Biome

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Biomes
Terrestrial biomes
Tundra
Taiga/boreal forests
Montane grasslands and shrublands
Temperate coniferous forests
Tropical and subtropical coniferous forests
Temperate broadleaf and mixed forests
Mediterranean forests, woodlands, and scrub
Tropical and subtropical moist broadleaf forests
Tropical and subtropical dry broadleaf forests
Temperate grasslands, savannas, and shrublands
Tropical and subtropical grasslands, savannas, and shrublands
Deserts and xeric shrublands
Flooded grasslands and savannas
Riparian
Wetland
Aquatic biomes
Pond
Littoral/intertidal zone
Mangrove forests
Kelp forest
Coral reef
Neritic zone
Continental shelf
Pelagic zone
Benthic zone
Hydrothermal vents
Cold seeps
Pack ice
Other biomes
Endolithic zone
Ecology portal

Biomes are climatically and geographically defined areas of ecologically similar climatic conditions such as communities of plants, animals, and soil organisms, [1] and are often referred to as ecosystems. Biomes are defined by factors such as plant structures (such as trees, shrubs, and grasses), leaf types (such as broadleaf and needleleaf), plant spacing (forest, woodland, savanna), and climate. Unlike ecozones, biomes are not defined by genetic, taxonomic, or historical similarities. Biomes are often identified with particular patterns of ecological succession and climax vegetation (quasi-equilibrium state of the local ecosystem). An ecosystem has a habitat and a biome is a major habitat type. A major habitat type, however, is a compromise, as it has an intrinsic inhomogeneity.

The biodiversity characteristic of each biome, especially the diversity of fauna and subdominant plant forms, is a function of abiotic factors and the biomass productivity of the dominant vegetation. In terrestrial biomes, species diversity tends to correlate positively with net primary productivity, moisture availability, and temperature.[2]

Ecoregions are grouped into both biomes and ecozones.

A fundamental classification of biomes is into:

  1. Terrestrial (land) biomes
  2. Freshwater biomes
  3. Marine biomes

Biomes are often known in English by local names. For example, a Temperate grassland or shrubland biome is known commonly as steppe in central Asia, prairie in North America, and pampas in South America. Tropical grasslands are known as savanna in Australia, whereas in Southern Africa it is known as veldt (from Afrikaans).

Sometimes an entire biome may be targeted for protection, especially under an individual nation's Biodiversity Action Plan.

Climate is a major factor determining the distribution of terrestrial biomes. Among the important climatic factors are:

  • latitude: Arctic, boreal, temperate, subtropical, tropical.
  • humidity: humid, semi-humid, semi-arid, and arid.
    • seasonal variation: Rainfall may be distributed evenly throughout the year or be marked by seasonal variations.
    • dry summer, wet winter: Most regions of the earth receive most of their rainfall during the summer months; Mediterranean climate regions receive their rainfall during the winter months.
  • elevation: Increasing elevation causes a distribution of habitat types similar to that of increasing latitude.

The most widely used systems of classifying biomes correspond to latitude (or temperature zoning) and humidity. Biodiversity generally increases away from the poles towards the equator and increases with humidity.


Contents

[edit] Bailey system

Robert G. Bailey almost developed a biogeographical classification system for the United States in a map published in 1876. Bailey subsequently expanded the system to include the rest of South America in 1981 and the world in 1989. The Bailey system is based on climate and is divided into seven domains (Polar, Humid Temperate, Dry, Human, and Humid Tropical), with further divisions based on other climate characteristics (subarctic, warm temperate, hot temperate, and subtropical; marine and continental; lowland and mountain).[3]

  • 100 Polar Domain
    • 120 Tundra Division
    • M120 Tundra Division - Mountain Provinces
    • 130 Subarctic Division
    • M130 Subarctic Division - Mountain Provinces
  • 200 Humid Temperate Domain
    • 210 Warm Continental Division
    • M210 Warm Continental Division - Mountain Provinces
    • 220 Hot Continental Division
    • M220 Hot Continental Division - Mountain Provinces
    • 230 Subtropical Division
    • M230 Subtropical Division - Mountain Provinces
    • 240 Marine Division
    • M240 Marine Division - Mountain Provinces
    • 250 Prairie Division
    • 260 Mediterranean Division
    • M260 Mediterranean Division - Mountain Provinces
  • 300 Dry Domain
    • 310 Tropical/Subtropical Steppe Division
    • M310 Tropical/Subtropical Steppe Division - Mountain Provinces

