西藏森林生态安全动态评价研究

Research on Dynamic Evaluation of Tibet Forest Ecological Security

青藏高原对我国乃至亚洲生态安全具有重要的屏障作用,而森林生态系统作为陆地上最大的生态系统,在陆地生态系统中发挥着调节气候、涵养水源、保持水土、防风固沙等功能。基于西藏地区生态安全和森林生态系统的重要性,本文结合压力-状态-响应(PSR)模型,对西藏自治区2008~2017年的森林生态安全进行了动态评价。结果显示,西藏地区2008~2014年间森林生态安全状况在动态恶化,2008~2010年处于“临界安全”等级,2011~2014年处于“较不安全”等级;2015~2017年森林生态安全状况得到改善,但仍处在“较不安全”等级;导致森林生态安全状况恶化的因素主要是单位森林面积蓄积量、森林病虫鼠害发生率、自然保护区面积、封山育林面积和环境污染治理投资占GDP比重。

The Qinghai-Tibet Plateau plays an important role as a barrier to the ecological security in China and even Asia.As the largest ecosystem on the land,the forest ecosystem plays a role in regulating climate,conserving water sources,maintaining water and soil,and preventing wind and sand.Based on the importance of ecological security in Tibet and the importance of forest ecosystems,this article combined the pressure-state-response(PSR)model to dynamically evaluate the forest ecological security in the Tibet Autonomous Region from 2008 to 2017.The results showed that the forest ecological security situation in Tibet had deteriorated dynamically from 2008 to 2014,and was at the"critical security"level from 2008 to 2010 and"less secure"level from 2011 to 2014.The forest ecological security improved from 2015 to 2017,but still at the“less safe”level.The factors leading to the deterioration of forest ecological security mainly were the storage volume per unit forest area,the incidence of forest pests and rodents,the area of nature reserves,the area of closed forests for afforestation and the proportion of investment in environmental pollution control in GDP.