Biodiversity and Vegetation - Northern Territory

What major vegetation groups occurred in prior to European settlement?
What was the area of major vegetation groups in prior to European settlement?
Methods
Applications
Limitations
What major vegetation groups occur in (circa 1997)?
What is the area of major vegetation groups in (circa 1997)?
Methods
Applications
Limitations
What is the extent of native vegetation in ?
Methods
Limitations
Link to native vegetation information for 's bioregions
Knowledge, data and information gaps
References
Partnerships
Further information

Northern Territory

What major vegetation groups occurred in prior to European settlement?

Map: Pre-European Major Vegetation Groups in

Source:

Major vegetation groups V1.0 (1km), National Land and Water Resources Audit 2001. Data used are assumed to be correct from suppliers.

The summary maps provide information on Australia's native vegetation collated within the National Vegetation Information System (NVIS) at July 2001 and with additional mapped information. The NVIS will be updated as vegetation mapping becomes available.

The map is a compilation of data collected at different scales by different organisations. Major Vegetation Groups were compiled by Environment Australia based on data collated by the Bureau of Rural Sciences and provided by Environment ACT, Department of Urban Services; NSW National Parks and Wildlife Service; NSW Royal Botanic Gardens; NSW State Forests; NT Department of Infrastructure, Planning and Environment; Queensland Herbarium, Environmental Protection Agency; SA Department for Environment and Heritage; Tasmanian Department of Primary Industries, Water and Environment; Flora Section, Department of Natural Resources and Environment; Agriculture Western Australia; Western Australia Department of Conservation and Land Management and Geoscience Australia, National Mapping Division.

Map: Extent of the National Vegetation Information System data

What was the area of major vegetation groups in prior to European settlement?

Table 1: Area of vegetation groups in prior to European settlement
Major Vegetation Group	Area (km²)	% total extent
Rainforest and vine thickets	978	.1
Eucalyptus open forest	59,346	4.4
Eucalyptus low open forest	70	0
Eucalyptus woodlands	123,992	9.2
Acacia forest and woodlands	30,442	2.3
Melaleuca forest and woodlands	19,402	1.4
Other forests and woodlands	29,508	2.2
Eucalyptus open woodlands	175,842	13.1
Tropical Eucalyptus woodland/grasslands	109,430	8.1
Acacia open woodlands	48,814	3.6
Mallee woodlands and shrublands	35,450	2.6
Acacia shrublands	86,272	6.4
Other Shrublands	5,473	.4
Tussock grasslands	83,678	6.2
Hummock grasslands	490,363	36.4
Other grasslands, herblands, sedgelands and rushlands	7,666	.6
Chenopod shrub, samphire shrub and forblands	33,757	2.5
Mangroves, tidal mudflat, samphire and bare areas, claypan, sand, rock, salt lakes, lagoons, lakes	5,551	.4

Methods

The material below is an extract from the Australian Native Vegetation Assessment 2001 report. For ease of cross reference, figure, table and section references pertain to the chapter structure of this report. The Further Information section provides links to the full graphics version of the material below and the Australian Native Vegetation Assessment 2001 report.

Pre-European vegetation of Australia has been reconstructed using a variety of interpolation and modeling techniques from mapping and information on the present types and extent, historical records and early aerial photographs. It is assumed that Australia had experienced no significant clearing other than changes due to fire regimes prior to European settlement.

The underlying data used to describe the pre-European vegetation is in many cases the same as that representing the present vegetation. Some States and Territories have assumed that vegetation types mapped as pre-European vegetation also approximate the present vegetation.

This presents varying problems in interpreting changes in vegetation. There are very few areas in Australia that have not undergone some modification in species or structure following European settlement (e.g. changes in fire regime). Australian scientists are still developing systems and techniques to assess the condition and changes to condition of native vegetation.

In all states, adding the present vegetation data from the National Vegetation Information System to the available pre-European mapping provided the source for the pre-European major vegetation groups. In South Australia, New South Wales and Tasmania the pre-European vegetation is presented as an interim product to be used at broad State and national scales. In Tasmania the pre-European data set was derived from modelling techniques and is yet to be finalised.

