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Conservation of fauna and flora in the New South Wales wheatbelt
Issues for nature conservation in the New South Wales wheatbelt
- The wheatbelt of New South Wales is an economically important part of Australia, supporting both wheat and sheep, two of our most important exports.
- Much of the native vegetation has been cleared for agricultural production.
- Clearing has caused a decline in the diversity and abundance of native plants and animals that live in the wheatbelt.
- Clearing and subsequent cultivation of the land has also resulted in its degradation.
Where is the Wheatbelt of NSW?
Map of Australia with area of the NSW Wheatbelt highlighted in yellow
Why does clearing cause problems for native plants and animals?
- Clearing leads to a reduction in the total amount of native vegetation.
- Clearing usually occurs in many different places and leads to the breaking-up or "fragmentation" of the native vegeatation.
- Habitat fragmentation has two main effects:
- It leads to patches of native woodland becoming interspersed among farmland which causes isolation of native woodland remnants from one another.
- It increases the proportion of woodland which now borders farmland (ecologists refer to this as "edge habitat")
Reduction
A reduction in the amount of native vegetation means there is less for those plants and animals that depend upon it. Less land means fewer animals and fewer animals means smaller populations. Small populations are more vulnerable to extinction than large populations.
Isolation
 Isolation causes problems for native plants and animals because it means that the individuals living in one patch (called a "subpopulation") are physically separated from individuals living in other patches. If all the individuals in one patch die out because of a bushfire or overgrazing, the survivors in other patches may not be able to recolonise the empty patch and so the total number of individuals in the region is reduced.
As the native woodland is broken up or "fragmented" different sized patches of woodland are left. Small patches become essentially all edge habitat with no real interior (see diagram below) and therefore tend to be favoured by species like Noisy Miners and Australian Ravens which like to live in edge habitat. Some of these animals may therefore become more abundant in the landscape and have a negative effect on other species. For example, Noisy Miners are highly aggressive and drive out small birds. Australian Ravens may prey on the eggs of other species at a rate which leads to their decline. Large patches, which are now quite rare in the wheatbelt, have comparatively less edge and become the only areas with sufficient interior habitat to support species which rely on such interiors, like the Eastern Yellow Robin.
What is being done to solve these problems?
- Many people and groups such as Landcare are actively attempting to stop land degradation (such as salinity and erosion) by replanting.
- Replanting is also being conducted in order to connect existing remnants of vegetation which are presently isolated.
- The value of remaining patches of native vegetation is being recognised and efforts are being made to conserve them and protect them from degredation.
- More research is being conducted on remaining patches of native woodland and the native species in an effort to develop better management practices.
To help provide this information the Terrestrial Ecology section of the Australian Museum is carrying out the following research in the wheatbelt of New South Wales:
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