Wednesday, August 4, 2010

PS 56-97: The effects of canopy thinning and burning on transplantation of federally threatened Scutellaria montana (large-flowered skullcap) in a southeastern deciduous forest

H. Mae Kile, Joey Shaw, and Jennifer N. Boyd. University of Tennessee at Chattanooga

Background/Question/Methods

Federally threatened Scutellaria montana (large-flowered skullcap) is a perennial forb endemic to 11 counties in southeastern Tennessee and northern Georgia. One population was found in 2002 at the 648-hectare Tennessee Army National Guard Volunteer Training Site (VTS) in Catoosa County, Georgia. While surveying VTS, we observed numerous healthy S. montana individuals growing in locations with moderate canopy cover and recent fire. However, earlier work suggested that S. montana prefers a closed canopy, while the quantitative effects of fire on this species have received little attention. To comply with Department of Defense directives, 8-m buffer zones must be cleared around VTS’s perimeter, which includes some S. montana habitat. To improve understanding of transplantation as a mitigative action and better understand the effects of light availability and fire on S. montana, 80 affected S. montana individuals were relocated to an unaffected area on the site during winter 2010. Another 20 plants were left in the buffer zone as a control. Transplanted individuals were evenly divided into four 25-m2 plots with interactive overstory clearing and low-grade burning treatments. Growth and physiological measurements, including leaf-level gas-exchange and photosynthetic light-response characteristics, are being used to evaluate the plants’ success in the different plots.

Results/Conclusions

Our data show that plants exhibited greater photosynthetic rates in locations with increased light availability. Our findings also suggest that sites with recent prescribed burning had a positive influence on plant density. Collectively, these results indicate that transplantation success may be improved with overstory thinning and low-grade burning treatments.