新疆天池景区生态安全度时空分异特征与驱动机制

本研究基于2000、2010年新疆天池风景名胜区的TM遥感影像、2000-2010年新疆统计年鉴、野外实地调查等数据,构建研究区的景观生态安全度,采用ESDA、半变异函数空间分析、逐步回归等方法,分析各样点景观生态安全度的时空演变特征,探讨导致格局演变的驱动机制。结果表明:① 2000-2010年,高景观生态安全度范围由南向北转移;中景观生态安全度区域由南北向中部集中;低景观生态安全度呈现由南向北扩散的趋势。② 景观生态安全度全局空间自相关较显著,随时间演变,空间集聚水平降低;局域空间自相关呈现集群分布向随机分布转变的趋势。③ 变程范围内,景观生态安全度值的各向异性与弱空间相关性特点是结构性因素和随机性因素综合作用的结果。④ 经度、纬度、海拔因子对景观生态安全度的影响显著;放牧、旅游以及政策活动影响景观生态安全度中小尺度格局,对景观生态安全度的演变有重要影响。

Characteristics of temporal-spatial differences in landscape ecological security and the driving mechanism in Tianchi scenic zone of Xinjiang

The Tianchi scenic zone of Xinjiang, one of Xinjiang Tianshan Mountain's world natural heritage sites, contains well-preserved natural landscapes. Landscape ecological security is an important environmental protection indicator. In this article, gridded spatial models for the degrees of landscape ecological security in the scenic zone are constructed based on TM images from 2000 to 2010, almanacs of Xinjiang from 2000 to 2010 and the data of field survey. By using ESDA and semi-variogram for spatial analysis, and the stepwise regression methods, the characteristics and the driving forces of the evolvement of temporal-spatial differences among the individual quadrats are analyzed. The results indicate that: (1) During 2000-2010, the areas with high degrees of landscape ecological security shifted from south to north; the areas with medium degrees shifted to the center from the south and north; the areas with low degrees showed a trend of expanding from south to north. (2) From 2000 to 2010, Moran's I reflected positive spatial autocorrelation of landscape ecological security, but the level of spatial concentration decreased and was unstable with time. The local indicators of spatial association showed that the degrees of landscape ecological security exhibited a trend of change from a clustered to a random distributed pattern. (3) Within the variation range, the value of landscape ecological security exhibited anisotropy and weak spatial correlation features, as a result of combined effects of structural and stochastic factors. (4) The longitude, latitude and altitude significantly affected the degree of landscape ecological security. In small and medium landscape scales, grazing, tourism, and policy activities had major impacts on the evolvement of the landscape ecological security.