Once you have determined the type of bush you have on your property you will need to assess its health or condition. The overall condition of the bush will help you decide what management is necessary.
Threatened species
Threatened plants and animals are not necessarily found in bush in excellent condition. Gorse provides shelter for bandicoots and prevents the grazing of some threatened plant species such as Gunns stackhousia (
Stackhousia gunnii) and spur velleia (
Velleia paradoxa). In areas where the habitat has been extensively modified only degraded habitat may remain for some species. Lowland silver tussock grassland, a community that is almost extinct in Tasmania, is often represented by badly degraded remnants. Despite the degradation these remnants are essential habitat for the threatened Ptunarra brown butterfly.
If you suspect that you may have threatened species on your property please contact DPIPWE's Threatened Species Unit on
03 6165 4340 See
Threatened Species for more information.
General assessment of bush condition
Bush in all types of condition can be important. An area of bush in poor condition may be one of the few examples of its type that has survived and it may contain threatened species. Nevertheless, it is obviously better to have bush in excellent condition than bush in poor condition - as long as you do not destroy a population of threatened species in the process of improving it.
The condition of bush relates closely to its management needs. Bush in excellent condition has obviously been managed well and generally requires only a continuation of that management. Bush in good condition can generally be improved by modifying current management practices. Bush in poor condition usually requires active restoration measures to improve it.
To determine the condition of your bush you need to consider a number of things, including:
- the
health of the bush
- the presence or absence of widespread dead or dying trees
- the presence or absence of weeds, pests and diseases
- the presence or absence of soil erosion and land degradation
- the impact of your present management practices, including stocking levels, fire regimes, drainage of wetlands, gravel and sand mining, and nutrient drift from adjacent land.
Excellent condition
Bush in excellent condition is entirely or almost entirely composed of native species in all its layers. There may be occasional exotic annual grasses such as hair grass (
Aira species) or quivery grass (
Briza species), or exotic herbs such as flatweed (
Hypochoeris species and
Leontodon species). However, exotic shrubs such as gorse or broom are absent or rare. Woodlands and forests in excellent condition have a healthy tree layer, a healthy understorey, and some evidence of younger trees emerging in the gaps. Treeless vegetation in excellent condition has sufficient spaces between the tussocks or shrubs to allow smaller species to survive.
Good condition
Bush in good condition has native species providing more than half the cover in all the layers. The exotic grasses and herbs can generally be distinguished from the native grasses and herbs by their greener and wider leaves. Most of these exotic species are found in pastures and as weeds in gardens. The most common exotic shrubs are gorse, broom, hawthorn and briar rose. Woodlands and forests in good condition may have unhealthy trees and little evidence of tree regeneration in the gaps but the understorey will be dominated by a rich variety of native plants. Treeless vegetation in good condition may be dominated by natives but may have little space for smaller species between the tussocks or shrubs.
Poor condition
Bush in poor condition has exotic species comprising more than half the cover in at least one layer. If the trees are healthy there may be little or no regeneration in the gaps and an understorey dominated by exotics. If the trees are dying or dead there will also be little or no regeneration and the understorey will be dominated by exotic species.
Where native species comprise less than ten percent of the cover in all layers the area is no longer regarded as bush. However, some such areas may have populations of threatened species and therefore will be worthy of attention.