The accuracy of volumetric computation of small diameter logs based on mathematical formulae was evaluated. Plantation logs of 13-year-old Hopea odorata with diameter measurements of 20 to 30 cm were assessed using Huber's, Smalian's, Newton's and truncated cone formulae. The reference volume of each log was determined using the fundamental method of water-displacement. Results of average values showed that all measurements were higher, compared to reference volume. Empirical evidence indicated that the truncated cone formula was the most precise measurement compared to other formulae. In the analyses of the separated sections, strong linear correlations between mathematical computations and reference volume were observed in middle logs. In contrast, evaluation of bottom and top logs showed lower r 2 values. A correction factor was developed and proposed to estimate a more accurate volume of bottom logs. Based on standard geometrical profile of the logs, other plantation species fit for similar computation were suggested.

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Coastal dune and ex-mining lands are considered as unproductive acreages. Plantation forestry is deemed to be the most potential approach to improve the function of land. It is also the most natural technique to restore the value of the soil through phytoremediation. Considering that it has been almost two decades since the initial planting on degraded lands, mechanical and durability tests were conducted on the timbers of Acacia mangium and Khaya ivorensis. The main objective of the study was to explore the characteristics of timber grown on coastal dune and ex-mining lands. Mechanical tests of static bending, compression parallel to grain, shear parallel to grain and Janka hardness were conducted on a total of 614 green and dried timber specimens. All tests were based on BS 373 standard methods for testing of small clear specimens of timber (BSI 1957). The mechanical properties of Acacia mangium planted on a coastal dune site demonstrated a considerably higher value than existing records. The strength values of Acacia mangium and Khaya ivorensis from Setiu and Bidor varied from 25 to 71%, relatively. Decay ratings were classified as moderately resistant.

The timber of ramin and rubberwood are highly valued for furniture, panelling and decorative mouldings. With the trade restriction of ramin and escalated market price of rubberwood, the widely distributed Tamarindus indica is a potential alternative for light-coloured timber. The tamarind tree was introduced to Malaysia for food and medicinal uses. This article reports on some physical and mechanical properties of T. indica timber. Timber specimens of a 15-year-old T. indica were tested for modulus of rupture (MOR), modulus of elasticity (MOE), compressive strength parallel to the grain, compressive strength perpendicular to the grain, shearing strength, Janka hardness and specific gravity according to BS 373 standard methods. The sapwood of T. indica is pale yellow to cream in colour and the heartwood is poorly distinguished. Planing of the timber produced good to excellent surfaces and was rated as easy. The green and air-dry MOR values were 79.9 and 95.3 N mm-2 respectively. The green and air-dry MOE values were 8530 N mm-2 and 8476 N mm-2 respectively. Janka hardness of T. indica was 4747 N, indicating a potential usage for high foot-traffic flooring such as for offices, showrooms, indoor sport arenas and restaurants. The specific gravity values were recorded in the range of 0.637 to 0.724.