The Great Western Woodlands is located in the southwest of Australia. The woodlands cover almost , a region larger in size than England and Wales combined. The boundary of the Great Western Woodlands runs from the Nullarbor Plain in the east to the Western Australian Wheatbelt in the west; from north of Esperance through to the inland mulga country and deserts that are found north of Kalgoorlie.
Researchers from the Australian National University, working with The Wilderness Society, established the region's boundaries based on satellite data of its natural ecosystems and vegetation types. The Great Western Woodlands' vegetation is botanically diverse, consisting of mature eucalypt woodlands dominating the landscape, interspersed with large areas of mallee, Shrublands and grasslands.
The Great Western Woodlands region is one of the world's "global biodiversity hotspots", the South West Western Australia Floristic Province, with new flora and fauna species still being discovered. Current research shows there are close to 3,500 plant species found in the Great Western Woodlands region; as many as half of these species are endemic to Southwest Australia. The region is also home to at least 49 species of mammals, 14 species of frogs, 138 species of reptiles and 215 species of birds.
The natural values of the Great Western Woodlands make the area a place of continental and global significance. Beyond this region's high rates of biodiversity, scientists have also established that the Great Western Woodlands region contains 950 million tonnes of carbon stored in the vegetation and soil.
The Great Western Woodlands is vulnerable to a number of threats including fire, feral animals, noxious weeds and fragmentation caused by ad hoc development.
History
Pre-European history and native title
Archaeological evidence shows that Aboriginal people have had a direct and continuous role in the maintenance and use of locations in the Great Western Woodlands region for at least 22,000 years.
There are around ten distinct Aboriginal language groups whose lands lie within or include parts of the Great Western Woodlands.
Land use by the Aboriginal people over so many years has directly influenced the characteristics of the environment that are observed today. These include, for example, the changes resulting from implementing different fire regimes across the landscape and specialised hunting practices. Aboriginal survival in this region required an intimate understanding of the landscape and the biota that lived within it. As an essential part of their life, the Aboriginal people of this region also constructed and maintained deep wells in order to access water.
Today, Indigenous communities with strong cultural and legal ties to country are located in many centres in the Great Western Woodlands. There are several native titles and land rights claims covering more than 95% of the landscape of the Great Western Woodlands area.
Since 2014, two major Indigenous native title claims covering parts of the woodlands have been determined in favour of the traditional owners – the Ngadju and Esperance Nyungar claims.
Geological history
The majority of the Great Western Woodlands sits atop the stable geological formation known as the Yilgarn craton, formed between 2,400 and 3,700 million years ago. This formation contains some of the oldest mineral deposits ever recorded on the Earth's surface. The region also has a series of geological intrusions running parallel to the Earth's surface, known as the greenstone belts. These formations house large quantities of gold and nickel, and also provide very rich and mineralised soils, which have led in part to the evolution of locally distinctive flora.
A major geological event in the history of the Great Western Woodlands was a period of glaciation that occurred between 250 and 330 million years ago. During this time, a massive ice-sheet covered most of Australia, flattening much of the landscape. Since then, the Great Western Woodlands region has remained undisturbed by glaciation, and the remaining granite outcrops are now significant landmarks.
Salt lakes are found throughout the Great Western Woodlands. These are remnants of ancient drainage systems (such as rivers) from about 65 million years ago, and are valuable habitats supporting a variety of vertebrates and invertebrates.
Conservation and science involvement
The name Great Western Woodlands was given to the region in 2004 by scientists from the Australian National University working with conservation groups. The name is intended to reflect the significant scale of the region, its western location, and its main ecological character. An appropriate Indigenous name is still being sought.
Since 2004, The Wilderness Society has worked with a wide range of organisations and local groups to increase public awareness of the scale and ecological value of the woodlands, the threats to its value, and options for improved protection and management.
Since 2005, other non-government environmental organisations and science organisations have become involved. They include Gondwana Link Inc, The Nature Conservancy and Pew Environmental Group, BirdLife Australia and CSIRO.
Characteristics
Boundary
The Great Western Woodlands covers close to , an area larger than England and Wales combined. Prior to 2006, the northern part of the region was often known locally as the Goldfields, with many local names used in the southern part.
Researchers at the Australian National University mapped the Great Western Woodlands boundary using satellite-derived Modis data. The boundary separates the eucalypt woodlands from the Acacia aneura complex dominated country to the north, the treeless Nullarbor Plain to the east, the higher rainfall coastal heath to the south east, and agricultural land to the west and south.
