Tolerance analysis of habitat loss for multispecies conservation in western Riverside County, California, USA

Abstract

Understanding the structure of a reserve network and the tolerance of habitat loss within a reserve network system is important for regional species conservation management. To date, there exist only theoretical models of design using randomized spatial structure in which to test alternatives. The Western Riverside Multiple Species Habitat Conservation Plan provides a complex reserve pattern in which to hypothesize and test outcomes for very different species and groups of organisms. This study uses data analysis and computer simulation to investigate (i) the relationship between species richness and habitat quantity and (ii) tolerance of a reserve network to habitat loss. The results indicated exponential decay between species richness and habitat quantity for plants, reptiles, mammals, birds and all species. The current network of habitats for each species group has low tolerance for loss, especially for mammals. A conceptual model of an ecological safety net between habitat loss and connected networks has an 'S' shape, which means high tolerance for species conservation even under possible habitat loss. Reserve areas with viable buffers and corridors are essential to preserve biodiversity and to increase the ecological safety net of the entire habitat network at risk in areas such as western Riverside County of California.