Basic density and static bending properties of coppiced African rosewood (Pterocarpus erinaceus Poir) grown in the Savannah Zone of Ghana

Abstract

ABSTRACT African rosewood (Pterocarpus erinaceus Poir) is of economic importance for Ghana, and the Savannah Ecological Zone has the highest population of the species. But lack of information on the properties of coppiced wood of the species limits its use and leads to overexploitation of the non-coppiced ones. This current study aimed at evaluating basic density and static bending properties of the coppiced wood and the extent to which they are influenced by age and wood position in the tree, towards encouraging its utilization to supplement the non-coppiced ones. Ten trees of five age groups were sourced from natural forests in the zone and test specimens were taken from different tree sections. Density and bending properties were evaluated per the ASTM D143-48 standard and the BS 373 standard, respectively. Generally, basic density ranged from 477 kg/m3 to 803 kg/m3. MOE ranged from 12,233 N/mm2 to 18,958 N/mm2, whereas MOR ranged from 103 N/mm2 to 188 N/mm2. Both basic density and bending properties significantly (P < 0.05) increased with the ageing of the tree but decreased from the base to the top of the tree. Age, wood position in trees and their interactions cumulatively explained 98%, 99%, and 90% of the variabilities in density, MOE, and MOR, respectively. Basic density proved to be a good predictor of MOE (89% accuracy) and MOR (76% accuracy). Coppiced rosewood is recommended for use to supplement non-coppiced rosewood, especially for applications where static bending properties are the requirements. Additional property studies should be conducted on coppiced rosewood to enhance their adoption for utilization.