As hardwood trees grow and develop, surface defects such as limb stubs and wounds are overgrown and encapsulated into the tree. Evidence of these defects can remain on the tree's surface for decades and in many instances for the life of the tree. The location and severity of internal defects dictate the quality and value of products that can be obtained from logs. Thus, log surface defect indicators such as log diameter at defect and surface indicator width, length, and rise provide a viable means of estimating the location and severity of internal defects. Evaluation of white oak (Quercus alba) log defects revealed that good correlations exist between external indicators and internal features for most severe defect types. Weaker correlations were observed with less severe defect types, such as bark distortions and adventitious knots.

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Author notes

The author is Research Scientist, USDA Forest Serv., Forestry Sci. Lab., Princeton, West Virginia ( This paper was received for publication in November 2011. Article no. 11-00123.