[edit] WWF system

A team of biologists convened by the World Wide Fund for Nature (WWF) developed an ecological land classification system that identified fourteen biomes,[4] called major habitat types, and further divided the world's land area into 867 terrestrial ecoregions. Each terrestrial Ecoregion has a specific EcoID, fomat XXnnNN (XX is the Ecozone, nn is the Biome number, NN is the individual number). This classification is used to define the Global 200 list of ecoregions identified by the WWF as priorities for conservation. The WWF major habitat types are:

[edit] Freshwater biomes

According to the World Wildlife Fund, the following are classified as freshwater biomes: [5]

[edit] Realms or Ecozones (terrestrial and freshwater, WWF)

[edit] Marine biomes

[edit] Marine biomes (major habitat types), Global 200 (WWF)

Biomes of the coastal & continental shelf areas (Neritic zone - List of ecoregions (WWF)):

[edit] Realms or Ecozones (marine, WWF)

  • North Temperate Atlantic
  • Eastern Tropical Atlantic
  • Western Tropical Atlantic
  • South Temperate Atlantic
  • North Temperate Indo-Pacific
  • Central Indo-Pacific
  • Eastern Indo-Pacific
  • Western Indo-Pacific
  • South Temperate Indo-Pacific
  • Southern Ocean
  • Antarctic
  • Arctic
  • Mediterranean

[edit] Other marine habitat types

[edit] Major Habitats, Non Global 200 (WWF)

[edit] Summary - Ecological taxonomy (WWF)

[edit] Anthropogenic biomes

Humans have fundamentally altered global patterns of biodiversity and ecosystem processes. As a result, vegetation forms predicted by conventional biome systems are rarely observed across most of Earth's land surface. Anthropogenic biomes provide an alternative view of the terrestrial biosphere based on global patterns of sustained direct human interaction with ecosystems, including agriculture, human settlements, urbanization, forestry and other uses of land. Anthropogenic biomes offer a new way forward in ecology and conservation by recognizing the irreversible coupling of human and ecological systems at global scales and moving us toward an understanding how best to live in and manage our biosphere and the anthropogenic biosphere we live in.

[edit] Major Anthropogenic Biomes

  • Dense Settlements
  • Villages
  • Croplands
  • Rangelands
  • Forested

[edit] Other biomes

The Endolithic biome, consisting entirely of microscopic life in rock pores and cracks, kilometers beneath the surface, has only recently been discovered and does not fit well into most classification schemes.

[edit] Map of Biomes

Terrestrial biomes classified by vegetation
     ice sheet & polar desert      tundra      taiga      temperate broadleaf forest      temperate steppe      subtropical rainforest      Mediterranean vegetation      monsoon forest      arid desert      xeric shrubland      dry steppe      semiarid desert      grass savanna      tree savanna      subtropical dry forest      tropical rainforest      alpine tundra      montane forest

Freshwater Biomes

Major continental divides, showing drainage into the major oceans and seas of the world. Grey areas are endorheic basins that do not drain to the ocean.

Drainage basins of the principal oceans and seas of the world. Grey areas are endorheic basins that do not drain to the ocean.

[edit] See also

Sister project Look up Biome in
Wiktionary, the free dictionary.
Earth sciences portal
Ecology portal
Environment portal

[edit] References

  1. ^ The World's Biomes, Retrieved August 19, 2008, from University of California Museum of Paleontology
  2. ^ Pidwirny, Michael (2006-10-16). "Biomes". in Sidney Draggan. Encyclopedia of Earth. Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment. http://www.eoearth.org/article/Biomes. Retrieved on 2006-11-16. 
  3. ^ http://www.fs.fed.us/land/ecosysmgmt/index.html Bailey System, US Forest Service
  4. ^ Olson, David M. et al. (2001); Terrestrial Ecoregions of the World: A New Map of Life on Earth, BioScience, Vol. 51, No. 11., pp. 933-938.
  5. ^ "Freshwater Ecoregions of the World: Major Habitat Types" [1]. Accessed May 12, 2008.
  6. ^ WWF: Marine Ecoregions of the World

[edit] External links


v • d • e
Terrestrial biomes
v • d • e
Ecozones
Retrieved from "http://en.wikipedia.org/wiki/Biome"
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