Durable eucalypts in New Zealand
Early plantings in New Zealand did include a number of durable timber-producing species (Classes 1 or 2 in the Australian durability standard). However, the development of chemical treatment techniques for radiata pine, and the subsequent availability of relatively cheap, durable treated pine products, has meant limited interest in naturally durable timbers until recently.
We now know that chemical treatment of timber causes a range of environmental problems. A major problem is the disposal of CCA-treated timber - for example, disposal of broken CCA-treated posts from vineyards is a real headache for growers and local authorities. As a result, treated timbers are becoming unacceptable to many sectors and markets.
This leaves a large gap which can best be filled by naturally durable timbers.
The NZDFI is identifying the eucalypt species with most potential, and applying advanced tree breeding techniques learnt from decades of radiata pine research to produce improved planting stock. There has been very little formal genetic improvement work on any durable eucalypts to date, so the potential for improvement is huge.