Editing Biome (section)

== Classifications ==
To divide the world into a few ecological zones is difficult, notably because of the small-scale variations that exist everywhere on earth and because of the gradual changeover from one biome to the other. Their boundaries must therefore be drawn arbitrarily and their characterization made according to the average conditions that predominate in them.<ref>{{cite book |last1=Schultz |first1=Jürgen |date=1995 |title=The ecozones of the world |pages=2–3 |isbn=978-3-540-28527-4 |publisher=Springer}}</ref>

A 1978 study on North American [[grasslands]]<ref>{{cite journal |last1=Sims |first1=Phillip L. |last2=Singh |first2=J.S. |title=The Structure and Function of Ten Western North American Grasslands: III. Net Primary Production, Turnover and Efficiencies of Energy Capture and Water Use |journal=[[Journal of Ecology]] |date=July 1978 |volume=66 |issue=2 |pages=573–597 |publisher=[[British Ecological Society]] |doi=10.2307/2259152 |jstor=2259152|bibcode=1978JEcol..66..573S }}</ref> found a positive [[Logistic regression|logistic correlation]] between [[evapotranspiration]] in mm/yr and above-ground net primary production in g/m<sup>2</sup>/yr. The general results from the study were that precipitation and water use led to above-ground primary production, while [[solar irradiance|solar irradiation]] and temperature lead to below-ground primary production (roots), and temperature and water lead to cool and warm season growth habit.<ref>{{cite book |editor1-last=Pomeroy |editor1-first=Lawrence R. |editor2-last=Alberts |editor2-first=James J. |title=Concepts of Ecosystem Ecology |location=New York |publisher=[[Springer-Verlag]] |date=1988}}</ref> These findings help explain the categories used in Holdridge's bioclassification scheme (see below), which were then later simplified by Whittaker. The number of classification schemes and the variety of determinants used in those schemes, however, should be taken as strong indicators that biomes do not fit perfectly into the classification schemes created.

=== Holdridge (1947, 1964) life zones ===
[[Image:Lifezones Pengo.svg|thumb|upright=2.3|Holdridge life zone classification scheme. Although conceived as three-dimensional by its originator, it is usually shown as a two-dimensional array of hexagons in a triangular frame.]]
{{Main|Holdridge life zones}}
In 1947, the American botanist and climatologist [[Leslie Holdridge]] classified climates based on the biological effects of temperature and [[rainfall]] on [[vegetation]] under the assumption that these two [[abiotic]] factors are the largest determinants of the types of vegetation found in a habitat. Holdridge uses the four axes to define 30 so-called "humidity provinces", which are clearly visible in his diagram. While this scheme largely ignores soil and sun exposure, Holdridge acknowledged that these were important.

=== Allee (1949) biome-types ===
The principal biome-types by Allee (1949):<ref>{{Cite book|last=Allee |first=W.C. |date=1949 |title=Principles of animal ecology |location=Philadelphia |publisher=Saunders Co. |url=https://www.biodiversitylibrary.org/bibliography/7325#/summary |archive-url=https://web.archive.org/web/20171001021240/http://www.biodiversitylibrary.org/bibliography/7325#/summary |archive-date=2017-10-01}}</ref>
* [[Tundra]]
* [[Taiga]]
* [[Deciduous|Deciduous forest]]
* [[Grassland]]s
* [[Desert]]
* [[High plateau]]s
* [[Tropical forest]]
* [[Minor terrestrial biomes]]

=== Kendeigh (1961) biomes ===
The principal biomes of the world by Kendeigh (1961):<ref>{{cite book|last=Kendeigh |first=S.C. |date=1961 |title=Animal ecology |location=Englewood Cliffs, NJ |publisher=[[Prentice-Hall]]}}</ref>
* ''Terrestrial''
** [[Temperate deciduous forest]]
** [[Taiga|Coniferous forest]]
** [[Woodland]]
** [[Chaparral]]
** [[Tundra]]
** [[Grassland]]
** [[Desert]]
** [[Tropical savanna]]
** [[Tropical forest]]
* Marine
** [[Ocean]]ic [[plankton]] and [[nekton]]
** Balanoid-gastropod-[[thallophyte]]
** [[Pelecypod]]-[[annelid]]
** [[Coral reef]]

