Clear lumber is not produced by trees until they have shed their lower branches and covered the dead stubs with clear wood. Although it is common knowledge that knots in lumber result from sawing limby trees into boards much remains to be known about the development of knots or branches. How long do branches live, for example; how long after death before they fall from the bole; what is the tree's age when the production of clear lumber starts? A knowledge of branch development will answer these questions and also explain why trees produce red-knotted lumber, black-knotted lumber, and knot-free lumber. Closely related is the probability of controlling the proportion of each kind of lumber through forest management and cultural work.
Document Type: Journal Article
Northern Rocky Mountain Forest and Range Experiment Station
Publication date: March 1, 1939
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The Journal of Forestry is the most widely circulated scholarly forestry journal in the world. In print since 1902, the Journal has received several national awards for excellence. The mission of the Journal of Forestry is to advance the profession of forestry by keeping forest management professionals informed about significant developments and ideas in the many facets of forestry: economics, education and communication, entomology and pathology, fire, forest ecology, geospatial technologies, history, international forestry, measurements, policy, recreation, silviculture, social sciences, soils and hydrology, urban and community forestry, utilization and engineering, and wildlife management. The Journal is published bimonthly: January, March, May, July, September, and November.