Integrating refugia modeling and decision science to support climate-adaptive conservation in the Sierra Nevada

To reduce detrimental impacts of anthropogenic change, natural resource managers often look for place-based solutions to minimize biodiversity loss. Climate-change refugia, areas buffered from contemporary climate change, can enable the persistence of valued natural resources and prolong the benefits of conservation action. Here we combine climate-change refugia modeling with structured decision-making to inform conservation decisions for the endangered foothill yellow-legged frog (Rana boylii) in the Sierra Nevada region of California, USA. We used an ensemble of species distribution models to identify areas projected to remain suitable into the 2040s and the 2080s under an RCP 8.5 emissions scenario, as well as areas projected to transition to suitable habitat during this time. We integrated these projections with a structured decision-making process to align management strategies with refugia model outcomes for R. boylii in a subset of the study area. Habitat suitability for R. boylii is projected to decline in the study area by over 90% by the 2040s and by a subsequent 15% by the 2080s. Climate-change refugia are projected to occupy ~7% of present-day suitable habitat, with high agreement between GCMs and model timesteps. Areas projected to transition to suitable habitat within the existing R. boylii clade boundaries are negligible. Collectively, climate-change refugia modeling and structured decision-making provide opportunities to improve resource allocation and empower conservation practitioners in climate change adaptation for at-risk species.