Modelaje de parámetros de albura y duramen en árboles de Tectona grandis L.f. en plantaciones forestales de distintas edades en Costa Rica.

Abstract

The forest specie Tectona grandis L.f (teak) from tropical zones, is recognized because when mature it produces wood of hardwood with high value in the international market. Teak heartwood highlighted by characteristics of durability, strength, color and greater proportion to the ratio heartwood-sapwood in fast growing plantations, therefore the importance of characterizing planting this species and its properties. Moreover, the dynamic modulus of elasticity (MOEd) is an ideal property to characterize the quality of wood, related to its rigidity. The aim of this study is to characterize and model the variation of properties of sapwood and heartwood, and the dynamic modulus of elasticity at different ages and heights in the tree T. grandis species in Costa Rica. To carry out this research, 54 plantations with ages between 2 and 24 years were sampled, for a total of 162 trees (3 samples x 54 sites), in different regions of Costa Rica. The sapwood thickness (Ea), bark thickness, heartwood radius (Rd), proportion of heartwood (Dp) and MOEd in the transverse plane and at different height of the stem, in addition to the maximum heartwood height (Hd) and volume of heartwood (V), they were determined. The thickness of the bark decreased with the height of the trees. The diameter of heartwood (Dd) and Dp increased with the age of plantation and the dap (cm), and decreased with the increasing in height of the tree. The Ea presented two patterns of distribution according to the age of plantation (the Ea is greater between 2 to 10 years than the trees from 11 to 24 years old) and varied between 0,5 and 6,5 cm. The age of heartwood formation was between 2 and 3 years at the height of the base of the trees, and the heartwood formation at the height of dap was at 4 years. The Hd in the trees varied between 0,1 to 22,8 m. The MOEd did not show marked variation along the stem, it varied from 480,8 to 4779,4 MPa. Finally, in this study the parameters of age of plantation (Ea), radius and heartwood (Rd), maximum height of heartwood (Hd), proportion of heartwood (Dp) and volume of heartwood (V) were modeled, with the dasometric variables of the trees, and the respective coefficients were determined: 19% for Ea, 84% for (Rd), 86% for Hd, 68% for DP and finally 81% for V.