Fraser Fir Forests

Fraser fir is a species of red spruce found only at high-elevation sites in the southern Appalachians. With its familiar blue-green needles, it is well-known to many Americans as a popular Christmas tree species. Fraser fir occupied an estimated 30,000 to 35,000 acres at elevations around 4,500 feet prior to European settlement. Most of the original stands were logged during the late 19th century. Great Smoky Mountains National Park protected about 75 percent of the remnants.

Fraser fir is severely threatened by a non-native pest, the balsam woolly adelgid, which attacks and kills mature trees. About 95 percent of the remnant spruce forest in Great Smoky Mountains National Park has been destroyed by the adelgid. Infestation is almost invariably fatal to the tree, which has no natural defenses against the insect.

Changes in the abiotic environment, particularly deposition of heavy metals and acid precipitation carried with prevailing winds from industrial areas of southern Ohio and Indiana, have changed soil and water chemistry in the southern Appalachian highlands. Scientists believe that this pollution stresses the Fraser fir, leaving trees more vulnerable to adelgid infestation and compromising their ability to survive, while contaminating the understory and inhibiting regeneration.

The demise of the Fraser fir forest has implications for the rare species associated with high-altitude Appalachian spruce forests, which include the northern flying squirrel, Weller’s salamander, the spruce-fir moss spider, mountain ash, and rock gnome lichen.