Landscape selection of Green Salamanders, Aneides aeneus, and a model of their potential distribution to guide future surveys in Tennessee
Dustin B. Thames,*, Josh R. Campbella, Christopher S. Ogleb, Daniel R. Istvankoc
Green salamander, Aneides aeneus, populations have declined in parts of their geographic range. In response to these declines, the United States Fish and Wildlife Service has been petitioned to protect the species under the Endangered Species Act. Additional information is needed on the geographic distribution and the ecological requirements of green salamanders in Tennessee to aid regulatory decision making and conservation management. The objectives of our research were to determine what environmental characteristics best predict landscape suitability for green salamanders and to create a map of the model to guide future surveys. We compiled green salamander occurrence records from the Tennessee Wildlife Resources Agency’s State Wildlife Action Plan database and from researchers currently conducting research. We used maximum entropy modeling to evaluate the relative importance of environmental characteristics across the landscape and we projected the model into geographic space to map the potential distribution of green salamanders in Tennessee. Environmental variables associated with rock outcroppings, tree canopy cover, and elevation contributed most to the model. Green salamanders select areas on the landscape with rocks at the soil surface, but not necessarily bedrock, with a high percent canopy cover at moderate elevations. Rocks at the soil surface likely represent large rocks and boulders deposited on the landscape by geological processes that are not parent material. The model can be used to guide future surveys and may make surveys more efficient at locating new populations in Tennessee. Accumulating up-to-date occurrence records will enable managers to better assess the current distribution of green salamanders in Tennessee and may improve conservation efforts.
Key Words.—conservation, ecological niche modeling, habitat suitability, occurrences