SOILS AND BURROWING MEGAFAUNA OF THE NORTH CENTRAL HILLS PROVINCE OF MISSISSIPPI

The North Central Hills physiographic province of Mississippi consists generally of dissected uplands formed on erosive soils developed on loess and the Paleocene-Eocene Wilcox and Claiborne Groups. Unconsolidated parent material and sandy soils are exploited by a variety of burrowing megafauna, enhancing erosion rates, which is problematic for land management. The University of Mississippi Field Station (UMFS) is located within the North Central Hills province in Lafayette County, Mississippi, and offers the opportunity to evaluate the impacts of soil megafauna on erosion. The purpose of this project is to identify soil fauna and their preferred soil habitats to predict which areas are most vulnerable to enhanced erosion caused by burrowing megafauna. Ongoing research at the UMFS has been describing soil pedons at various catena positions and observing the distribution of burrowing animals. Soil profiles are accessed by trenching or through outcrop exposures. Soil properties are determined in the sedimentology laboratory at the University of Mississippi and from samples sent to the Mississippi State Extension Service for chemical analyses. Estimates of the volume of soil displaced by burrowing activity are obtained by casting burrows with plaster, resin, or expanding spray foam, and scanning casts with a NextEngine laser scanner to create 1:1 scale digital models. Volume and other metrics are measured from the digital models. The identities of soil fauna are obtained by collecting animals encountered within the soil profile during fieldwork and by aiming trail cameras at active burrow openings. Soils belong to the Lexington series (Alfisols) and the Smithdale series (Ultisols). The highest diversity of soil fauna has been encountered at the toeslope position, which is adjacent to a pond, suggesting the importance of a readily available water source. A variety of invertebrates has been encountered, but the largest burrows are excavated by vertebrates. Trail cameras captured eastern gray squirrels (Sciurus carolinensis), eastern cottontail rabbits (Sylvilagus floridanus), and raccoons (Procyon lotor), which are all soil disturbing vertebrates, but the only animal photographed in direct association with large diameter burrows thus far is the nine-banded armadillo (Dasypus novemcinctus).