Farm Forestry New ZealandClosely related to E. botryoides, producing a rich red moderately durable heartwood. Excellent growth rates and form, sometimes superior to radiata pine. Not as resilient to wind as E. botryoides and prefers sheltered valleys with deep soil. Does not require good soil drainage or fertility but prefers deep soils.
Health: Susceptible to a range of insect pests. There are provenances available in Northland with some resistance to these. Susceptible to browsing by possums at all ages.
Timber: Medium density. Heartwood red with straight grain, decorative and hard. Large logs are preferred by processors because of low sawn recoveries resulting from a large core of compression wood along with a wide sapwood band. The heartwood is moderately durable and suitable for decking, flooring and structural applications. Potential for structural products such as appearance glulam, because of excellent stiffness properties. Because the sapwood is white, this is usually excluded for appearance applications. The sapwood is susceptible to lyctus borer so would require boron treatment for internal applications.
| Species | Density (dry) | Bending strength, MoR (MPa) | Stiffness, MoE (GPa) | Hardness, Janka (kN) |
|---|---|---|---|---|
| Eucalyptus saligna, Sydney blue gum | 675 | 100 | 13.5 | 6.75 |
Siting: E. saligna grows best in moist sites and can tolerate fairly poor soil drainage. It also grows well in low fertility soils, provided there is some soil depth. Fairly adaptable to a wide range of soil conditions, including heavy clays. Best form is in sheltered sites. Intolerant of wind exposure (can suffer from limb and top breakages).
Steep slopes: Suitable for the bottom of steep slopes and reasonably sheltered mid-slopes with good levels of soil moisture, a coppicing species with fast growth rates. Well-suited to continuous cover forestry because of high timber value, adaptability to a range of sites and fast growth rates.
Species characteristics: Fast growing, yielding a high quality rich red heartwood but with low sawn recoveries. Prefers sites with good soil moisture and can grow in poorly drained (but not swampy) soils.
Recommended regime: Plant at 1600-2000 stems per hectare. Thin in 3-4 stages down to 400-600 stems per hectare. This gives a 4:1 thinning ratio. Because available seedlines are unimproved, a high initial stocking is recommended for a sufficiently high thinning ratio and greater selection for growth and form. Lower tree stockings require costly form pruning for sufficient quality in residual crop trees.
For clearwood production prune potential crop trees to 6-8m in 3-4 lifts and thin down to 300 pruned stems per hectare. However, although pruning improves grade recoveries from those logs, this is not necessary to produce clearwood because eucalypt trees self-prune provided tree stocking is sufficiently high to induce this. The tradeoff is between the cost of pruning and higher establishment costs. A higher thinning ratio also provides greater selection for growth and form.
Key message: Best planted on sheltered moderately fertile sites with good soil depth and moisture, but adaptable to a range of soil conditions. A high initial stocking is recommended for selection of well formed, fast growing trees and self-pruning.
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