Open Access Open Access  Restricted Access Subscription or Fee Access


Thomas M Gorman, David E Kretschmann, David W Green, Michael C Wiemann


Juvenile wood (core wood) in softwood species is typically characterized as being less dimensionally stable and having lowermechanical properties thanmature wood.Determining the age of transition between juvenile wood and mature wood is important when making judgments about utilization options for naturally occurring stands of trees in the intermountain west region of the United States. Lodgepole pine (Pinus contorta Dougl. ex. Loud.) trees were harvested from four different sites in the US Inland Northwest to include site variations that affect growth, such as elevation, precipitation, and length of growing season. Longitudinal shrinkage was measured in each sample as it dried fromgreen to oven-dry conditions. Later, averagemicrofibril angle was determined for the same samples. Although the two methods for estimating the juvenile wood transition period were not in agreement regarding the number of years to mature wood, there was agreement in a ranking of the four sites from shortest transition period to longest transition period. A significant difference in the juvenile wood transition period was found among sites; longer transition periods were attributed to stands in which trees exhibited persistent lower branches rather than to geographic influences. Thiswork illustrates that stand conditions for sources of lodgepole pine can have a substantial influence on physical characteristics of this material when it is used as structural roundwood or solid-sawn products.



Lodgepole pine, juvenile wood, mature wood, longitudinal shrinkage, microfibril angle, Pinus contorta

Full Text:



Abdel-Gadir AY, Krahmer RL (1993) Genetic variation in

the age of demarcation between juvenile wood and mature

wood in Douglas-fir. Wood Fiber Sci 25(4):384-394.

Bendtsen BA, Senft, J (1986) Mechanical and anatomical properties in individual growth rings of plantation-grown eastern cottonwood and loblolly pine. Wood Fiber Sci 18(1):23-38.

Clark A, Daniels RF, Jordan L (2006) Juvenile/mature wood transition in loblolly pine as defined by annual ring specific gravity, proportion of latewood and microfibril angle. Wood Fiber Sci. 38:292-299.

Clark A III, Saucier JR (1989) Influence of initial planting density, geographic location, and species on juvenile wood formation in southern pine. Forest Prod J 39(7/8):42-48.

Flora of North America Editorial Committee (1993) Flora of

North America north of Mexico. Pteridophytes and

gymnosperms, Vol. 2. Oxford University Press, Inc., New

York, NY. Pages 395-396.

Forest Service (2003) A strategic assessment of forest biomass and fuel reduction treatments in western states. USDA Forest Service, Washington, DC. 21 pp.

Green DW, Evans JW, Murphy JF, Hatfield CA, Gorman TM (2005) Mechanical grading of 6-inch diameter lodgepole pine logs for the travelers’ rest and rattlesnake creek bridges. Research Note FPL-RN-0297. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 17 pp.

Green DW, Gorman TM, Evans JW, Murphy JF (2004) Improved grading system for structural logs for log homes. Forest Prod J 54(9):52-62.

Green DW, Gorman TM, Evans JW, Murphy JF (2006) Mechanical grading of round timber beams. J Mater Civil Eng (Jan/Feb 2006):1-10.

Harris JM, Meylan, BA (1965) The influence of microfibril angle on longitudinal and tangential shrinkage in Pinus radiata. Holzforschung 19(5):144-153.

Jozsa LA, Middleton GR (1994) A discussion of wood quality attributes and their practical implications. Special Publication No. SP-34. Forintek Canada Corp., Vancouver, BC.

Koch P (1996) Lodgepole pine in North America. Forest Products Society, Madison, WI. 1096 pp.

Koch P (1972) Utilization of the southern pines, volume 1. Agricultural Handbook SFES-AH-420. USDA Forest Service, Southern Forest Experiment Station, Ashville, NC. 734 pp.

Koch P, Barger, RL (1988) Atlas of 28 selected commercial forest areas with unutilized stands of lodgepole pine. General Technical Report INT-GTR-246. USDA Forest Service, Intermountain Research Station, Odgen, UT. 171 pp.

Kretschmann DE, Alden HA, Verrill S (1997) Variations of

microfibril angle in loblolly pine: Comparison of iodine

crystallization and X-ray diffraction techniques. Pages

-177. In Proc. IAWA/IUFRO International Workshop

on the Significance of Microfibril Angle to Wood Quality,

November 1997, Westport, New Zealand.

Larson D, Mirth R, Wolfe R (2004) Evaluation of small-diameter ponderosa pine logs in bending. Forest Prod J 54(12):52-58.

Larson PR, Kretschmann DE, Clark III A, Isebrands JG (2001) Formation and properties of juvenile wood in southern pines. General Technical Report FPL-GTR-129. USDA Forest Service, Forest Products Laboratory, Madison, WI. 42 pp.

Mansfield SD, Parish R, Di Lucca CM, Goudie J, Kang K-Y, Ott P (2009) Revisiting the transition between juvenile wood and mature wood: A comparison of fibre length, microfibril angle and relative wood density in lodgepole pine. Holzforchung 63(4):449-456.

Mansfield SD, Parish R, Goudie JW, Kang K-Y, Ott P (2007) The effects of crown ratio on the transition from juvenile to mature wood production in lodgepole pine in western Canada. Can J Forest Res 37(8):1450-1459.

Shuler CE, Markstrom DD, Ryan MG (1989) Fibril angle in young-growth ponderosa pine as related to site index, D.B.H., and location in the tree. Research Note RM-RN-492. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 4 pp.

Smith WB, Miles PD, Perry CH, Pugh SA (2009) Forest resources of the United States, 2007. General Technical Report WO-78. USDA Forest Service, Washington DC. 336 pp.

Verrill SP, Kretschmann DE, Herian VL (2006) JMFA 2—A graphically interactive java program that fits microfibril angle X-ray diffraction data. Res. Note FPL-RP-0635. USDA Forest Service, Forest Products Laboratory, Madison, WI. 44 pp.

Vissage JS, Miles PD (2003) Fuel reduction treatment: A west-wide assessment of opportunities. J Forest 101(2):5-6.

Voorhies G, Groman WA (1982) Longitudinal shrinkage and occurrence of various fibril angles in juvenile wood of young-growth ponderosa pine. Arizona Forestry Notes No. 16. University of Northern Arizona, Flagstaff, AZ. 36 pp.

Woodall CW (2003) Coming soon: A national assessment of fuel loadings. J Forest 101(2):4-5.

Ying L, Kretschmann DE, Bendtsen BA (1994) Longitudinal shrinkage in fast-grown loblolly pine plantation wood. Forest Prod J 44(1):58-62.


  • There are currently no refbacks.