Assessment of Late Pleistocene to recent climate-induced vegetation changes in and near Shenandoah National Park (Blue Ridge Province, VA)

Abstract

Pollen evidence from a shallow core in the Blue Ridge Mountains (Big Meadows, Virginia) and from other outcrops in and adjacent to Shenandoah National Park, indicates that from the Late Pleistocene through the Holocene (45-0 ka) regional vegetation in north-central Virginia fluctuated from warm temperate forests to fully developed taiga (boreal forest). Present day analogues to these vegetation zones can be found in the forests and forest transitions extending from central Georgia (approximately 32° N latitude) to central Ontario, Labrador, and northern Newfoundland (approximately 52-55° N latitude). It is still undetermined (on the basis of our pollen evidence) whether it was ever cold enough in the study area during this 45,000-year time interval to develop alpine tundra extensively along these ridge tops. Current evidence from the study area suggests that the forests in and around Shenandoah National Park changed frequently in composition through the studied time interval. Most of the forests previously established in the study area were of types that favored notably cooler mean annual temperatures than the forest type that is established currently in the proximity of the Park. Although this fossil record is a partial one, the radiometric carbon evidence verifies that we now have discovered pollen assemblages of full-glacial age (last glacial maximum) in the Blue Ridge, of multiple forest types.