Limon, Vanessa Yvonne (2020-01). Effect of Mass Mortality of Feral Hogs (Sus Scrofa): Lateral and Vertical Transport of Nutrients Through Soil. Master's Thesis.
Mass deaths of livestock can present an environmental issue in terms of changes in soil chemistry (Chowdbury et al. 2019) and overall soil/environmental health. The population of some wildlife species have been increasing and are influenced by factors such as water availability, habitat, lack of competition for resources, and lack of predation or disease. One such wildlife species is feral hogs whose population has proven environmentally and economically detrimental to many states in the US. The baiting and killing of these hogs may contribute to a secondary mass mortality event (MME) scenario where decomposition products directly impact soil, plant and insect functions in riparian areas and specifically in areas with soils that are conducive to nutrient transport (such as those sites with higher saturated hydraulic conductivity). On July 5th, 2016, Mississippi State University researchers simulated an MME to study the effects on an ecosystem in terms of entomology, microbiology, and plant physiology (Lashley et al., 2017; Tomberlin et al. 2017; Wilcox 2017). Three tons of donated feral hog cadavers were placed in experimental plots at 5 different sites in the John Starr Forest in Starkville, Mississippi, USA. Their study served as a site for my research with a major objective of examining the lateral and vertical migration of carbon (C), nitrogen (N) and phosphorus (P) compounds in the cadaver decomposition islands (CDIs) of feral hogs. This research showed low cadaver mass (<= 181 kg) decomposition sites did not pose significant threats to the soil environment based on nutrient concentrations. However, as cadaver mass on a site was increased, such as in sites 4 and 5 with masses >= 363 kg, the potential environmental impacts from high NO3?N, NH4?N, and PO4?P are prevalent. The depth at which these nutrients can move and remain in the soil is also concerning, particularly when characteristics of the soil are conducive to high transport. For example, soils with a higher saturated hydraulic conductivity will likely see nutrient movement to deeper depths. Scavenging tended to spread nutrients laterally throughout the experimental plots but the concentrations tended to be lower whereas protected cadavers tended to have a high concentration of nutrients at the center of the CDI.