Threshold Requirements for Burning Downed Honey Mesquite

Abstract

Forty-one headfires were burned on 0.1-ha test plots on 2 west Texas study sites in the spring of 1984. The purpose of these burns was to develop a prescription for predicting whether downed honey mesquite will be consumed by a prescribed fire. It was found, using regression analysis and discriminant analysis techniques, that critical variables for predicting ignition and combustion of downed honey mesquite are: (1) windspeed, (2) stem moisture content, (3) stem diameter, and (4) proportion of green fuel in the fuel bed. Threshold values for ignition were 6 km/hr windspeed, 6% stem surface moisture content, 5 cm stem diameter, and 15% green:total fine fuel. Threshold values for sustained combustion were 15 km/hr windspeed, 6 cm stem diameter, and 6% stem moisture content at 1.25 cm below the stem surface. A prescription for burning downed honey mesquite was developed.