• Walker, Nancy K.
  Forest Products Laboratory, University of California
  
• Dodd, Richard S.
  Forest Products Laboratory, University of California
  

A method is proposed for quantifying the variation in wood density as recorded by X-ray densitometry. This method uses the sum of the squared deviations from the mean denstiy, and so approximates a true statistical variance. This gives greater meaning to variation than has previously been described. The density variation can be computed for a single growth ring, or several growth rings. The calculations are shown using data from 11-year-old Pinus radiata trees.