Date of Award

2001

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Geography and Anthropology

First Advisor

Kent Mathewson

Abstract

Although located near the middle of the Southeastern Coastal Plain, the hardwood forests of the Loess Hills of the Lower Mississippi Embayment have never been thoroughly studied or satisfactorily described in the literature. This dissertation is a case study of the biogeographic variation in the species composition and structure of the mature ravine hardwood forests within the southern section of the Loess Hills, from Warren County, Mississippi, south to East Baton Rouge and Vermilion Parishes, Louisiana, as affected by latitude, physiography, edaphic conditions, and disturbance. A parallel goal is, on the basis of the current biogeographic conditions and successional dynamics, to make a reconstructive assessment of the original forests. The empirical findings of the study suggest that the effects imposed on the vegetation by the combined action of the different biogeographic factors are intricately interrelated, resulting in the complex, synergistic effect. A very strong impact on the species composition, structure, and even the biogeographic variation is caused by the anthropogenic disturbance. During the Holocene, the forests of the Loess Hills evolved in the conditions of the persistent and growing anthropogenic pressure. This trend culminated during the 19th and 20th centuries when the landscape of the Loess Hills became strongly modified the agricultural exploitation and industrial timbering. The anthropogenic disturbance appears to have influenced selectively different groups of species depending on latitude and depth of the loess mantle. It also seems to have caused an expansion of the understory and subcanopy species which may have played a lesser role in the original forests. This study may contribute to the better understanding of the biogeographic variation and successional dynamics of the Coastal Plain forests in general and the Loess Hills forests in particular, as well as to the conservation and restoration of the latter.

ISBN

9780493328546

Pages

650

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