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Ecoregion

Ecoregions:

Ecoregion

Source: World Wildlife Fund Source: World Wildlife Fund
Published:
Updated: July 4, 2012, 10:03 pm
Topics: Ecoregions Biodiversity Conservation Biology Biogeography Biomes Ecology Theory
This article has been reviewed by the following Topic Editor: Cutler J. Cleveland

An ecoregion is a relatively large unit of land or ocean that contains geographically distinct assemblage of natural communities with boundaries that approximate the original extent of natural communities prior to major land use change. Ecoregions:

  • share a large majority of their species and ecological dynamics;
  • share similar environmental conditions, and;
  • interact ecologically in ways that are critical for their long-term persistence.

Classification

The motivation for the ecoregion classification system is that scarce resources and dwindling time force conservationists to target their actions to stem the loss of biodiversity — a pragmatic approach, given the highly uneven distribution of species and threats. Unfortunately, the ability to focus strategically is hindered by the absence of a global biodiversity map with sufficient biogeographic resolution to accurately reflect the complex distribution of the Earth’s natural communities. Without such a map, many distinctive biotas remain unrecognized.

Ecoregions reflect the distribution of a broad range of fauna and flora across the entire planet, from the vast Sahara Desert to the diminutive Clipperton Island (eastern Pacific Ocean). They are classified with a system familiar to all biologists: biogeographic realms and biomes. Ecoregions, representing distinct biotas, are nested within the biomes and realms and, together, these provide a framework for comparisons among units and the identification of representative habitats and species assemblages.

World Wildlife Fund (WWF) Classification

The WWF system subvides the terrestrial world into 14 biomes and eight biogeographic realms (Figure 1). Nested within these are 867 ecoregions (Figure 2). WWF has assessed these ecoregions and identified the Global 200 -- the most biologically distinct terrestrial, freshwater, and marine ecoregions of the planet.

 

Figure 1: The ecoregions are categorized within 14 <a data-cke-saved-href='/article/Biome' href='/article/Biome' title='Biome'>biomes</a> and eight biogeographic realms to facilitate representation analyses. (Source: <a data-cke-saved-href='http://www.worldwildlife.org' href='http://www.worldwildlife.org' class='external text' title='http://www.worldwildlife.org' rel='nofollow'>WWF</a>) Figure 1: The ecoregions are categorized within 14 biomes and eight biogeographic realms to facilitate representation analyses. (Source: WWF)

 

 

Figure 2: The map of terrestrial ecoregions of the world recognizes 867 distinct units, roughly a four fold increase in biogeographic discrimination over that of the 193 units of Udvardy (1975). Maps of freshwater and marine ecoregions are similarly needed for conservation planning. (Source: <a data-cke-saved-href='http://www.worldwildlife.org' href='http://www.worldwildlife.org' class='external text' title='http://www.worldwildlife.org' rel='nofollow'>WWF</a>) Figure 2: The map of terrestrial ecoregions of the world recognizes 867 distinct units, roughly a four fold increase in biogeographic discrimination over that of the 193 units of Udvardy (1975). Maps of freshwater and marine ecoregions are similarly needed for conservation planning. (Source: WWF)

 

Australasia


Tropical & Subtropical Moist Broadleaf Forests

Tropical & Subtropical Dry Broadleaf Forests

Temperate Broadleaf & Mixed Forests

Tropical & Subtropical Grasslands, Savannas, & Shrublands

Temperate Grasslands, Savannas & Shrublands

Montane Grasslands and Shrublands

Tundra

Mediterranean Forests, Woodlands, & Shrub

Deserts & Xeric Shrublands
  • Carnarvon xeric shrublands
  • Central Ranges xeric scrub
  • Gibson desert
  • Great Sandy-Tanami desert
  • Great Victoria desert
  • Nullarbor Plains xeric shrublands
  • Pilbara shrublands
  • Simpson desert
  • Tirari-Stuart stony desert
  • Western Australian Mulga shrublands

