Abiotic and biotic factors reduce the viability of a high‐elevation salamander in its native range

• Published in: The Journal of applied ecology 2023-08, Vol.60 (8), p.1684-1697
• Main Authors: Campbell Grant, Evan H., DiRenzo, Graziella V., Brand, Adrianne B.
• Format: Article
• Language: English
• Subjects: abiotic; amphibian declines; Biotic factors; biotic interactions; Climate change; Colonization; Decision making; Endangered & extinct species; Endangered species; Environmental stress; high elevation; interspecific competition; management; occupancy models; Parameters; Population; Population status; population viability analysis; Projection model; Species extinction; Threatened species
• ISSN: 0021-8901; 1365-2664
• DOI: 10.1111/1365-2664.14431

Amphibian populations are undergoing worldwide declines, and high‐elevation, range‐restricted amphibian species may be particularly vulnerable to environmental stressors. In particular, future climate change may have disproportional impacts to these ecosystems. Evaluating the combined effects of abiotic changes and biotic interactions simultaneously is important for forecasting the range of future outcomes. This information is necessary to aid conservation decision‐making. We use field data to estimate population demographic parameters for an exemplary high‐elevation amphibian species, the federally endangered Shenandoah salamander Plethodon shenandoah. These parameters were entered into a Markov projection model which we used to forecast the future population status of the Shenandoah salamander. We found that if the population maintains its current site colonization and persistence rates, it is at the risk of extinction that could be exacerbated by both climate and interspecific competition. Synthesis and applications. Managers have a fundamental objective directed by official policy of maintaining the species ‘for the foreseeable future’. Our evaluation of multiple hypotheses about population drivers reveals that extinction is projected for this species. Our analysis suggests that considering active management need not depend on resolving the uncertainty. Managers have a fundamental objective directed by official policy of maintaining the species ‘for the foreseeable future’. Our evaluation of multiple hypotheses about population drivers reveals that extinction is projected for this species. Our analysis suggests that considering active management need not depend on resolving the uncertainty.