"All of the park's hemlocks are now infested," says BRP plant ecologist Chris Ulrey.
The park's highest concentration of hemlocks occurs between Grandfather Mountain and Linville Falls and in isolated patches south of Asheville.
Hemlocks north of Boone are not being treated "because those trees are too far gone"-already dead or nearly so.
The treatments, in which adelgid-killing chemicals are injected around the trees' roots, are conducted from mid-April to mid-June, "because that's when they seem to work best."
Most of the $40,000-50,000 the park receives annually from the US Forest Service to fight HWA
will go to treating trees at Linville Falls (MP 316.4) and an old growth forest just north of Sims Pond (MP 295.9), Ulrey
At Linville Falls, some trees treated the first year will be retreated.
The chemical seems to protect trees from HWA
for 3-4 years.
Treated trees are "looking good," he
says, while untreated ones-and there are legions of them-are dead or dying.
Priority is given to Linville Falls' Carolina hemlocks, a rare species that occurs only in isolated places in the Virginia, Georgia and North and South Carolina mountains, and to hemlocks in developed areas-along roads, trails and in campgrounds and picnic areas.
The funding the park receives allows Ulrey's
crew of 2-3 seasonal employees to treat about 1,000 hemlocks annually.