Great Victoria Desert

Category: Desert Biomes.

Geographic Location: Australia.

Summary: Covering a vast stretch of the Outback, the Great Victoria Desert is a harsh arid environment but one that supports great diversity of plant and animal species.

The Great Victoria Desert is one of the 10 largest deserts in the world and the largest Australian desert. Stretching some 430 miles (700 kilometers) from east to west in the states of South Australia and Western Australia, the desert covers an area of at least 164,000 square miles (424,400 square kilometers). It is bound by the Musgrave Range to the north, and by other deserts and shrublands, and is separated from the Indian Ocean by the limestone Nullarbor Plain to its south.

Dunes in the Great Victoria Desert generally run east-west and can vary between 16 to 66 feet (5 to 20 meters) in height, and up to 62 miles (100 kilometers) in length. Groundwater here is largely recharged by precipitation, which is unpredictable. Yearly rainfall average varies between 8 and 10 inches (20 and 25 centimeters). During summer, days are extremely hot, with average temperature ranging between 86 and 104 degrees F (30 and 40 degrees C), while in winter the range is 68–77 degrees F (20–25 degrees C). At night, temperatures can drop to the freezing point.

In spite of its harsh arid nature, the Great Victoria Desert does encompass some wetlands, including two—Yeo Lake and Lake Throssell—certified as of national significance by the Australian government. Both are considered in ecologically good condition; ongoing restoration of their habitats consists mainly of removal of remnant herds of domesticated grazing animals and of feral fauna such as rabbits, goats, foxes, and cats.

Two additional wetlands within the desert biome are Lake Minigwal and Lake Rason, both intermittent saline lakes. Here, too, the aftereffects of pastoral land use are being mitigated. Additionally, both of these wetlands, and Lake Minigwal in particular, have seen some hypersaline discharges into their waters due to mining activity; some structural hydrological mitigation is needed at Lake Minigwal to restore its habitat viability. All four of these areas have been subjected to invasive plant expansion, another ongoing threat.

Biota

The Great Victoria Desert is full of life. After a heavy rain, flowering plants break out in dizzying displays. A characteristic tree is the marble gum (Eucalyptus gonglocarpa), which can grow up to 66 feet (20 meters) tall. There are several species of eucalypts, also known as malles: The Ooldea mallee (Eucalyptus youngiana) has red or yellow flowers from June to October, while the kingsmill mallee (Eucalyptus kingsmillii) has white-cream or red flowers.

Among the acacia species is the western myall (Acacia papyrocarpa), an endemic (found only in this biome) tree which grows on limestone plains and attains heights of up to 23 feet (7 meters). The true mulga (Acacia aneura) is a tall tree with a life span of about 200 to 300 years.

Shrub species endemic to Australia are the bluebush (Maireana sedifolia) and bladder saltbush (Atriplex vesicaria). The latter grows around salt lakes, coastal dunes, and limestone ridges. The desert quandong (Santalum acuminatum) is a hemiparasitic tall bush; its shiny red fruit ripens in late spring and is used as an exotic flavoring. The bitter bush (Pittosporum phylliraeoides) is a native shrub to western Australia with white-cream flowers. It grows in sand, clay, and limestone; its fruit has medicinal properties to indigenous people. Spinifex and porcupine grass are among the most widespread ground vegetation across the biome.

Animals have adapted extraordinarily to the extreme environment. However, over the past 200 years, Australia has suffered as much as half of the world's mammal extinctions. Threatened species here include the sandhill dunnart (Sminthopsis psammophila), crest-tailed mulgara (Dasycercus cristicauda), and the southern marsupial mole (Notoryctes typhlops).

Birds of this biome include the endangered night parrot (Geopsittacus occidentalis). The vulnerable malleefowl (Leipoa ocellata) is a ground-dwelling bird that rarely flies. Among the reptiles, the desert hosts at least 100 species. One of them is the vulnerable great desert skink (Egernia kintorei), which was recently rediscovered after being considered extinct.

Human Interaction

The former dwellers of the Great Victoria Desert are traced back to around 24,000 years ago. Aboriginal groups of the western portion of the desert shared similar social structure and language. They developed survival skills to thrive with the limited water resources in the desert, from digging many wells and rock holes to store water, to finding water in the roots of trees, to damming water on the natural clay pans. The Ooldea Soak, a permanent freshwater oasis in the southern Great Victoria Desert, was one of the few well-known reliable sources of water. It became a trading and ceremonial gathering center.

European explorers of the 19th century made the stop at Ooldea Soak, as well as the intermittent Queen Victoria Spring and Empress Spring, both in the western reaches of the desert. Development in the Great Victoria Desert has tended to be limited to agricultural grazing and some mining activity. Additionally, nuclear weapons testing began here in the 1950s. One result of that episode was the granting of land titles to displaced indigenous peoples, an outcome that consequently helps preserve some parts of the biome.

Mamungari Conservation Park, formerly known as Unnamed Conservation Park, is one of the many efforts to preserve pristine wilderness and culturally significant areas. Straddling both the Great Victoria Desert and the Nullarbor Plain, it encompasses an area of about 8,260 square miles (21,400 square kilometers). Established in 1970, Mamungari was designated a World Biosphere Reserve in 1977.

Another conservation area is Queen Victoria Spring Nature Reserve, a vital watering and nesting area for many bird species. The reserve covers 667,000 acres (270,000 hectares) of mostly yellow sandplain habitat in the rugged hills of the western desert. Largest of the protected sites is the Great Victoria Desert Nature Reserve, comprising 6.2 million acres (2.5 million hectares) in the central-southern realm of the desert.

Global warming is projected to potentially lead to harsher temperature and moisture gradients, which could unbalance the desert's fire regime. The Great Victoria Desert, except for some swaths of the eastern desert, has in general been spared the worst effects of habitat fragmentation; this could change with increased fire severity. The number and intensity of fires in Australia have increased significantly in the 2020s due to climate change. Acacia (shrubs and trees) growing in much of the desert are a key species that would be a visible early indicator of habitat stress from fire regime alteration, drastic precipitation change, or incremental temperature rise.

Bibliography

Bryson, Bill. In a Sunburned Country. New York: Broadway, 2001.

Cogger, Harold G. Reptiles and Amphibians of Australia. Fort Myers, FL: Ralph Curtis Books, 2000.

Duncombe, Jenessa. "Dunes Dance to a New Rhythm in Climate Change." EOS, 17 Dec. 2021, eos.org/articles/dunes-dance-to-a-new-rhythm-in-climate-change. Accessed 6 Aug. 2022.

Greenslade, Penelope, Leo Joseph, and Rachel Barley, eds. The Great Victoria Desert. Adelaide: Nature Conservation Society of South Australia, 1986.