Growth Ring Contrast Enhancement and the Differentiation of Sapwood and Heartwood Zones

Authors

  • K. C. Yang

Keywords:

Sapwood, heartwood, growth rings, differentiation

Abstract

A simple technique for growth ring contrast enhancement and the differentiation of sapwood and heartwood zones is described. A dried wood specimen was smoothed and wetted before the image of the growth rings and the boundary between the sapwood and heartwood was copied with a paper copy machine. The high contrast image of the growth rings and the sapwood and heartwood boundary was attributed to the capillary phenomenon of various sizes of cell elements and the difference of permeability between the sapwood and heartwood. This technique can be used for most species, and is especially useful for those species with a narrow latewood zone and without color differentiation between the sapwood and heartwood. This method is very helpful for data interpretation with various comparative studies of wood properties.

References

Bamber, R. K., and R. L. Colley. 1983. A histochemical test for sapwood and heartwood in Pinus radiata. J. Inst. Wood Sci. 9(5):228.nBarton, G. M. 1973. Chemical colour tests for Canadian woods. Can. For. Industries. Pp. 57-61.nBehr, E. A. 1974. Distinguish heartwood in northern white cedar. Wood Sci. 6(4):394-395.nCummins, N. H. O. 1972. Heartwood differentiation in Pinus species—A modified Azo-dye test. N.Z. J. For. Sci. 2(2):188-191.nDouglass, A. G. 1941. Note on the technique of tree-ring analysis, II. Tree-Ring Bull. 7(4):28-34.nEades, H. W. 1958. Differentiation of sapwood and heartwood in western hemlock by colour tests. For. Prod. J. 8(3):104-106.nEisendrath, D. B., Jr. 1938. On photographing the rings of oak specimens. Tree-Ring Bull. 5(1):7-8.nKeith, C. T. 1977. A method for differentiating heartwood and sapwood in unseasoned timber. Bimonthly Res. Notes, For. Prod. Lab., Can. For. Serv., Ottawa 33(3):24-25.nKutscha, N. P., and I. B. Sachs. 1962. Colour tests for differentiating heartwood and sapwood in certain softwood tree species. For. Prod. Lab., Forest Service, U.S.D.A., Madison, Wis. Rept. No. 2246.nLarson, P. R. 1959. Preparation of small wood blocks for photomicrography. Stain Technology 34:155-156.nParker, M. L., G. M. Barton, and J. H. G. Smith. 1976. Annual ring contrast enhancement without affecting X-ray densitometry studies. Tree-Ring Bull. 36(1):29-31.nSandermann, W., and G. Schmitz. 1965. New methods of the differentiation of sapwood, heartwood and growth ring. Part I. The concrete-relief analysis. Holz Roh-Werkst. 23:221-227. Translated by L. Paszner.nWengert, E. M. 1976. A quick method to distinguish aspen heartwood and sapwood. Wood Fiber 8(2):114-115.n

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Published

2007-06-22

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Research Contributions