Fire Temperatures and Physical Characteristics of a Controlled Burn in the Upper Sonoran Desert

Abstract

Fire temperatures at 4 vertical locations within 3 desert microhabitats were measured during a controlled burn using both temperature pellets and thermocouples. Examples of maximum air temperatures (30 cm) during the fire were 138 degrees C in open interspaces, 352 degrees C within a shrub, and 442 degrees C under a palo verde tree. Fire temperatures among other levels and microhabitats varied considerably. Environmental conditions during the fire were monitored. Soil water repellency at 4 vertical locations within 3 microhabitats showed minimal changes after burning. Soil surface albedo increased by 5% following the fire resulting from 70% perennial plant cover removal and subsequent white ash release. Soil and air temperatures did not vary significantly after the fire when compared to an unburned control.