Presentation on theme: "Introduction Methods Results and Conclusions References Acknowledgements Figures and Tables Table 1. Habitat suitability index for forests with different."— Presentation transcript:
Introduction Methods Results and Conclusions References Acknowledgements Figures and Tables Table 1. Habitat suitability index for forests with different burn histories. How Controlled Burning in the Sandhills Affects Habitat Selection by Terrapene carolina Gareth Hoffmann, Lucas Baxley, and Dr. John H. Roe University of North Carolina at Pembroke 1 University Drive Pembroke, NC Microhabitat Variables Unburned (Fig. 4) 4 years post burn (Fig. 5) < 1 year post burn (Fig. 6) %CWD WSD (n) %LITTER LITTER DEPTH (cm) DIST. LOG (m) DIST. SAPLING (m) DIST. SHRUB (m) %VINE %FERN %BARE Photo 1:CWD/ Litter Photo 2: CWD/ Log Photo 3: WSD/ Litter Photo 4: Vine/ Litter Green: HighL. Yellow: Med. White: Low Figure 4. Hardwood habitat includes 5/10 highly suitable, and 2/10 medium suitable factors for turtles. Figure 5. Four year post burn habitat includes 2/10 highly suitable and 8/10 medium suitable factors for turtles. Figure 6. Less than 1 year post burn microhabitat includes 3/10 highly suitable, and 1/10 medium suitable factors for turtles. Figure 3. Examples of one or more suitable microhabitat factors attractive to turtles. Prescribed burning is a management practice that serves a dual purpose. The anthropocentric purpose is to lessen the chances of catastrophic wildfires. The ecocentric purpose is to preserve habitats as naturally as possible. Fire benefits target species, such as the red-cockaded woodpecker, but the effect of fire on non-target species is unknown. One study of Gopher Frogs documented mortality as a direct effect of fire management practices (Humphries and Sisson 2012). The goal of this study is to identify the effects of fire on Eastern Box Turtles, Terrapene carolina, a species of special concern in NC (NCWRC 2005). Turtles are not only slow, but they also grow and reproduce slowly. Thus, these creatures may be particularly vulnerable to any negative impacts fire may have. Understanding how fire impacts habitat selection and suitability in box turtles will provide insight on fire management practices in longleaf pine forests. Turtles selected microhabitats with significantly more coarse woody debris (CWD), higher woody stem density (WSD), litter depth, % litter, % vine, % fern, and were closer to logs, saplings, and shrubs than random while avoiding bare ground (P 0.05). Eastern Box Turtles in mountain wetlands of NC showed no preference for woody stems or litter depth (Rossell et al. 2006), suggesting that box turtles at our site in the Sandhills physiographic region of NC use different environmental features in selecting suitable habitat. Assessing site-specific variation in behavior of box turtles is thus important for designing management practices. Burn history significantly influenced microhabitat structure (Table 1). Generally, longer intervals post fire resulted in overall higher habitat suitability for CWD, WSD, litter coverage and depth, vine and fern density, and proximity to logs, saplings, and shrubs (P < 0.05, Figs. 4 – 6). Importantly, habitats 4-years post burn contained numerous habitat features attractive for turtles. Burn managers should consider implications for box turtles (i.e., injury and mortality) attracted to habitats after recovery from fire. Closer examination of when the turtles use the burn areas is necessary to inform fire management (i.e., timing and frequency of burns). We tracked 21 turtles using radiotelemetry (Fig. 1) at Weymouth Woods State Park (6M, 5F) where fire management is used, and Lumber River State Park (5M, 5F) where fire is not used. At each turtle location and an associated random location within 25 m, we collected data on several habitat variables in a 1m 2 plot. These included woody stem density, litter depth, and percent coverage of canopy, litter, bare ground, coarse woody debris, herbaceous vegetation, wiregrass, water, vine and fern. We also measured distances to the nearest log, tree, sapling and shrub. Turtle locations were compared to random points using paired T tests or Wilcoxon Signed Rank Tests. Additionally, we assessed habitat variables at 35 – 50 random sites within three different burn treatments: 1) forest <1 year post-burn, 2) forest 4 years post-burn, and 3) unburned hardwood forest. We compared burn treatments using ANOVA and Kruskal Wallis tests. Humphries, J., and M. Sisson (2012). Long Distance Migrations, Landscape Use, and Vulnerability to Prescribed Fire of the Gopher Frog (Lithobates capito) Journal of Herpetology, 46(4), Rossell, C., I. Rossell, and S. Patch (2006). Microhabitat Selection by Eastern Box Turtles (Terrapene c. carolina) in a North Carolina Mountain Wetland. Journal of Herpetology, 40(2), North Carolina Wildlife Resources Commission (2005). North Carolina Wildlife Action Plan. Raleigh, NC. The authors are grateful for support of this research by the UNCP RISE Program, funded by the National Institutes of General Medical Sciences (grant # NIGMS-5R25GM Additional funding was provided by the Pembroke Undergraduate Research Center (PURC). Figure 1. Eastern Box Turtle (Terrapene carolina) with radio transmitter. Figure 2. Difference between turtle and paired random microhabitat variables. Positive values indicate turtle preference and negative indicates avoidance.