In order to investigate the extent of vegetation change during the Pleistocene Period, a study of three high elevation southern Appalachian bogs was undertaken. Three North Carolina sites were chosen that were suitable for pollen and paieoecological analysis: Flat Laurel Gap bog near Pisgah Mountain south of Asheville (elevation 1500 m), Boone Fork bog near Blowing Rock (elevation 1024 m), and Long Hope Valley bog north of Boone (elevation 1450 m).
Existing vegetation was sampled by transects of 10 x 10 m plot relev6s that crossed a section of forest and open bog areas. While each site included a characteristic southern Appalachian bog, each differed: Flat Laurel Gap is predominately a heath community with interfingerings of open grassy glades which grade into a mixture of northern hardwoods and spruce; Boone Fork bog is a disturbed mixture of northern hardwoods which grades into a mixture of scattered shrubs and open glades predominated by Sphagnum; and Long Hope Menyanthes bog is an open herbaceous and grassy glade with scattered shrubs which grades abruptly into northern hardwoods and old-growth spruce. As might be expected, the more northern Long Hope Valley site had more northern taxa, such as Menyanthes trifoliata, Lonicera canadensis, and Vaccinium macrocarpon. The southern site also had a few boreal taxa such as Eriophorum virginicum.
Perhaps the best interpretation for these long-established southern Appalachian bogs is that they have provided continuously suitable habitats for relict northern species since the peak of the glacial ice advance 18,000 years ago.