=== Whittaker (1962, 1970, 1975) biome-types ===
[[File:Climate influence on terrestrial biome.svg|thumb|The distribution of vegetation types as a function of mean annual temperature and precipitation.]]
[[Robert Harding Whittaker|Whittaker]] classified biomes using two abiotic factors: precipitation and temperature. His scheme can be seen as a simplification of Holdridge's; more readily accessible, but missing Holdridge's greater specificity.

Whittaker based his approach on theoretical assertions and empirical sampling. He had previously compiled a review of biome classifications.<ref>{{cite journal|last=Whittaker |first=Robert H. |journal=[[Botanical Review]] |title=Classification of Natural Communities |volume=28 |number=1 |date=January–March 1962 |pages=1–239|doi=10.1007/BF02860872 |bibcode=1962BotRv..28....1W |s2cid=25771073 }}</ref>

==== Key definitions for understanding Whittaker's scheme ====
* [[Physiognomy]]: sometimes referring to the plants' appearance; or the biome's apparent characteristics, outward features, or appearance of ecological communities or species – including plants.
* Biome: a grouping of terrestrial ecosystems on a given continent that is similar in vegetation structure, physiognomy, features of the environment and characteristics of their animal communities.
* [[Formation (vegetation)|Formation]]: a major kind of community of plants on a given continent.
* Biome-type: grouping of convergent biomes or formations of different continents, defined by physiognomy.
* Formation-type: a grouping of convergent formations.

Whittaker's distinction between biome and formation can be simplified: formation is used when applied to [[plant communities]] only, while biome is used when concerned with both plants and animals. Whittaker's convention of biome-type or formation-type is a broader method to categorize similar communities.<ref name="Whittaker1975">{{cite book|last1=Whittaker |first1=Robert H. |title=Communities and Ecosystems |location=New York |publisher=[[MacMillan Publishing]] |date=1975}}</ref> <!---The world biome-types, as displayed on a world map, can be viewed at the following link: [http://www.marietta.edu/~biol/biomes/biomemap.html here] (This link is now dead.)--->

==== Whittaker's parameters for classifying biome-types ====
Whittaker used what he called "gradient analysis" of [[ecocline]] patterns to relate communities to climate on a worldwide scale. Whittaker considered four main ecoclines in the terrestrial realm.<ref name="Whittaker1975"/>
# Intertidal levels: The wetness gradient of areas that are exposed to alternating water and dryness with intensities that vary by location from high to low tide
# Climatic moisture gradient
# Temperature gradient by altitude
# Temperature gradient by latitude

Along these gradients, Whittaker noted several trends that allowed him to qualitatively establish biome-types:
* The gradient runs from favorable to the extreme, with corresponding changes in productivity.
* Changes in physiognomic complexity vary with how favorable of an environment exists (decreasing community structure and reduction of stratal differentiation as the environment becomes less favorable).
* Trends in the diversity of structure follow trends in species diversity; alpha and beta species diversities decrease from favorable to extreme environments.
* Each growth-form (i.e. grasses, shrubs, etc.) has its characteristic place of maximum importance along the ecoclines.
* The same growth forms may be dominant in similar environments in widely different parts of the world.

Whittaker summed the effects of gradients (3) and (4) to get an overall temperature gradient and combined this with a gradient (2), the moisture gradient, to express the above conclusions in what is known as the Whittaker classification scheme. The scheme graphs average annual precipitation (x-axis) versus average annual temperature (y-axis) to classify biome-types.

