Acacia aneura

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Mulga
Acacia aneura habit.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Caesalpinioideae
Clade: Mimosoid clade
Genus: Acacia
Species:
A. aneura
Binomial name
Acacia aneura
Acacia aneuraDistMap47.png
Occurrence data from AVH
Mulga acacia (Fabaceae) Flowers and leaves at Kaumalapau Hwy, Lanai, Hawaii. Starr 070402-6316 Acacia aneura.jpg
Mulga acacia (Fabaceae) Flowers and leaves at Kaumalapau Hwy, Lanai, Hawaii.
A. aneura var. aneura Acacia aneura var. aneura.jpg
A. aneura var. aneura

Acacia aneura, commonly known as mulga or true mulga, is a shrub or small tree native to arid outback areas of Australia. It is the dominant tree in the habitat to which it gives its name (mulga) that occurs across much of inland Australia. Specific regions have been designated the Western Australian mulga shrublands in Western Australia and Mulga Lands in Queensland.

Contents

Description

Mulga woodland in Southwestern Queensland. The tallest trees in this photograph are close to 7 m. Mulga.jpg
Mulga woodland in Southwestern Queensland. The tallest trees in this photograph are close to 7 m.
Acacia aneura branch with seed pods Acacia aneura pods.jpg
Acacia aneura branch with seed pods
Acacia aneura bark Acacia-aneura-bark3.jpg
Acacia aneura bark

Mulga trees are highly variable, in form, in height, and in shape of phyllodes and seed pods. They can form dense forests up to 15 metres (49 ft) high, or small, almost heath-like low shrubs spread well apart. Most commonly, mulgas are tall shrubs. Because the mulga is so variable, its taxonomy has been studied extensively, and although A. aneura is likely to be split into several species eventually, there is as yet no consensus on how or even if this should be done[ citation needed ]. Although generally small in size, mulgas are long-lived, a typical life span for a tree undisturbed by fire is of the order of 200 to 300 years.

Mulga has developed extensive adaptations to the Australian desert. Like many Acacia species, it has thick-skinned phyllodes. These are optimised for low water loss, with a high oil content, sunken stomata, and a profusion of tiny hairs which reduce transpiration. During dry periods, mulgas drop much of their foliage to the ground, which provides an extra layer of mulch and from where the nutrients can be recycled.

Like most Australian Acacia species, mulga is thornless. [2] The needle-like phyllodes stand erect to avoid as much of the midday sun as possible and capture the cooler morning and evening light. Any rain that falls is channelled down the phyllodes and branches to be collected in the soil immediately next to the trunk, providing the tree with a more than threefold increase in effective rainfall. Mulga roots penetrate far into the soil to find deep moisture. The roots also harbour bacteria that fix atmospheric nitrogen and thus help deal with the very old, nutrient-poor soils in which the species grows.

Aboriginal peoples of the Coober Pedy area in South Australia refer to mulga trees as Umoona, which means "long life". [3]

Habitat and ecology

Mulga grows as a widely spaced shrub in Southwestern Queensland. The tallest plants are about 2.5m high. Mulga heath.jpg
Mulga grows as a widely spaced shrub in Southwestern Queensland. The tallest plants are about 2.5m high.

Mulga savanna and mulga codominant tussock grasslands cover roughly 20% of the Australian continent, or about 1.5 million square kilometres. The mean rainfall for much of the habitat for A. aneura in Australia is roughly 200–250 mm/year, but it goes to as high as 500 mm/year in New South Wales and Queensland. The lowest mean rainfall where it grows is about 50–60 mm/year. [4] Both summer and winter rainfall are necessary to maintain mulga, and the species is absent from semiarid regions that experience summer or winter drought. [5]

Mulga scrub is distinctive and widespread, with the Mulga Lands of eastern Australia defined as a specific bioregion. The dominant species in these woodlands is mulga, with poplar box ( Eucalyptus populnea ) forming an increasingly important codominant in the eastern districts. [6] [7] The extent of ground cover in mulga woodlands varies with canopy density of the overstorey, becoming almost nonexistent in extremely dense stands. In more open stands, the herbaceous layer consists of wire grasses ( Aristida spp.)mulga is long-lived, mulga oats ( Monocather sp.), mulga mitchell ( Thyridolepis sp.), wanderrie ( Eriachne spp.), finger grasses ( Digitaria spp.) and love grasses ( Eragrostis spp.). Various other woody species are also significant in mulga woodlands, particularly hop bushes ( Dodonaea spp.), Eremophila and cassia ( Senna spp.). [5] [7]

In contrast to the eucalypt woodlands that dominate much of Australia, mulga woodlands are not well adapted to regular fire and species in mulga communities vary in their ability to survive fires. [8] [9] Many species, including mulga, have a very limited ability to resprout after fire, and rely instead on mechanisms of seed production for species survival. Many plants produce hard, woody fruits or seeds, which can not only survive intense heat, but also may require the stimulus of fire to scarify and promote germination. Long-lived seed stores in soil is also common in these woodlands. [9] [10] [11]

The recognised varieties are:

Uses

Agriculture

Mulga can be planted with sandalwood in plantations as a host tree. The tree's flowers provide forage for bees, especially when there is enough water available. [12]

Mulga is of great economic importance to the Australian pastoral industry. Despite containing considerable amounts of indigestible tannins, mulga leaves are a valuable fodder source, particularly in times of drought, as they are palatable to stock and provide up to 12% crude protein. [12]

The seeds of Acacia aneura are traditionally used to make seedcakes. The mulga apple is an insect gall commonly eaten by Aboriginal people. [13] Mulga tree gum (ngkwarle alkerampwe in the Arrernte language) is a type of lerp scale found on mulga branches. It provides a tasty, honey-like treat. [12]

Wood

Wood from Acacia aneura stands up very well to being buried in soil, so it is used for posts. The wood has a density of about 850–1100 kg/m3. [12] It is also good as firewood, and good-quality charcoal can be produced from it. [12]

Mulga is a vital tree to Aboriginal Australians in central and Western Australia; the wood is a good hardwood for making various implements, such as digging sticks, woomeras, shields and wooden bowls. [14]

Related Research Articles

<span class="mw-page-title-main">Sclerophyll</span> Type of plant

Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes and leaf orientation which is parallel or oblique to direct sunlight. The word comes from the Greek sklēros (hard) and phyllon (leaf). The term was coined by A.F.W. Schimper in 1898, originally as a synonym of xeromorph, but the two words were later differentiated.

<span class="mw-page-title-main">Savanna</span> Mixed woodland-grassland ecosystem

A savanna or savannah is a mixed woodland-grassland ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. According to Britannica, there exists four savanna forms; savanna woodland where trees and shrubs form a light canopy, tree savanna with scattered trees and shrubs, shrub savanna with distributed shrubs, and grass savanna where trees and shrubs are mostly nonexistent.

<i>Acacia brachystachya</i> Species of plant

Acacia brachystachya, commonly known as umbrella mulga, turpentine mulga or false bowgada, is a shrub in the family Fabaceae. The species occurs in mulga and heath communities on sandhills and rocky ridges in all mainland states of Australia, except Victoria.

<i>Acacia kempeana</i> Species of plant

Acacia kempeana, commonly known as wanderrie wattle, witchetty bush or granite wattle, is a shrub in subfamily Mimosoideae of family Fabaceae that is endemic to arid parts of central and western Australia.

<i>Acacia ligulata</i> Species of plant

Acacia ligulata is a species of Acacia, a dense shrub widespread in all states of mainland Australia. It is not considered rare or endangered. Its common names include sandhill wattle, umbrella bush, marpoo, dune wattle, small coobah, wirra, and watarrka.

<span class="mw-page-title-main">Deserts of Australia</span> Deserts in Australia

The deserts of Australia or the Australian deserts cover about 2,700,000 km2 (1,000,000 sq mi), or 18% of the Australian mainland, but about 35% of the Australian continent receives so little rain, it is practically desert. Collectively known as the Great Australian desert, they are primarily distributed throughout the Western Plateau and interior lowlands of the country, covering areas from South West Queensland, Far West region of New South Wales, Sunraysia in Victoria and Spencer Gulf in South Australia to the Barkly Tableland in Northern Territory and the Kimberley region in Western Australia.

<i>Acacia harpophylla</i> Species of legume

Acacia harpophylla, commonly known as brigalow, brigalow spearwood or orkor, is an endemic tree of Australia. The Aboriginal Australian group the Gamilaraay peoples know the tree as Barranbaa or Burrii. It is found in central and coastal Queensland to northern New South Wales. It can reach up to 25 m (82 ft) tall and forms extensive open-forest communities on clay soils.

<i>Acacia ayersiana</i> Species of plant

Acacia ayersiana is a plant that grows in arid areas of Australia.

Acacia ayersiana var. latifolia is a plant that grows in arid areas of Australia.

<i>Acacia stenophylla</i> Species of tree

Acacia stenophylla is a species of Acacia commonly referred to as the shoestring acacia. It is an evergreen tree in the family Fabaceae native to Australia. It is not considered rare or endangered.

<span class="mw-page-title-main">Mulga Lands</span>

The Mulga Lands are an interim Australian bioregion of eastern Australia consisting of dry sandy plains with low mulga woodlands and shrublands that are dominated by Acacia aneura (mulga). The Eastern Australia mulga shrublands ecoregion is coterminous with the Mulga Lands bioregion.

<i>Acacia cana</i> Species of legume

Acacia cana, or commonly named as boree or the cabbage-tree wattle or broad-leaved nealie, is part of the family Fabaceae and sub-family Mimosoideae. It is a dense shrub- tree that can grow to 6 metres (20 ft) high and is a perennial plant meaning it has long life span and doesn’t necessary produce a high amount of seed. The cabbage-tree wattle heavily flowers from August till October and relies on animals and insects for pollination and dispersal of seeds. This least concern acacia species is found in the western plains of New South Wales and Central Queensland the habitats of these areas are found to be sandy soils and gibber plains.

