Despiece comercial potencial de teca (tectona grandis l.f) clonal a la edad de 10 años en diferentes calidades de sitio, en Zona Norte de Costa Rica

Abstract

Resulta esencial cuantificar el volumen de madera y de los productos comercializables a obtener del rodal. El objetivo de este estudio consiste en elaborar tablas de volumen comercial y obtener el despiece comercial por producto en distintas calidades de sitio, para plantaciones clonales de Tectona grandis. A 266 árboles (119 en IS 27, 119 en IS 24 y 28 en IS 21, se le midió el diámetro a 1,3 m y cada 1,5 m hasta la altura total. El volumen del árbol se obtuvo mediante la sumatoria de cada sección cubicada mediante Smalian. Para cada índice de sitio, se ajustaron modelos por el método de mínimos cuadrados ordinarios, utilizando Statgraphics Centurion XVI. Se verificó la autocorrelación de los residuos mediante Durbin-Watson. La selección del modelo se basó en la sumatoria de los parámetros estadísticos normalizados. Para el despiece comercial se evaluaron los siguientes productos: aserrío grueso (≥30 cm de diámetro), aserrío delgado (<30 cm ≥20 cm), tarima (<20 cm ≥12 cm), leña (<12 cm ≥5 cm) y los residuos < 5 cm. Los modelos seleccionados tuvieron ajustes aceptables (R2≥ 94 %), bajos errores de estimación (< 3 %), y practicidad por utilizar el diámetro normal (DAP) como única variable predictora, tornándose en una herramienta útil para conocer, rápido y preciso, el volumen comercial. En el despiece comercial en el IS 27, diámetros < a 13 cm corresponde a leña (88-40 %), desde 13 cm hasta 24 cm, corresponde a tarima, en adelante domina el aserrío delgado, mientras >28 cm, el aserrío grueso y delgado (representan el 75% del volumen comercial). Las tablas de volumen y el despiece comercial por árbol, son herramientas útiles para la cuantificación del volumen comercial y la distribución potencial por tipo de producto, en teca clonal de diez años, en zona norte de Costa Rica.

t is essential to reliably quantify and predict the volume of timber and marketable products to be obtained from the stand, to assist in the management and planning of forest production. This study aimed to develop commercial volume tables and commercial assortment by product in different qualities of site, for clonal plantations of Tectona grandis. A sample of 263 trees (119 in IS 27, 120 in IS 24 and 28 in IS 21, the stump diameter was measured, 1.3 m from the ground and every 1.5 m to the total height. The volume of each section was obtained with the Smalian formula and the volume of the tree by the sum of each section For each site index, models were adjusted by the method of ordinary least squares with the Stat graphics Centurion XVI statistical package The self-correlation of the residues was verified using Durbin-Watson. The model selection was based on the sum based on the standardization of the statistical parameters evaluated. For the elaboration of the assortment table the following products were evaluated: thick sawmill (≥30 cm in diameter), thin sawmill (<30 cm ≥20 cm), pellets (<20 cm ≥12 cm) and firewood (<12 cm ≥5 cm) and residues <5 cm. The selected models had good adjustments (R2≥ 94%), low estimation errors (<3%), very practical for using only the normal diameter (DAP) as a predictor variable and are an important tool to quantify, quickly and accurately , the commercial volume with clonal teak bark up to 15 cm in diameter. The volume of the product with the highest value increased as the tree diameter increased and the volume of the products with the lowest value decreased. In IS 27, wood with diameter <13 cm corresponds to firewood (88-40%), from 13 cm to 24 cm, corresponds to pallet, from now on dominates the thin sawmill, diameter> 28 cm the thick and thin sawmill ( 75% of the commercial volume). The five products evaluated are present in trees of IS 27 and IS 24; in IS 21 no wood was registered for this product. The volume and commercial assortment tables represent an important tool in the quantification and distribution of the potential commercial volume by type of product in 10-year-old clonal teak, in northern Costa Rica.