Listening for Expensive Wood

The Finns are much concerned with their forests. Jean Sibelius wrote a musical work, "Tapiola," about them. One particularly valuable tree, a hardwood used in making fine furniture, is the curly birch, a natural mutant of the silver birch. The former, up to 20 percent denser and possessing a curious curled grain, is rare, while the latter, used for veneers or pulp, is common. From the outside the two types of birch look essentially identical. Now a team of physicists in Helsinki has developed a method for telling the two apart by seeing how they conduct ultrasound waves At a level of 93 percent confidence, a curly birch tree can be detected and saved, at least temporarily, from the ax. It would be allowed to grow larger, while the less useful silver birch would be cut at the 10-13 year mark.

Salmi et al., to appear in Journal of Applied Physics
Contact Ari Salmi
University of Helsinki
ari.salmi@helsinki.fi