CARACTERÍSTICAS DE CRESCIMENTO E PROPRIEDADES DA MADEIRA JUVENIL DE Pinus taeda L.

Abstract

In the last decades, pine forests have been implanted in larger spacing and harvested in shorter rotation, which could influenced the physical and mechanical properties of the wood, as they are younger trees, which do not yet have a significant amount of adult wood in its composition. In this context, the aim of this research was to study the relationship between growth characteristics and the physical-mechanical properties of juvenile wood of Pinus taeda L. The apparent density, MOR and MOE in static bending, strength and stiffness in parallel compression and shear strength were evaluated. The average size and the percentage of late wood of the growth rings in the specimens used in the mechanical tests were also evaluated. The planting spacing evaluated did not cause significant changes on the percentage of late wood and the mechanical properties of Pinus taeda L wood at 13 and 15 years old. In cases where there was a difference (apparent density and average size of the growth rings), it was not possible to clearly identify its tendency. There was a significant correlation between the growth characteristics of the tree and the strength and stiffness of the wood, although of small magnitude. In general, the use of different spacing did not directly influence the mechanical properties of Pinus taeda L. wood until the ages evaluated. On the other hand, the strength, the stiffness, the average ring size and the percentage of late wood of the growth rings increased significantly with the increase in the harvesting age from 13 to 15 years.