Presettlement Vegetation and Fire in Escambia and Covington Counties, Alabama

Abstract

This study was the first to examine presettlement forests in the lower coastal plain of Alabama. The primary data source is General Land Office public land survey field notes, which contain an unintentional, but systematic sample of presettlement trees. 12,637 witness trees were recorded and geo-referenced from the surveys covering Escambia and Covington counties, Alabama. Cluster analysis was used to derive four witness tree communities including; the pine dominated community, hardwood community, mixed pine-oak community and bay community. Environmental variables, soil suborder, slope, and distance from water, were sampled in a GIS on an individual witness tree basis. Environmental variables were tested for association with witness tree communities using multinomial logistic regression. Each environmental independent variable was found to be important in the distribution of witness tree communities.

The distribution of witness tree communities with respect to environmental variables, coupled with modern knowledge of these systems, pointed to fire as important in shaping presettlement forests. Specifically, the pine dominated and mixed pine-oak communities are fire maintained communities. This notion was further supported by bearing distance and surveyor qualitative descriptions. In an effort to ascertain the ignition source for presettlement fire, archeological information was gathered regarding Native American settlement prior to the surveys. Knowledge of Native American settlement, combined with an understanding of the history of the region, yielded the conclusion that lightning was the primary presettlement ignition source prior to the surveying of the study area.