PARENT SESSION
Poster Session 11: Disturbance Ecology
Tuesday, August 9, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Response of a mixed longleaf (Pinus palustris) and loblolly pine (Pinus taeda) community to long-term dormant season prescribed burning.
Outcalt, Kenneth*,1, Wade, Dale1, 1 USDA Forest Service, Athens, Georgia
ABSTRACT- The wet pinelands of the Southern Coastal Plain historically burned at frequent intervals, primarily during the growing season, with low intensity surface fires. Because of rapid fuel buildup and increased risk of wildfires, land managers have routinely prescribed burned these forest systems. Although we know that these frequent burns, every 3 to 4 years during the dormant season, keep fuel loads at acceptable levels, the long-term effects of fire frequency on community composition is less well known. This study was established on the Francis Marion National Forest, South Carolina in 1958. Since then plots have been burned annually, biennially, every 3 years, every 4 years, or left unburned. To assess the effect of burn frequency on understory vegetation data were recently collected from vegetation transects. Shrubs and small trees dominated understory layers of all but the annually burned plots. Grasses increased with more frequent burning, covering annually burned areas and much of the biennially burned plots. Forbs were significantly higher with fire frequencies of 2 years or less, as were legumes. Species richness increased on all burned areas but was highest on with 1 or 2 year fire return intervals. The data show significant changes in understory communities at fire frequencies of 1 and 2 years. A two-year cycle also favored longleaf pine regeneration while loblolly pine seedlings were more prevalent with longer fire frequencies. Thus, composition of the understory and the eventual overstory can be directed by choosing the appropriate fire frequency.
Key words: longleaf, fire, understory