• Lowell, Eini C.
  USDA Forest Service, Pacific Northwest Research Station, Forestry Sciences Laboratory, Portland, OR
  
• Krahmer, Robert L.
  Department of Forest Products, College of Forestry, Oregon State University
  

Certain wood qualities may be affected by lean in red alder (Alnus rubra Bong.) trees. Such characteristics as shrinkage and density can potentially cause problems in the manufacture of products from red alder. Thirty-six trees with varying degrees of lean (0 to 20 degrees) and different diameters (12 to 24 inches) were selected. Cross-sectional disks were cut from the top of the first 10-foot log and used for measuring shrinkage (longitudinal, radial, and tangential) and density. Wood density was measured using an X-ray densitometer. Each sample was categorized as coming from the tension or compression side of the stem. Subsampling within sides permitted examination of the effect on shrinkage of position in relation to the pith. Longitudinal, radial, and tangential shrinkages were affected by all or some of the following factors: lean, side, and position. There was no significant effect of lean or side on wood density.