East Tennessee is home to one of the most environmentally important animals.
In fact, East Tennessee and Western North Carolina alone are home to more species than can be found in most countries and 80 percent of North America’s salamander population lives within 500 miles of Chattanooga, Tennessee.
The Tennessee cave salamander is the official state amphibian.
A new study published in Oecologia, an environmental science journal, found climate change may endanger the communities of certain salamander species.
The study, conducted at the Tennessee Aquarium Conservation Institute (TACI), used seal salamanders and black-bellied salamanders to show how fragile these communities are.
Since salamanders are both predators and prey, they are responsible for maintaining much of the region’s ecological stability, and any change in their communities can endanger their environments as well.
Salamanders usually live in single streams. Larger species live toward the center of streams, where the water is cooler. Smaller species tend to live further out from the center, with the smallest salamanders living on land. This kind of organizing among animals is called niche-partitioning, according to John Ennen, an aquatic conservation biologist at the Tennessee Aquarium Conservation Institute.
The study found that a rise in stream-water temperatures collapses these communities. With warmer streams, smaller salamander species may move toward the center of the water, since they are better adapted to warmer climates than other larger species.
If that happens, it may push the larger species out from the water and force them onto the edge of the streams, where they are less adapted for survival.
It could also mean smaller salamanders spend less time on land, which means that predators which eat them may be forced to go without a vital food source. Larger salamanders may need to compete more for their food as well.
“With warming temperatures, these community structures could switch, which could have a huge impact on the future, long-term stability of salamander communities,” said Ennen..
Warmer stream temperatures mean salamander communities will not be structured the same way.
Since salamanders play such a large role in their ecology due to their large population, any change in their communities could spread ripple effects throughout their environments and endanger the region’s ecological stability.
Study looks at more than salamanders
The study, led by Mary Lou Hoffacker, was conducted in the winters of 2016 and 2017 at TACI. Hoffacker studied the behavior of black-bellied and seal salamander communities when their artificial streams rose by five degrees.
Hoffacker found that when the water temperature rose, the two species did not compete as much as they normally did for space towards the center of the stream. The two species shared the center of the stream more often.
“We didn’t just want to look at how salamanders will be affected by climate change,” Hoffacker said. “We also wanted to see what those changes could mean for their surrounding communities and the other organisms that rely on them acting the way that they do.
“Understanding the broad effects that rising temperatures are going to have on important communities like these is essential in helping us to prepare and better understand how we can protect them in the future.”
Kristen Cecala, a co-author of the study and assistant professor of Hoffacker’s at Sewanee: The University of the South, said the two species are “like siblings fighting over toys.”
The older, larger sibling gets what he or she wants and forces the younger sibling to try something else. Then, the younger sibling grows up and the “balance of power is disrupted.”
And if that happens, according to Ennen, the size structuring that allows for so many species to live in Appalachia could be thrown out of balance.