Managing for climate change in the mountains, the Shenandoah salamander Plethodon shenandoah

Background/Question/Methods

Amphibian populations are experiencing declines worldwide and up to one third of all amphibian species are estimated to be threatened.  Climate change is hypothesized to be one of the principal causes driving these declines as the behavioral, physiological, and ecological characteristics of amphibians make them especially vulnerable to this type of disturbance.   Therefore, in this study we examined the effects of climate change on the Shenandoah salamander, Plethodon shenandoah, a federally endangered salamander species restricted to three mountaintops within Shenandoah National Park in the central Appalachian mountains.  High elevation habitats are predicted to be greatly altered from climate change, and the limited range of this species poses an additional risk. Climate data was used to assess changes in Shenandoah salamander occupancy under anticipated future climate scenarios and assess its risk of extinction due to global climate change.  We used two-species occupancy models implemented in a Bayesian hierarchical modeling framework to investigate the effects of climate, habitat type, and competition with a congener (the red-backed salamander Plethodon cinereus) on the Shenandoah salamander’s probability of persistence.

Results/Conclusions

Our results indicated a low occurrence of the Shenandoah salamander which makes it vulnerable to changing climatic conditions in the Shenandoah National Park.  In addition, negative effects of competition with the red-backed salamander appear to restrict the Shenandoah salamander’s distribution; this may restrict migration and exacerbate population declines.  Due to their already limited high-elevation range, it is predicted that climate change will have negative effects on population persistence. Overall, the model predictions obtained from this study will be used to develop an adaptive management plan for the Shenandoah salamander in conjunction with decision makers at Shenandoah National Park, and be used more broadly as a guide for mitigating the effects of climate change on high elevation communities.