Indicators of Catchment Condition in the Intensive Land Use Zone of Australia – Native vegetation fragmentation

\n\nIt should be noted that this data is now somwhat dated!\n\nThe resilience and pristine quality of native vegetation areas is influenced\nby the size of the surviving patches. Small areas are more vulnerable to\ndisease, fire, weed invasion and extinction. This affects native plant and\nanimal populations. Substantial patches of habitat are also required to\nsustain larger native animals. Native vegetation extent has been derived from\nmapping by the individual states at scales ranging from 1:25,000 to\n1:1,000,000, with the more detailed mapping concentrated in intensively used\nareas.\n\n merged nationwide dataset was created at 1:200,000 and was used to create\nthe indicator. Methods and definitions of native vegetation vary between\nstates. The quality of areas of remnant treed vegetation was estimated as the\npercentage of a catchment occupied by intact patches greater than 50 hectares\nin extent. The higher the percent the better the catchment is with respect to\nhabitat.\n\nThe main forested and wooded areas with significant remnant patches are in\nTasmania, eastern Victoria, the near-coastal areas and escarpment ranges of\nNew South Wales, and Far North Queensland. There are significant forested\nareas in southwest Western Australia, and wooded areas remain in the drier\npart of the Avon catchments. similar picture emerges for the various scales.\n\nThe large majority of the Murray-Darling Basin, areas south and east of Port\nAugusta in South Australia and the wheat belt in W have an indicated poor\ncondition. In western areas of the Murray-Darling Basin the area mapped as\npoor condition is due to an initial absence of forested and wooded lands in\nsemi-arid and arid rangelands. Tasmania and northern Australia have the best\nrating for retention of habitat.\n\nInterpretation of this product should take into account the varying\nmethodology and scales. The reliability and precision of the data are\nspatially variable.\n\nData are available as:\n\n * continental maps at 5km (0.05 deg) cell resolution for the ILZ;\n * spatial averages over CRES defined catchments (CRES, 2000) in the ILZ;\n * spatial averages over the AWRC river basins in the ILZ.\n\nSee [further metadata](http://data.daff.gov.au/anrdl/metadata_files/pa_iccilr9ab\n__07021axx.xml) for more detail.\n\n