Landscape network approach to assess ecological impacts of road projects on biological conservation

Awareness of the adverse ecological effects of road and other large construction projects has resulted in a rapidly growing demand to quantitatively predict and evaluate the effects on gene flow among plants and animals in natural habitats. In this study, we evaluated the effects of different road construction scenarios on animal species movement by using the methods of ecological landscape connectivity in the typical regions of Yunnan Province, China. The results showed landscape connectivity levels (Probability of Connectivity (PC)) decreased after road construction and species with lower dispersal abilities were more affected to the subsequent habitat fragmentation. First level roads affected landscape connectivity most significantly. At a distance of 100 m, the PC index decreased more than 50%. Further analysis suggested that the use of landscape connectivity to assess landscape processes revealed the adverse effects on the species movement more effectively compared with the traditional landscape pattern analysis. In addition, we conducted a graph theory and a least-cost modeling discussion, it is obvious that they are powerful tools to represent and analyze landscape networks with respect to related species movement. Network analysis offers a quantitative and simple but effective tool for ecological process assessment and biological conservation on large scales.