Fire in a Thermic Oak-Pine Forest in Linville Gorge Wilderness Area, North Carolina: Importance of the Shrub Layer to Ecosystem Response

ABSTRACT
In the fall of 2000, a ground fire burned much of the Linville Gorge Wilderness Area, North Carolina, providing an opportunity to study the effects of fire on an oak-pine forest that had not been burned in 50 years. There was no immediate overstory mortality in our study plots. Most aboveground stems of Kalmia latifolia were killed back, but most survived and subsequently resprouted. Fire reduced surface organic horizons by nearly 50%, and increased light penetration- 15%, resulting in greater soil temperature extremes. Fire increased species richness in the herb layer and allowed establishment of pine seedlings and also the exotic invasive tree species Paulownia tomentosa. Rates of soil respiration and litter decomposition were significantly lower in burned plots one year post-fire. Changes in the microenvironment in the lower strata following fire were caused primarily by the disappearance of the Kalmia canopy. This temporary loss of the shrub layer appeared to influence composition of the ground layer as well as the re-accumulation of surface soil carbon via reduced litter decay.