Ignition patterns & prescribed fire behavior in southern pine stands
As an aid to forest managers who use or contemplate using aerial ignition techniques in their prescribed burning programs, a study was designed to evaluate the magnitude of the differences that could occur depending on whether lines of fire were used (ignited by a helitorch) or a spot-fire technique was used (ignited by aerial ignition devices). Six experimental fires of a simultaneously ignited backfire, flank fires, and headfires of line origin and spot origin were observed, and flame spread distances were recorded at 1-minute intervals to time of burnout. Of special note were the differences in rate of spread of headfires from line and spot origin during early development. Headfires of line origin traveled at rates that varied from 1.5 to 5.9 times faster than those of spot origin. Line fires would, therefore, develop higher fire intensities than spot fires.