Species selected for genetic improvement
From a long-list of many potential durable eucalypt species, NZDFI has identified three species on which to focus breeding work, and a further four secondary species which will have some limited genetic improvement. A wider range of species has been planted in demonstration trials.
Selected species for breeding work
Primary species which are the focus of tree improvement work:
- E. bosistoana Coast grey box
- E. globoidea White stringybark
- E. quadrangulata White-topped box gum
Secondary species with limited genetic improvement work:
- E. argophloia Western white gum
- E. cladocalyx Sugar gum
- E. macrorhyncha Red stringybark
- E. tricarpa Red ironbark
The NZDFI believes it is important at this stage to work with a relatively large range of species, rather than narrowing its genetic improvement efforts down to only one or two species. This approach will reduce the risks associated with certain eucalypts’ vulnerability, for example, to frost or pests and diseases.
Species selection criteria
Some of the species were selected partly on performance in earlier trials; others were chosen specifically for their timber properties or ability to hybridise. All species meet the following criteria:
- Class 1 or 2 durability (Australian standard)
- Good growth
- Good stiffness and strength properties
- Drought resistance
- Relatively good frost tolerance
- Established timber potential from experience in Australian markets.