Because of advances in tree breeding programs and silvicultural practices, trees in intensively managed forest stands reach harvestable size at younger ages and with higher percentage of juvenile wood than in natural stands. Significant differences exist between properties of juvenile and mature wood. The length of juvenile period differs among genera and among species within genera depending upon the property being measured and may be affected by several factors, including geographic location, site and genetic differences, silvicultural practices. Therefore, generalizations as to the length of the juvenile period and age related variability of juvenile wood may be misleading. Not only the juvenile wood quality but also the number of years required for the transition to mature wood are of concern especially in case of intensively managed stands.
In this paper, investigation of within-tree variability of anatomical properties and specific gravity for some hardwood species are presented in relation to genetics, site, management practices and growth rate. Some natural wood defects such as incidence of interlocked grain, tension wood, and occurrence of tyloses in juvenile wood zone are also discussed.
Since the presence of increased amounts of juvenile wood has major implications for the manufacture of a variety of products including solid wood products, wood composites, and pulp and paper, results of this investigation may contribute to the more efficient utilization of plantation wood and to the wiser use of resources invested in tree improvement programs.
Key words: hardwoods, juvenile wood quality, interlocked grain, tension wood.
Correspondence: Ilona Peszlen, University of Sopron, Department of Wood Science, Pf: 132, 9401 Sopron, Hungary
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E-mail: h7759pes@ella.hu