| Ord Victoria Plain Australia | |||||||||||||||
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 The interim Australian bioregions, with the Ord Victoria Plain in red | |||||||||||||||
| Area | 125,407.03 km2 (48,419.9 sq mi) | ||||||||||||||
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The Ord Victoria Plain, an interim Australian bioregion, is located in the Northern Territory and Western Australia, comprising 12,540,703 hectares (30,988,750 acres). [1] [2]
The bioregion draws its name from the Ord River and the Victoria River.
This is an area of large plains of dry grassland lying between the Tanami Desert to the south and the wetter, greener grassland to the north towards the coast. Sandstone outcrops rise from the grassland, the most famous of which is the Bungle Bungle Range in Purnululu National Park. The grasslands have long been used for cattle grazing. The climate is wetter in the north (ave annual rainfall 1200mm), which receives some coastal monsoonal rain, and drier in the south (ave 600mm). The rainy season is between November and March and the whole area is almost completely dry for the rest of the year and the climate is hot with maximum temperatures between 25 °C and 35 °C year round.
The plain is largely covered with Mitchell grass scattered with bloodwood Eucalyptus / Corymbia trees, native bauhinia ( Bauhinia cunninghamii ) and large patches of lancewood acacia ( Acacia shirleyi) woodland. The sandstone outcrops have thinner cover of eucalyptus over hummock grass or heathland scattered with Grevillea and Acacia trees. Riverine ecosystems around permanent water courses consist of paperbark ( Melaleuca ), river redgum ( Eucalyptus ) and river pandanus ( Pandanus ).
There are few endemic species as these grasslands are typical of much of northern Australia at this latitude but the grasslands are nonetheless largely intact and rich in wildlife. Mammals include the large common wallaroo, northern nail-tail wallaby (Onychogalea unguifera), and the long-tailed planigale which is the smallest marsupial in the world. The lancewoods are home to the spectacled hare-wallaby (Lagorchestes conspicillatus), while the Bungle Bungle has some unique plants and an endemic Lerista skink lizard the Lerista bunglebungle. Mammals that have become depleted or disappeared from these grasslands include the bilby (Macrotis lagotis), northern quoll (Dasyurus hallucatus) and golden bandicoot (Isoodon auratus).
Birds include Australian bustards, singing bushlark, and red-backed fairy-wren while there are important populations of purple-crowned fairywren (Malurus coronatus) along the rivers especially the Victoria. The eucalyptus trees are habitat for lorikeets, friarbirds, and honeyeaters. Termites are a source of food for many of these birds and animals. The wildlife of the grasslands is still being researched so for example a new species of Ctenotus skink has been discovered quite recently.
In general this is a large area of relatively unspoilt grassland used for grazing cattle. Some damage results from intensive cattle ranching leading to overgrazing and disrupting the traditional Aboriginal fire regimes in which the grasslands are systematically burnt and allowed to regenerate. Woodlands next to rivers and other water sources were severely altered when ranching began, causing siltation along the Ord River and destroying important habitat of the white-browed robin (Poecilodryas superciliosa) and the purple-crowned fairywren. Habitats have also been damaged by introduced species of plants such as bellyache bush ( Jatropha gossypifolia), and castor oil plant (Ricinus communis). There are some protected areas, mainly other types of habitat rather than grazing land. Areas such as the caves of Gregory National Park are still being researched by botanists and zoologists. [3]
The Carnarvon xeric shrublands is a deserts and xeric shrublands ecoregion of Western Australia. The ecoregion is coterminous with the Carnarvon Interim Biogeographic Regionalisation for Australia (IBRA) bioregion.
The Murchison is a loosely defined area of Western Australia located within the interior of the Mid West region. It was the subject of a major gold rush in the 1890s and remains a significant mining district. The Murchison is also included as an interim Australian bioregion. The bioregion is loosely related to the catchment area of the Murchison River and has an area of 281,205 square kilometres (108,574 sq mi).
