The Mitchell Grass Downs is a
tropical and subtropical grasslands, savannas, and shrublands ecoregion
An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...
in northeastern
Australia. 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
The Victoria Plains tropical savanna is a tropical and subtropical grasslands, savannas, and shrublands ecoregion in northwestern Australia.
Geography
The ecoregion lies in the central Northern Territory, extending into northeastern Western ...
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 Australian desert, with an area of .
The desert is underlain by the ...
to the south, and the
Eastern Australia mulga shrublands to the southeast.
The ecoregion includes three
IBRA regions –
Mitchell Grass Downs
The Mitchell Grass Downs is a tropical and subtropical grasslands, savannas, and shrublands ecoregion in northeastern Australia. It is a mostly treeless grassland, characterised by Astrebla, Mitchell grasses (''Astrebla'' spp.).
Location an ...
,
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 camaldulensis'', commonly known as the river red gum, is a tree that is endemic to Australia. It has smooth white or cream-coloured bark, lance-shaped or curved adult leaves, flower buds in groups of seven or nine, white flowers a ...
(''Eucalyptus camuldulensis''),
coolibah (''E. coolabah''), and
paperbark
''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles or tea-trees (although the last name is also applied to species of ''Leptospermum''). They range in size ...
(''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
*
References
{{Reflist
Biogeography of the Northern Territory
Ecoregions of Queensland
Tropical and subtropical grasslands, savannas, and shrublands