Wildlife Corridors - San Joaquin Valley

The California Departments of Fish and Game, Parks and Recreation, and Transportation (Caltrans) are collaborating to improve planning information for wildlife connectivity statewide. The results of an inquiry to identify existing information on wildlife corridors in California produced eight data sets covering three parts of California and a single statewide data set. Not all data sets represent the same data gathering and analysis criteria for designating corridors.

The data set groups and their creators are:
Statewide Corridors, by South Coast Wildlands - one data set
Central California Coast Corridors, by Univ. of California, Davis - one data set
San Joaquin Valley Corridors, by Endangered Species Recovery Program - three data sets
San Joaquin Valley Corridors, by Information Center for the Environment - two data sets
Southern California Corridors, by South Coast Wildlands - one data set

Patrick Huber at the Information Center for the Environment, University of California, Davis, identified potential corridors connecting conservation opportunity areas in the San Joaquin Valley region. These potential corridors were identified using a tool called Corridor Creator that is a modified version of the least cost corridor ArcMap tool. This tool identifies a connectivity surface rather than single line - we then selected the highest rated raster cells from the resulting surfaces and converted them to polygons. For this analysis we used a more complex model to create our cost surface. We included, in addition to current land cover and management, road density, urban area density, natural area density, and waterway density. We created cost surfaces for three broad suites of species - forest, open/shrub, and aquatic/riparian. These 3 surfaces were then summed to create one overall, generic cost surface for the region.