The Appalachian region is home to more salamander species than anywhere else in the world, making it a true hotspot for salamander biodiversity. Thanks to the area’s diverse forest and freshwater ecosystems, many different salamander species have adapted to the relatively cool, mid- and high-elevation highlands. With almost half of all salamander species listed as threatened or endangered and populations already declining for unknown reasons, the Appalachian region has become a primary focus of salamander conservation research and planning.
Many of the species unique to Appalachia belong to the Plethodontidae, a family of lungless salamanders that breathe entirely through their skin. These salamanders are particularly sensitive to water quality, temperature, and changes in precipitation since they must constantly keep their skin moist and cannot move through dry areas. Unfortunately, these needs may make it especially hard for some species to adapt to a changing climate.
Climate models predict a 2-6°C increase in average annual temperature in the Appalachian region over the next century. While some salamander species may be able to adapt to warmer temperatures or extend their ranges northward, others do not have these options. High-elevation species are often specialized for cool microclimates and become easily stressed when exposed to increased temperatures or drought. This means that many mountaintop species have nowhere to go, since they will not be able to migrate down through warmer valleys to find a new, cooler environment. In addition to the direct threats of climate change, mountain-top salamanders may face increased competition as lower-elevation species expand their ranges upward.
Scientists predict that precipitation will become less frequent, with longer drought periods between short periods of intense rainfall. This pattern will reduce the amount of time salamanders are able to move around in their territory, resulting in fewer opportunities to eat and find mates. The amount of water in waterways will change dramatically and small, ephemeral pools will become fewer and more transient, further reducing breeding opportunities for salamanders that lay eggs in water. Finally, the increased number of intense rainstorms can flush pollutants into stream habitats or wash away eggs and juvenile salamanders.
Since we cannot protect salamanders from climate change in the same way we can mitigate pollution or habitat loss, we need to determine how each particular species will be affected in order to develop effective strategies to help them survive. This includes making detailed observations of the physiology of different species, their current ranges, and ability to withstand or adapt to climate change. A few species may adapt relatively easily to a warmer, more variable climate. Ensuring that “corridors” are available for migration of salamanders northward to healthy, cooler habitats may work for others. Mountaintop species may require relocation if they become too pressured by climate change or competitive species. Finally, raising salamanders in captivity will establish an assurance colony to guard against extinction in the wild and provide us with more opportunities for research.