Barkly Tableland

Barkly Tableland Northern Territory
Location of the Barkly Tablelands
Population:	6,330(2007) [1]
Area:	320000 km² (123,552.7 sq mi)
State District:	Barkly
Federal Division:	Lingiari

Brolgas, Brunette Downs station, Barkly Tableland, NT

The Barkly Tableland is a rolling plain of grassland which runs from the eastern part of the territory into western Queensland. It is one of the five regions in the Northern Territory, Australia and covers 283,648 km², 21% of the Northern Territory. The Barkly Tableland runs parallel to the southern shore of the Gulf of Carpentaria, from about Mount Isa, Queensland to near Daly Waters.

History

William Landsborough, discovered the tableland and named it after Sir Henry Barkly, then governor of Victoria.

In 1877 the overlander, Nathaniel Buchanan and Sam Croker crossed the Barkly Tableland and rode on to the Overland Telegraph Line opening new land for settlement. It was not until the introduction of generous leasing arrangements on the Barkly in the late 1870s that the region became more settled.^[2]

Harry Redford (Captain Starlight) in 1883 drove a mob of cattle to the Barkly and subsequently established Brunette Downs (then called Corella Creek), with outstations at Anthony Lagoon and Creswell Creek, for Macdonald, Smith and Co. In 1884, 2,500 cattle were driven to Brunette Downs and in 1885, Redford brought in 1,200 mixed cattle from Burketown.

Geography

The Barkly Tableland rises to more than 300 metres (1,000 feet) near the Queensland and Northern Territory border. Black soil plains cover much of the Barkly Tableland ^[3]. Rainfall in this inland area is low (350mm pa) and subject to extreme seasonal fluctuations with rains occurring from November to March during the hot (up to 40°C) summer. Winters are cool and frost may occur, especially in the southern section of the plain in Queensland.

The Barkly Tableland is a distinct physiographic province of the larger West Australian Shield division. It includes the Mueller Plateau and Sandover-Pituri Platform physiographic sections between the desert uplands in the west and Mount Isa, Queesnland in the east. The Tableland drains into the Gulf of Carpentaria via the Flinders River while the southwestern plains drain into Lake Eyre via the Diamantina River or into the Simpson Desert via the Georgina River which has its source on the Tableland. Mount Isa meanwhile is drained by the Leichardt River. Waterways on the Tableland itself are small as most water drains into the porous limetone, sometimes forming salt lakes such as Lake Buchanan in Queensland. Tarrabool Lake, the largest wooded swamp in tropical Australia, when completely filled, is located in the west of the Tablelands. Other important water sources on the downs are the artesian springs such as those of the Edgbaston Reserve.

The Barkly region, with a population of just over 5,900 people, has the lowest population of any region in the Northern Territory. Most live in the main towns of Tennant Creek and Renner Springs ^[4] Barkly has a diverse economy including agriculture, fishing, and defence but the main source of income is cattle ranching as the area includes some of the best beef cattle grazing country in the country. Some of the very large cattle stations located on the Tableland include Alexandria Station, Anthony Lagoon, Austral Downs, Avon Downs, Banka Banka, Brunette Downs, Creswell Downs, Eva Downs, Helen Springs, Newcastle Waters and Lake Nash.

The region attracts more than 140,000 tourists average each year.

Ecology

The dominant flora of the Tableland is semi-arid savanna of Mitchell Grass and the area forms most of the Mitchell Grass Downs ecoregion which covers an area running 1500 km from here southeast into the Channel Country of Queensland. To the south and west of these grasslands lies the central Australian desert. The grasslands are mostly used for cattle grazing and are home to some threatened species of plants and animals. The higher areas of Mount Isa and the Selwyn Range have their own unique wildlife.

Flora

Mitchell Grass is hardy with long roots so is well adapted to dry soils and periods of drought. The grasslands support other distinctive plants alongside the grasses but there are no areas of thick woodland, only acacia trees scattered across the plain.

Fauna

The habitat of the Mitchell Grass Downs is mostly a uniform cover of grassland and therefore does not support a great variety of wildlife ^[5]. The few mammals include the Brushtail Possum (Trichosurus vulpecula) and the Alexandria False Antechinus (Pseudantechinus mimulus), a small carnivorous marsupial found only in a number of small, isolated localities in northern Australia, including Alexandria Station on the Barkly Tableland. Meanwhile the section of the Mitchell grasslands in Queensland are home to another endangered marsupial the Julia Creek Dunnart.

There are healthy populations of grassland birds such as the Flock Bronzewing, while the endangered Night Parrot has been spotted in Diamantina National Park in Queensland. The seasonal wetlands of the downs are important habitats, particularly as breeding grounds for waterbirds. These include the Lake Tarabool swamp, Lake Woods, Lake Buchanan and Lake Galilee (Queensland).

There are also many snakes and other reptiles and amphibians adapted to the clay soils that crack in the long dry season and turn to mud after the rains. These include burrowing frogs that emerge to breed in the mud and the Long-haired Rat which irrupts in huge numbers after the monsoon and spreads across the grasslands. Endemic reptiles of the downs include the Dwarf Dtella gecko (Gehyra minuta), some species of Ctenotus and Lerista skinks, an agamid lizard (Pogona henrylawsoni), and a monitor lizard (Spencer's Goanna). The snakes include the Elapidae; Speckled Brown Snake (Pseudonaja guttata), Ingram's Brown Snake (Pseudonaja ingrami), and Collett's Snake, all of which are venomous. Insects include a number of endemic species of ant.

Threats and preservation

Some of the grassland is protected but most is pasture and although largely unspoilt is vulnerable to overgrazing, particularly areas of Queensland bluebush (Chenopodium auricomum). The downs are home to a number of endangered species and localised habitats that are threatened. Protected areas that contain areas of Mitchell grassland include in Northern Territory Connells Lagoon National Park and in Queensland: Astrebla Downs National Park, which is part of the national initiative to resuscitate the endangered bilby marsupial; ; Moorrinya National Park and Bladensburg National Park, both home to the Julia Creek Dunnart; Diamantina National Park; and White Mountains National Park which contains areas of desert uplands at the western edge of the tableland. The Mount Isa area is more or less unprotected except that part of it is in Boodjamulla National Park.

References

1. ^ Australian Bureau of Statistics (2 October 2008). "Australian Demographic Statistics" (PDF). http://www.ausstats.abs.gov.au/ausstats/subscriber.nsf/0/6C2E0D5EB9791D50CA2574D50014B9A0/$File/13627_2008.pdf. Retrieved 2008-06-24. 
2. ^ "Chisholm, Alec H.". The Australian Encyclopaedia. Sydney: Halstead Press. 1963. 
3. ^ Surface geology of Australia Retrieved on 2 September 2008
4. ^ Barkly Tablelands Region
5. ^ http://www.worldwildlife.org/wildworld/profiles/terrestrial/aa/aa0707_full.html

External links

• Barkly Tablelands info