PARENT SESSION
Poster Session #18: Fire Ecology I.
Tuesday, August 6. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC
18
Vegetation response to stand restoration burning in oak/pine forest types in the Conasauga River Watershed of western Georgia and eastern Tennessee.
ELLIOTT, KATHERINE*,1, VOSE, JAMES1, CLINTON, BARTON1, 1 COWEETA HYDROLOGIC LABORATORY, SOUTHERN RESEARCH STATION, USDA FOREST SERVICE, Otto, NC
ABSTRACT- Interactions between past land-use and fire exclusion have resulted in undesirable successional trajectories in forest ecosystems in the Conasauga River Watershed (CRW), in northwestern Georgia and southeastern Tennessee. Heavy logging at the turn of the century has increased densities of Pinus virginiana in many oak/pine (Quercus/Pinus echinata) stands, which are now succeeding to Pinus strobus. Anecdotal information, from prescribed burning treatments currently being applied in the CRW, suggests that prescribed burning might be an effective tool for restoring these stands to a Quercus/Pinus echinata community type. We initiated a study on restoration burning in the CRW to answer the question: What are the effects of restoration burning on regeneration patterns, biodiversity, and understory productivity? We selected six sub-watersheds (similar in vegetation, soil type, stream size and location, and disturbance history) within the CRW; four of the sites were prescribed fire in March 2001, and two sites were designated as controls. Before and after the prescribed fire, we measured vegetation in five 10-m x 20-m plots per site by vertical layers (overstory included tree species >5.0 cm dbh; understory included woody species >0.5 m height and <5.0 cm diameter at breast height (dbh); and ground flora included herbaceous + woody species <0.5 m height). Flame temperature, soil temperature, and forest floor consumption were variable among the four burned sites. In the overstory, only a few small sized (5.0 to 15.0 cm dbh) trees were killed by the fire. However, we did find significant mortality and subsequent regeneration in the understory the first growing season after the burn. Pinus virginiana and Pinus strobus (two undesirable species) decreased in the understory; while, Liriodendron tulipifera, Acer rubrum, Quercus coccinea, and Vaccinium species increased in abundance. However, no regeneration of Pinus echinata (a desirable species) had occurred in the first growing season after the fire. In addition, we found no significant differences between control and burned sites for ground flora percent cover, species richness, or diversity.
KEY WORDS: disturbance, restoration, fire, watersheds