,a comprehensive evaluation index system of forest ecological security was established based on the definition of forest ecological security,and a scenario analysis and control model of forest ecological security based on SD model was established. Four scenarios,developing reasonable forest management policies,the medium-speed socioeconomic development, strengthening environmental management,Forest-socio-economic-environment coordinated development,were designed and simulation and dynamic evaluation analysis were carried out on the forest ecological security situation in each scenario. The initial FES index value(in Scenario 0),the comprehensive assessment value of forest ecological security(FES)in Beijing increased from 2000 to 2020,and reached to its highest level of 0.527 in 2013,but it declined slightly to 0.519 in 2020. The improvement of forest ecosystem security is not obvious. In Scenarios 1-4,the FES index value will reach 0.541,0.525,0.559 and 0.604 respectively in 2020,which all enhance the forest ecological security in varying degrees compared with Scenario 0,and the quantity and quality of forest resources will also be improved in varying degrees. The implementation of forest management policies,socioeconomic development and environmental management combine to affect the FES in Beijing. Only by maintaining the productivity and sustainable vitality of forest resources,maintaining the stability and health of the forest ecological environment,and guiding the orderly development of social economy(Scenario 4),the forest ecological security of Beijing will be significantly improved. In order to improve the forest ecological security of Beijing,the government might attach more attention to the following five aspects:(1)appropriately controlling the growth rate of population as well as the private vehicles;(2)adjusting the industrial structure and optimizing the energy consumption structure;(3)formulating scientific and reasonable forestry policy,that is increasing investment in forestry development and reasonable setting forest cutting quota;(4)strengthening technical innovation and collaboration so as to effectively control and treat the pollution;(5)constructing an persistent ecological security assessment institution and safeguard mechanism.

Key words: forest ecological security, integrated evaluation, scenario simulation, system dynamics model, Beijing