THINNING YOUNG LOBLOLLY-PINE STANDS WITH FIRE

The relationship between fire-caused stem girdling and groundline diam eter (GLD) in loblolly pine (Pinus taeda L.) was determined. Results o f 10 experimental prescribed bums conducted across a wide range of amb ient temperature conditions during both the dormant and growing season demonstrate that low-intensity backing fires (< 346 KW/m) are an effe ctive tool to eliminate loblolly pines less than 3.8 cm (1.5 in.) GLD. Wide differences in ambient temperature at time of burning did not af fect stem kill of unscorched trees in this study. Virtually all fire-c aused mortality took place within four months postburn. A predictive m odel that explained 92% of the variation in mortality was developed to facilitate the use of fire to thin young, overcrowded loblolly pine s tands in the southeastern United States. Use of this model in conjunct ion with a preburn stand survey allows estimation of the number and di stribution of survivors prior to ignition.