Woodworker's Journal 2008-32-5, страница 36

African Imposter?

Khaya gradifoliola and K.senegalensis

By Tim Knight

This lovely African mahogany has rich coloration complementing its tight-grained appearance. But is it really a mahogany?

African mahogany is a name applied to a variety of species of African hardwoods in the genus Khaya. Each of the species are adapted to different conditions, and these conditions range from the tropical rainforests of the West Coast to the sub-Saharan dry lands of east Africa. Although in the same family as the American mahoganies (Swietenia spp.), scientists have long debated whether the African varieties are true mahogany. African mahogany can grow to heights exceeding 1 15 feet, with diameters exceeding five feet. Some of the species are widely planted as shade trees in their native Africa as well as Asia. Some are valued for medicinal purposes by natives. Mahogany was first used by Europeans as early as Cortez: it is recorded that he used mahogany to repair his ships. By 1750, American mahogany was widely used, and by 1880 exploitation of natural stands led to the search for alternatives. Exportation of African mahogany to America and Europe began around 1890 and has increased in volume ever since. United States imports of African mahogany increased almost fivefold from 1991 to 1998: from about 144,000 cubic feet in 1991 to about 710,000 cubic feet in 1998.

The bulk of the timber shipped in the past consisted of two species of African mahogany (K. ivorensis and K. anthotheca from the Ivory Coast, Gabon and Nigeria). These were the more tropical species and were low to moderate in density and pale to medium-red in color. As these species became more difficult to find, more recent exports have turned to K. grandifolia and K. senegalensis which are native to the Sudan, Uganda and French Guinea. They are generally more dense and darker in color and more closely resemble their American counterparts.

Due to very slow initial growth, pests and high costs, past attempts to establish plantations of African mahogany were not very successful. However, improved techniques through research, and concentration on K. senegalensis, has led to the establishment of this species in numerous plantations in Sri Lanka, Malaysia and, more recently, in the dry tropics of Australia. Around 1,235 acres of plantations have been established in Sri Lanka, with plans to increase

that by 500 acres each year. Similar efforts are underway in the other countries mentioned.

African mahogany is suffering from the same pressures as other tropical hardwoods in that over-exploitation and mismanagement is leading to a dwindling supply. Although the United States is the top importer of African mahogany, China will soon overtake that position as much furniture manufacturing has moved to that country. Hopefully, efforts to establish sizable acres of plantations will reduce pressures on the naturally occurring stands remaining. Jfr

for Sandor's bedside table on page 44.

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October 2008 Woodworker's Journal