==== Biome-types ====
{{Div col}}
# [[Tropical rainforest]]
# [[Tropical seasonal rainforest]]
#* [[deciduous]]
#* [[semideciduous]]
# [[Temperate giant rainforest]]
# [[Montane rainforest]]
# [[Temperate deciduous forest]]
# [[Temperate evergreen forest]]
#* [[needleleaf]]
#* [[sclerophyll]]
# Subarctic-subalpine needle-leaved forests ([[taiga]])
# [[Elfin woodland]]
# [[Thorn forest]]
# [[Thorn scrub]]
# [[Temperate woodland]]
# [[Temperate shrublands]]
#* [[deciduous]]
#* [[heath]]
#* [[sclerophyll]]
#* [[subalpine-needleleaf]]
#* [[subalpine-broadleaf]]
# [[Savanna]]
# [[Temperate grassland]]
# [[Alpine grasslands]]
# [[Tundra]]
# [[Tropical desert]]
# [[Warm-temperate desert]]
# [[Cool temperate desert scrub]]
# [[Arctic-alpine desert]]
# [[Bog]]
# [[Tropical fresh-water swamp forest]]
# [[Temperate fresh-water swamp forest]]
# [[Mangrove swamp]]
# Salt marsh
# Wetland<ref>Whittaker, R. H. (1970). ''Communities and Ecosystems''. Toronto, pp. 51–64, [https://books.google.com/books?id=T6m0AAAAIAAJ].</ref>
{{Div col end}}

=== Goodall (1974–) ecosystem types ===
The multi-authored series ''Ecosystems of the World'', edited by [[David W. Goodall]], provides a comprehensive coverage of the major "ecosystem types or biomes" on Earth:<ref>{{cite book|editor-last=Goodall |editor-first=D. W. |title=Ecosystems of the World |publisher=[[Elsevier]] |location=Amsterdam |volume=36 |url=https://www.elsevier.com/books/book-series/ecosystems-of-the-world |archive-url=https://web.archive.org/web/20160918205830/https://www.elsevier.com/books/book-series/ecosystems-of-the-world |archive-date=2016-09-18}}</ref>

{{Ordered list |list_style_type=upper-roman
|Terrestrial Ecosystems
  {{Ordered list |list_style_type=upper-alpha
  |Natural Terrestrial Ecosystems
    {{Ordered list
    |Wet Coastal Ecosystems
    |Dry Coastal Ecosystems
    |Polar and Alpine Tundra
    |Mires: Swamp, Bog, Fen, and Moor
    |Temperate Deserts and Semi-Deserts
    |Coniferous Forests
    |Temperate Deciduous Forests
    |Natural Grasslands
    |Heathlands and Related Shrublands
    |Temperate Broad-Leaved Evergreen Forests
    |Mediterranean-Type Shrublands
    |Hot Deserts and Arid Shrublands
    |Tropical Savannas
    |Tropical Rain Forest Ecosystems
    |Wetland Forests
    |Ecosystems of Disturbed Ground
    }}
  |Managed Terrestrial Ecosystems
    {{Ordered list|start = 17
    |Managed Grasslands
    |Field Crop Ecosystems
    |Tree Crop Ecosystems
    |Greenhouse Ecosystems
    |Bioindustrial Ecosystems
    }}
  }}
|Aquatic Ecosystems
  {{Ordered list |list_style_type=upper-alpha
  |Inland Aquatic Ecosystems
    {{Ordered list|start = 22
    |River and Stream Ecosystems
    |Lakes and Reservoirs
    }}
  |Marine Ecosystems
    {{Ordered list|start = 24
    |Intertidal and Littoral Ecosystems
    |Coral Reefs
    |Estuaries and Enclosed Seas
    |Ecosystems of the Continental Shelves
    |Ecosystems of the Deep Ocean
    }}
  |Managed Aquatic Ecosystems
    {{Ordered list|start = 29|Managed Aquatic Ecosystems}}
  }}
|Underground Ecosystems
  {{Ordered list|start = 30|Cave Ecosystems}}
}}

