SITE PREPARATION BURNING TO IMPROVE SOUTHERN APPALACHIAN PINE-HARDWOOD STANDS - FIRE CHARACTERISTICS AND SOIL-EROSION, MOISTURE, AND TEMPERATURE

Three southern Appalachian stands with sparse and unproductive pine-ha rdwood overstories and dense Kalmia latifolia L. understories were tre ated to restore productivity and diversity on steep slopes. An adaptat ion of the fell and burn practice was applied in summer and fall 1990. About one-half of the woody fuels were consumed at each site. A range of fire intensities was observed. Flame temperatures approached 800-d egrees-C, but the heat pulse into the forest floor only reached 60-deg rees-C at 5 cm. Humus and chaffed leaf litter remained on most of the surface after burning. Evidence of soil erosion was spotty and related to points of local soil disturbance. No soil left the sites. At the e nd of the first growing season, 23% of the burned surfaces were covere d by growing plants and 62% by residual forest floor and woody debris. Felling and burning reduced evapotranspiration so that soil in the tr eated areas remained moister than under adjacent uncut stands. Opening the sites increased soil temperatures 2 to 5-degrees-C at 10 cm durin g the first 16 months after treatment.