Mallee Woodlands and Shrublands is one of 32 Major Vegetation Groups defined by the Australian Government

Department of the Environment and Energy The Department of the Environment and Energy (DEE) was an Australian government department in existence between 2016 and 2020. The department was responsible for matters including environment protection and conservation of biodiversity as well ...

Description

" Mallee" refers to the growth habit of a group of (mainly)

eucalypt Eucalypt is a descriptive name for woody plants with capsule fruiting bodies belonging to seven closely related genera (of the tribe Eucalypteae) found across Australasia: ''Eucalyptus'', ''Corymbia'', ''Angophora'', '' Stockwellia'', ''Allosyn ...

species that grow to a height of , have many stems arising from a

lignotuber A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. Other woody plants may develop basal burls as a similar survival strategy, often as a response t ...

and have a leafy canopy that shades 30–70% of the ground. The term is also applied to a vegetation association where these mallee eucalypts grow, on land that is generally flat without hills or tall trees and where the climate is

semi-arid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

. Of the 32 Major Vegetation Groups classified under the National Vegetation Information System, "Mallee Woodlands and Shrublands" (MVG14): * are

areas dominated by mallee eucalypts; * may also have co-dominant species of '' Callitris'', '' Melaleuca'', ''

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

'' and ''

Hakea ''Hakea'' ( ) is a genus of about 150 species of plants in the Family ''Proteaceae'', endemic to Australia. They are shrubs or small trees with leaves that are sometimes flat, otherwise circular in cross section in which case they are sometimes d ...

''; * have an open tree or

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

layer with more than 10% foliage cover and more than 20%

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

cover, distinguishing MVG 14 from "Mallee Open Woodland" (MVG14) and "Sparse Mallee Shrublands" (MVG32); * have an

understorey In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abo ...

composition strongly influenced by rainfall, soil type and fire regime; * are among the most fire prone of all plant communities in semi-arid and arid zones. The major vegetation subgroups of MVG14, based mainly on the

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...

components of the understorey are: * mallee with hummock grass (''

Triodia scariosa ''Triodia scariosa'', is more commonly known as porcupine grass or spinifex (not to be confused with '' Spinifex spp.''), and belongs to the endemic Australian grass genus'' Triodia.'' The species is perennial and evergreen and individuals grow ...

'' and ''

Triodia irritans ''Triodia irritans'' is a species of plant that forms low and dense mounds of tough grassy vegetation. It is found on sandplains in arid regions of southern and central Australia. The species was first described by Robert Brown in 1810. A comm ...

''); * mallee with a dense, shrubby understorey; * mallee with an open shrubby understorey; * mallee with a

tussock grass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perenni ...

(''

Themeda ''Themeda'' is a genus of plants in the grass family native to Asia, Africa, Australia, and Papuasia. There are about 18Barkworth, M. E''Themeda''.Grass Manual. Flora of North America. to 26Potdar, G. G., et al. (2003)A new species of ''Themeda'' ...

'', '' Poa'' and ''

Astrebla ''Astrebla'' is a small genus of xerophytic (adapted to survive in an environment with little liquid water) grasses found only in Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the main ...

'' species) understorey. Mallee woodlands and shrublands occur in 39 IBRA biogeographic regions.

Changes since European settlement

The present extent of this vegetation group is estimated to be about but the estimate prior to 1750 is . In 2001, the area covered by this vegetation group is estimated to be 65% of its pre-1750 coverage. The most extensive area of this vegetation association in Australia today is found in the

Great Victoria Desert The Great Victoria Desert is a sparsely populated desert ecoregion and interim Australian bioregion in Western Australia and South Australia. History In 1875, British-born Australian explorer Ernest Giles became the first European to cros ...

. Prior to 1750, the largest area is estimated to have occurred in the Murray-Darling basin. About 33% of the clearing of this vegetation type is estimated to have accounted for 10% of the total area of land clearing in Australia. In South Australia, clearing of the mallee started in the late 19th century, following the introduction of the

stump-jump plough The stump-jump plough, also known as stump-jumping plough, is a kind of plough invented in South Australia in the late 19th century by Richard Bowyer Smith and Clarence Herbert Smith to solve the particular problem of preparing mallee lands fo ...

in 1876.

References

{{Reflist Mediterranean forests, woodlands, and scrub in Australia Biogeography of New South Wales Biogeography of South Australia Biogeography of Victoria (Australia) Biogeography of Western Australia Vegetation of Australia Sclerophyll forests