Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Preliminary observations on the utilisation and wood properties of plantation teak (Tectona grandis ) and African mahogany (Khaya senegalensis) grown near Kununurra, Western Australia.

Abstract

The wood properties and wood quality were assessed of single trees of 22-yr-old teak (Tectona grandis) and 8-yr-old African mahogany (Khaya senegalensis), grown in irrigated plantations in northern Western Australia. Logs were cut into 25 mm backsawn boards using a thin kerf 'Wood-mizer' bandsaw, and the boards dried to 7% moisture content in solar kilns. Basic wood properties (green density, basic density, air-dry density and shrinkage), as well as recoveries, sawing and drying behaviour and working properties (sawing, sanding, colour, planing, nailing and staining) were assessed. Green sawn recoveries for teak and African mahogany were 56.5 and 36.0%, respectively. The African mahogany logs were larger than the teak logs, but the fluted shape of the butt log reduced recovery. Teak had a mean basic density of 610 kg m-3 and mean air-dry density of 700 kg m-3 and African mahogany a mean basic density of 600 kg m-3 and a mean air-dry density of 680 kg m-3. The plantation teak was golden brown in colour with dark markings, and African mahogany a pale orange with pink streaks. Both species were glued with urea formaldehyde ('Grasp') by hand clamping and cold pressed for 24 h, and both had good working and staining properties. Nailing teak boards caused splitting, and drilling before nailing is recommended. In some cases, African mahogany boards may require drilling before nailing. The results indicate that the single sample of both species processed shows potential for value adding, and testing of a larger sample to confirm plantation versus natural grown material comparisons is recommended. Providing that a large plantation resource is developed in the region, considerable potential probably exists for a new industry based on these high value tropical timbers.