Ecoregions

Ecoregion

Content Cover Image

Source: World Wildlife Fund

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.

 

caption Figure 1: The ecoregions are categorized within 14 biomes and eight biogeographic realms to facilitate representation analyses. (Source: WWF)

 

 

caption 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
 
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
Glossary

Citation

Fund, W. (2014). Ecoregion. Retrieved from http://www.eoearth.org/view/article/51cbed7a7896bb431f692731

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