Green salamanders have always been a bit weird. The only eastern member of the genus Aneides, a group of arboreal salamanders found on the West Coast, they’re long and flat, with googly eyes and tree frog toes. Found in the moist fissures of rock shelves from Northern Mississippi to Southern Pennsylvania, they’re the only member of their family to spend much time on the ground, and the only Appalachian salamander to regularly climb trees. They’re the kind of salamander you rarely see unless you’re looking for it; even then, it takes quite a bit of luck.
But recently, these elusive amphibians, which the International Union for Conservation of Nature lists as “near threatened,” have been cropping up in an unexpected place: on flattened mountaintops that were ecologically devastated for coal mining. Understanding how these hardy salamanders have managed to hang on could help scientists figure out how to preserve the species, and even how certain animals could flourish in a world scarred by fossil fuel development.
One afternoon in April of 2016, Dr. Wally Smith wandered out onto the old surface mine behind the Wise County campus of the University of Virginia. A biologist at UVA, Smith and his colleague Kevin Hamed of Virginia Highlands Community College have been trying to pin down the green salamander’s distribution and habits, which involves figuring out how widespread they actually are. Smith had assumed for years that the half-acre patch of trees and stone outcrops at the mine was probably too small for the salamanders to populate. But on a whim, he went out to check some of the crevasses—and immediately saw a pair of huge eyes peeking out at him.
“I was actually screaming for joy in the forest when I found it,” Smith said. “It was really exciting. I’d just assumed the population wouldn’t be there...that’s what jump-started our urgency to get out onto some of these mines and see what’s happening.”
According to a study by Appalachian Voices, around 1.2 million acres in Appalachia have been surface mined for coal, and more than 500 mountains flattened. In Wise County alone, some 40% of the land area bears the impacts of mining, sometimes in the subtle shape of a reforested contour mine, sometimes in the wastelands where mountaintops were blasted away and rock fills the valleys and streams. The fossil fuel industry leaves behind a patchwork landscape of fragmented habitats, a major factor in a species’ extinction risk.
Deforestation from mines often leaves hot, hard-packed soil, where invasive autumn olive grass crowds out native plants; coal spoil and silt taints the water chemistry of Appalachia’s creeks. Such changes have contributed to the declines of everything from mayflies and crayfish to birds like the Cerulean warbler.
Salamanders and other amphibians, which are particularly sensitive to changes in forests and streams, are often hard hit by mining activity. Without the moist undergrowth and leaf litter of the forest, they often disappear, and can be slow to return even when areas are reforested. “Fewer salamander species are found in streams impacted [by mining],” said Steven Price, a biologist with the University of Kentucky. “And there’s often fewer numbers of whatever species we do find.” The idea that a habitat specialist like the green salamander might be hanging on around mined areas provided a hopeful glimmer in a very dark picture: it would have been reasonable to assume that there weren’t any at all.
After Smith’s discovery behind campus, he and Hamed began investigating mined areas more thoroughly, looking at 45 rock outcrops at five different surface mining operations. Unsurprisingly, hillsides and rock walls that had been directly carved up or deforested didn’t hold any salamanders. But around 70 percent of the surviving natural outcrops did—often in surprisingly healthy numbers. As long as the old crevasses and tree-cover were present, the species showed up, regardless of the racket and disturbance nearby. “The salamanders in these pockets seem to be doing pretty well,” Smith said. “They’re abundant, they’re reproducing, which are signs that the populations are still hanging on.”
Figuring out why the salamanders are still present around the mines is now part of the team’s larger project to nail down the species’ population dynamics and habitat preferences. In certain parts of the salamander’s national range, Hamed says, population numbers declined abruptly from the 1970s to 1990s. When Smith and Hamed began working together in 2014, the salamanders were known at only 15 sites in Virginia. But their reclusiveness meant nobody was certain how widespread the salamanders were in the state, or how environmentally sensitive they were. That made it difficult to know what kind of protection they needed.
Since Virginia’s private lands made surveying difficult— “You can’t go on private land without getting arrested or shot,” Smith said—the team enlisted local landowners and citizens to aid in their search. Soon they’d confirmed sightings at over 70 locations, including a motherload of salamanders in the municipal park of a local city. “Usually if you’re lucky, you find one or two a day. There, we were finding 70 to 100 per hour.” With data gathered from the park and other sites, they were able to pin down the species’ preferences: naturally moist, dark and deep furrows in the stone, preferably close to trees for easy climbing. If either aspect was missing, the salamanders often were, too.
There are important questions to be answered about the populations living around the mines, Smith said. First, are the salamanders in the slivers of remaining habitat part of the original population that lived in those areas, or animals that have recolonized the bluffs? If they have recolonized, how? Can the species use corridors of regrown forest, or manage to move across open ground? The ability of the salamanders to get across disturbed habitat is key to the remnant populations staying genetically healthy: after all, it doesn’t do the species much good if the resilient animals can’t get out and breed with each other. The best way to investigate will be to look at the genetics of the different salamander populations.
“You really have to go down to the molecular level to address those questions,” Smith said. “We’ve had a huge amount of habitat disturbance not just in the coal fields but throughout the species range, with roads and clear cutting and urban development. There’s a lot of concern about what that could mean for the long term survivorship of some of these populations.” There’s already a big effort throughout Virginia to reforest surface mines, remove invasive species, and replace them with hardwoods like the American chestnut, he said. A bit of extra work could show how best to restore connectivity between the green salamanders on old mines and other populations nearby.
Things have been rough for amphibians lately, and are likely to get rougher: populations are in steep decline globally, battered by habitat loss, infectious diseases and climate change. While the green salamander isn’t immune to any of these threats, the fact that it’s hanging on at all is good news. The findings show that even habitats subjected to something as destructive as surface mining aren’t totally lost, Smith said. Some rare species might be just holding on in an out-of-the way pocket, and you’ll never know unless you check.