Comparison of density and selected microscopic characteristics of stem and branch wood of two commercial trees in Ghana

Abstract

The objective of this study was to investigate density and some microscopic characteristics (fibre length, vessel lumen diameter, and vessel, fibre and parenchyma proportions) of stem and branch wood of Terminalia superba (ofram) and Pterygota macrocarpa (koto). Branch and stem wood samples were obtained from two natural forest reserves. Wood density was determined in accordance with ISO 3131, whereas the anatomical investigations followed the IAWA Committee 1989 recommendations. The results indicated that at 5 % level of significance, wood density was significantly higher (p 0.1) in the branch wood of koto than that of their respective stem wood counterparts. For both species, significant difference (p 0.1) was found in ray parenchyma proportion. Branch wood density correlated significantly and positively with only fibre (r = 0.216, p < 0.05) and axial parenchyma (r = 0.286, p < 0.05) proportions but stem wood density correlated significantly and positively with fibre length (r = 0.417, p < 0.01) and fibre proportion (r = 0.490, p < 0.01) but negatively with vessel proportion (r = −0.669, p < 0.01) and vessel lumen diameter (r = −0.291, p < 0.05). The results from the present study indicated that the position of wood in a tree (stem or branch) is a factor for consideration in processing and utilizing the two species as the fibre length, vessel lumen diameter, and vessel and fibre proportions affect the strength, porosity, leachability, natural durability and drying of the lumber.