Fire scar closure rates in oak and the implications to prescribed burning

by

Michael C. Stambaugh and Kevin T. Smith

University of Missouri, Department of Forestry, stambaughm@missouri.edu; U.S. Forest Service, Northern Research Station, ktsmith@fs.fed.us

Abstract – In burned forestlands, fire scars commonly occur on trees as a result of cambial heating. These wounds include both cell disruption and death of the vascular cambium. Wound closure rates are important to understand in the context of forest management such as in areas where prescribed burning occurs in a silvicultural system that depends on tree survival and wood products or where tree cavities may be desired for wildlife habitat. The objectives of this study were to 1) quantify wound closure duration and rates for white oaks across a range of fire scar sizes, and 2) determine the environmental and tree factors related to closure rates. Cross-sections of fire scarred trees were collected on each of 30 white oaks (Q. alba) at the Rudolf Bennitt Conservation Area, in Randolph and Howard Counties, Missouri. Tree measurements included dbh, height, and social position. Trees were felled and cross-sections were collected from the ground level and near the top of fire scars. Site conditions such as slope, aspect, position, canopy position, and basal area were measured. In the laboratory, cross-section surfaces were prepared by planing and sanding to a high polish until the cellular detail is clear. Cross-sections including scars were scanned and measured using WinDendro software (Regent Instruments Inc.). Scar size was measured as the circumference of the scar arc on the transverse plane. Here, we report on wound closure rates of scars and tree growth rates associated with scarring.