Mallee (biogeographic Region) - Biogeography

Biogeography

Early biogeographic regionalisations of Western Australia do not recognise the Mallee region. It cannot be distinguished in Ludwig Diels' 1906 regionalisation of the South West, and is treated as part of the Wheatbelt in Edward de Courcy Clarke's 1926 map. It first appeared in Beard's 1980 phytogeographic regionalisation of Western Australia, but with an eastern limit of Point Culver. Beard named it "Roe Botanical District" in honour of John Septimus Roe, who explored the area in 1848. By 1984, Beard's phytogeographic regions were being presented more generally as "natural regions", and as such were given more widely recognisable names. Thus the "Roe Botanical District" became "Mallee".

When the IBRA was published in the 1990s, Beard's regionalisation was used as the baseline for Western Australia. The Mallee region was accepted as defined by Beard, and has since survived a number of revisions. The only significant change to its boundary is the extension of its eastern boundary eastwards along the coast as far as Eyre. The most recent revision, Version 6.1, defines two sub-regions for the Mallee region, Western Mallee and Eastern Mallee.

Under the World Wildlife Fund's biogeographic regionalisation of the Earth's land into "ecoregions", Mallee is combined with Esperance Plains to form the Esperance mallee ecoregion.