Mallee Woodlands and Shrublands is one of 32 Major Vegetation Groups defined by the Australian Government Department of the Environment and Energy[1] [2] and one of the 189 habitats in the HOTW habitats of the World classification.[3]
"Mallee" refers to the growth habit of a group of (mainly) eucalypt species that grow to a height of, have many stems arising from a lignotuber 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.[4] [5]
Of the 32 Major Vegetation Groups classified under the National Vegetation Information System, "Mallee Woodlands and Shrublands" (MVG14):
The major vegetation subgroups of MVG14, based mainly on the perennial components of the understorey are:
Mallee woodlands and shrublands occur in 39 IBRA biogeographic regions.
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. 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 in 1876.