Goshen Springs: Late Quaternary Vegetation Record for Southern Alabama

Abstract

The sediments of Goshen Springs, Pike County, Alabama, USA, provide a late Quaternary biostratigraphic record that extends from the Altonial Substage of the Wisconsinan Glacial Stage to the present. Diagrams showing percentages of palynomorphs and concentrations of plant macrofossils permit the reconstruction of both local and regional vegetation. At Goshen Springs, a drying trend during the Altonian Substage (>28 000 yr BP) resulted in the replacement of mesic—temperate forests by southern pines, oaks, and hickories. Climatic conditions of warmth and summer drought favored oak—hickory—southern pine forests from 26 000 yr BP in the mid—Farmdalian substage, through the full glacial and late glacial, until the mid—Holocene (5000 yr BP). During the full glacial, a strong climatic gradient and major vegetation ecotone extended across central Alabama and Georgia, separating northern boreal—like forests of spruce and jack pine from warm—temperate oak—hickory—southern pine forest on the Gulf Coastal Plain. The Goshen Springs record documents the persistence of many warm—temperate deciduous and broadleaf evergreen tree taxa in southern Alabama through the full and late glacial. The early Holocene forests, dominated by oak and hickory, were replaced by widespread southern pine forest on the sandy uplands of the Gulf Coastal Plain about 5000 yr ago. During the mid—Holocene, the attainment of the present climatic regime, characterized by abundant precipitation throughout the growing season, and the return of sea level to near—modern position resulted in the establishment of the southern pine forests and of widespread swamps and marshes in the Gulf and Southern Atlantic Coastal Plains.