Heathy woodland and forest has an understorey that is less than 2 m tall and dominated by small-leaved shrubs and/or bracken. Typical shrubs include acacias, heaths and legumes. The canopy may be dominated by a range of eucalypts. Most heathy black peppermint (Eucalyptus amygdalina
) woodlands and forests and silver peppermint (Eucalyptus tenuiramis
), candlebark (Eucalyptus rubida
) forests are classed as heathy woodland and forest. A number of other eucalypt woodland and forest types may also be classed as heathy woodland and forest, including Smithton peppermint (Eucalyptus nitida
), Tasmanian ironbark (Eucalyptus sieberi
), stringybark (Eucalyptus obliqua
), white peppermint (Eucalyptus pulchella
), white gum (Eucalyptus viminalis
), and lowland cabbage gum (Eucalyptus pauciflora
The trees in woodland are spaced such that the gaps between their crowns are wider than the crowns. The crowns are closer together in forest. The terms woodland and forest are used interchangeably and the management guidelines apply to both.
Heathy woodland and forest is usually associated with nutrient-poor sandy soils that form on sandstone, quartzite and sand sheets. However, heathy understories can also be found on shallow soils on dolerite where the rainfall is moderate to high.
Heathy woodland and forest grades into grassy woodland and forest at one end of its spectrum and shrubby forest at the other. Where these intergrades occur the forest type is often described as grassy/heathy woodland and forest and heathy/shrubby forest.
Where to see heathy woodland and forest
Heathy woodland and forest is most extensive in the north east and in the Furneaux Group of islands. It can be seen near the Pub With No Beer just south of Bothwell, Huntingfield just south of Hobart, Narawntapu National Park, Rocky Cape National Park, Freycinet National Park and Mt William National Park.
Biodiversity values of heathy woodland and forest
Heathy woodland and forest has been heavily cleared over the last 20 years and many of its vegetation communities are threatened. Heathy silver peppermint and heathy black peppermint forests are poorly reserved. Heathy candlebark forests are not protected in any state reserve. Only a few remnants of heathy cabbage gum woodland and forest survive. Refer to Threatened Species for more information.
Management issues in heathy woodland and forest
- Degradation of the understorey over time as a result of fire or fire followed by grazing.
- Weed invasion in bush in good or poor condition. It is also something to watch for in bush in excellent condition in order to prevent future weed invasion and subsequent degradation. In particular, woody weeds such as gorse and broom are a serious problem in heathy woodland and forest.
- Rural tree decline is becoming widespread in heathy woodland and forest.
If threatened species are present in your heathy woodland or forest you should consider their needs first. These needs may conflict with other aspects of management. Some threatened species are found in remnants that are in poor condition. This is because the past management regime has favoured their survival. If the management is changed these species may be lost.
Managing by condition
The best management regime for heathy woodland and forest will depend on the condition of the bush. Management guidelines based on the condition of the bush are given below. However, the specific needs of threatened plants may override these recommendations. If you are unsure what condition your bush is in refer to Condition of Your Bush
Heathy woodland and forest in excellent condition is characterised by:
- A healthy and diverse shrub layer. This bush is a profusion of colour in spring and it may be rich in orchids.
- Low levels of weed invasion.
This bush is an asset. Maintain your current management. There is no need to change your management practices unless there is an obvious reason to do so. However, if there are signs of weed invasion an active weed control program, particularly for gorse and broom, may be needed to maintain the integrity of the bush.
Heathy woodland and forest in good condition is characterised by:
- A limited number of species. There may be only a few native shrub species and the wildflower component will have almost disappeared.
- Weed invasion. Gorse can be a major problem in heathy woodland and forest. Broom is invading heathy bush on mudstone in the Oatlands district.
- Extensive areas of bare soil and erosion.
Management will need to focus on reducing stock levels so that the bush can recover. Destocking may be the best option in some situations. This will also reduce the risk of soil erosion by restoring a perennial ground cover. You may decide to limit access to sensitive areas through strategic fencing. These include areas with highly palatable species and areas where soil erosion is a problem.
Heathy woodland and forest in poor condition is characterised by:
- Little diversity in the ground cover.
- Extensive areas of bare ground.
- No regeneration of trees and shrubs.
- Severe weed problems, particularly gorse and broom.
- Heathy woodland and forest in poor condition usually recovers well through natural regeneration. You will probably need to destock for a number of years to allow the bush to recover. Once stock are excluded the results can be dramatic. Small wildflowers and orchids appear in areas where they have never been seen before. Shrubs and small trees may need two good seasons in succession to become established.
Management should aim to maximise regeneration in areas with poor understories or areas affected by rural tree decline. Where natural regeneration does occur, it is important to exclude stock and fire from the area until the saplings are tall enough to survive. Dense bracken can act as a nursery for young trees and shrubs by protecting them from grazing.
Consider rehabilitation in bush that is severely degraded, particularly if there is extensive erosion.
There will be little economic return from grazing heathy bush. It has a low nutritional value, a low stock carrying capacity, and the soils have low fertility. Heathy bush can provide shelter for off-shears and some winter grazing, but excluding stock is the best option. However, light grazing by sheep does not appear to harm heathy bush.
The recommended average interval between fires for heathy woodland and forest is 15-30 years. However, a range of fire intervals is best if biodiversity is to be maintained. Look at your patch of bush to determine the appropriate fire interval, keeping in mind the past fire regime.
For example, too frequent fires will increase the risk of bracken dominating and increase soil erosion causing bare ground.
Grazing too soon after fire will impede regeneration of the new plants. Keep stock out for at least five years after a fire if you are managing the area to maintain biodiversity or for tree regeneration.
Weeds in heathy woodland and forest
Woody weeds such as gorse and broom are the most serious weeds in heathy woodland and forest. See also Weeds on this site for more information.