ALTERNATIVE TIMBER SPECIES - A REVIEW OF THEIR PROPERTIES AND USES

Abstract

As the timber species originating from natural forests have become limited in Sri Lanka, there is a growing concern of using timber species that originate from sources other than natural forests (sustainable sources) for construction and furniture. Popularization of a timber species depends on its technical properties as well as on its commercial properties such as availability. Timber property studies carried out on the species grown in Sri Lanka have been limited. This limited data, along with some primary data gathered in the present study on technical and commercial properties of these species, are presented. Key technical properties such as specific gravity, surface texture, shrinkage, workability and durability, and key commercial properties such as availability and price levels are presented along with the end uses.

The following timber species are suggested as alternative species, which have good prospects for construction, joinery and/or furniture in future: Albizia (Paraserianthes falcataria), Lunumidella (Melia dubia), Kadju (Anacardium occidentale), Toona (Cedrella toona), Cypress (Cupressus macrocarpa), Rubber (Hevea brasiliensis), Pinus species (Pinus caribaea, Pinus pilularis and Pinus insularis), Mango (Mangifera indica), Ginisapu (Michelia champaca), Sabukku (Gravillea robusta), Havarinuga (Alstonia macrophylla), Gansooriya (Thespesia populnea), Eucalyptus species (Eucalyptus grandis, Eucalyptus pilularis, Eucalyptus robusta, Eucalyptus microcorys, Eucalyptus citradora, Eucalyptus globulus and Rambutan (Nephelium lappaceum). Properties of three high rated popular alternative species, Teak (Tectona grandis), Mahogany (Swietenia macrophylla) and Jak (Artocarpus heterophyllus), are also presented for comparison.

Most of these species are fast growing, and have rotations of about 20-30 years, hence selection of suitable species from this list in establishing future forest plantations and agroforestry systems to meet the timber demand is recommended.