QUALITY OF SAWNTIMBER ACACIA MANGIUM WILLD. FROM PLANTING BY AGRO-FORESTRY PRATICES

Abstract

Twelve logs of seven-years old Acacia mangium Willd .; which have diameter 18 - 30 cm. (average 20 cm.) showed lumber recovery approximately 35.6 %. There are fifty percent of heart lumber which is 0.5 - 1.5 cm. in width and average heart length 33.8 cm, per one meter. Warping of sawntimbers after air seasoning bow, crook and twist are 3.7, 2.5, and 4.0 mm. per one - meter length respectively. Most of knots are sound knot, average size is 3.2 cm. In diameter and compose of 2.98 knots per one-meter length of tested sawntimber. Heartwood is dark brown and sapwood is whitish yellow. The heartwood occupy 66 % of the cross section area which averages from dish diameters varied from 16.7 - 28.2 cm. The physical properties are as follow ; air-dry density at 12 %, moisture content is 0.57 g / cm³ , basic density 0.49 g./cm³. Shrinkage from green to air-dry, T-shrinkage (1.9 - 3.8 %) average 3.05 % R - shrinkage (0.7 - 2.2 %) average 1.3 % and shrinkage from green to oven - dry. T - shrinkage (4.1 - 7.3 %) average 6.12 % R - shrinkage (1.8 - 3.8%) average 2.8 %. A. mangium has fine texture, straight - interlocked grain, machining properties are easy to medium. The strength properties of A. mangium is similar to teak from plantation Generally, A. mangium timber is suitable for furniture, flooring, joinery products, frame, household utensil, toy, carving and turning.