The major vegetation groups that are mapped, represent the dominant vegetation occurring in a particular area.

Applications

The inferred pre-European vegetation mapping can provide:

a broad baseline to document change in the extent and type of native vegetation;
information to assist in understanding the landscape for management and conservation of biodiversity;
an understanding of native vegetation cover which, coupled with details on Australia's soils, topography and climate variability assists construction of a modelled; assessment of natural soil erosion. This then allows us to understand changes in soil erosion patterns that have accompanied land use and are now impacting on the condition of our rivers, estuaries and near shore zones (NLWRA in prep.);
species and vegetation community information to assist in regional revegetation activities; and
information to assist in understanding changes in water balance, the key driver of dryland salinity (NLWRA 2001a) and changes in catchment surface water hydrology (NLWRA 2001b).

Limitations

The variety of methods used to map pre-European vegetation, the scale of some of the data and the difficulty of mapping in fragmented landscapes has resulted in an Australia-wide map which presents a combination of very broad and detailed mapping.

Queensland, Western Australia, Victoria and the Northern Territory National Vegetation Information System data have the greatest reliability. The New South Wales, South Australia and Tasmanian data are interim products and provide a broad scale view of Australia's pre-European vegetation.

The Guidelines section of this report provides guidelines on the use of the information and Appendix 8 presents information on the sources of data that have been collated into the National Vegetation Information System to represent Australia's pre-European vegetation including the extent, scale and date of collection.

Figures 6 and 7 provide information on the location and extent of data sets, their scale and level of classification used to develop the major vegetation groups.

What major vegetation groups occur in (circa 1997)?

The Northern Territory has a diversity of vegetation that is maintained by its variety of climate and soils (Parks and Wildlife Commission, no date):

the climate gradually moves from seasonally wet tropical in the north to arid in the south; and
areas of rocky escarpment and plateau break a low relief landscape in the north while the south contains rocky ranges.

In the north, the vegetation is typically tropical savanna (eucalypt woodland and eucalypt open woodland with a grassy understorey). This landscape experiences dramatic seasonal changes with intense growth in the wet season (summer) and widespread fires in the dry season (winter). Famous worldwide for the tropical wetlands and rugged sandstone escarpments of Kakadu National Park the wetlands are of importance for conservation, providing breeding areas, habitat and refuge for important wildlife populations (Parks and Wildlife Commission, no date).

From the north a transition area moves from eucalypt woodlands into areas of melaleuca and acacia forests and woodlands and south into the spinifex (hummock grasslands), Mitchell grass (tussock grasslands) and acacia woodlands and shrublands. The vegetation increases in diversity around Alice Springs with areas of mulga, mallee, chenopods, hummock grasslands, small pockets of eucalypt woodlands and salt lakes.

The Northern Territory is the only area in Australia that does not have conspicuous temperate flora.

Bioregions in Northern Territory

Tiwi-Cobourg

This bioregion has gently sloping terrain and includes the mainland Cobourg Peninsula and the Tiwi Islands. It is within the tropical monsoonal north of Australia, with a distinct wet dry season and high temperatures throughout the year.

Dominated by eucalypt open forests and smaller areas of tropical eucalypt woodlands/grasslands and mangroves.
Patches of rainforest and vine thickets, acacia shrublands, samphire shrublands, melaleuca forests and woodlands and grasslands occur.

Major land uses are traditional Indigenous uses and nature conservation.

Arnhem Coast

This bioregion has gently undulating plains and low plateaus and is within the tropical monsoonal north of Australia, with distinct wet and dry seasons, and high temperatures throughout the year. It includes the northern Arnhem coast and Groote Eylandt.

Dominated by eucalypt open forests and tropical eucalypt woodlands/grasslands.
Patches of mangroves, melaleuca forests and woodlands and the grasslands group occur.

The major land use is traditional Indigenous use.

Darwin Coastal

This bioregion has gently undulating plains and is within the tropical monsoonal north of Australia, with a distinct wet dry season and high temperatures throughout the year. It includes the city of Darwin.