Mangrove

Antarctic


Tundra

Afrotropic


Tropical & Subtropical Moist Broadleaf Forests

Tropical & Subtropical Dry Broadleaf Forests

Tropical & Subtropical Grasslands, Savannas, & Shrublands

Temperate Grasslands, Savannas & Shrublands

Flooded Grasslands and Savannas

Montane Grasslands and Shrublands

Mediterranean Forests, Woodlands, & Shrub

Deserts & Xeric Shrublands

Mangrove

Indo-Malayan


Tropical & Subtropical Moist Broadleaf Forests

Tropical & Subtropical Dry Broadleaf Forests

Tropical & Subtropical Coniferous Forests

Temperate Broadleaf & Mixed Forests

Temperate Coniferous Forests

Tropical & Subtropical Grasslands, Savannas, & Shrublands

Flooded Grasslands and Savannas

Montane Grasslands and Shrublands

Deserts & Xeric Shrublands

Mangrove

Nearctic


Tropical & Subtropical Dry Broadleaf Forests

Tropical & Subtropical Coniferous Forests

Temperate Broadleaf & Mixed Forests

Temperate Coniferous Forests

Boreal Forests/Taiga

Tropical & Subtropical Grasslands, Savannas, & Shrublands
  • Western Gulf coastal grasslands

Temperate Grasslands, Savannas, & Shrublands

Tundra

 
Mediterranean Forests, Woodlands, & Shrub

 
Deserts & Xeric Shrublands

Mangrove

Neotropic


Tropical & Subtropical Moist Broadleaf Forests

Tropical & Subtropical Dry Broadleaf Forests

Tropical & Subtropical Coniferous Forests

Temperate Broadleaf & Mixed Forests

Tropical & Subtropical Grasslands, Savannas, & Shrublands

Temperate Grasslands, Savannas, & Shrublands

Flooded Grasslands and Savannas

Montane Grasslands and Shrublands

Mediterranean Forests, Woodlands, & Shrub
  • Chilean matorral

Deserts & Xeric Shrublands

Mangrove

Oceania


Tropical & Subtropical Moist Broadleaf Forests

Tropical & Subtropical Dry Broadleaf Forests

Tropical & Subtropical Grasslands, Savannas, & Shrublands

Palearctic


Tropical & Subtropical Moist Broadleaf Forests

Temperate Broadleaf & Mixed Forests

Temperate Coniferous Forests

Boreal Forests/Taiga

Temperate Grasslands, Savannas, & Shrublands

Flooded Grasslands and Savannas

Montane Grasslands and Shrublands

Tundra
  • Arctic desert
  • Bering tundra
  • Cherskii-Kolyma mountain tundra
  • Chukchi Peninsula tundra
  • Kamchatka Mountain tundra and forest tundra
  • Kola Peninsula tundra
  • Northeast Siberian coastal tundra
  • Northwest Russian-Novaya Zemlya tundra
  • Novosibirsk Islands arctic desert
  • Scandinavian Montane Birch forest and grasslands
  • Taimyr-Central Siberian tundra
  • Trans-Baikal Bald Mountain tundra
  • Wrangel Island arctic desert
  • Yamalagydanskaja tundra

Mediterranean Forests, Woodlands, & Shrub

Deserts & Xeric Shrublands

References

  • Eric D. Wikramanayake. 2002. Terrestrial ecoregions of the Indo-Pacific: a conservation assessment. Island Press. 643 pages
  • Robin A. Abell. 2000. Freshwater ecoregions of North America: a conservation assessment. World Wildlife Fund. Island Press. 639 pages

Citation

World Wildlife Fund (Lead Author);Cutler J. Cleveland (Topic Editor) "Ecoregion". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth February 21, 2010; Last revised Date July 4, 2012; Retrieved May 23, 2013 <http://www.eoearth.org/article/Ecoregion?topic=49597>

The Author

World Wildlife FundKnown worldwide by its panda logo, World Wildlife Fund (WWF) leads international efforts to protect endangered species and their habitats. Now in its fifth decade, WWF works in more than 100 countries around the globe to conserve the diversity of life on Earth. With nearly 1.2 million members in the U.S. and another 4 million worldwide, WWF is the world's largest privately financed conservation organization. WWF directs its conservation efforts toward three global goals: 1) saving endangered ... (Full Bio)

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