Holocene vegetational changes in the southern Appalachian mountains, U.S.A.

Abstract

During the late Pleistocene, tundra occurred at least as far south in the Appalachian Mountains as Cranberry Glades, West Virginia. Boreal forest of northern Diploxylon Pinus, Picea, Abies, and Larix was extensive over a wide altitudinal range in the southern Ridge and Valley and Blue Ridge provinces of southwestern Virginia, Tennessee, and North Carolina. Northern hardwoods forest of Acer, Fagus, and Tsuga replaced the boreal forest at low elevations in the late-glacial period as Picea and Abies were restricted to higher elevations. By 9000 yr B.P., warm-temperate oak-chestnut forests dominated by Quercus and Castanea were widespread in the region, with cool-temperate and boreal taxa restricted to elevations generally above 1000 m and 1500 m, respectively. Holocene paleoecological records from Sphagnum bogs and fens ranging in elevation from 500 m to over 1500 m indicate that current patterns of distribution of many rare plants in the Southern Appalachian Mountains are the result of climatic change, migrational history, past and present habitat diversity, and natural and anthropogenic disturbance history.