Eastern fox squirrel (Sciurus niger L.) populations have declined due to habitat loss and encroachment by other squirrel species. In North Carolina fox squirrel populations currently only exist in the Coastal Plain and NE region of the western mountains. Within these two areas, fox squirrel habitat exists as isolated pockets separated by areas of unsuitable habitat. This separation makes fox squirrels vulnerable to loss of genetic diversity associated with small population sizes, genetic drift and lack of gene flow. To determine if these effects are causing populations of fox squirrels in North Carolina to diverge genetically, genetic structure among and within populations was quantified using seven microsatellite loci from DNA extracted from muscle tissue of squirrels accidentally killed by cars and preserved tissues from the NC Museum of Natural Science. Amplified DNA was sequenced and fragment length used to distinguish different alleles within and among individuals. Allelic data were used to calculate Wright’s F statistics to compare genetic diversity within and between the mountain and coastal fox squirrel populations. Results will be presented summarizing the impact of isolation, genetic drift and lack of migration via the degree of differences among populations in allelic diversity as indicated FST values where a higher value indicates development of population structure. This information can be used to determine if and where barriers to gene flow exist, as well as determine candidate donor populations if it is decided that fox squirrels should be relocated within the state.
126 • Emma Sheffield1, Rita Malia Fincher2, R, Scott Duncan3
Initiation of Prescribed Burning May Initially Delay Mountain Longleaf Pine Regeneration
Prescribed burning is a widely accepted method of preserving and restoring longleaf pine ecosystems. This study examined the effects of introducing infrequent prescribed burning on longleaf pine seedling and sapling density in Oak Mountain State Park. In order to understand how fire may interact with microclimatic variables, we examined relationships between slope aspect, temperature, light availability, soil moisture, and juvenile longleaf density in burned and unburned plots. In this site, fires had been suppressed for many decades and the initial burn was quite hot, especially on the southeastern slopes. We found that juvenile density was dramatically higher in unburned southeast-facing slopes than the other burn/aspect combinations. Canopy cover was lower in southeastern slopes, burned plots, and above seedlings as opposed to random locations. Average daily high temperatures were much higher in the burned plots. Leaf litter depth and moisture were lower in the burned plots. The burned plots had an overall microclimate more suitable to longleaf recruitment and still had extremely low seedling and sapling density, indicating that the initiation of burning in forests where fire suppression has been a long standing policy may be associated with initial declines juvenile longleaf density.
1 Eckerd College, Petersburg, FL; 2 Dept of Biological and Environmental Science, Samford University, Birmingham, AL; 3 Dept of Biology, Birmingham Southern College, Birmingham, AL
127 • Ashley D. Montgomery, Laura E. DeWald
Predicting Suitable Habitat of Federally Threatened Species Isotria Medeoloides (Pursh) in the Southern Appalachian Region Using Maxent Model
Isotria medeoloides (Pursh) Raf. (small whorled pogonia) is one of the rarest orchids in the eastern US and is currently threatened by habitat loss in the southern Appalachians. The purpose of this study was to predict potential suitable habitat of Isotria medeoloides by creating a regional habitat model that will help focus future surveys and conservation efforts in the region. Maxent model was created to predict potential suitable habitat in the southern Appalachian region of NC, SC, TN, and GA. Habitat characteristics were measured at 10 extant locations and this information was combined with digital environmental variables selected based on field habitat assessments to develop the habitat model. Habitat assessments indicated Isotria medeoloides presence was associated with mid-successional, mixed-deciduous/coniferous forests; sparse ground cover; features and disturbance creating persistent canopy gaps; acidic soils covered in leaf litter that contain an impervious layer; and topographic positions at the base of steep slopes or on benches at mid-slope positions. A jacknife test evaluated the importance of the digital environmental variables on the predicted model. The Maxent model had high predictive performance with a statistically significant AUC value >90. Suitable areas, as predicted by the regional model, will be surveyed to find new Isotria medeoloides populations. Results from the upcoming field surveys will be used to determine if the Maxent modeling approach is useful for predicting suitable habitat for the rare Isotria medeoloides in the southern Appalachians, where few location records are available.
Dept of Biology, Western Carolina University, Cullowhee, NC
128 • J. Christopher Havran1, Kirk A. Stowe2
Educational Opportunities at Biological Field Stations of the Southeastern United States
Biological field stations serve as important sites for biological research, education, and conservation. The Southeastern United States is host to many field stations that offer access to a variety of terrestrial, freshwater, and marine ecosystems. Many field stations offer educational opportunities that can enrich undergraduate and graduate student curricula. The Education Committee of the Association of Southeastern Biologists has organized a symposium to highlight educational programs at Southeastern field stations that offer access to a variety of different ecosystems. We will introduce field station representatives or experts from Kentucky, North Carolina, South Carolina, Mississippi, and Florida who will provide presentations that focus on the educational opportunities at their particular field station. The symposium will end with a question and answer session, with all representatives involved, that will emphasize how students and educators can better use the opportunities available at the Southeast’s field stations.
