Abstract:

[Objective] Evaluation of forest ecological security of 31 provinces, municipalities and autonomous regions of China, and analysis of its changing trend are conducive to know the situation of forest ecological security in 31 provinces, municipalities and autonomous regions, and differences among them. The study was to provide a scientific basis for establishing policies to improve the ecological environment based on the local conditions. [Method] Based on the PSR model, improvements were made to develop an indicators system of evaluation of forest ecological security. The indicators system was applied in the evaluation of forest ecological security in 31 provinces, municipalities, autonomous regions using the entropy method based on the yearbook data from 1999 to 2012. [Result] In the forest ecological carrying capacity indicators, the weight of resource indicator (0.536) and the complexity indicator (0.188) were significantly greater than others, indicating that the status of forest resources and complexity of the forest ecosystem was the main reason for variation among different years in the forest ecological carrying capacity in the provinces. In the human behavior indicators, the negative effect of human pressure on forests(0.995)was greater than the positive effect(0.005)brought by the maintenance of forests. Between 1999 and 2012, the comprehensive evaluation of forest ecological safety displayed a trend of increase, indicating an evident improvement of forest ecological safety in China. But there were still some provinces, such as Shanghai, Tianjin, Ningxia, Qinghai showed a far lower value (around 0.35 on average of 3 representative years) of the comprehensive evaluation than the national average ( 0.546), measures need to be taken to prevent degradation of the forest ecosystem.The comprehensive evaluation of the large provinces in forestry such as Jilin and Yunnan, far higher than those of Ningxia and Shanghai. The differences among provinces of forest ecological safety has now become increasing. In the evaluation of forest ecological safety, the forest ecological carrying capacity plays a main role followed by the role of human activities. [Conclusion] The overall situation of forest ecological security in China tended to improve, however, there are big differences among provinces, municipalities and autonomous regions. The main factors causing changes in forest ecological security are the quantity and quality of forest resources. Protection of existing forests, especially the natural forest should be strengthened.Attention needs to be given to optimization of stand structure and specie composition, persistence to sustainable development, and reduction of destruction to forest resources.A pre-warning mechanism for forest ecological security should be established to prevent deterioration of forest ecological security.

Key words: forest ecological security, forest ecological carrying capacity, human behavior's impact, comprehensive evaluation