Dominant vegetation is eucalypt open forests, tropical eucalypt woodlands/grasslands, melaleuca forests and woodlands and grasslands group on the floodplains.
Patches of the mangroves group and other shrublands are present.

Major land uses are traditional Indigenous uses, nature conservation (including parts of Kakadu National Park and World Heritage Area and Litchfield National Park), urban and other intensive uses and grazing. Approximately 85 000 hectares have been cleared.

Pine Creek

This bioregion consists of hilly to rugged terrain and is within the tropical monsoonal belt of northern Australia.

Dominant vegetation is tropical eucalypt woodlands/grasslands with some eucalypt open forests, melaleuca forests and woodlands and rainforest and vine thickets.

The region has undergone some localised clearing and the major land uses are grazing, nature conservation (including parts of Kakadu National Park and World Heritage Area and Litchfield National Park), traditional Indigenous uses and other intensive uses including horticulture.

Arnhem Plateau

This bioregion consists of rugged dissected terrain and plateaus and is within the tropical monsoonal belt of northern Australia.

Dominant vegetation is eucalypt woodlands and open woodlands (spinifex understorey) with some eucalypt open forests and rainforest and vine thickets.

Major land uses are traditional Indigenous uses and nature conservation (including parts of Kakadu National Park and World Heritage Area).

Central Arnhem

This bioregion consists of gently sloping terrain and low hills and is within the tropical monsoonal belt of northern Australia.

Dominant vegetation is tropical eucalypt woodlands/grasslands and eucalypt open forests.
Smaller patches of eucalypt woodlands, melaleuca forests and woodlands and samphire shrublands on the coast are present.

The major land use is traditional Indigenous use.

Daly Basin

This bioregion consists of gently undulating plains and scattered low plateau remnants and has a tropical monsoonal climate with distinct wet and dry seasons and high temperatures throughout the year.

Dominant vegetation is tropical eucalypt woodlands/grasslands and eucalypt open forests.
Smaller patches of eucalypt woodlands and melaleuca forests and woodlands are present.

The major land use is grazing on native pastures and traditional Indigenous uses with some horticulture, grazing on modified pastures and nature conservation. The region has undergone some clearing (approximately 167 000 ha) for these developments.

Victoria Bonaparte

This region extends into Western Australia and consists of a number of basins and the interior is dominated by the Victoria River Plateau, a large highly dissected plateau up to about 350 m above sea level. It has a dry winter, warm monsoon climate.

Dominant vegetation is tropical eucalypt woodlands/grasslands, eucalypt open woodlands, tussock grasslands, eucalypt woodlands and melaleuca forests and woodlands.
Small patches of eucalypt open forests and samphire shrublands on the coast occur.

The major land use is grazing on native pastures, traditional Indigenous uses and nature conservation.

Ord-Victoria Plains

This bioregion extends into Western Australia and consists of level to gently undulating plains with scattered hills and a climate that is dry, hot and tropical with summer rainfall.

Dominant vegetation is eucalypt and open woodlands, hummock and tussock grasslands, other forests and woodlands (Terminalia and Lysiphyllum spp.) and small areas of acacia shrublands.

Major land uses are cattle grazing and some nature conservation (e.g. Gregory National Park).

Sturt Plateau

This bioregion consists of gently undulating plains with a hot, summer rainfall climate.

Dominated by eucalypt woodlands, acacia forests and woodlands (including lancewood-Acacia shirleyi), hummock grasslands, eucalypt open woodlands.
Small patches of melaleuca forests and woodlands, other forests and woodlands, acacia shrublands and tussock grasslands occur.

Major land uses are traditional Indigenous uses and cattle grazing.

Gulf Fall Uplands

This bioregion falls mainly in the Northern Territory with a very small part in Queensland. It consists of undulating terrain with scattered low steep hills and a dry, hot, summer rainfall climate.

Dominant vegetation is eucalypt woodlands in the north and eucalypt open woodlands in the south with small pockets of melaleuca and acacia and other forests and woodlands.

Major land uses are cattle grazing and traditional Indigenous uses.

