Editing Biome (section)

=== 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}}