Species selected for genetic improvement
The NZDFI’s tree improvement programme focuses on five species. Having a range of species reduces the risk from biotic and abiotic threats, and increases the potential choice of suitable site types. Having five species will also enable hybridisation between some species, combining their best genetic traits.
The Top Five
The ‘Top 5’ species with the most potential for New Zealand dryland sites are:
- E argophloia Western white gum
- E bosistoana Coast grey box
- E globoidea White stringybark
- E quadrangulata White-topped box gum
- E tricarpa Red iron bark
We have also established NZ seed stands for three more species: E. macrorhyncha (Red stringybark), E camaldulensis (Red river gum) and E cladocalyx (Sugar gum). Further tree improvement with these species is planned in due course.
We selected species on a range of criteria. Some have performed well in earlier New Zealand trials, others were chosen specifically for their heartwood colour and ability to hybridise. All species meet the following criteria:
- Class 1 or 2 durability (Australian standard)
- good growth
- good stiffness and strength properties
- drought resistant
- relatively good frost tolerance
- established timber potential from experience in Australian markets.