The Mitchell Grass Downs is a
tropical and subtropical grasslands, savannas, and shrublands
Tropical and subtropical grasslands, savannas, and shrublands is a terrestrial biome defined by the World Wide Fund for Nature. The biome is dominated by grass and/or shrubs located in semi-arid to semi- humid climate regions of subtropical and ...
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 ...
in northeastern
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
. It is a mostly treeless grassland, characterised by
Mitchell grasses (''Astrebla'' spp.).
Location and description
The ecoregion is bounded on the north and east by tropical savanna ecoregions – the
Victoria Plains tropical savanna to the northeast, the
Carpentaria tropical savanna to the north, the
Einasleigh Uplands savanna to the northeast, and the
Brigalow tropical savanna to the east. More arid ecoregions lie to west and south – the
Great Sandy-Tanami desert to the southwest, the
Simpson Desert
The Simpson Desert is a large area of dry, red sandy plain and dunes in the Northern Territory, South Australia and Queensland in central Australia. It is the fourth-largest Deserts of Australia, Australian desert, with an area of .
The Wangka ...
to the south, and the
Eastern Australia mulga shrublands to the southeast.
The ecoregion includes three
IBRA regions –
Mitchell Grass Downs,
Mount Isa Inlier, and
Desert Uplands.
Climate
The climate is tropical and semi-arid. Average annual rainfall varies across the ecoregion, from 350 mm to 750 mm. In much of the ecoregion rainfall is seasonal, coinciding with the summer monsoon. Rainfall becomes less seasonal towards the southeast.
Flora
The vegetation consists mostly of grasses along with wildflowers and low shrubs, including
Queensland bluebush (''Chenopodium auricomum''). There are scattered dry acacia woodlands, predominantly of
gidgee (''Acacia cambagei''). Watercourses support woodlands of
red river gum (''Eucalyptus camuldulensis''),
coolibah (''E. coolabah''), and
paperbark (''Melaleuca'' spp.).
The Desert Uplands has dry woodlands of ''
Eucalyptus populnea
''Eucalyptus populnea'', commonly known as poplar box, bimble box or bimbil box, is a species of small to medium-sized tree that is endemic to eastern Australia. It has rough, fibrous or flaky bark on the trunk and branches, egg-shaped, elliptic ...
,
E. melanophloia'', and ''
E. similis''. Low open woodlands of
snappy gum (''Eucalyptus leucophloia''),
Cloncurry box (''E. leucophylla''), and
silver box (''E. pruinosa'') grow in the Mount Isa Inlier.
External links
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References
{{Reflist
Biogeography of the Northern Territory
Ecoregions of Queensland
Tropical and subtropical grasslands, savannas, and shrublands