=== Walter (1976, 2002) zonobiomes ===
The eponymously named [[Heinrich Walter]] classification scheme considers the seasonality of temperature and precipitation. The system, also assessing precipitation and temperature, finds nine major biome types, with the important climate traits and [[vegetation classification|vegetation types]]. The boundaries of each biome correlate to the conditions of moisture and cold stress that are strong determinants of plant form, and therefore the vegetation that defines the region. Extreme conditions, such as flooding in a swamp, can create different kinds of communities within the same biome.<ref name="WalterBreckle"/><ref>{{cite book |last=Walter |first=H. |date=1976 |title=Die ökologischen Systeme der Kontinente (Biogeosphäre). Prinzipien ihrer Gliederung mit Beispielen |language=de |trans-title=The ecological systems of the continents (biogeosphere). Principles of their outline with examples |location=Stuttgart}}</ref><ref>{{cite book |last1=Walter |first1=H. |last2=Breckle |first2=S-W. |date=1991 |title=Ökologie der Erde |language=de |trans-title=Ecology of the Earth |volume=1, Grundlagen |location=Stuttgart}}</ref>

{| class="wikitable"
! Number
! Zonobiome
! Zonal soil type
! Zonal vegetation type
|-
! ZB I
| [[Equatorial region|Equatorial]], always moist, little temperature seasonality
| Equatorial brown clays
| Evergreen [[tropical rainforest]]
|-
! ZB II
| [[Tropical]], summer rainy season and cooler "winter" dry season
| Red clays or red earths
| [[Tropical seasonal forest]], seasonal [[Tropical and subtropical dry broadleaf forests|dry forest]], scrub, or savanna
|-
! ZB III
| [[Subtropical]], highly seasonal, [[arid]] climate
| Serosemes, sierozemes
| Desert vegetation with considerable exposed surface
|-
! ZB IV
| [[Mediterranean]], winter rainy season and summer drought
| Mediterranean brown earths
| [[Sclerophyll]]ous (drought-adapted), frost-sensitive shrublands and woodlands
|-
! ZB V
| Warm temperate, occasional frost, often with summer rainfall maximum
| Yellow or red forest soils, slightly podsolic soils
| Temperate evergreen forest, somewhat frost-sensitive
|-
! ZB VI
| [[Nemoral]], moderate climate with winter freezing
| Forest brown earths and grey forest soils
| Frost-resistant, [[deciduous]], temperate forest
|-
! ZB VII
| [[continental climate|Continental]], arid, with warm or hot summers and cold winters
| Chernozems to serozems
| Grasslands and temperate deserts
|-
! ZB VIII
| [[Boreal climate|Boreal]], cold temperate with cool summers and long winters
| Podsols
| Evergreen, frost-hardy, needle-leaved forest ([[taiga]])
|-
! ZB IX
| [[polar climate|Polar]], short, cool summers and long, cold winters
| Tundra humus soils with solifluction ([[permafrost]] soils)
| Low, evergreen vegetation, without trees, growing over permanently frozen soils
|-
|}

=== Schultz (1988) eco-zones ===
Schultz (1988, 2005) defined nine ''ecozones'' (his concept of ecozone is more similar to the concept of biome than to the concept of [[biogeographic realm|ecozone]] of BBC):<ref name="Schultz">Schultz, J. ''Die Ökozonen der Erde'', 1st ed., Ulmer, Stuttgart, Germany, 1988, 488 pp.; 2nd ed., 1995, 535 pp.; 3rd ed., 2002; 4th ed., 2008; 5th ed., 2016. Transl.: ''The Ecozones of the World: The Ecological Divisions of the Geosphere''. Berlin: Springer-Verlag, 1995; 2nd ed., 2005, [https://books.google.com/books?id=V9L8yPzAjxIC].</ref>
{{Div col}}
# polar/subpolar zone
# boreal zone
# humid mid-latitudes
# dry mid-latitudes
# subtropics with winter rain
# subtropics with year-round rain
# dry tropics and subtropics
# tropics with summer rain
# tropics with year-round rain
{{Div col end}}

