Formation and Properties of Juvenile Wood in Southern Pines: A SynopsisU.S. Department of Agriculture, Forest Service, Forest Products Laboratory, 2001 - Juvenile wood - 42 pages To satisfy the increasing demand for forest products, much of the future timber supply will be from improved trees grown on managed plantations. This fast-grown resource will tend to be harvested in short age rotations and will contain higher proportions of juvenile wood than that of current harvests. In anticipation of this resource, definitive information is needed on the influence of juvenile wood on lumber properties so that grading rules and the associated allowable design stresses can be modified as needed. This document reports the results of an extensive review of the literature on juvenile wood in southern pines. This report defines and discusses the extent, occurrence, and characteristics of juvenile wood. It reviews the effects that environment and silviculture have on the amount of juvenile wood produced. Finally, the impacts that juvenile wood has on mechanical properties were quantified. The results of this quantification are significant to all producers of fast-grown plantations. Research has clearly shown that juvenile wood will have a detrimental impact on allowable design stresses for visually graded lumber. It is critical that methods are developed to more carefully manage fast-grown plantation wood for its most efficient use. This review should serve as an overall collection of knowledge pertaining to juvenile wood research in southern pines and should help in the decision-making efforts to improve seedling selection techniques and silvicultural practices to maximize the potential for fast-grown plantations of southern pines. |
Common terms and phrases
average Bendtsen branches breast height cell wall compression wood conifers correlated decrease diameter and wall effect elliottii fast-grown fertilization fibril angles Forest Products Journal Forest Products Laboratory Forest Service geographic location growth conditions growth rate growth ring width heartwood height growth increase initial spacing juve juvenile core juvenile growth rings juvenile wood knots knotwood Larson living crown loblolly pine longitudinal shrinkage longleaf pine lower stem lumber mature wood pattern percentage of summerwood pith plantation position in stem progeny tests radial diameter radiata pine Research rings per inch secondary wall silvicultural practices slash pine soil moisture solid wood products southern pines specific gravity values spiral grain springwood and summerwood springwood tracheids stand density stem taper summerwood percentage summerwood tracheids taeda TAPPI Journal tensile strength thinning tracheid length transition tracheids U.S. Department variation vary Vascular Cambium wall thickness wood characteristics wood formation wood properties wood quality characteristics wood specific gravity Zobel zone