NEOICHNOLOGY OF SOIL MEGAFAUNA IN THE NORTH CENTRAL HILLS PROVINCE OF MISSISSIPPI

The North Central Hills physiographic province of Mississippi is characterized by uplands developed on sands and clays of the Paleocene-Eocene Wilcox and Claiborne Groups. The high erodibility of the soils and unconsolidated parent material has resulted in deeply dissected landscapes. In these landscapes, enhanced erosion from burrowing megafauna is particularly concerning for land management. The purpose of this research is to investigate the properties of megafaunal burrows and associated soils at the University of Mississippi Field Station, a protected research facility in the North Central Hills. Soils were characterized in select locations by trenching, field description, and laboratory analyses of collected samples. The ongoing research includes soil data from the Lexington series (Alfisols) and the Smithdale series (Ultisols). Fieldwork included observations of open burrows on soil surfaces and in gully walls. Smaller vertical burrows were cast with plaster or resin, while large horizontal burrows were cast with expanding spray foam insulation. Burrow casts were excavated, cleaned, and scanned with a NextEngine laser scanner to enable quantification of burrow volume. Burrow volume is used as an estimate of the volume of sediment moved by the tracemaker that is susceptible to erosion. The largest of these burrows have diameters greater than 10 cm and lengths greater than 50 cm. These were subhorizontally to horizontally oriented and found in gully walls in a forested area surrounding a lake on the property. Tracemakers were most likely mammals, but definitive identifications cannot be made at this time. Trenched soil profiles were not associated with large-diameter burrows, but intersected smaller invertebrate burrows, including fire ant (Solenopsis sp.) nests. Future work will include mounting trail cameras in locations that are commonly burrowed to assist in identification of tracemakers and calculation of bioturbation rates. Once sufficient data are collected, correlations between burrow morphologies and soil properties will be evaluated to enhance interpretations of paleosol properties based on fossil burrow properties.