Forest Ecological Security (FES) means coordinated development of forest ecosystems, social economies, and the forest environment. In this paper, we evaluate FES in Beijing under different designed scenarios using a dynamic systems model and find that first, the initial FES index value (in Scenario 0) increased to its highest level of 0.529 in 2012, but declined slightly to 0.485 by 2020. Second, in Scenarios 1-4, the FES index value reached 0.545, 0.516, 0.585 and 0.637 respectively in 2020, which was enhanced in varying degrees when compared with Scenario 0. The simulation shows the implementation of forest management policies, socioeconomic development and environmental management combine to affect the FES in Beijing. The FES could develop into a good state when the productivity of forest resources, the stability of forest environments and the orderly development of the social economy are carefully maintained (in Scenario 4). This research could provide decision-making in support of the overall improvement of forest conditions while promoting sustainable forestry in Beijing.

Greater contradiction and conflict among urban green space, the development of social economy and the environment have occurred in Beijing. However, few studies have been conducted that consider the three subsystems as a whole. In this study, we defined sustainable development of green space (SDGS) as the coordinated development of the urban green system, social economy, and environment. Based on the datasets from 2000 to 2015, we forecast the SDGS in Beijing under multiple scenarios based on real-world policies using a system dynamics model. We found that the historical SDGS value increased to its highest level in 2012, but declined slightly by 2015. Second, the forecasted SDGS values declined over time in all scenarios, but the decline was greater in scenarios placing a high priority on economic development. In these scenarios, the performance of the indices only improved in certain subsystems. The simulation shows the implementation of the four policies proposed by the government failed to improve the overall level of SDGS in Beijing. This study could provide support for decision-making designed to improve the overall condition of urban green space in Beijing through integrated forecast and scenario simulation.