Abstract: Road networks fragmentize regional landscapes, block ecological processes and damage landscape functions. The effective evaluation of the ecological impact of roads provides valuable information for road route design, ecological restoration and landscape planning. Based on resistance surface concept and the minimal cost model, we calculated the landscape resistance, patch quality, accessibility of corridors, and landscape connectivity, and quantitatively evaluated the impact of road networks on species migration process. Results showed that roads increased the corridor length by 30% on average, the corridor curvature by 0.19. Roads also reduced the accessibility of ecological corridors by 90%, and the decrement was in linear relation to the minimal cost of the corridors, with a correlation coefficient of 0.76. Landscape connectivity was decreased by 30.8%, and the weaker the diffusion ability of corridors is, the more it will be affected by the roads. The proposed methods can be used to determine the key pattern of a specific ecological- process on the landscape scale, and provide information for the design of ecological corridors and quantitative analysis of landscape connectivity for ecological landscape planning.

Key words: leaf senescence, endogenous hormone., light quality