Computerized Scanning Densitometer For Automatic Recording Of Tree-Ring Width And Density Data From X-Ray Negatives


  • M. L. Parker
  • J. Schoorlemmer
  • L. J. Carver


X-ray densitometry, dendrochronology, wood density, specific gravity, annual growth increments, computer processing


A scanning densitometer has been developed to produce tree-ring width and density data as digital output and graphic plots. The densitometer is part of a data acquisition system that includes an on-line digital computer. X-ray negatives of wood samples are scanned and intra-ring specific gravity is measured at 0.01-mm intervals. Ring boundaries are automatically recorded; and values such as earlywood width, latewood width, minimum ring density, maximum ring density, average latewood density, total ring density and total sample density are produced.


Cameron, J. F., P. F. Berry, and E. W. J. Phillips. 1959. The determination of wood density using beta rays. Holzforschung 13 (3):78-84.nEchols, R. M. 1970. Moving-slit radiography of wood samples for incremental measurements. Pages 34-36 in J. H. G. Smith and J. Worrall, eds. University of British Columbia, Faculty of Forestry, Bull. 7.nEchols, R. M. 1971. Patterns of wood density distribution and growth rate in ponderosa pine. Proc. Symp. Eff. Growth Accel. Prop. Wood, U.S. For. Prod. Lab., Madison, Wis. 12 pp.nEllis, J. C. 1971. Use of X-rays in measuring ring widths from increment borings. N.Z. J. For. Sci. 1(2):223-230.nFletcher, J. M., and J. F. Hughes. 1970. Uses of X-rays for density determinations and dendrochronology. Pages 41-54 in J. H. G. Smith and J. Worrall, eds. University of British Columbia, Faculty of Forestry, Bull. 7.nFritts, H. C. 1972. Tree rings and climate. Sci. Am. 226(5):92-100.nGreen, H. V. 1964. Supplementary details of construction of the stage and drive assembly of the scanning microphotometer. Pulp Pap. Res. Inst. Can., Res. Note 41. 7 pp.nGreen, H. V. 1965. Wood characteristics IV: The study of wood characteristics by means of a photometric technique. Pulp Pap. Res. Inst. Can., Tech. Rep. 419. 17 pp.nGreen, H. V., and J. Worrall. 1964. Wood quality studies. I. A scanning microphotometer for automatically measuring and recording certain wood characteristics. Tappi 47(7): 419-427.nHarris, J. M. 1969. The use of beta rays in determining wood properties—Parts 1-5. N.Z. J. Sci. 12(2):396-451.nHarris, J. M., and D. V. Birt. 1972. Use of beta rays for early assessment of wood density development in provenance trials. Silvae Genet. 21(1, 2):21-25.nHarris, J. M., and H. Polge. 1967. A comparison of X-ray and beta ray techniques for measuring wood density. J. Inst. Wood Sci. 19:34-42.nHenoch, W. E. S., and M. L. Parker. 1972. Dendrochronological studies relating to climate, river discharge, and flooding in several regions of western Canada. Int. Geogr. 1:231-233.nHiggs, M. L., and P. Rudman. 1972. Quality or quantity? A study of the effect of fertilizing and thinning on wood properties of E. regnans F.v.M. Presented at Appita, Tasmania, March 1972. 12 pp.nJones, F. W., and M. L. Parker. 1970. G.S.C. tree-ring scanning densitometer and data acquisition system. Tree-Ring Bull. 30:23-31.nKawaguchi, Masao. 1969. A Fourier analysis of growth ring photo-electric analysis curves. J. Jap. Wood Res. Soc. 15(1):6-10.nMarian, J. E., and D. A. Stumbo. 1960. A new method of growth ring analysis and the determination of density by surface texture measurements. For. Sci. 6(3):276-291.nMackay, J. 1972. Application of water temperature to the problem of lateral mixing in the Great Bear-Mackenzie River system. Can. J. Earth Sci. 9(7):913-917.nMcKinnell, F. H., and P. Rudman. 1973. Potassium fertilizer and wood density of radiata pine. Appita 26(4):283-286.nMegraw, R. A., and W. T. Nearn. 