The objective of this study was to examine the potential of acoustic measurement as a rapid and nondestructive method to predict the dimensional stability of young-growth Sitka spruce and western hemlock. Ultrasonic velocity, peak energy, specific gravity, and radial and tangential shrinkages were measured on twenty-four 25-×102-×y 25-mm specimens obtained from a 58-year-old stand in Southeast Alaska. We found that specific gravity and peak energy of ultrasonic signals were not good predictors of transverse shrinkage, as indicated by poor correlations. Ultrasonic velocity, on the other hand, was found to be a significant predictor of transverse shrinkage and therefore has good potential to be used as a field method to evaluate dimensional stability. The single-parameter prediction model explained 86% of transverse shrinkages in western hemlock and 71% of transverse shrinkages in Sitka spruce. Further study is needed to test the capability and feasibility of using acoustic velocity to predict both longitudinal and transverse shrinkages of wood in standing trees.
Bibliographical noteFunding Information:
This project was conducted under the cooperative research agreement between Istanbul University and the U.S. Forest Service, Forest Products Laboratory (FPL; No.09-JV-11111133-073) and sponsored in part by The Scientific and Technological Research Council of Turkey (TUBITAK). We thank Mr. James T Gilbertson of FPL for his technical assistance during this study.
- Peak energy
- radial shrinkage
- tangential shrinkage
- ultrasonic velocity
- young-growth wood