Relações entre comportamento do fogo e danos causados a um povoamento de Pinus taeda

Abstract

This study intends to evaluate the damages caused to a Pinus taeda stand by forest fires ocurred on September 9, 10 an 11, 1981. The stand was located in Palmeira county, State of Paraná, Brazil, and the ages of the trees ranged from 8 to 10 years. Four levels of fire intensity were visually defined: I) Surface burning, without lethal crown scorch; II) Surface burning, with partial lethal crown scorch; Ill) Partial consumption of the crowns by the flames, and IV) Total consumption of the crowns by the flames. The estimated fire behavior parameters were flame height, Byram's fire intensity, and lethal scorch height. The average fire intensities were 44.3 kcal/ m-s for level I; 293.0 kcal/m-s for level II; 1,680.6 kcal/m-s for level lll; and 12,345.6 kcal/m-s for level IV. Average lethal scorch height were 1.4 and 9.7 m for Ievels l and II respectively, surpassing the trees height for levels lll and lV. In the areas where fire intensity reached levels lII and IV all the trees were killed by the fire. On level ll damage was partial and the trees recovered well. On level I fire intensity was too low to cause any kind of damage to the trees.