Influence of Acoustic Velocity, Density, and Knots on the Stiffness Grade Outturn of Radiata Pine Logs


  • Trevor G. Jones
  • Grant W. Emms


Acoustic velocity, density, knots, modulus of elasticity, radiata pine


The prediction of log-average lumber modulus of elasticity (MOE) from log measurements of acoustic velocity, green density, heartwood content, and branch and whorl variables was evaluated for green and kiln-dried boards of unpruned second and third logs of mature radiata pine. The use of principal component analysis showed there were strong associations between the log acoustic velocity and branch size variables, the number of branches and whorls and mean internode length, and the green density and heartwood content. These relationships were reflected in the regression models that showed good predictions of log-average green and kiln-dried board MOE from log acoustic velocity and green density or heartwood content with only a small contribution from branch and whorl variables.


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Research Contributions