Land Clearing
Vegetation - Clearing and Wildlife in the NT
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Vegetation-clearing trends
In many regions in eastern and western Australia, vegetation clearing for agriculture, forestry, or urban development has left less than 15% of the original vegetation intact. This is in stark contrast to the NT where, taken as a whole, less than 1% of the vegetation has been cleared.
Agriculture has had a difficult history in the NT, but is now expanding in several regions. In particular, in both the rural area of Darwin and the Daly River basin about 8% of vegetation has already been cleared and there are plans for many new farms.
Developments are also underway or being explored around Katherine, Alice Springs, Ti Tree, Mataranka, Melville Island and the Ord catchment.
 The Northern Quoll - this species has gone from the most fragmented areas |
Wildlife and Vegetation Clearance
Clearing vegetation has two main effects on animals and plants. Most importantly, their habitat is removed, but also the habitat that is left is usually restricted to small, unconnected patches. These habitat fragments can be too small to support some wildlife populations, which gradually disappear from them. On the other hand, some species can use or even prefer the new mix of habitats created by the vegetation clearing, but most of these tend to be common species.
 The Black-footed Tree-rat: a species that declines under woodland fragmentation. |
A study conducted by PWCNT in savanna woodlands in the NT found that nearly half the animal species in the woodlands showed a negative response to habitat fragmentation. That is to say, over and above the loss of habitat, they are less common in the remaining fragments than they are in unfragmented woodland. The worst affected species were medium-sized mammals such as the Northern Quoll and Black-footed Tree-rat, and small birds such as the Weebill and Striated Pardalote. One species in five had a positive response to fragmentation.
 A 15m wide corridor in the Darwin rural area. This is a valuable habitat for some species. |
The study found that several design rules could help to minimise the impact of clearing on animals.
- Retain native vegetation in all areas (30% of the landscape was recommended).
- Make fragments as large as possible (although all fragments have some value).
- Retain corridors between fragments (most animals use corridors).
Other Issues Relating to Vegetation Clearing
Retaining native vegetation has benefits other than for wildlife:
- It helps to prevent soil erosion and runoff of farm chemicals into the rivers.
- It helps to maintain water infiltration and prevent dryland salination.
- It is a wind-break and habitat for pollinators and predators of pests.
- It is a major attraction for a booming tourism industry.
Also, vegetation clearing is a major source of carbon emissions responsible for global warming. There is growing pressure internationally and within Australia to limit vegetation clearing.
A Vital Opportunity
We have a chance in the NT to avoid the environmental problems that have accompanied broad-scale clearing in other parts of Australia and overseas. By planning land uses on a regional scale, we can ensure that agriculture and towns can thrive while retaining most of the wildlife that occurred before development. To achieve this vision requires the co-operation of all sectors of the community: the government, the farmers and all the other residents of the NT. If we fail, the NT will eventually lose its unique character of the real outback Australia.
Further Information
In December 2002, the NT Government introduced new legislation to control clearing on freehold and Aboriginal lands.
- See the text of the study: Draft Guidelines for the Retention of Vegetation in Top End Woodlands (2001).
- Contact Dr. Owen Price at the Parks and Wildlife Service (P.O. Box 496, Palmerston, NT 0831 AUSTRALIA; Ph +61 (0)8 8944 8467).
