Calculation of Wood Density Variation From X-ray Densitometer Data

Authors

  • Nancy K. Walker
  • Richard S. Dodd

Keywords:

X-ray densitometry, wood density, density variation, Pinus radiata

Abstract

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 density, 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.

References

Bolstad, P. V., and W. J. Libby. 1982. Comparisons of radiata pine cuttings of hedge and tree-form origin after seven growing seasons. Silvae Genetica 31(1):9-13.nCameron, J. F., P. F. Berry, and F. W. J. Phillips. 1959. The determination of wood density using beta rays. Holzforschung 13(3):78-84.nEchols, R. M. 1973. Uniformity of wood density assessed from X-rays of increment cores. Wood Sci. Tech. 7(1):34-44.nElliott, G. K. 1970. Wood density in conifers. Tech. Commun. Commonw. For. Bur. No. 8. 44 pp.nFerrand, J. C. 1982. Reflexions sur la densité du bois. 2° eme Partie: Calcul de la densité et de son heterogeneite. Holzforschung 36(3):153-157.nHarris, J. M. 1969. The use of beta rays in determining wood properties. New Zeal. J. Sci. 12(2): 419-431.nKanowski, P. 1985. Densitometric analysis of a large number of wood samples. J. Inst. Wood Sci. 10(4):145-151.nLarson, P. R. 1972. Evaluating the quality of fast grown coniferous wood. Proceedings of 63rd Western Forestry Conference. 6 pp.nOlson, J. R., and D. G. Arganbright. 1977. The uniformity factor. A proposed method for expressing variations in specific gravity. Wood Fiber 9(3):202-210.nOlson, J. R., P. Rygiewicz, and D. G. Arganbright. 1978. Current status of the U.C.F.P.L. X-ray densitometric system. Internal Report No. 36.01.106. University of California For. Prod. Lab. 65 pp.nPolge, H. 1963. Une nouvelle methode de determination de la texture du bois: L'analyse densi-tométrique de clichés radiographiques. Ann. Sci. For. 20:533-581.nWalker, N. 1984. The effect of maturation on wood specific gravity of Pinus radiata D. Don. M.S. thesis. University of California, Berkeley. 87 pp.nWangaard, F. F. 1958. Research on quality of wood in relation to its utilization as fiber for papermaking. Norsk. Skogind. 12:286-299.nWood Handbook. 1974. USDA Forest Products Lab. Agr. Handbook No. 72. 528 pp.n

Downloads

Published

2007-06-22

Issue

Section

Research Contributions