=== Bailey (1989) ecoregions ===
[[Robert Bailey (geographer)|Robert G. Bailey]] nearly developed a [[biogeography|biogeographical]] classification system of [[ecoregion]]s for the United States in a map published in 1976. He subsequently expanded the system to include the rest of North America in 1981, and the world in 1989. The Bailey system, based on climate, is divided into four domains (polar, humid temperate, dry, and humid tropical), with further divisions based on other climate characteristics (subarctic, warm temperate, hot temperate, and subtropical; marine and continental; lowland and mountain).<ref>{{cite web |url=http://www.fs.fed.us/land/ecosysmgmt/index.html |archive-url=https://web.archive.org/web/20090101030631/http://www.fs.fed.us/land/ecosysmgmt/index.html |archive-date=2009-01-01 |title=Bailey System |publisher=[[US Forest Service]]}}</ref><ref>{{cite journal |last=Bailey |first=R. G. |date=1989 |title=Explanatory supplement to ecoregions map of the continents. |journal=[[Environmental Conservation (journal)|Environmental Conservation]] |volume=16 |issue=4 |pages=307–309|doi=10.1017/S0376892900009711 |bibcode=1989EnvCo..16..307B |s2cid=83599915 }} [With map of land-masses of the world, "Ecoregions of the Continents – Scale 1 : 30,000,000", published as a supplement.]</ref>
* '''100 Polar Domain'''
** 120 [[Tundra]] Division (Köppen: [[Ice Cap Climate|Ft]])
** M120 Tundra Division&nbsp;– Mountain Provinces
** 130 Subarctic Division (Köppen: [[Tundra|E]])
** M130 Subarctic Division&nbsp;– Mountain Provinces
* '''200 Humid Temperate Domain'''
** 210 Warm Continental Division (Köppen: portion of [[Humid continental climate|Dcb]])
** M210 Warm Continental Division&nbsp;– Mountain Provinces
** 220 Hot Continental Division (Köppen: portion of [[Humid continental climate|Dca]])
** M220 Hot Continental Division&nbsp;– Mountain Provinces
** 230 Subtropical Division (Köppen: portion of [[Humid subtropical climate|Cf]])
** M230 Subtropical Division&nbsp;– Mountain Provinces
** 240 Marine Division (Köppen: [[Oceanic climate|Do]])
** M240 Marine Division&nbsp;– Mountain Provinces
** 250 Prairie Division (Köppen: arid portions of [[Humid subtropical climate|Cf]], [[Humid continental climate|Dca]], [[Humid continental climate|Dcb]])
** 260 Mediterranean Division (Köppen: [[Mediterranean climate|Cs]])
** M260 Mediterranean Division&nbsp;– Mountain Provinces
* '''300 Dry Domain'''
** 310 Tropical/Subtropical Steppe Division
** M310 Tropical/Subtropical Steppe Division&nbsp;– Mountain Provinces
** 320 Tropical/Subtropical Desert Division
** 330 Temperate Steppe Division
** 340 Temperate Desert Division
* '''400 Humid Tropical Domain'''
** 410 Savanna Division
** 420 Rainforest Division

{{Anchor|Biome_WWF_System}}

=== Olson & Dinerstein (1998) biomes for WWF / Global 200 ===
{{Main|Global 200}}

