Technical note: velocity of ultrasonic waves in live trees and in freshly-felled logs.

The objective of this study was to evaluate variations between the velocity of ultrasonic wave propagation in trees and in freshly felled logs as well as to investigate the correlation between those speeds and corrections that would improve this correlation. The study was conducted using 210 exotic trees growing in Brazil, including the species Eucalyptus grandis, Pinus elliottii, Toona ciliata , and Eucalyptus resulting from cloning. Although the velocity of ultrasonic wave propagation in a tree ( V t ) is not equal to that in a freshly felled log ( V t ), the two values are correlated such that V t can be obtained from V st. The regression indicated a nonlinear equation for determining the log velocity from the tree velocity.