Understanding blackwood (<i>Acacia melanoxylon</i>) markets; an opportunity for improving blackwood plantation returns

Authors: Ian Nicholas
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 2007, Issue N.Z.J.For. 52(3) 2007, pp 17-20, Nov 2007
Publisher: New Zealand Institute of Forestry

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Abstract: The most important wood characteristic recognised by processors and manufacturers of blackwood (Acacia melanoxylon) in Australia and New Zealand was colour and the most important issue was supply of logs and timber. Most of the trade in blackwood for high quality furniture or cabinetry is based on select or clear grades of timber, often in short lengths. This provides an opportunity for improving plantation returns through silviculture by producing long clear lengths of defect free heartwood timber.

The Australasian blackwood market is based on clear heartwood timber production. Markets for knotty material above the pruned butt log, such as flooring, have been identified as new markets with potential.

To maximise future value from blackwood stands, blackwood managers’ regimes should have the objective to maximise defect free heartwood. The current recommended regime is to have a stand with 200 stems/ha, pruned to 6 m with form pruning, clearwood pruning and thinning completed by age 10 years. A rotation length of 35 years is expected from fertile sites in New Zealand. Further analysis is needed to evaluate potential rotation lengths in Australia.

Evaluation of regime trials at age 18 years on five North Island sites in New Zealand show that wood quality is little affected by silviculture. Fast growing sites/regimes produce denser timber and a lowering of heartwood percentage, but have little influence on colour. Site had some influence on wood colour and other characteristics, but there was wide variation in the characteristics evaluated.

The poor conversion rates to timber from poor quality logs from native stands in Australia or untended stands in New Zealand provides an opportunity for premium prices from pruned good form plantation logs in the future. Therefore plantation management should be based on clearwood heartwood production for high quality furniture from well managed plantation grown blackwood.

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