[[File:Biomes_of_the_world.svg|thumb|upright 2
|<small>Terrestrial biomes of the world according to Olson & Dinerstein et al. and used by the WWF and Global 200.
{{Legend|#447821|01. [[Tropical and subtropical moist broadleaf forests]]}}
{{Legend|#D4AA00|02. [[Tropical and subtropical dry broadleaf forests]]}}
{{Legend|#66FF00|03. [[Tropical and subtropical coniferous forests]]}}
{{Legend|#71C837|04. [[Temperate broadleaf and mixed forests]]}}
{{Legend|#005500|05. [[Temperate coniferous forests]]}}
{{Legend|#2CA05A|06. [[Taiga|Taiga and Boreal forest]]}}
{{Legend|#FFDD55|07. [[Tropical and subtropical grasslands, savannas, and shrublands]]}}
{{Legend|#CDDE87|08. [[Temperate grasslands, savannas, and shrublands]]}}
{{Legend|#80B3FF|09. [[Flooded grasslands and savannas]]}}
{{Legend|#C6AFE9|10. [[Montane grasslands and shrublands]]}}
{{Legend|#87DECD|11. [[Tundra]]}}
{{Legend|#C87137|12. [[Mediterranean forests, woodlands, and scrub]]}}
{{Legend|#FFF6D5|13. [[Deserts and xeric shrublands]]}}
{{Legend|#D400AA|14. [[Mangrove forest|Mangroves]]}}
{{Legend|#ECECEC|[[w:fr:Zones terrestres abiotiques|Rock and Ice, or Abiotic Land Zones (French)]]}}
</small>
]]

A team of biologists convened by the [[World Wide Fund for Nature|World Wildlife Fund]] (WWF) developed a scheme that divided the world's land area into [[biogeographic realm]]s (called "ecozones" in a BBC scheme), and these into [[ecoregion]]s (Olson & Dinerstein, 1998, etc.). Each ecoregion is characterized by a main biome (also called major habitat type).<ref name="Olson1998">Olson, D. M. & E. Dinerstein (1998). The Global 200: A representation approach to conserving the Earth's most biologically valuable ecoregions. ''Conservation Biol.'' 12:502–515, [http://planet.uwc.ac.za/nisl/Biodiversity/pdf/OlsonDinerstein1998.pdf] {{Webarchive|url=https://web.archive.org/web/20161007001330/http://planet.uwc.ac.za/nisl/Biodiversity/pdf/OlsonDinerstein1998.pdf|date=2016-10-07}}.</ref><ref name="Olson2001">Olson, D. M., Dinerstein, E., Wikramanayake, E. D., Burgess, N. D., Powell, G. V. N., Underwood, E. C., D'Amico, J. A., Itoua, I., Strand, H. E., Morrison, J. C., Loucks, C. J., Allnutt, T. F., Ricketts, T. H., Kura, Y., Lamoreux, J. F., Wettengel, W. W., Hedao, P., Kassem, K. R. (2001). Terrestrial ecoregions of the world: a new map of life on Earth. ''Bioscience'' 51(11):933–938, [http://wolfweb.unr.edu/~ldyer/classes/396/olsonetal.pdf] {{Webarchive|url=https://web.archive.org/web/20120917072415/http://wolfweb.unr.edu/~ldyer/classes/396/olsonetal.pdf|date=2012-09-17}}.</ref>

This classification is used to define the [[Global 200]] list of [[ecoregion]]s identified by the WWF as priorities for conservation.<ref name="Olson1998" />

For the [[terrestrial ecoregions]], there is a specific EcoID, format XXnnNN (XX is the [[biogeographic realm]], nn is the biome number, NN is the individual number).

==== [[Biogeographic realm]]s (terrestrial and freshwater) ====
[[File:Western palearctic biomes.svg|thumb|upright 2|<small>The western [[Palearctic realm|Palearctic terrestrial ecozone]] has 9 of the 14 biomes numbered by Olson & Dinerstein et al.
{{Legend|#71C837|04. [[Temperate broadleaf and mixed forests]]}}
{{Legend|#005500|05. [[Temperate coniferous forests]]}}
{{Legend|#2CA05A|06. [[Taiga|Taiga and Boreal forest]]}}
{{Legend|#CDDE87|08. [[Temperate grasslands, savannas, and shrublands]]}}
{{Legend|#80B3FF|09. [[Flooded grasslands and savannas]]}}
{{Legend|#C6AFE9|10. [[Montane grasslands and shrublands]]}}
{{Legend|#87DECD|11. [[Tundra]]}}
{{Legend|#C87137|12. [[Mediterranean forests, woodlands, and scrub]]}}
{{Legend|#FFF6D5|13. [[Deserts and xeric shrublands]]}}
{{Legend|#ECECEC|Rock and Ice, or Abiotic Land Zones}}
</small>]]

