Fraser Fir ( Abies fraseri ), the high-altitude evergreen species feared doomed in the Appalachians by the invasion of the wooly adelgid, resisted the initial infestation of the insect and again covers the high summits.
Dr. Kevin M. Potter, Assistant Professor in the North Carolina State University Department of Forestry Research and Environmental Resources and noted Fraser Fir authority, attributes the survival of the species to a basic fir trait: a trunk that remains smooth until the tree matures. Wooly adelgids require bark fissures in order to enter the tree, by which time Fraser Firs have already dropped crops of cones to succeed them after these original trees succumb to the beetles.
According to current thought, the species originated near ancient glacial advances. At one time, when the continental glaciers occupied the central United States, a single fir species accompanied the ice sheet. This species spread its seeds both eastward and westward following glacial retreat. The trees they produced evolved into subalpine fir in the Rockies and both Fraser Fir and balsam fir in the Appalachians. The origin of the species in cold climates makes it vulnerable to global warming.
Dr. Potter points out that the new generation of mature Fraser Firs that followed the initial infestation may display greater resistance to wooly adelgid beetles because of different growth habits that limit insect entry, coupled with the diminished vitality of the beetles due to passage of time. In the near future, scientists will re-enter the fir stands to assess their defensive strength.
Convenient stands of Fraser Fir from the standpoint of tourists grow near Mount Mitchell State Park, in the Black Mountains of western North Carolina. Park at the Mountains-to-Sea trail juncture with the Blue Ridge Parkway and hike to the highest elevation. The trail here reaches the 6,000-foot level amidst a mixed forest of red spruce and Fraser Fir.