Landscape pattern changes under the disturbance of road networks

摘要

Road ecologists have dedicated their efforts in analyzing the interactions between road networks and the surrounding landscape ever since the establishment of Road Ecology. The understanding of the interactions has been promoted by the proposed quantification parameters of road networks' impacts such as road density, buffer zone and so on. Using these parameters, we analyzed the road network's disturbance effect on the landscape pattern with the newly proposed index-RV (Roadless Volume) in the study. Based on the sampling of square quads all over the Longitudinal Range-Gorge Region (LRGR) during 1980-2000, the changes of the different patches such as forest, grassland, cropland and urban land under different disturbance degrees of road networks classified by RV value have been examined. The results showed that: the decreased area and number of forest and arable patches changed with the disturbance degree of road networks' logarithmically; The area and number of grassland decreased at the highest disturbance level but increased in some lower disturbance level; The area of urban land increased at the high disturbance level which followed the logarithmical trend with the disturbance level. These results imply that the road networks generally transformed the landscape pattern from the forest and cropland to large patch of urban land surrounding roads.