River redgum
Eucalyptus camaldulensis
Size of tree and type of forest
Its natural occurrence is the most widely distributed of all eucalypts. Although it is typically a riverine species, it is found throughout mainland Australia with the exception of southern parts of WA, the Nullabor plain, and most of the coastal fringe of Vic, NSW and Qld. It occurs along or near almost all seasonal watercourses in the arid and semi-arid areas and within proximity to many other streams and rivers in the south east of the continent, mainly on the inland side of the Great Dividing Range. It is the most common tree along the Murray River and its tributaries. River redgum grows in a wide range of climatic conditions, tolerating extremes of heat/cold and great variation in rainfall (150mm – 1250mm per year). In low rainfall areas it relies on seasonal flooding and/or the presence of a high water table.
Distinctive Features
A heavy-boled, spreading, canopied tree growing to between 20m and 40m tall. It is extensively planted throughout the world in arid and semi-arid areas. Under favourable conditions, early growth can be swift. Some provenances demonstrate salt tolerance. It does not exhibit strong apical dominance. As a consequence, the stem form is generally poor, hence has not been extensively used for sawn timber. It coppices well and has been known to coppice up to 6 times off the same stump.
Wood
description [more
info]
Heartwood is red to reddish-brown. Sapwood to 40mm wide and is distinct by its pale colour. Texture relatively fine and even. Grain usually interlocked and often wavy, producing an attractive ripple or ‘fiddleback’ pattern. Gum veins are common.
Leaves
The foliage varies from green to blue-green. Leaves are frequently very long and narrow. Seedling – opposite for around 4-6 pairs, then alternate, petiolate, broad lanceolate, elliptical or ovate (7.5-15 X 2.5-7cm, green, grayish-green or bluish.
Wood density [more info]
- Green – approx’ 1130kg/m-3.
- Air-dry – approx’ 900kg/m-3.
- Basic – approx’ 710 kg/m-3
Drying and shrinkage [more info]
Needs close stickering and weighted stacks when drying to minimize warping. Some collapse occurs. Shrinkage about 4% radial, 8% tangential and after reconditioning about 2.5% radial, 4.5% tangential.
Workability [more info]Necessary to adjust cutting angles when dressing due to the interlocked grain. Unsuitable for steam bending due to difficulty in obtaining straight-grained timber. Provided the grain is relatively straight it has good resistance to surface checking when exposed to the weather.
Durability [more info]
In-Ground – 2
Above-Ground – 1
Marine – 2
Termite resistant
| Class | Life years |
|---|---|
| 1 | More than 25 |
| 2 | 15 to 25 |
| 3 | 8 to 15 |
| 4 | Less than 8 |
Lyctus-susceptibility
Sapwood susceptible to attack by Lyctus borers.
Strength grouping and properties [more info]
S5 and SD5.
The classification is low because bending-strength is affected considerably by the grain which is noticeably interlocked.
Minimum values (Mpa) for green timber
| Strength Property | S1 | S2 | S3 | S4 | S5 | S6 | S7 |
|---|---|---|---|---|---|---|---|
| MOR | 103 | 86 | 73 | 62 | 52 | 43 | 36 |
| MOE | 1630 | 14200 | 12400 | 10700 | 9100 | 7900 | 6900 |
| MCS | 52 | 43 | 36 | 31 | 26 | 22 | 18 |
Minimum values (Mpa) for green timber
| Strength Property | SD1 | SD2 | SD3 | SD4 | SD5 | SD6 | SD7 | SD8 | MOR | 150 | 130 | 110 | 94 | 78 | 65 | 55 | 45 |
|---|---|---|---|---|---|---|---|---|
| MOE | 21500 | 18500 | 16000 | 14000 | 12500 | 10500 | 9100 | 7900 |
| MCS | 80 | 70 | 61 | 54 | 47 | 41 | 36 | 30 |
Strength Properties
| Strength Property | Green | Dry |
|---|---|---|
| MOR (MPa) | 64 | 101 |
| MOE (GPa) | 8 | 11 |
| MCS (MPa) | 33 | 55 |
| Impact (Izod value) (J) | 14 | 8.1 |
| Hardness (Janka) (kN) | 7.7 | 10 |
Uses [more
info]
It is hard, durable, resistant to termites and is often used for heavy construction, flooring, framing, fencing plywood, veneer manufacture, turnery, paneling, sills and posts.
Availability [more info]
Mainly in Victoria and south-western New South Wales.
References
- Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnson, RD, Kleinig, DA and Turner, JD (1984) Forest trees of Australia; Nelson, CSIRO. Melbourne.
- Bootle, KR (1983); Wood in Australia. Types, properties and uses. McGraw-Hill Book Company, Sydney.
- Cremer, KW (Ed). (1990); Trees for rural Australia. Inkata Press, Melbourne.
- Hillis, W.E. and Brown, A.G. (1984) Eucalypts for wood production. Academic Press, Melbourne.
- Standards Association of Australia (1986); Timber - Classification into strength groups. AS2878-1986.
