The Pilbara shrublands is a

deserts and xeric shrublands Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (Ancient Greek 'dry') shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this habitat ...

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

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 ...

. It is coterminous with the Pilbara

IBRA The Interim Biogeographic Regionalisation for Australia (IBRA) is a biogeography, biogeographic regionalisation of Australia developed by the Australian government's Department of Sustainability, Environment, Water, Population and Communities ( ...

region. For other definitions and uses of "Pilbara region" see

Pilbara The Pilbara () is a large, dry, sparsely populated regions of Western Australia, region in the north of Western Australia. It is known for its Indigenous Australians, Aboriginal people; wealth disparity; its ancient landscapes; the prevailing r ...

Geography

The Pilbara shrublands is bounded on the north by the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

, and on the west, south, and east by other deserts and xeric shrubland ecoregions - the Carnarvon xeric shrublands to the west, the Western Australian mulga shrublands to the south, and the Great Sandy-Tanami desert to the east and northeast. The

geographic region covers most of the ecoregion, and extends east into the Great Sandy desert. The

Hamersley Range The Hamersley Range is a mountainous region of the Pilbara region of Western Australia. The range was named on 12 June 1861 by explorer Francis Thomas Gregory after Edward Hamersley, a prominent promoter of his exploration expedition to the ...

, a region of mountain ranges and plateaus dissected by gorges, lies in the southern portion of the ecoregion. The Fortescue Plains extend east and west to the north of the Hamersley Range, forming the upper basin of the

Fortescue River The Fortescue River is an ephemeral river in the Pilbara region of Western Australia. It is the third longest river in the state. Course The river rises near Deadman Hill in the Ophthalmia Range about 30 km south of Newman, Western Austr ...

. The Chichester Plateau lies north of the Fortescue Plains. The Roebourne subregion encompasses the coastal plain along the Indian Ocean, including the Dampier Archipelago.Heterick, B.E., B. Durrant, and N.R. Gunawardene (2010). "The ant fauna of the Pilbara Bioregion, Western Australia". ''Records of the Western Australian Museum, Supplement'' 78: 157–167 (2010).Kendrick, Peter (2001). "Pilbara 3 (PIL3 – Hamersley subregion)". in ''A Biodiversity Audit of Western Australia’s 53 Biogeographical Subregions in 2002'', Department of Conservation and Land Management, Western Australia Government, October 2001. The ecoregion lies on the Pilbara craton, a block of ancient

Archean The Archean ( , also spelled Archaean or Archæan), in older sources sometimes called the Archaeozoic, is the second of the four geologic eons of Earth's history of Earth, history, preceded by the Hadean Eon and followed by the Proterozoic and t ...

rock. The Chichester region is characterized by exposed

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

and greenstone basement rocks. The Hamersley region includes iron-rich carbonate sedimentary carbonate rocks over a volcanic substrate (the Fortescue formation) which rest on the older craton. The Fortescue basin and coastal plain are alluvial.

Climate

The climate is tropical semi-desert. Rainfall averages 300 mm annually, typically from summer cyclonic storms and thunderstorms.

Flora

In the Hamersley region, mulga woodland occurs on fine-textured valley soils, with '' Acacia aneura'' over the grasses '' Aristida'' spp. and ''

Enneapogon ''Enneapogon'' is a Cosmopolitan distribution, cosmopolitan genus of plants in the Poaceae, grass family. They are also called bottle washers or pappus grass. These perennial grass species are found in tropical and warm temperate areas. They ha ...

'' spp. Snappy gum (''Eucalyptus leucophloia'') occurs with the grass '' Triodia brizoides'' on the skeletal soils of the ranges. The Fortescue Plains include the northernmost mulga woodlands, along with short grasslands. Year-round watercourses and springs support stands of red river gum, (''Eucalyptus camaldulensis refulgens''), ''

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 ...

'', and the palm '' Livistona alfredii''. Sheltered gorges along the edge of the Chichester Plateau provide water and protection from fire, and support relict communities of '' Terminalia, Erythrina'', and '' Ficus''.Kendrick, Peter (2001). "Pilbara 2 (PIL2 – Fortescue Plains subregion)". in ''A Biodiversity Audit of Western Australia’s 53 Biogeographical Subregions in 2002'', Department of Conservation and Land Management, Western Australia Government, October 2001. The Chichester Plateau is principally scrub steppe, with the shrub '' Acacia inaequilatera'' and the bunch grass '' Triodia wiseana''. Scrub steppe also dominates the Roebourne coastal plain, with '' Acacia translucens'' and '' Triodia pungens''. " Fairy circles" (known as "linyji" in the Manyjilyjarra language and "mingkirri" in the Warlpiri language) which are circular patches of land barren of plants, varying between 2 in diameter and often encircled by a ring of grass, are found in the western part of the Great Sandy Desert. It has not yet been proven what causes these formations, but one theory suggests that they have been built and inhabited by Australian harvester termites since the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

Fauna

Native animals include the red kangaroo (''Osphranter rufus''), bilby (''Macrotis lagotis''), northern quoll (''Dasyurus hallucatus''), Pilbara leaf-nosed bat (''Rhinonicteris aurantia'', Pilbara form), ghost bat (''Macroderma gigas''), Pilbara ningaui (''Ningaui timealeyi''), Pilbara olive python (''Liasis olivaceus barroni''), Pilbara bandy bandy (''Vermicella snelli''), and Airlie Island ctenotus (''Ctenotus angusticeps'')."Pilbara Conservation Strategy". Department of Parks and Wildlife,

Government of Western Australia The Government of Western Australia is the States and territories of Australia, Australian state democratic administrative authority of Western Australia. It is also commonly referred to as the WA Government or the Western Australian Governmen ...

. 2017

/ref> Rothschild's rock-wallaby (''Petrogale rothschildi''), Pilbara rock monitor (''Varanus pilbarensis''), Pilbara death adder (''Acanthophis wellsi''), Pilbara toadlet (''Uperoleia saxatilis''), and the Pilbara threadtail (''Nososticta pilbara'') are endemic to the ecoregion.

Subregions

Protected areas

6.47% of the ecoregion is in protected areas. Protected areas include: * Barrow Island Nature Reserve * Boodie, Double Middle Islands Nature Reserve * Cane River Conservation Park * Eighty Mile Beach Marine Park * Great Sandy Island Nature Reserve *

Karijini National Park Karijini National Park is an List of national parks of Australia, Australian national park centred in the Hamersley Ranges of the Pilbara region in the northwestern section of Western Australia. The park is located north of the Tropic of Capricor ...

* Lowendal Islands Nature Reserve * Millstream Chichester National Park * Montebello Islands Conservation Park * Montebello Islands Marine Park * Mungaroona Range Nature Reserve * Murujuga National Park

References

External links

* {{Interim Biogeographic Regionalisation for Australia (IBRA) Deserts and xeric shrublands Ecoregions of Western Australia IBRA regions Pilbara