Although over 40 years have passed since Jacobs (1945) convincingly
established the basic radial pattern of residual growth stress in
growing trees, yet this phenomenon is still not widely appreciated in
wood science and technology circles. This is in spite of the fact that
the presence of these stresses of sizeable magnitudes has long been
recognized as a primary cause of shakes and splits in logs as well as
the warping of lumber sawn in the green condition. The presentation of
the subject of growth stresses in trees presents some special problems
due to the wide range of specialists who potentially might have an
interest in the subject. For example, tree physiologists interested in
questions such as the relation of mechanical stress to stem taper and
the role of reaction wood and gravity forces in determining tree crown
form encounter growth stress models. Silvi- culturists interested in the
relation ofthinning practices to wood quality find that wood properties
are correlated with growth stress levels which are in turn significantly
changed by cutting practices. Wood techno- logists interested in the
relation of residual growth stress gradients in green logs to the
dimensional quality of sawn and seasoned lumber are forced to take a
more quantitative approach to the effect of growth stresses than might
have been the case in the past.