{{Div col}}
* NA: [[Nearctic realm|Nearctic]]
* PA: [[Palearctic realm|Palearctic]]
* AT: [[Afrotropical realm|Afrotropic]]
* IM: [[Indomalayan realm|Indomalaya]]
* AA: [[Australasian realm|Australasia]]
* NT: [[Neotropical realm|Neotropic]]
* OC: [[Oceanian realm|Oceania]]
* AN: [[Antarctic realm|Antarctic]]<ref name="Olson2001" />
{{Div col end}}
The applicability of the realms scheme above – based on Udvardy (1975)—to most freshwater taxa is unresolved.<ref name="Abell">Abell, R., M. Thieme, C. Revenga, M. Bryer, M. Kottelat, N. Bogutskaya, B. Coad, N. Mandrak, S. Contreras-Balderas, W. Bussing, M. L. J. Stiassny, P. Skelton, G. R. Allen, P. Unmack, A. Naseka, R. Ng, N. Sindorf, J. Robertson, E. Armijo, J. Higgins, T. J. Heibel, E. Wikramanayake, D. Olson, H. L. Lopez, R. E. d. Reis, J. G. Lundberg, M. H. Sabaj Perez, and P. Petry. (2008). Freshwater ecoregions of the world: A new map of biogeographic units for freshwater biodiversity conservation. ''BioScience'' 58:403–414, [http://www.feow.org/downloads/Abell_et_al_08_BioScience.pdf] {{Webarchive|url=https://web.archive.org/web/20161006151241/http://www.feow.org/downloads/Abell_et_al_08_BioScience.pdf|date=2016-10-06}}.</ref>

==== Biogeographic realms ([[Marine ecoregion|marine]]) ====
{{Div col}}
* [[Arctic]]
* [[Temperate Northern Atlantic]]
* [[Temperate Northern Pacific]]
* [[Tropical Atlantic]]
* [[Western Indo-Pacific]]
* [[Central Indo-Pacific]]
* [[Eastern Indo-Pacific]]
* [[Tropical Eastern Pacific]]
* [[Temperate South America]]
* [[Temperate Southern Africa]]
* [[Temperate Australasia]]
* [[Southern Ocean]]<ref name="Spalding" >Spalding, M. D. et al. (2007). Marine ecoregions of the world: a bioregionalization of coastal and shelf areas. ''BioScience'' 57: 573–583, [http://algae.thu.edu.tw/lab/2013_Meeting_FebJune/2007_Marine_ecoregions_of_the_world.pdf] {{Webarchive|url=https://web.archive.org/web/20161006104440/http://algae.thu.edu.tw/lab/2013_Meeting_FebJune/2007_Marine_ecoregions_of_the_world.pdf |date=2016-10-06 }}.</ref>
{{Div col end}}

