The Ord Victoria Plain, an interim Australian bioregion, is located in the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

and

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

, comprising .IBRA Version 6.1
data The bioregion draws its name from the Ord River and the Victoria River.

Location and description

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

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...

al 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.

Flora

The plain is largely covered with Mitchell grass scattered with bloodwood ''

Eucalyptus ''Eucalyptus'' () is a genus of more than 700 species of flowering plants in the family Myrtaceae. Most species of ''Eucalyptus'' are trees, often Mallee (habit), mallees, and a few are shrubs. Along with several other genera in the tribe Eucalyp ...

'' / ''

Corymbia ''Corymbia'', commonly known as bloodwoods, is a genus of about one hundred species of tree that, along with ''Eucalyptus'', '' Angophora'' and several smaller groups, are referred to as eucalypts. Until 1990, corymbias were included in the g ...

'' trees, native bauhinia ('' Bauhinia cunninghamii'') and large patches of lancewood acacia (''

Acacia ''Acacia'', commonly known as wattles or acacias, is a genus of about of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa, South America, and Austral ...

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 ''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles, bottlebrushes or tea-trees (although the last name is also applied to species of '' Leptospermum''). They ...

''), river redgum (''

'') and river pandanus ('' Pandanus'').

Fauna

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 Skinks are a type of lizard belonging to the family (biology), family Scincidae, a family in the Taxonomic rank, infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one o ...

lizard the '. 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

honeyeater The honeyeaters are a large and diverse family, Meliphagidae, of small to medium-sized birds. The family includes the Australian chats, myzomelas, friarbirds, wattlebirds, miners and melidectes. They are most common in Australia and New Gui ...

Termite Termites are a group of detritivore, detritophagous Eusociality, eusocial cockroaches which consume a variety of Detritus, decaying plant material, generally in the form of wood, Plant litter, leaf litter, and Humus, soil humus. They are dist ...

s 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

has been discovered quite recently.

Threats and preservation

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.

Location and description

Flora

Fauna

Threats and preservation

See also

References

Further reading