Abstract:

Urban green space as an environmental factor plays an important role in advancing the sustainable development of urban. Study on landscape pattern and connectivity with different scale of urban green space is a focal point and hotspot in landscape ecology. In this paper, the effects of grid size on landscape indices were discussed based on landscape map of Changsha City with the technological support of GIS and RS. The results showed: (1) all the landscape indices had obvious scale effects. All indexes had scale inflexions with the grain increased from 5-150 m. The information of diversity, complexity and geometrical characteristics of landscape can be lost rapidly due to the scale inflexions by swallowing patches and modifying patch edges. The appropriate grain size should be chosen in the first scale domain. Based on the above, the appropriate grain extents were identified to calculate landscape indices for the landscape map of Changsha City, which was from 80 m to 90 m. (2) The relative importance of patches in landscape was not obvious scale-dependent. The scale-dependent on the identification of patches prioritization would be reduced by changing the dispersal distance of the animals. IIC and PC were not strong scale-dependent. (3)Large patches with more important value were less and uneven distributed; which caused the lack of communication between the patches, and made the landscape ecological process interrupted and the landscape stability not high.