Mitchell Grass Downs

This bioregion extends into Queensland and consists of undulating plains with deep heavy clay soils and a hot arid climate.

Dominant vegetation is tussock grasslands and eucalypt open woodlands in the north with small areas of chenopod shrublands, hummock grasslands, acacia open woodlands and low closed forests and woodlands.

Major land uses are cattle grazing (with much of the region dependent on the underlying Great Artesian Basin for water) and some nature conservation.

Davenport Murchison Ranges

The bioregion is characterised by a chain of rocky ranges and a hot and dry climate.

Dominant vegetation is eucalypt open woodlands and mallee woodlands and shrublands, with acacia open woodlands, acacia shrublands and hummock grasslands in the south.

Major land uses are grazing, traditional Indigenous uses, minimal use (vacant crown land) and some nature conservation.

Tanami Desert

This bioregion extends into Western Australia and consists of hills and ranges with sand plains and a hot arid climate with summer rain.

Dominant vegetation is hummock grasslands (Triodia spp.) with small areas of eucalypt open woodlands, tussock grasslands, low closed forests and closed shrublands, salt lakes, acacia shrublands and mallee communities.

Major land uses are traditional Indigenous uses, grazing and some minimal use and nature conservation (Puurta Co-Management Area).

Great Sandy Desert

This bioregion extends into Western Australia and includes extensive sand plains, dune fields, lakes and remnant rocky outcrops with a hot, arid climate. The monoliths Uluru and Kata Tjuta are in the very south-east of the bioregion.

Dominated by hummock grasslands with small areas of acacia shrublands, low closed forest and closed shrublands, lakes (Lake Neale and Lake Amadeus), eucalypt open woodlands and chenopod shrublands.

Major land uses are traditional Indigenous uses, grazing and nature conservation (including the Uluru-Kata Tjuta National Park and World Heritage Area).

Burt Plain

This bioregion consists of plains and low rocky ranges with an arid climate.

Dominant vegetation is acacia shrublands and open woodlands, and mallee woodlands and shrublands.
Small areas of eucalypt open woodlands occur in drainage depressions.

The major land use is cattle grazing with some traditional Indigenous uses.

Channel Country

This bioregion extends largely into Queensland and South Australia with a small area in New South Wales. It is characterised by low hills and braided river systems with an arid climate that has very dry, hot summers and short, dry winters.

Dominated by acacia open woodlands with some acacia shrublands, mallee communities, hummock grasslands and eucalypt open woodlands in the drainage depressions.

The major land use is cattle grazing.

Simpson-Strzelecki Desert

This bioregion extends into South Australia with small areas in Queensland and New South Wales. It consists of arid dune fields and sand plains.

Dominant vegetation is hummock grasslands with mallee woodlands and shrublands, chenopod shrublands, acacia open woodlands and eucalypt open woodlands in the north.

Major land uses are grazing, minimal use (vacant crown land) and traditional Indigenous uses.

Finke

This bioregion extends into South Australia and consists of arid sand plains, dissected uplands and valleys with a hot arid climate.

Dominated by hummock grasslands, chenopod shrublands and acacia shrublands.
Small areas of acacia open woodlands and eucalypt open woodlands occur.

The major land use is cattle grazing.

MacDonnell Ranges

This bioregion consists of high relief and foothills with an arid climate modified by the presence of the mountain ranges.

Dominated by hummock grasslands and acacia shrublands with small areas of acacia open woodlands and eucalypt open woodlands.

Major land uses are traditional Indigenous uses, nature conservation (including the Finke Gorge and West MacDonnell National Parks) and cattle grazing.

Central Ranges

This bioregion extends into Western Australia and South Australia and consists of ranges and sand plains and has an arid climate.

Dominated by hummock grasslands, chenopod shrublands, acacia shrublands and mallee woodlands and shrublands.

The major land use is traditional Indigenous uses.

Map: Major Vegetation Groups in (circa 1997)

Source:

Major vegetation groups V1.0 (1km), National Land and Water Resources Audit 2001. Data used are assumed to be correct from suppliers.

Map: Extent of the National Vegetation Information System data