1972. Detailed dbh density profiles of several trees from Douglas-fir fertilizer thinning plots. Proc. Symp. Eff. Growth Accel. Prop. Wood. U.S. For. Prod. Lab., Madison, Wis. 24 pp.nNicholls, J. W. P. 1971a. The effect of environmental factors on wood characteristics. 1. The influence of irrigation on Pinus radiata from South Australia. Silvae Genet. 20(1-2): 26-33.nNicholls, J. W. P. 1971b. The effect of environmental factors on wood characteristics. 2. The effect of thinning and fertilizer treatment on the wood of Pinus pinaster.Silvae Genet. 20(3):67-73.nNicholls, J. W. P., and A. G. Brown. 1971. The ortet-ramet relationship in wood characteristics of Pinus radiata.Appita 25(3): 200-209.nParker, M. L. 1970. Dendrochronological techniques used by the Geological Survey of Canada. Pages 55-66 in J. H. G. Smith and J. Worrall, eds. University of British Columbia, Faculty of Forestry, Bull. 7. (Also Geol. Surv. Can., 1971, Pap. 71-25. 30 pp.).nParker, M. L. 1972. Techniques in X-ray densitometry of tree-ring samples. Presented at 45th Annual Meeting Northwest Science Association, Forestry Section, Western Washington State College, Bellingham.nParker, M. L., and W. E. S. Henoch. 1971. The use of Engelmann spruce latewood density for dendrochronological purposes. Can. J. For. Res. 1(2):90-98.nParker, M. L., and L. A. Jozsa. 1973. X-ray scanning machine for tree-ring width and density analysis. Wood Fiber 5(3): 192-197.nParker, M. L., and K. R. Meleskie. 1970. Preparation of X-ray negatives of tree-ring specimens for dendrochronological analysis. Tree-Ring Bull. 30:11-22.nPolge, H. 1963. L'analyse densitométrique de clichés radiographiques. Ann. Ec. Natl. Eaux Forêts Stn. Rech. Expér. 20(4):533-581.nPolge, H. 1965a. Study of wood density variations by densitometric analysis of X-ray negatives of samples taken with a Pressler auger. Proc. IUFRO Sect. 41, Melbourne, Australia. 19 pp.nPolge, H. 1965b. The use of curves of density variation for the study of environmental factors and in particular of climatic factors. Proc. IUFRO Sect. 41, Melbourne, Australia, v. 2. 8 pp.nPolge, Hubert. 1966. Etablissement des courbes de variation de la densité du bois par exploration densitométrique de radiographies d'échantillons prélevés à la tarière sur des arbres vivants. Applications dans les domaines technologique et physiologique. Ann. Sci. For. 23(1):1-206.nPolge, H. 1967. Propositions pour une meil-leure utilisation des courbes de variations de la densité du bois. XIV. IUFRO Cong., Munich, West Germany.nPolge, Hubert. 1970a. Biological aspects of wood quality research in France. For. Prod. J. 20(1):8-9.nPolge, Hubert. 1970b. The use of X-ray densitometric methods in dendrochronology. Tree-Ring Bull. 30(1-4):1-10.nPolge, H. 1971a. Héritabilité de la densité du bois de sapin pectiné. Ann. Sci. For. 28(2): 185-194.nPolge, Hubert. 1971b. Le "message" des arbres. La Rech. 2(11):331-338.nPolge, Hubert. 1971c. Perfectionnements récents de l'analyse densitométrique du bois. Dép. Exploit. Util. Bois, Univ. Laval, Québec, P.Q. 26 p.nPolge, H., and Simone Garros. 1971. Influence de défoliaisons sur la structure du bois de pin maritime. Ann. Sci. For. 28(2): 195-206.nPolge, H., and R. Keller. 1969. La xylo-chronologie, perfectionnement logique de la dendrochronologie. Ann. Sci. For. 26(2): 225-256.nPolge, H., and J. W. P. Nicholls. 1971. Quantitative radiography and the densitometric analysis of wood. Wood Sci. 5(1): 51-59.nRudman, P., and F. H. McKinnell. 1970. Effect of fertilizers on wood density of young radiata pine. Aust. For. 34(3): 170-178.nRudman, P., F. McKinnell, and M. Higgs. 1969. Quantitative determination of wood density by X-ray densitometry. J. Inst. Wood Sci. 4(6): 37-43.n






Research Contributions