Land tenure
The dominant land tenure in the Great Western Woodlands is Unallocated Crown Land (UCL), which makes up 60% of the area. UCL is the lowest category of land classification under Western Australian state law – sometimes called "orphan country". Pastoral leases cover 20 % of the area. Conservation reserves of various types represent about 15% of the region, with Class A conservation protection over 3.6% of the land, Class B on 4.5% and Class C on 4.5%. Class B and C reserves have relatively little security of tenure, while Class A reserves require parliamentary approval for any tenure changes. The remaining land in the Great Western Woodlands is divided between shire reserves, Crown reserves and freehold land.
Biodiversity
More than 20% of Australia's flowering plant species and 30% of Australia's eucalyptus species are found within the Great Western Woodlands, making it a highly significant bioregion at a national and international level. Understanding of the Great Western Woodlands' biodiversity is still expanding through ongoing scientific work. The Great Western Woodlands account for a significant component of the plant diversity found in the Australia's South West Global Biodiversity Hotspot. One of the main reasons why the Great Western Woodlands is biologically rich is its position within the path of significant environmental gradients. It is located in the "interzone" between Australia's moist, cooler south-west corner and its desert interior. This means the region has elements of both these climatic zones, but has also created conditions to allow for natural speciation to occur.
Vegetation types
The Great Western Woodlands region is a matrix of four broad vegetation types: woodlands, mallee, grasslands and sandplain shrublands. Woodlands are the most common type of habitat, covering more than . Woodlands are defined as treed habitats that contain less than 30% canopy cover (in contrast, "forests" are defined as having greater than 30% canopy cover). Woodlands therefore resemble forests with greater distances between the trees, and more open canopies. Likewise, the understorey in woodlands is often very spacious compared to that of forests.
Flora
According to the Herbarium of Western Australia's records, there are 3,314 flowering plant species from 119 families and over 4,200 taxa (including undescribed species, subspecies, hybrids and varieties) recorded so far for the Great Western Woodlands. It is estimated that almost half of these species are endemic to the south west of Australia. This diversity can be attributed in part to the wide range of habitats throughout the region, from heavy soil valley floors, to sandplain, salt lakes, granite hills, banded ironstone hills, greenstone belt mosaics and many others. Each of these environments provides the conditions for unique types of flora. The amount of plant diversity in the Great Western Woodlands is comparable to the plant diversity in Canada, a country more than 60 times the size of this region.
Fauna
The Western Australian Museum and BirdLife Australia have recorded that within the Great Western Woodlands there are 49 species of mammals, 14 species of frogs, 138 species of reptiles, and 215 species of birds. As more biological surveys are done in the area it is expected that these numbers will grow. The region's high number of reptiles stands out as exceptional compared to other reptile communities around the world.
Some of the mammals found in the Great Western Woodlands region include the greater long-eared bat (Nyctophilus timoriensis), western brush wallaby (Macropus irma), red-tailed phascogale (Phascogale calura), and the western quoll or chuditch (Dasyurus geoffroii).
Reptiles found in the region include the carpet python (Morelia spilota imbricata), the western bearded dragon (Pogona minor minima), and the common slender blue tongue (Cyclodomorphus branchialis).
Birds found in the region include the Australian bustard (Ardeotis australis), the bush stone-curlew (Burhinus grallarius), Carnaby's cockatoo (Calyptorhynchus latirostris), and the malleefowl (Leipoa ocellata).
Threatened species
As part of the Great Western Woodlands overall biodiversity, the region is home to a variety of threatened species. Currently there are 44 plant species in the Great Western Woodlands that are listed as "declared rare flora" by the West Australian Government. In addition to this there are 422 "priority" species of flora in the region. Species are listed as "priority" if they appear in only small or limited populations, which are threatened. Such small populations can be due to plant life having very specific environmental tolerances or to plants being adapted to rare habitats. The classification can also indicate species that are poorly known, and in need of further survey work to establish their status.
The region is also home to many fauna species that are rare and vulnerable. There are 32 threatened vertebrate species on the endangered fauna list of the Western Australian Government, which include 16 mammals, 8 birds and 8 reptiles, all of which exist or are likely to exist in the Great Western Woodlands. Furthermore, the pig-footed bandicoot, the long-tailed hopping mouse, the crescent nail-tailed wallaby and the broad-faced potoroo that were once found in the Great Western Woodlands, are now considered globally extinct.
Human settlements, communities and economy
The Great Western Woodlands has been home to numerous Aboriginal language groups for thousands of years. This long-term management of the land by Aboriginal people has influenced the characteristics of the environment.
European prospectors discovered gold in the region in the late 1800s, which triggered a mining boom throughout the area. The population around this time increased to 50,000 people located in over 50 towns. Most people living in the area around this time were employed in the mining sector or other service related industries.