It should be noted that this data is now somwhat dated!
The resilience and pristine quality of native vegetation areas is influenced
by the size of the surviving patches. Small areas are more vulnerable to
disease, fire, weed invasion and extinction. This affects native plant and
animal populations. Substantial patches of habitat are also required to
sustain larger native animals. Native vegetation extent has been derived from
mapping by the individual states at scales ranging from 1:25,000 to
1:1,000,000, with the more detailed mapping concentrated in intensively used
areas.
merged nationwide dataset was created at 1:200,000 and was used to create
the indicator. Methods and definitions of native vegetation vary between
states. The quality of areas of remnant treed vegetation was estimated as the
percentage of a catchment occupied by intact patches greater than 50 hectares
in extent. The higher the percent the better the catchment is with respect to
habitat.
The main forested and wooded areas with significant remnant patches are in
Tasmania, eastern Victoria, the near-coastal areas and escarpment ranges of
New South Wales, and Far North Queensland. There are significant forested
areas in southwest Western Australia, and wooded areas remain in the drier
part of the Avon catchments. similar picture emerges for the various scales.
The large majority of the Murray-Darling Basin, areas south and east of Port
Augusta in South Australia and the wheat belt in W have an indicated poor
condition. In western areas of the Murray-Darling Basin the area mapped as
poor condition is due to an initial absence of forested and wooded lands in
semi-arid and arid rangelands. Tasmania and northern Australia have the best
rating for retention of habitat.
Interpretation of this product should take into account the varying
methodology and scales. The reliability and precision of the data are
spatially variable.
Data are available as:
- continental maps at 5km (0.05 deg) cell resolution for the ILZ;
- spatial averages over CRES defined catchments (CRES, 2000) in the ILZ;
- spatial averages over the AWRC river basins in the ILZ.
See further metadata for more detail.
