A bioregion is an ecologically and geographically defined area that is smaller than a biogeographic realm, but larger than an ecoregion or an ecosystem, in the World Wide Fund for Nature classification scheme. There is also an attempt to use the term in a rank-less generalist sense, similar to the terms "biogeographic area" or "biogeographic unit".
It may be conceptually similar to an ecoprovince.
It is also differently used in the environmentalist context, being coined by Berg and Dasmann (1977).
WWF bioregions
The World Wide Fund for Nature (WWF) scheme divides some of the biogeographic realms into bioregions, defined as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)." The WWF bioregions are as follows:
Afrotropical realm
Western Africa and Sahel
Central Africa
Eastern and Southern Africa
Horn of Africa
Madagascar–Indian Ocean
Antarctic realm
Australasian realm
Australia
New Guinea and Melanesia
New Zealand
Wallacea
Indomalayan realm
Indian subcontinent
Indochina
Sunda Shelf and Philippine Archipelago
Nearctic realm
Canadian Shield
Eastern North America
Northern Mexico and Southwestern United States
Western North America
Neotropical realm
Amazonia
Caribbean
Central America
Central Andes
Eastern South America
Everglades
Northern Andes
Orinoco
Southern South America
Oceanian realm
Micronesia
Polynesia
Palearctic realm
Asia
East Asia north of the Himalayan system's foothills to the Arctic
Himalayan
Tibetan Plateau steppe
Yunnan–Guizhou Plateau
Northeast Asia
Russian Far East
Central Asia – Iranian Plateau and north to the Arctic. Temperate Asia biocountry Mongolian Plateau Eurasian Steppe Asian Russia (central) Asian-Siberian region Western Asia Arabian Desert Mediterranean Near East (roughly corresponds to the Levant) Anatolian Plateau Transcaucasia Northern Africa Atlantic coastal desert Sahara Desert Mediterranean Maghreb Atlas montane Europe European Mediterranean Basin Iberian Peninsula Balkan Peninsula North Caucasus Alps montane Carpathians Scandinavia European Russia Euro-Siberian region Macaronesia
See also
Ecological classification
Interim Biogeographic Regionalisation for Australia (IBRA)