The koa tree, which many might know as acacia koa or Hawaiian koa, is native only to a few of the Hawaiian islands. For the tree to thrive, the elevation must be high enough to stay above the marine fog but low enough to not freeze. It needs lots of rain and ashy volcanic soil. It’s one of the first trees to grow back over young volcanic soil, and often dominates in Hawaiian forests.
Acacia koa is not yet considered endangered, but environmentalists and woodworkers alike are beginning to be concerned – only an estimated 10 percent of standing koa remains, compared to a century ago. That still amounts to tens of thousands of acres across the five islands, but the number of trees continues to shrink under the same old pressures of timber harvesting, urban expansion, agricultural clearing and cattle grazing.
Koa wood was popular with the ancient Hawaiians for wa’a (outrigger canoes) and papa he’e nalu (surfboards), and it remains popular today with woodworkers, boat-builders, and furniture makers. It’s especially popular with instrument makers, as a strikingly beautiful alternative to black walnut, which has a similar strength and density.
But for all that popularity, no one is growing it commercially. Trees take approximately thirty years to reach a useful size, making them an investment with a slow, uncertain return. This makes it difficult to attract the private sector to conservation efforts.
“They can’t look around at neighbors who have done it,” said James Friday, an extension forester at the University of Hawaii. “Nobody’s gone around and waited for decades.”
Hawaii’s Department of Land and Natural Resources estimates that, as things stand today, the current harvest of koa is at approximately 300 percent of what is sustainable. Demand is not likely to lessen, so it’s vital that steps be taken to ensure that koa forests can replenish, rather than dwindle past the point of no return.