Inferences from growing trees backwards

Abstract

The objective of this paper is to illustrate how longitudinal stress wave techniques can be useful in tracking the future quality of a growing tree. Monitoring the quality of selected trees in a plantation forest could provide early input to decisions on the effectiveness of management practices, or future utilization options, for trees in a plantation. There will likely be utilization options that will include the production of structural products that use modulus of elasticity (MOE) as part of the grading criteria. Examples include machine stress rated (MSR), solid- sawn lumber and veneer for laminated veneer lumber (LVL). Existing U.S. log and tree grading procedures only make visual assessments of log and tree quality. These procedures do not incorporate estimates of log or tree MOE. Research has shown good correlation between log and lumber MOE. In the pilot study reported herein, monitoring the properties of a growing tree was simulated by periodically measuring the MOE of a log as annual rings are peeled from the log. Such reverse monitoring allowed us to assess the potential of this approach without having to take measurements every year for 15 to 30 years, as the tree adds successive growth increments. Results from a southern pine log indicate that tree MOE and stress wave speed show a more regular pattern with age than does specific gravity. Results from a yellow-poplar log were not as definitive.

Citation

Green, David W.; McDonald, Kent A. 1997. Inferences from growing trees backwards. Timber management toward wood quality and end-product value : proceedings of the CTIA/IUFRO international wood quality workshop, August 18-22, 1997, Quebec City, Canada. Saint-Foy, Quebec : Forintek Canada Corp., [1997]: pages II.19-II.24.