The Barkly Tableland is a region in the Central East if the Northern Territory, extending into Western Queensland. The region was named after Sir Henry Barkly. The epithet “Tableland” is inaccurate, since the region is neither elevated relative to adjacent landforms, nor are the boundaries marked by a distinct change in elevation.
Esperance Plains, also known as Eyre Botanical District, is a biogeographic region in southern Western Australia on the south coast between the Avon Wheatbelt and Hampton bioregions, and bordered to the north by the Mallee region. It is a plain punctuated by granite and quartz outcrops and ranges, with a semi-arid Mediterranean climate and vegetation consisting mostly of mallee-heath and proteaceous scrub. About half of the region has been cleared for intensive agriculture. Recognised as a bioregion under the Interim Biogeographic Regionalisation for Australia (IBRA), it was first defined by John Stanley Beard in 1980.
Mallee, also known as Roe Botanical District, is a biogeographic region in southern Western Australia. Located between the Esperance Plains, Avon Wheatbelt and Coolgardie bioregions, it has a low, gently undulating topography, a semi-arid mediterranean climate, and extensive Eucalyptus mallee vegetation. It has an area of 73,975.59 square kilometres (28,562.13 sq mi). About half of the region has been cleared for intensive agriculture. Recognised as a region under the Interim Biogeographic Regionalisation for Australia (IBRA), it was first defined by John Stanley Beard in 1980.
The Avon Wheatbelt is a bioregion in Western Australia. It has an area of 9,517,104 hectares. It is considered part of the larger Southwest Australia savanna ecoregion.
Coolgardie is an Australian bioregion consisting of an area of low hills and plains of infertile sandy soil in Western Australia. It has an area of 129,122.09 square kilometres (49,854.32 sq mi). It includes much of the Great Western Woodlands.
Hampton is an interim Australian bioregion located in southeastern coastal Western Australia, with a small portion (4%) extending into adjacent South Australia. It has an area of 1,088,198 hectares. The Hampton bioregion is part of the Coolgardie woodlands ecoregion.
Yalgoo is an interim Australian bioregion located in Western Australia. It has an area of 5,087,577 hectares. The bioregion, together with the Avon Wheatbelt and Geraldton Sandplains bioregions, is part of the larger Southwest Australia savanna ecoregion as classified by the World Wildlife Fund.
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.
The Kimberley tropical savanna is a tropical and subtropical grasslands, savannas, and shrublands ecoregion in northwestern Australia, covering portions of Western Australia and the Northern Territory south of the Timor Sea.
The Einasleigh Uplands is an interim Australian bioregion, with vegetation consisting of savanna and woodland located on a large plateau in inland Queensland, Australia. It corresponds to the Einasleigh Uplands savanna ecoregion, as identified by the World Wildlife Fund.
The Victoria Plains tropical savanna is a tropical and subtropical grasslands, savannas, and shrublands ecoregion in northwestern Australia.
The Eyre Yorke Block, also known as the Eyre and Yorke mallee, is an interim Australian (IBRA) bioregion and a World Wildlife Fund ecoregion covering part of the Eyre Peninsula and all of Yorke Peninsula as well as land to its immediate east in South Australia.
The Central Ranges xeric scrub is a deserts and xeric shrublands ecoregion of Australia.
The Western Australian Mulga shrublands is a deserts and xeric shrublands ecoregion of inland Western Australia. It is one of Australia's two mulga ecoregions, characterized by dry woodlands of mulga trees interspersed with areas of grassland and scrub.
The Daly Basin, an interim Australian bioregion, is located in the Northern Territory, comprising an area of 2,092,229 hectares of central Arnhem Land in the Top End of the Northern Territory.
Gawler is an interim Australian bioregion located in South Australia. It has an area of 12,002,883 hectares. Gawler bioregion is part of the Tirari–Sturt stony desert ecoregion.
The Southern Volcanic Plain is an interim Australian bioregion located in western Victoria and south-eastern South Australia. It has an area of 2,440,340 hectares. The Southern Volcanic Plain bioregion is part of the Southeast Australia temperate forests ecoregion. The Natural Temperate Grassland of the Victorian Volcanic Plain lies on the plain.
