Effects of prescribed fires on first-year establishment of white oak (Quercus alba L.) seedlings in the Upper Piedmont of South Carolina, USA

Effects of prescribed fires on the 1-year establishment of white oak seedlings were investigated on the Clemson Experimental Forest, South Carolina, USA. Three stands, each consisting of a burn and a control treatment of about 1 ha in size, were examined in the study. On each burn and control treatment, six to eight dominant white oak trees were randomly selected along the slope and four 2-m radius quadrats were set up around each selected tree. Prescribed fire increased seedling biomass but it did not affect seedling mortality and root to shoot ratio. Effects of prescribed fire on seedling density, forest floor depth, and understory light intensity depended on stands, where burning increased seedling density in stands 1 and 3 but not in stand 2. Burning also reduced forest floor depth and increased understory light intensity in stands 1 and 3 but not in stand 2. Regression analyses indicated that forest floor depth and understory light intensity were significantly related to seedling density and biomass, with thinner forest floor and higher light intensity favoring the establishment of new oak seedlings. We conclude that burning can benefit the establishment of new white oak seedlings as long as it significantly reduces forest floor depth and increases understory light intensity.