Physical Properties of Wood in Selected Lessor Known Tree Species in Botswana

Abstract

A study was carried out to evaluate physical properties of wood of four indigenous tree species. Samples were obtained at random from the logs at a timber and wood processing yard. Acacia burkea and S. Africana possess heartwood that is distinctly different in colour from the sapwood. Acacia burkeashowed very dark colour in the heartwood while that of Spirostachys africana was dark greyish brown in colour. Wood of P. africanum and Terminelia serecia displayed no dis-tinctly different colours between the sapwood and the heartwood. Density also varied in different woods with the highest density values recorded at 0.97 g cm 3 in the A. burkeaand the lowest was 0.70 g cm 3 in P. africanum. There were significant differences in densities between wood of all these species. The highest change in dimensions was recorded in the tangent side of all woods except for A. burkea. The highest dimensional changes were recorded at 9.02± 4.02 percentin the tangent side of P. africanum. The lowest dimensional changes were recorded at 0.41±0.08 percent in the longitudinal section of the P. africanumwood. Overall the lowest changes were recorded in the longitudinal side of wood.