PS 22-47 - The influence of environmental variables on the spatial configurations of suitable areas of conservation for amphibians in drylands of the Southwest United States and Northern Mexico

Abstract: Spatial conservation prioritization is becoming increasingly crucial for identifying areas representing all or most species in a relatively small set of selected sites (high-priority conservation areas-HPCA). HPCA are used to advocate for particular conservation actions, such as creating protected areas. Climate change and megadroughts strongly threaten HPCA in drylands, especially in the Southwest United States and Northern Mexico. Thus, a significant challenge in conservation biogeography is identifying how environmental factors and processes influence the spatial distribution of HPCA. In this study, we aimed to (1) provide the geographical distribution of HPCA for amphibians; (2) evaluate how well HPCA are related to species richness and rarity weighted richness (RWR), commonly used as a surrogate of vertebrate diversity, and to (3) identify the association between the spatial configuration of HPCA of amphibians and environmental variables, especially climate. Recent studies have shown that climate will significantly modify the habitat suitability of desert areas, especially for amphibians. To accomplish these goals, we considered distribution maps for 201amphibian species and Zonation, a complementarity-based analysis, to identify HPCA. Then, we used the species accumulation index (SAI) to test the association between HPCA and richness or RWR. We implemented 25 environmental predictor variables grouped into six categories (e.g., temperature, water, topography) and random forest models to test the association between HPCA and environmental variables. Ours is the first study to illustrate that climate, especially water-related variables, significantly influenced the spatial configuration of HPCA of amphibians in drylands of the Southwest United States and Northern Mexico. We report the low association between richness and HPCA. The results from this study will open new inquiries for biogeography and conservation biology and have a practical use to state and federal natural resource agencies and environmental managers in the United States and Mexico to monitor changes to HPCA and plan for recovery if needed.