各等级道路网对纵向岭谷区景观结构健康的影响

Effects of different level road networks on landscape structure health in the Longitudinal Range-Gorge Region

景观健康是近年来景观生态学与生态系统健康学相互交叉、相互耦合的一个新的研究领域.从景观结构角度,利用缓冲区、情景对比和景观指数等分析方法,研究了各等级道路对我国西南纵向岭谷区景观结构健康的影响.研究结果表明,我国西南纵向岭谷区道路影响生态系统的面积占区域面积比例的5.42%,低等级道路对生态系统的面积和景观破碎化影响较显著,而对耕地和建设用地的影响弱于高等级道路;由于道路对生态系统变化的驱动作用,使耕地和建设用地在道路影响域的面积比例高于其在全区的比例.随着道路网的扩展,景观结构健康指数从不考虑道路对生态系统影响下的0.42下降至考虑所有道路对生态系统影响下的0.24,从一般状态下降到亚健康状态,景观结构健康随着道路网密度的增加,其下降幅度较大.纵向岭谷区具有特殊的地理环境与生态系统,研究道路对该区的景观结构健康的影响,具有理论与现实意义.

Landscape health is a new subject in landseape ecology anti ecosystem health. Approaehing the problem from the landscape structure point of view. aualytical methods including buffer, scenario, comparison and landscape index aualysis were used to study the effect of roads on landscape heahh in the Longitudiual Range-Gorge Region （LRGR）in southwestern China. Using GIS, the road effect zone divided into six classes. Eight scenarios including no road, expressway, first-class road, second-class road, third-class road, fourth-class road, and substandard road were set in this study and each scenario represented one ecosystem type. The results sbowed that the area of ecosystem influenced by road networks accounted for 5.42% of the total area. The effects of low-level roads on ecosystem and landscape were more significant, while they affected farmland and construction-land less significantly than high-level roads. Due to driving of road projects on ecosystem changes, the percentages of farmland and construction-land in the road effect zone were higher than those of other land types. With extension of road networks, the landscape structure health index （LSHI） dropped from 0.42 （healthy） in the scenario of no road effect on the ecosystem to 0.24 （sub-healthy） considering the integrated effects of all road systems in the region on the ecosystem. With the increase of road network density, the extent of LSH deelined substantially. In terms of the particular natural environment and the ecological features of LRGR, the study of the effect of road networks on LSH in this region is valuable in both theory and practice.