- Southwest Australia
:"This article is about an ecoregion; for other uses, see
Southwest, Western Australia."
Southwest Australia is a
biodiversity hotspotthat includes the Mediterranean forests, woodlands, and shrub ecoregions of Western Australia. The region has a wet-winter, dry-summer Mediterranean climate, one of five such regions in the world. The region covers 356,717 km², consisting of a broad coastal plain 20-120 kilometers wide, transitioning to gently undulating uplands made up of weathered granite, gneissand laterite. Desert and xeric shrublands lie to the north and east across the center of Australia, separating Southwest Australia from the other Mediterranean and humid-climate regions of the continent.
The vegetation in the region is mainly woody, including
forests, woodlands, shrublands, and heathlands, but no grasslands. Predominant vegetation types are " Eucalyptus" woodlands, eucalyptus-dominated Malleeshrublands, and kwonganshrublands and heathlands, which correspond to the chaparral, matorral, maquis, and fynbosshrublands found in other Mediterranean-type regions. The region has generally nutrient-poor sandy or lateritic soils, which has encouraged rich speciationof plants adapted to specific ecological niches. The region hosts a great diversity of endemic species, notably among the protea family ( Proteaceae).
The region corresponds to the Southwest Botanic Province and the
floristic provinceof Southwest Australia. The World Wide Fund for Natureand Interim Biogeographic Regionalisation for Australia(IBRA) divide the region up into a number of ecoregions:
Coolgardie woodlands(IBRA Coolgardie)
Esperance mallee(IBRA Esperance Plains and Mallee)
Jarrah-Karri forest and shrublands(IBRA Warren)
Kwongan heathlands(IBRA Swan Coastal Plain)
Southwest Australia savanna(IBRA Geraldton Sandplains, Avon Wheatbelt, and Yalgoo)
*Southwest Australia woodlands (IBRA Jarrah Forest)
* [http://www.biodiversityhotspots.org/xp/Hotspots/australia/ Southwest Australia (Conservation International)]
* Thackway, R and I D Cresswell (1995) "An interim biogeographic regionalisation for Australia : a framework for setting priorities in the National Reserves System Cooperative Program" Version 4.0 Canberra : Australian Nature Conservation Agency, Reserve Systems Unit, 1995. ISBN 0642213712
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