Abstract:
Prior to European settlement of America in the late 16th century, a relatively pristine environment existed on the North American continent. Since that time, landscape-altering processes such as logging, deforestation for agricultural cultivation, channelization, and the removal of natural ecosystems engineers such as the beaver (Castor canadensis) have left little of its natural state unchanged. Alluvial floodplains within the upper Gulf Coastal Plain of Mississippi and the bottomland hardwoods that occupy them are especially sensitive to change, already being naturally dynamic environments in which loose sedimentary soil participates in a perpetual cycle of deposition and erosion as the main river channel meanders across their broad valleys. These changes result in microhabitats with varying degrees of inundation, rates of deposition, and elevation. This thesis attempts to reconstruct the pre-European settlement ecology of northern Mississippi alluvial floodplains through the use of General Land Office (GLO) survey records of the area from the early 19th century. A specific effort will be made to detect wetland environments based upon a surveyor's recorded bearing trees and line descriptions. A bearing tree, or a witness tree, is a tree that is physically marked by a surveyor to indicate a nearby survey corner. Geographic data given by each surveyor (e.g., section, township, range, and distance in chains from each section corner) allow for the relatively accurate plotting of each bearing tree within a Geographic Information System. Digitization of data allows for historical GLO data to be analyzed by location and relation to modern datasets to detect land use change and anthropogenic disturbance in the study area. Specific attention will be paid to two highly flood tolerant species, Taxodium distichum and Nyssa aquatica, to detect these changes for wetland environments.
