The hemlocks at Cloudland Canyon are becoming infected with an aphid called the Hemlock Woolly Adelgid (HWA).
“It’s a microscopic bug that feeds on the tree itself, takes nutrients from the tree and will kill it,” said Angela Kaiser, assistant manager at the park.
The infestation is so serious that some park supporters are concerned that it could kill off all the hemlock in little more than a decade. Some biologists and foresters are already suggesting that the impact of the HWA would be as serious an issue as the Chestnut Blight was a century ago.
Kaiser said losing the hemlocks could have a tremendous ripple effect.
The hemlocks tend to grow along the streams that feed the twin waterfalls at Cloudland Canyon. Their role in the ecology of the area is to provide a natural canopy of shade. Some trees have been known to grow to more than 120 feet in height.
“If we lose that shade tree we’ll get too much sunlight on the creeks. Therefore, things that live in the creeks are going to die,” Kaiser said. “It’s going to kill off a lot of our plants in the creek that our fish feed off of. So, not only are the hemlocks aesthetically beautiful, but if you lose them you’re going to do away with our brook trout population.”
Kaiser said the HWA is believed to have originated in China. It first appeared in the U.S. Pacific Northwest, and in recent years it’s moved across the southern Appalachian region and has become a serious problem in the Great Smoky Mountain National Park.
Bob Quigley with the Lumpkin Coalition is an organizer of Hemlockfest, which is held each November in Dahlonega. Quigley said the issue should have been more forcefully addressed when evidence of the aphid in the Southeast Appalachians started appearing nearly a decade ago.
“There is a lot more at stake than just the survival of one species of tree,” he said. “It would be a shame to the degradation of the water sources across the region.”
The HWA can be found in hemlocks on top of the mountain at Cloudland Canyon, as well as down in the canyon.
“I’m not sure where it’s worse. Once they take hold, these bugs they just go,” Kaiser said.
North Georgia State College and University has become a leading institution in research to produce a predator beetle that could eradicate the HWA. Young Harris College and Clemson University also have predator beetle labs in a bid to produce enough of the beetles to combat the aphid.
“We do know that the predator beetle program is yielding some very good data and some very good results,” Quigley said. “Certain species of the beetles are actually reproducing in the wild, and seem to be doing very well in this climate and on this topography.”
On the other hand, Quigley said it’s unfortunate that the studies are requiring an extensive amount of time and data because the HWA acts so quickly in destroying the hemlock.