Abstract
Recent outbreaks of red oak borer (
Enaphalodes rufulus Haldeman) are causing unprecedented economic devaluation of red oak timber in many areas of the Ozarks in the Midwestern United States. Managers have few guidelines for coping with this problem in the long-term. Here we present a retrospective analysis of degrade in wood quality and value focused on cumulative degrade caused by oak borers over a period of approximately 80 years. This study is intended to provide managers with guidance on the temporal aspects of changes in wood quality as these are related to timber value and damage from oak borers. A
dendrochronological determination of the cumulative number of dated xylem tunnels and wounds, basal area, and stand age was used to assess changes in timber value in a red oak stand. We sampled 31 black (
Quercus velutina Lam.) and scarlet oaks (Q.
coccinea Meunchh.) along two belt transects in a forest with observable red oak borer activity and canopy dieback near Bixby, Missouri in the Ozark Highlands. Cross-sections were taken along tree boles at one m intervals beginning at one m above the ground. Annual growth increments were cross-dated (Stokes and Smiley 1968) and tree stem initiation dates determined. We identified and determined the year of occurrence of 745 borer wounds on 137 cross sections. We used the cumulative frequency of dated injuries that occurred between 1925 and 2001 as a proxy for the amount of economic degrade that occurred throughout the life of the stand. The cumulative distribution of dated borer wounds and tunnels increased exponentially from the date of stand origin (circa 1925) with a dramatic pulse beginning about 1975. Based on data from this location, the earliest time of harvest for maximum value was about 1975 at a rotation length of about 60 years. After 1975 value either stayed the same or decreased depending on the difference in price between degraded and sound wood. The study provides a new and important approach to assessing temporal changes in red oak borer degrade caused by wood boring beetles.
Parent Publication
Citation
Guyette, Richard P.; Muzika, Rose-Marie; Stevenson, Aaron. 2007. Rotation length based on a time series analysis of timber degrade cause by oak borers. e-Gen. Tech. Rep. SRS–101. U.S. Department of Agriculture, Forest Service, Southern Research Station: 176-180 [CD-ROM].
