Using Prescribed Burning to Restore Granite Rock Outcrop Ecotones in the Piedmont of the Southeastern United States

Abstract

Rock outcrop habitats in the Georgia Piedmont of the United States host many endemic and rare plants, and the sensitivity of these endemic species to fire is unknown. After surveying 2 granite rock outcrops for 1 yr, we applied a winter burn treatment to their margins to observe the effect of burning on the plant community. Using measures of vegetation class occurrence and species richness, along with hemispherical photographs, soil nutrients, and soil depth, we monitored the success of the restoration effort. Burning did not significantly alter soil nutrients, pH, or the abundance of different vegetation classes. In the 2–yr period following the prescribed burn, burning did not significantly increase canopy openness or noticeably alter total species richness or woody species richness. The burn treatment did not significantly change invasive species richness or abundance, and abundance of the 2 rare rock outcrop endemics present, tenpetal thimbleweed (Anemone berlandieri) and granite stonecrop (Sedum pusillum), was not significantly impacted. Prescribed fire has been used as an effective tool for managing forests in the Piedmont by clearing fuel buildup on the ground and suppressing invading secondary hardwoods. The findings of our study suggest that prescribed winter burns can be an appropriate management tool for outcrop ecotones, but rock outcrop habitats are variable and the benefits of prescribed fire should be evaluated on a site-specific basis.