There are several benefits in managing your own eucalypt forest. It can provide:

• Soil erosion control
• Wildlife habitats and corridors
• Employment
• Timber for building
• Cash flow

Management
Most areas of forest on private property in the region are in the regrowth phase and contain varying percentages of non-productive trees. To maximise returns from your forest, regardless of whether it is a few hectares or a few thousand hectares in size, you have to manage it in the same way as farmers manage their beef herd or crop of beans.

Forest types
Forests in this region can be divided into two basic groups: dry or moist sclerophyll.

Dry sclerophyll - These forests are composed of trees with hard leaves, eg. eucalypts such as spotted gum and ironbark, and have a shrub layer also consisting of hard leaved plants.

A feature of this forest is that most saplings develop from lignotubers which develop from seedlings. The lignotubers form shrubby growths that remain dormant for many years. When a gap occurs in the forest canopy, one stem from this growth will dominate and grow into a sapling and then a tree. These forests can be logged under a single tree selection system, because when a tree is removed, regeneration will occur in the gap. However, if maximum growth of the young tree is to be achieved, a gap of at least 70metres diameter should be created allowing sufficient light to fall on the young tree for good growth.

Moist sclerophyll - In these forests saplings develop directly from seeds. For this reason this type of forest requires substantial gaps in the canopy and soil disturbance, either by fire or physical means, for the trees to regenerate. This type of forest produces very few lignotuberous growths. If a gap does not occur the seeds either do not germinate or die soon after. These forests have to be logged in groups and the soil disturbed to allow regeneration to occur in the larger gap. Gaps need to be 75 to 100 metres in diameter.

Products
Unless you can sell the forest products you are growing, you are wasting your time in managing a private native forest for income. Different products have different values, so the higher the value of the product grown, the greater the return for your effort.

Poles - These are used as light, electricity or phone poles. They are the highest value product per cubic metre in native forests. They can also be logged sooner than the larger diameter sawlogs, and more per hectare can be grown. If possible, you should aim to grow trees to be sold as poles. Durable species such as ironbark, tallowwood and grey box are worth much more than non-durable species such as blackbutt. However spotted gum, a non-durable species, is sought after for pressure treatment. Pole trees are often only 20 to 30 years of age.

Veneer Logs - Some species including spotted gum and blackbutt maybe sold as veneer. Blackbutt and flooded gum are particularly sought after for export as rotary veneer, but a number of other species are utilised for domestic production or as sliced veneer. Veneer log harvesting operations would normally be integrated with pole or sawlog harvesting.

Sawlogs - These are cut up in sawmills for house timber or other sawn timber products. Their value varies with species, size, shape and defect. Again, the durable species such as tallowwood and ironbark are worth more than non-durable ones, but blackbutt is an exception. The larger and more defect-free the log, the greater its value per cubic metre. Small diameter, straight, solid logs are usually worth more than large defective logs.

Sleepers and fencing - Timber for these uses usually rates third in value. However, because they are often cut from defective logs or undesirable sawlog species such as bloodwood, these products are a profitable way of removing trees you find are not useful, or less desirable as timber trees.

Growth rates
As the average growth of healthy trees is about 0.5 cm in diameter a year at breast height (DBH), they will only grow 5 cm in diameter every 10 years. Some stands on good sites grow faster and some on poor sites grow slower, but 0.5 cm a year is a good average to plan on. Unhealthy trees with defective butts, dead limbs or mistletoe in the crown grow much more slowly and should be removed as soon as possible from your forest.

Harvesting timber
The ideal forest is one that can be harvested regularly. This means that in dry sclerophyll forest, a complete range of sizes occurs at all times with a lot of small trees, fewer medium ones, and even fewer large ones.

In the moist sclerophyll forests, there should be groups of different sizes which can be regularly thinned until the group is clearfallen. Remember, in this forest type, regeneration will not occur if only one tree is removed, so the regenerating groups have to be treated as a group until clearfallen. Groups should be of varying ages so that regular harvesting can take place.

The marking - Trees to be removed should be marked if you want your forest to give you a continued return. Those that are not marked are kept as the trees you will sell in the future. The best and healthiest trees grow the fastest and should be kept until they reach their optimum value before harvesting. Without tree marking, logging teams will naturally take the best, leaving you with a relatively low value stand with little potential. Remember, if they are healthy and actively growing, even large trees should be retained for harvesting at a later date if their value is still increasing.

Tree selection - In a forest managed for timber production, trees are harvested when they reach their maximum potential. Just as you would not keep a dry dairy cow or an infertile bull, you should not keep a tree that has also stopped 'paying the rent'.

To maximise your return, remove trees that:

• Have reached their highest value for the type of forest product you wish to produce. Every tree that could make a pole should be sold as a pole and not grown too big for a pole, or harvested for sleepers or fencing.
• Have become defective so their value will drop if they are kept. As trees age, defects can increase faster than growth.
• Are under attack by some injurious agent such as insects or mistletoe so that their growth rate is much slower than normal.
• Are inhibiting the growth of neighbouring trees of equal or better standard.

At each harvest keep trees that:

• Have not reached their highest value.
• Have not reached their maximum desired size. A tall tree may have the potential of growing into a long pole if left but could make a short pole now. It therefore has not reached its maximum desired size or value.
• Are not perfect but if removed will leave a stand that does not have the right size distribution for future crops.

Maximising your return
Assume you have 100 hectares of spotted gum/box type forest in good condition with the following volumes for sale:

• 1.5 cubic metres of poles/hectare
• 8.0 cubic metres of sawlogs/hectare
• 2.5 cubic metres of low quality logs/hectare

• Poles $70m³
• Logs $55m³
• Salvage $12m³

For high quality stands, particularly spotted gum, special sales such as for handle manufacture may attract considerably in excess of sawlog rates.

If managed properly, most stands can be logged at least every 10 years, as a new crop of pole size trees will have grown.

Conclusion
Forests are profitable, especially if you already have one growing in the bottom paddock. On most of our soils the return from forests is often higher than that of grazing, when the cost of clearing, pasture establishment and fertilising is considered. If you have a forest and are thinking of managing it for profit, consult first with a forester to develop a suitable management plan.

Peter Paunovic
State Forest of NSW

Updated October 2000

* These figures depend on market conditions, distance from mills, access to timber and topography of the area