Date of Award

Fall 12-11-1997

Document Type

Thesis

Degree Name

Master of Natural Sciences (MNS)

Department

Natural Sciences-Interdepartmental Studies

First Advisor

Liu, Kam-biu

Abstract

Fewer Quaternary palynological studies have been conducted in the Gulf Coastal Plain of the southeastern United States than In the northern United States and Canada, resulting in major gaps in the pollen record of this region. The existing studies display discrepancies in the chronology of the pine rise, appearance of the modem climatic regime and vegetation, and timing of the Hypsithermal. In order to fill a gap in the paleoecological data network of the Gulf Coastal Plain, pollen analysis, charcoal analysis, and sediment stratigraphic techniques were used to reconstruct the last 6500 years of Sweetbay Bog, Mississippi, and Minamac Bog, Alabama. and to document the appearance of the modem climatic regime and vegetation, the pine rise, the timing of the Hypsithermal, and natural and human disturbance. Synchronous peat initiation occurred at Minamac Bog and Sweetbay Bog at 6000 B.P., indicating a regional rise in the water table caused by the postglacial sea level rise, which stabilized at the modern level about 6000 B.P. The bogs developed in low upland areas by paludification. Pinus was the dominant upland vegetation as early as 7000 B.P. and possibly earlier. The data are inconclusive regarding the presence of the Hypsithermal. However, the paleoecological records suggest the presence of a warm and dry period from 6000 B.P. to 2800 B.P. The modern vegetation and climate became established at ca. 2800 B.P., with the establishment of a Sphagnum bog at Minamac Bog and a sedge-dominated fen at Sweetbay Bog. This synchronous wetland development suggests a regional climatic change to a cooler and more humid environment at 2800 B.P. European settlement was evidenced by an increase in Ambrosia pollen after 500 B.P. During the same time, fire suppression was shown by a decrease in charcoal, and the logging industry was reflected by a decrease In Pinus.

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