Integrating Multiple Distribution Models to Guide Conservation Efforts of an Endangered Toad

Authors: M Treglia; Robert N Fisher; L Fitzgerald
Contribution Number: 511

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0131628

Abstract/Summary

Species distribution models are used for numerous purposes such as predicting changes in species’ ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on the endangered arroyo toad (Anaxyrus californicus), which relies on open, sandy streams and surrounding floodplains in southern California, USA, and northern Baja California, Mexico. Declines of the species are largely attributed to habitat degradation associated with vegetation encroachment, invasive predators, and altered hydrologic regimes. We had three main goals: 1) develop a model of potential habitat for arroyo toads, based on long-term environmental variables and all available locality data; 2) develop a model of the species’ current habitat by incorporating recent remotely-sensed variables and only using recent locality data; and 3) integrate results of both models to identify sites that may be employed in conservation efforts. We used Random Forests to develop the models, focused on riparian zones in southern California. We identified 14.37% and 10.50% of our study area as potential and current habitat for the arroyo toad, respectively. Generally, inclusion of remotely-sensed variables reduced modeled suitability of sites, thus many areas modeled as potential habitat were not modeled as current habitat. We propose such sites could be made suitable for arroyo toads through active management, increasing current habitat by up to 67.02%. Our general approach can be employed to guide conservation efforts of virtually any species with sufficient data necessary to develop appropriate distribution models.

Publication details
Published Date: 2015-06-30
Outlet/Publisher: PloS ONE
Media Format: .PDF

ARMI Organizational Units:
Southwest, Southern California - Biology
Topics:
Management; Quantitative Developments; Species and their Ecology
Place Names:
California; San Diego County, CA
Keywords:
distribution; habitat; habitat use; land cover/land use; restoration; stream; threatened species
Notice: PDF documents require Adobe Reader or Google Chrome Browser (recommended) for viewing.