California Habitat Fragmentation

As habitat fragmentation in southern California split land, the integrity of the land changes. Habitat fragments that each has a decrease in area will have an increase in the total perimeter distance collectively (Morrison et al., 2006). This increased area around the habitat exposes more of the internal habitat to the elements, reduces the habitat buffer, and in turn creates less optimal habitat for species in the fragment (Morrison et al., 2006). This process, called edge effect, decreases the quality of the habitat and increases the potential risks abiotic and biotic influences, like natural disasters, pollutants, and invasive species, impacting the habitat (Johnson, 1999; Arroyo, 2000). An example of edge effect in southern California is the plant called Cap ivy; it invades once suitable interior habitat of the least Bell’s vireo in
In 2001, the National Wildlife Federation (NWF) conducted a study on the assessed imperilment species in California (Doyle et. al., 2001). They confirmed that like the national consensus, the leading cause of species imperilment in the state is sprawl (Doyle et. al., 2001). Sprawl development is based on “development densities, land mix use, activity centering, and street accessibility (Erwing & Hamidi, 2014, p. 2). Many metropolitan areas in California have ranked nationally on the urban sprawl index for having impacted urban areas (Erwing & Hamidi, 2014, p. 2). For example, the metro areas of Santa Barbara/Santa Maria/Goleta, CA, Santa Cruz/Watsonville, CA, and Santa Ana/Anaheim/Irvine, CA respectively ranked 4th, 6th, and 10th on the most compact, connected metro areas nationally (Erwing & Hamidi, 2014). In Los Angeles alone,“219 species and 12% of the remaining space are projected to be lost to development” (Ewing & et al., 2005, p. 1). This increase in metropolitan area sprawl can lead to a greater displacement of animals and