Measuring Landscape Connectivity in a Urban Area for Biological Conservation

Biodiversity conservation in urbanized area is an increasing challenge worldwide. A quantitative tool is needed to provide a spatially explicit representation of habitat mosaics and thus afford insight into the ecological consequences of landscape changes. We developed a method for identifying core habitats and generating a cost surface that was used to identify both the permeability of the landscape matrix and the quality of core habitats and then we developed a least-cost model to delimit the links between pairs of core habitats. We defined a graph-theoretic dispersal flow index to measure the dispersal potential of certain ecological processes, i.e. functional connectivity. A network consisting of core habitats and links was assembled in the rapid urbanized Shenzhen City of China. The results showed that the cell-based least-cost distance calculation between the core habitats can avoid the subjectivity of land cover-based approaches that rely on expert experience. A highly connected network can facilitate DF and reduce the ecological risk of extinction due to habitat fragmentation. For saving construction cost in the urban environment, urban planner can efficiently design ecological corridors along the least-cost paths to connect isolated core habitats and promote appropriate animal behaviors. The methodology described here will be useful in making better conservation decisions and predictions regarding the consequences of human activity and thereby promote sustainable development