Selection for Improved Growth and Wood Density in Lodgepole Pine: Effects on Radial Patterns of Wood Variation
Keywords:X-ray densitometry, wood density, density components, heterogeneity, radial pattern, early selection
AbstractChanges in growth and wood density traits were investigated across annual rings of 12-year-old trees from four selected subpopulations in lodgepole pine (Pinus contorta Dougl. Ex Loud var. latifolia Engelm) based on X-ray densitometry profile data. Four subpopulations were constructed based on height growth and wood density as follows: 1) fast growth and high wood density (FH); 2) slow growth and high density (SH); 3) fast growth and low density (FL); and 4) slow growth and low density (SL). Annual ring density was initially high, declined with age until age 10, and then plateaued. Significant differences among subpopulations were found for ring density, earlywood and latewood densities, ring width, earlywood width, latewood proportion, and earlywood width after age 6. Wood density decreased less from the pith to the bark in both overall and earlywood densities in the FH subpopulation, resulting in denser, more homogeneous wood than in other subpopulations. This suggests that it may be possible to increase wood density and homogeneity in juvenile wood of this species by selecting FH families. Overall ring density may be better improved by selecting for earlywood and latewood components separately. The earliest age of which families combining fast growth and high wood density can be accurately identified is about 7 years.
Burdon, R. D., and J. M. Harris. 1973. Wood density in radiata pine clones on four different sites. N.Z.J. For. Sci. 3:286-303.nFries, A. 1986. Volume growth and wood density of plus tree progenies of Pinus contorta in two Swedish field trials. Scand. J. For. Res. 1:403-419.nHarris, J. M. 1971. Physical properties, resin content, and tracheid length of lodgepole pine grown in New Zealand. N.Z.J. For. Sci. 3(1):91-109.nHarris, J. M., R. N. James, and M. J. Collins. 1976. Case for improving wood density in radiata pine. N.Z.J. For. Sci. 5:347-354.nHatton, J. V. 1997. Pulping and papermaking properties of managed second-growth softwoods. Tappi 80:178-184.nKennedy, R. W. 1995. Coniferous wood quality in the future: Concerns and strategies. Wood Sci. Technol. 29: 321-338.nKing, J. P. 1967. Seed source variation in tracheid length and specific gravity of five-year-old Jack pine seedlings. 8th lake States For. Tree Improv. Conf. U.S. For. Serv. Res. Pap., NC-23:5-9.nLadrach, W. E. 1986. Control of wood properties in plantations. IUFRO Congr. Ljubijana, Yugoslavia. Pp. 369-381.nLedig, F. T., J. B. Zobel, and M. M. Mathias. 1975. Geoclimatic patterns in specific gravity and tracheid length in wood of pitch pine. Can. J. For. Res. 5:318-329.nLarson, P. R. 1962. A biological approach to wood quality. Tappi 45:443-448.nLarson, P. R. 1969. Wood formation and the concept of wood quality. Yale Univ. For. Bull. 74. 75 pp.nLoo, J. A., C. G. Tauer, and B. J. Van Buutenen. 1984. Juvenile-mature relationships and heritability estimates of several traits in loblolly pine (Pinus taeda L.). Can. J. For. Res. 14:822-825.nLoo, J. A., C. G. Tauer, and R. W. McNew. 1985. Genetic variation in the time of transition from juvenile to mature wood in loblolly pine (Pinus taeda L.) Silvac Genet. 34:14-19.nPearson, R. G., and R. C. Gilmore. 1980. Effect of fast growth rate on the mechanical properties of loblolly pine. Forest Prod. J. 30(5):47-54.nReid, J. S. 1963. Wood quality in rapidly growing conifers planted in New Zealand. IUFRO Sect. 41 Comm. on Fibre Char. Melbourne, Australia. Pp. 1-38.nSas Institute Inc. 1989. SAS/STAT User's Guide, Version 6, 4th ed. Cary, NC.nStatistical Sciences. 1993. S-Plus Guide to statistical and mathematical analysis, Version 3.2, Seattle: StatSci, a division of MathSoft, Inc.nTaylor, F. W., E. I. C. Wang, and M. M. Micko. 1982. Differences in the wood of lodgepole pine in Alberta. Wood Fiber 14:296-309.nVan Buutenen, J. P., 1982. Fiber for the future. Tappi 65: 10-12.nWang, T., S. N. Aitken, and P. Rozenberg. 1999. Selection for height growth and Pilodyn pin penetration in lodge-pole pine: Effects on growth traits, wood properties and their relationships. Can. J. For. Res. 29 (4):434-445.nXie, C. Y., and C. C. Ying. 1996. Heritability, age-age correlations, and early selection in lodgepole pine (Pi-nus contorta ssp. latifolia). Silvae Genet. 45:101-107.nZobel, B. J., 1963. Improving wood quality through use of seed from selected parents and the effect of different environmental and growth conditions. Symp. Wood Quality North Carolina State Univ. Raleigh, NC. 10 pp.nZobel, B. J. 1980. Inherent differences affecting wood quality in fast-grown plantations. IUFRO Conf. Div. 5, Oxford, England. Pp. 169-188.nZobel, B. J., and J. B. Jett. 1995. Genetics of wood production. Springer, Berlin, Heidelberg, and New York. 367 pp.nZobel, B. J., and J. R. Sprague. 1998. Juvenile wood in forest trees. Springer, Berlin, Heidelberg, and New York. 300 pp.nZobel, B. J., and J. P. Van Buutenen. 1989. Wood variation, its causes and control. Springer, Berlin, Heidelberg, and New York. 363 pp.nZobel, B. J., J. B. Jett, and R. Hutto. 1978. Improving wood density of short rotation southern pine. Tappi 61:41-44.n
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