Road network impacts on wildlife animals: A simulation study

Habitat fragmentation is a harmful impact on wild animals. In this paper, we propose an agent-based simulation model to estimate the fragmentation impacts (FIs) on wild animals caused by road network. We employ predator-prey system as a simplified ecological system, and investigate FIs on wildlife by adding roads gradually into the habitat of wildlife. Simulation results are well consistent with the ecological observation from previous researches. We find that (1) when road density increasing, but still below the critical threshold, wolves´ population decrease monotonically; (2) when road density steps over the critical threshold, wolves are extinct; surprisingly, (3) after the extinction of wolves, sheep cannot recover to the carrying capacity of the initial state without wolves. Our simulation model provides not only a way to estimate the ecological impacts caused by the existed road network, but also a tool for considering alternative regional policies of road network planning.