The Brigalow Belt is a wide band of acacia-wooded grassland that runs between tropical rainforest of the coast and the semi-arid interior of Queensland and northern New South Wales, Australia. The
Interim Biogeographic Regionalisation for Australia (IBRA) divides the Brigalow Belt into two IBRA regions, or bioregions, Brigalow Belt North (BBN) and Brigalow Belt South (BBS). The North and South Brigalow Belt are two of the 85 bioregions across Australia and the 15 bioregions in Queensland. Together they form most of the Brigalow tropical savanna ecoregion.
Location and description
The Northern Brigalow Belt covers just over and runs from just north of
Townsville to Emerald and
Rockhampton on the Tropic of Capricorn, while the Southern Brigalow Belt runs from there down to the Queensland/New South Wales border and a little beyond, until the habitat becomes the
eucalyptus dominated Eastern Australian temperate forests.
This large, complex strip of countryside covers an area of undulating to rugged slopes, consisting of ranges as well as plains of ancient sand and clay deposits, basalt and alluvium. The Northern Brigalow Belt includes the coal producing Bowen Basin, with the nearby Drummond Basin and the fertile Peak Downs areas. The southern belt, which begins with the sandstone gorges of the Carnarvon Range of the Great Dividing Range, runs into the huge Great Artesian Basin. The south-west side includes the farming area of Darling Downs.
A number of important rivers drain the Brigalow Belt. The large Fitzroy River system and the Belyando River and Burdekin River rivers near the tropics all drain eastwards, while the south-western areas drain westwards into the Murray–Darling basin via the Maranoa River, Warrego River and .
In the north, there are tropical summer rains and warm weather all year round, while in the south the winter is slightly cooler and there is more rainfall outside of the summer months. Throughout the belt, the interior, with less than 500 mm of rainfall per year, is drier than the coast, which may have 750 mm or more.
Flora
The characteristic plant communities are woodlands of highly water stress tolerant brigalow (
Acacia harpophylla), a slender
acacia tree which thrives on the clay soil and once covered much of the area especially the fertile lowlands. Most of the brigalow has been cleared to make agricultural land, but the Queensland Bottle Tree is often left uncleared due to its leaves being fodder for cattle. Eucalypt woodlands of silver-leaved and narrow-leaved ironbarks, poplar box and other boxes, blackbutt and coolibah are also intact primarily on the higher slopes.
[Young, P.A.R., B.A. Wilson, J.C. McCosker, R.J. Fensham, G. Morgan, and P. M. Taylor. 1999. Brigalow Belt. Pages 11/1-11/81 in P. Sattler and R. Williams, editors. The Conservation Status of Queensland'
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Dichanthium grasslands are another typical habitat of the area while pockets of thicker woodland of brigalow mixed with Casuarina cristata and Cadellia occur in moister valleys and vine thickets, wetlands, and softwood scrubs are sometimes found although in their undeveloped state, these specialised micro-habitats are rare today. There is a particularly rich variety of habitats in areas such as Isla Gorge and Blackdown Tableland in the sandstone belt of the Carnarvon Range. The Northern Brigalow Belt is one of fifteen national biodiversity hotspots in Australia.
Fauna
The region is home to the unadorned rock-wallaby and the black-striped wallaby, which lives in the areas of vine thicket along with a wingless dung beetle ( Onthophagus apterus). Two endangered mammals are found in the Brigalow Belt; the bridled nail-tail wallaby in Taunton and Idalia National Parks, and the burrowing northern hairy-nosed wombat in the grassland and eucalyptus of Epping Forest National Park. There are also populations of dunnart, wallaby, bat and
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A variety of spiders and insects are found there, including Euoplos dignitas, an armoured trapdoor spider discovered in 2023.
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Threats and preservation
Together with the Mulga Lands, the Brigalow Belt are where most of Queensland's land clearing is occurring.[
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Protected areas
A little more than two per cent of the Brigalow Belt lies within national parks and other protected areas.
Subregions
IBRA of the Brigalow Belt North include Townsville Plains, Bogie River Hills, Cape River Hills, Beucazon Hills, Wyarra Hills, Northern Bowen Basin, Belyando Downs, Upper Belyando Floodout, Anakie Inlier, Basalt Downs, Isaac–Comet Downs, Nebo–Connors Ranges, South Drummond Basin and Marlborough Plains.
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Sattler, P. S. and R. D. Williams (1999) (eds) The Conservation Status of Queensland’s Bioregional ecosystems. Environmental Protection Agency, Brisbane
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IBRA Version 6.1 data. (Search in "Title" for "IBRA").
External links
