基于景观结构的吉林西部生态安全动态分析

Analysis on the Dynamic Trend of Ecological Security in the West Part of Jilin Province, China Based on the Landscape Structure

景观结构的调整和重建是构建安全的区域生态格局的关键途径。基于景观生态学的基本理论 ,在景观干扰度和脆弱度指标构建的基础上 ,引入生态安全指数 ,并利用区变量理论对吉林西部 1980 - 2 0 0 0年的生态安全状况进行时空动态分析。结果表明 ,由于景观结构变化导致的生态安全指数时空变异显著。全区生态安全程度整体有所下降 ,且安全程度较高的地区降低的幅度更大。生态安全指数的空间分布符合球状模型 ,2 5 0km以内表现为显著的各向同性 ,自相关范围都在 5 0 0km以上 ,小尺度不存在结构性因素的影响。 9个市县中 ,生态安全指数最高的是前郭 ,最低的是通榆 ,环境恶化程度最大的是大安。

Regulation and rebuilding of landscape structure are the keys to redevelop the regional safe ecological pattern. In this paper, the temporal and spatial dynamic trend of the ecological security in the west part of Jilin Province during the 20-year period from 1980 to 2000 is analyzed based on the landscape ecology theory and the disturbance and vulnerability of landscapes by using security indexes of ecological environment. The results show that the temporal and spatial change of the ecological security indexes caused by the change of landscape structure during the period from 1980 to 2000 is significant. The conditions of ecological security in 2000 were not as good as that in 1980, especially in the regions with high indices previously. The spatial distribution of ecological security index in the west part of Jilin Province accords with the spherical model and is in an obvious isotropy within 250 km, and the autocorrelation extent exceeds 500 km. Among the 9 counties and cities, the distribution of ecological security index is the highest in the Qianguo region and the lowest in the Tongyu region, and the ecological environment is most seriously degenerated in Da’an County.