==== Biomes (terrestrial) ====
# [[Tropical and subtropical moist broadleaf forests]] (tropical and subtropical, humid)
# [[Tropical and subtropical dry broadleaf forests]] (tropical and subtropical, semihumid)
# [[Tropical and subtropical coniferous forests]] (tropical and subtropical, semihumid)
# [[Temperate broadleaf and mixed forests]] (temperate, humid)
# [[Temperate coniferous forests]] (temperate, humid to semihumid)
# [[Taiga|Boreal forests/taiga]] (subarctic, humid)
# [[Tropical and subtropical grasslands, savannas, and shrublands]] (tropical and subtropical, semiarid)
# [[Temperate grasslands, savannas, and shrublands]] (temperate, semiarid)
# [[Flooded grasslands and savannas]] (temperate to tropical, fresh or brackish water inundated)
# [[Montane grasslands and shrublands]] (alpine or montane climate)
# [[Tundra]] (Arctic)
# [[Mediterranean forests, woodlands, and scrub]] or [[sclerophyll forest]]s (temperate warm, semihumid to semiarid with winter rainfall)
# [[Deserts and xeric shrublands]] (temperate to tropical, arid)
# [[Mangrove]] (subtropical and tropical, salt water inundated)<ref name="Olson2001" />

==== Biomes (freshwater) ====
According to the WWF, the following are classified as [[freshwater]] biomes:<ref>"Freshwater Ecoregions of the World: Major Habitat Types" {{cite web |url=http://www.feow.org/mht.php |title=Freshwater Ecoregions of the World |access-date=2008-05-13 |url-status=dead |archive-url=https://web.archive.org/web/20081007024422/http://www.feow.org/mht.php |archive-date=2008-10-07}}</ref>
{{Div col}}
* Large [[lake]]s
* Large [[river deltas]]
* Polar [[freshwater]]s
* Montane [[freshwater]]s
* Temperate [[Upland and lowland (freshwater ecology)|coastal rivers]]
* Temperate floodplain rivers and [[wetland]]s
* Temperate [[Upland and lowland (freshwater ecology)|upland rivers]]
* Tropical and subtropical [[Upland and lowland (freshwater ecology)|coastal rivers]]
* Tropical and subtropical floodplain rivers and [[wetland]]s
* Tropical and subtropical [[Upland and lowland (freshwater ecology)|upland rivers]]
* Xeric freshwaters and [[endorheic basin]]s
* [[Oceanic islands]]
{{Div col end}}

==== Biomes (marine) ====
Biomes of the coastal and [[continental shelf]] areas ([[neritic zone]]):
* Polar
* Temperate shelves and sea
* Temperate [[upwelling]]
* Tropical [[upwelling]]
* [[Coral reef|Tropical coral]]<ref>{{cite web|website=[[World Wide Fund]] |url=http://www.worldwildlife.org/science/ecoregions/marine/item1266.html |title=Marine Ecoregions of the World |archive-url=https://web.archive.org/web/20090207101156/http://www.worldwildlife.org/science/ecoregions/marine/item1266.html |archive-date=2009-02-07}}</ref>

==== Summary of the scheme ====
* [[Biosphere]]
** [[Biogeographic realm]]s (terrestrial) (8)
*** [[Ecoregions]] (867), each characterized by a biome, a major habitat type (14)
**** [[Ecosystems]] ([[biotope]]s)
* [[Biosphere]]
** [[Biogeographic realm]]s (freshwater) (8)
*** [[Ecoregions]] (426), each characterized by a biome, a major habitat type (12)
**** [[Ecosystems]] (biotopes)
* [[Biosphere]]
** Biogeographic realms (marine) (12)
*** ([[Ecoregion#Marine|Marine provinces]]) (62)
**** [[Ecoregions]] (232), each characterized by a biome, a major habitat type (5)
***** [[Ecosystems]] (biotopes)

Example:
* [[Biosphere]]
** [[Biogeographic realm]]: [[Palearctic]]
*** [[Ecoregion]]: [[Dinaric Mountains mixed forests]] (PA0418); biome type: [[temperate broadleaf and mixed forests]]
**** [[Ecosystem]]: [[Orjen]], vegetation belt between 1,100 and 1,450 m, Oromediterranean zone, nemoral zone (temperate zone)
***** [[Biotope]]: ''Oreoherzogio-Abietetum illyricae'' Fuk. ([[Dinaric calcareous block fir forest#Plant list|Plant list]])
****** Plant: Silver fir (''[[Abies alba]]'')