Performing Department
West Florida Research and Education Center, Jay
Non Technical Summary
Florida is home to one of North America's most unique and diverse natural ecosystems, the seepage slope wetland. Unusual hydrology and frequent fires have resulted in a habitat that supports a variety of endangered carnivorous and sun-loving plants. Feral hog (Sus scrofa) foraging has resulted in widespread soil disturbances in seepage slope wetlands. This project investigates how feral hog disturbance affects the rate and trajectory of vegetation development in seepage slopes on Eglin Air Force Base, in the Florida Panhandle. To do so, this project is composed of four main objectives: 1) quantify changes in vegetation cover over the past ten years; 2) evaluate the role of disturbance intensity in vegetation development inside and outside exclosures erected in areas of varying disturbance intensity; 3) assess the role of disturbance frequency in determining vegetation composition and rate of recovery after experimental disturbance treatments; and 4) determine if hog disturbance inhibits fire carry by using a GPS to quantify areas of hog damage and areas left unburned after prescribed fires. These studies will provide insight concerning the long-term vegetation changes and the mechanisms driving shifts in plant composition in response to feral hog disturbance. This project will inform managers of the full impact of feral hog disturbance so that resources can be better prioritized and allocated.
Animal Health Component
(N/A)
Research Effort Categories
Basic
60%
Applied
40%
Developmental
(N/A)
Goals / Objectives
This project will quantify changes in the vegetation and provide an understanding of the mechanisms affecting the rate and trajectory of vegetation development in seepage slopes on Eglin AFB. The project is composed of four main objectives. Objective 1 is to investigate changes in dominant functional guilds of seepage slope vegetation over the past ten years. Objective 2 is to evaluate the influence of disturbance intensity on vegetation development inside and outside exclosures. Objective 3 is to quantify how disturbance frequency affects vegetation composition and rate of autogenic recovery. Objective 4 is to analyze the relationship between hog disturbance and fire carry. These studies will demonstrate how feral hog disturbance affects seepage slope revegetation. This has implications for the persistence of threatened and endangered plants under this novel disturbance pressure. This NIFA Fellowship Grant allows an additional year for data collection and dissemination of results. A longer-term data set will produce more meaningful results, while I gain additional field and teaching experience in the process. This funding also allows me to: 1) continue to refine my analytical skills through rigorous data analysis; 2) acquire expertise working with Geographical Information System (GIS) and Global Positioning System (GPS) technology; 3) progress as a leader by training and overseeing field technicians in plant identification and vegetation surveys during the summer and fall of 2012; 4) revise an existing distance education course in the fall of 2012, so that it will be updated when we teach it in the spring of 2013; and 5) further develop effective communication skills by publishing papers and presenting results. I will disseminate my results using the following approaches: 1) two EDIS Extension publications will be published online in the summer and fall of 2012; 2) four manuscripts will be submitted for publication in peer-reviewed journals during in the spring of 2013; and 3) presentations both inside and outside of the traditional circles of higher education will take place throughout this upcoming year.
Project Methods
This project is composed of four interrelated studies. The first is a descriptive study that uses data collected over ten years to assess vegetation dynamics. A modified Daubenmire scale was used to estimate cover of total vegetation, bare ground, forbs, grasses, woody species, uprooted vegetation, and Aristida stricta in stratified square meter plots. Richness and presence of hog disturbance was also recorded. This study provides explanatory inference about the pattern of vegetation structure and composition. It also identifies portions of the slope most susceptible to hog disturbance. The second is a quasi-experiment that investigates the hypothesis that high intensity hog disturbance impairs vegetation development in terms of rate and species composition. Wire fence exclosures were erected around square meter plots of varying hog disturbance intensity (light, moderate and heavy) to exclude future hog disturbance in the plot. Each exclosure was paired with an adjacent open plot. Plots will be surveyed once a year for four years using a modified Daubenmire scale as described. This evaluates the impact of disturbance intensity on revegetation potential. The third is a quasi-experiment that investigates the hypothesis that frequent soil disturbance adversely impacts cover, the quality of species (i.e., more r-strategists), and species richness. Artificial soil disturbances at four frequencies are used to simulate hog disturbance in undisturbed plots. Plots are being disturbed as one of the following categories: one disturbance, quarterly disturbances for one year, annual disturbances, and quarterly disturbances for two years. A shovel is used to overturn vegetation to a depth of ~7-10 cm, creating one square meter plot for two frequencies per site. All plots are protected by wire fence exclosures and surveyed using a modified Daubenmire scale every three months prior to disturbances. The study provides causal inference about how disturbance frequency affects species composition. These three studies will be analyzed using a combination of nonmetric multidimensional scaling in PC-ORD and various univariate analyses in SAS, including repeated measures analysis of variance. The last study is a quasi-experiment that investigates the hypothesis that hog disturbance inhibits fire spread necessary to maintain the open, prairie community. Routine prescribed burns, conducted in seepage slopes as management activities in 2010, 2011, and 2012, will be used in this study. A handheld Trimble GPS is used to capture areas where hog foraging has resulted in discontinuous fuels. Following the prescribed burns, the GPS is used to quantify areas of unburned vegetation. ArcGIS 9.2 software will be used to analyze the data. This study quantifies the impacts of hog disturbance on ecosystem processes. Also, two UF/IFAS Extension online publications (EDIS) will be published and views will be tracked to measure public interest. The revision and development of a distance education course will produce a new course that we will teach in the spring semester of 2013. Student evaluations will serve as a tool to assess and improve the course and my teaching skills.