<i>Acacia aptaneura</i> Species of plant

Acacia aptaneura, commonly known as slender mulga, is a shrub belonging to the genus Acacia and the subgenus Juliflorae. It is native to central and western parts of Australia.

<i>Acacia fuscaneura</i> Species of plant

Acacia fuscaneura, commonly known as sooty wattle, is a tree belonging to the genus Acacia and the subgenus Juliflorae. It is native to arid areas of central Australia.

<i>Acacia minyura</i> Species of legume

Acacia minyura is a tree or shrub belonging to the genus Acacia and the subgenus Juliflorae endemic to arid parts of central Australia.

<i>Acacia paraneura</i> Species of plant

Acacia paraneura, commonly known as weeping mulga, is a tree or shrub belonging to the genus Acacia and the subgenus Juliflorae. It is native to arid regions of Australia. The Indigenous Kurrama peoples know the tree as warlun.

<i>Acacia ramulosa</i> Species of plant

Acacia ramulosa, commonly known as horse mulga or bowgada wattle, is a shrub belonging to the genus Acacia and the subgenus Juliflorae endemic to arid areas of Australia.

<i>Acacia wanyu</i> Species of legume

Acacia wanyu, commonly known as wanyu or silver-leaf mulga, is a shrub or tree belonging to the genus Acacia and the subgenus Juliflorae that is endemic to arid parts of western Australia. The Kurrama people know it as Murruturu or Yirritiri while the Nyangumarta people know it as Wayartany.

<i>Acacia calcicola</i> Species of plant

Acacia calcicola is a shrub or tree of the genus Acacia and the subgenus Plurinerves that is native to parts of central Australia. Common names for this species include; shrubby wattle, shrubby mulga, myall-gidgee, northern myall and grey myall. Indigenous Australians the Pitjantjatjara peoples know the tree as ikatuka, the Warlpiri know it as jirlarti and the Arrernte know it as irrakwetye.

<span class="mw-page-title-main">Mulga (habitat)</span> Habitat dominated by the mulga tree

Mulga is a type of habitat composed of woodland or open forest dominated by the mulga tree, Acacia aneura, or similar species of Acacia.

References

Notes

  1. Malcolm, P. (2012). "Acacia aneura". IUCN Red List of Threatened Species . 2012: e.T19892219A19996730. doi: 10.2305/IUCN.UK.2012.RLTS.T19892219A19996730.en . Retrieved 12 November 2021.
  2. Arid Zone Trees Archived June 10, 2007, at the Wayback Machine
  3. "The History of Coober Pedy". Coober Pedy SA. Retrieved 13 October 2021.
  4. Doran, J.C.; Turnbull, J.W.; Boland, D.J.; Gunn, B.V. (1983). "Appendix 2. Notes on the main characteristics of the six acacia species of special interest". Handbook on seeds of dry-zone acacias. Food and Agriculture Organization of the United Nations.
  5. 1 2 Weston, E.J. (1988). "Native Pasture Communities". In Burrows, H.; Scanlan, J.C.; Rutherford, M.T. (eds.). Native pastures in Queensland their resources and management. Brisbane QLD: Department of Primary Industries.
  6. Harrington, G.N.; Mills, D.M.D.; et al. (1984). "Semi-arid woodlands". In Harrington, G.N.; Wilson, A.D. (eds.). Management of Australia's Rangelands. CSIRO Publishing. pp. 189–. ISBN   9780643036147.
  7. 1 2 Burrows, W.H.; Carter, J.O.; Scanlan, J.C.; Anderson, E.R. (1990). "Management of savannas for livestock production in north-east Australia: contrasts across the tree-grass continuum". Journal of Biogeography. 17 (4–5): 503–512. doi:10.2307/2845383. JSTOR   2845383.
  8. Hodgkinson, K.C.; Harrington, G.N.; et al. (1984). "Management of vegetation with fire". In Harrington, G.N.; Wilson, A.D. (eds.). Management of Australia's Rangelands. CSIRO Publishing. pp. 141–. ISBN   9780643036147.
  9. 1 2 Dyer, R.; Craig, A.; et al. (1997). "Fire in northern pastoral lands". In Grice, T.C.; Slatter, S.M. (eds.). Fire in the management of northern Australian pastoral lands. Occasional Publication. Vol. 8. St. Lucia, Australia: Tropical Grassland Society of Australia. hdl:102.100.100/221918.
  10. White, M.E. (1986). The Greening of Gondwana. Reed Books. ISBN   9780730101543.
  11. Hodgkinson, K.C. (1991). "Shrub recruitment response to intensity and season of fire in a semi-arid woodland". Journal of Applied Ecology. 28 (1): 60–70. doi:10.2307/2404113. JSTOR   2404113.
  12. 1 2 3 4 5 World AgroForestry Centre
  13. J. H. Maiden (1889). The useful native plants of Australia : Including Tasmania. Turner and Henderson, Sydney.
  14. "Aboriginal Plant use and Technology" (PDF). Australian National Botanic Garden. Retrieved 11 November 2016.

General references