Indicator: BD-16 The proportion and area of native vegetation and changes over time

Data

Major vegetation groups

Prior to European settlement native vegetation covered most of Australia but now only 87% of the country is vegetated by native species. Most of the change has been from clearing of forests and woodlands, which originally covered 54% of the country and now covers 42% of the country. The following table provides a more detailed analysis of vegetation remaining.

Areas of estimated pre-1750 and remaining (2001-04)* vegetation in Australia (km)
percentage of remaining vegetation in reserves
Major Vegetation Group Estimated pre-1750 area (km) Area remaining (km) Percentage Remaining Percentage of remaining vegetation in reserves
Rainforest and vine thickets 53 469 35 200 65.8 54.4
Eucalyptus tall open forest 40 801 35 344 86.6 33.6
Eucalyptus open forest 394 280 272 121 69.0 22.7
Eucalyptus low open forest 4 726 3 952 83.6 35.1
Eucalyptus woodlands 1 362 263 892 920 65.5 8.1
Acacia forests and woodlands 495 059 408 632 82.5 8.8
Callitris forests and woodlands 40 278 32 296 80.2 6.1
Casuarina forests and woodlands 166 303 149 262 89.8 18.5
Melaleuca forests and woodlands 106 057 99 561 93.9 10.1
Other forests and woodlands 80 772 72 414 89.7 9.9
Eucalyptus open woodlands 498 663 458 905 92.0 6.2
Tropical eucalypt woodlands/grasslands 115 503 112 481 97.4 12.8
Acacia open woodlands 320 981 314 040 97.8 7.6
Mallee woodlands and shrublands 387 230 271 529 70.1 36.8
Low closed forest and tall closed shrublands 25 819 16 278 63.0 30.5
Acacia shrublands 865 845 851 274 98.3 10.0
Other shrublands 157 530 123 464 78.4 18.7
Heath 9 256 8 071 87.2 44.1
Tussock grasslands 559 850 525 888 93.9 3.0
Hummock grasslands 1 368 861 1 367 973 99.9 9.9
Other grasslands, herblands, sedgelands and rushlands 67 977 64 810 95.3 17.2
Chenopod shrublands, samphire shrubs and forblands 447 239 436 801 97.7 12.6
Mangroves 9 664 9 325 96.5 33.1
Total 7 578 427 6 562 541 86.6 11.5

* except for the NSW component, where most data are from 1997;

Source: Department of the Environment and Heritage 2006, National Vegetation Information System (NVIS) Stage 1, Version 3.0 Major Vegetation Groups, viewed 30 May 2006, http://www.deh.gov.au/erin/nvis/mvg/index.html, National Reserve System Programme Priority Review 2006 (in prep.) Parks Australia, DEH, Canberra.

Replace 20_veg_remaining_figure.xls with 20_veg_remaining_figure2.xls (Chart 1)

Insert map (from Matt Bolton)

Insert map (from Matt Bolton)

Current extent of woody vegetation

Insert map from document 20_veg_remaining_map1

What the data mean

About 87% of Australia’s estimated pre-1750 vegetation remains although clearing has not been uniform across major vegetation types. It is the densely settled coastal, temperate regions (originally mainly native forest and woodland), particularly on the eastern coast of the continent, that have lost most of their vegetation. Of the 13% of Australia’s original vegetation that has been lost since European settlement, most has been forests and woodlands - almost a quarter of Australia’s native forests and woodland has been cleared, mainly in what is now the intensive land use zone. It is generally assumed that more complex and species rich ecological communities are present in forest and woodland areas than in sparsely vegetated arid areas.

Many vegetation types have undergone significant changes since European arrival. ‘Low closed forest and tall closed shrublands’, for example, was uncommon and now is even more so, with only 63% remaining. About 66% of ‘rainforest and vine thickets’, remains. The rarest pre-European vegetation type was ‘Eucalyptus low open forest’ - about 83% remains. The most widespread pre-European vegetation type was hummock grasslands (covering about 18% of Australia) and most of it still remains although its condition and density of hummocks may have decreased due to grazing, weeds and other pressures.

Data Limitations

Methodologies for deriving quantitative assessments of the status of Australia’s native vegetation vary considerably.

The data does not indicate condition of the vegetation.

Woody vegetation is defined as vegetation with at least 20% canopy cover and potentially 2 metres tall.

The woody clearing and regrowth data is 'AGO Version May 2006', and are assumed correct at the time of supply.

The NLWRA reports that native plantings and small native remnants have not been included in its assessment.

The following table shows the NLWRA 2001 assessment of estimated pre-1750 vegetation (by major vegetation type) and the more recent NVIS assessment of estimated pre-1750 vegetation, with the Audit’s 2001 assessment of current vegetation and the NVIS 2005 assessment of current vegetation. The table shows the difficulty showing recent vegetation trends while methodologies for data collection and data interpretation continue to improve.

COMPARATIVE SUMMARY OF NLWRA AND NVIS DATA: PRE-EUROPEAN, AUDIT 2001 ASSESSMENT AND NVIS 2005 ASSESSMENT
Pre-European
(NLWRA 2001 assessment)
Pre-European (NVIS 2005 assessment) NLWRA 2001 assessment
(Data date 1997)
NVIS 2005
(Data date 2001-2004 excl. NSW 1997-2004)
Forest & woodland (inc. some associated shrub, heath and grassland) 3 724 754 4 092 204 2 878 795 3 174 935
Other shrub and heath 1 397 105 1 480 675 1 331 481 1 419 610
Hummock grass 1 756 962 1 368 861 1 756 104 1 367 973
Tussock grass 589 212 559 850 528 998 525 888
Other grassland 100 504 67 977 98 523 64 810
Other (inc. bare ground, water bodies, mangroves, etc) 112 063 106 999
Cleared/modified Nil Nil 982 051

Further Information