Biome

The term biome refers to the dominant community ( biocenosis ) or equal to the entire ecosystem of a dominant broad range of the earth's surface. This means that specific biomes large living rooms with the potentially occurring in plants and animals ( biocenosis ) and all inanimate factors. The term was originally created as a short form of the word Bioformation

The biome concept was developed for continental ( terrestrial ) biological communities and is today mainly used for those parts of the earth's surface. A terrestrial biome gets its own name according to its typical, fully developed plant formation or after a stand-out feature of his inanimate ( abiotic ) environment. These properties of the existing macro climate are often used. Only in recent years also aquatic biomes were reported.

The biome concept goes back to research approaches in the life sciences and is to this day called, especially in life science textbooks. The more geoscientifically coined term " eco-region " has a very large content similarity to biome and is therefore used today often synonymous. The same applies to the geozonalen derivatives " Zonobiom " (see below ) and " ecozone ", as well as a number of other terms coined by geoscientists.

The delineation of large ecosystems by artverwandtschaftlicher relationships based on a common geological development, are not referred to in biology as " biome ", rather than " Floren or Faunenreich ".

• 4.1 biome types
• 4.2 Landbiome

Term

The word biome is now interpreted as a short form of the word Bioformation.

• Bioformation: The entire biological community (plants, animals, fungi, micro-organisms ) of a vast area of ​​the earth's surface, recognizable by the plant formation of their climax vegetation.

The American botanist Frederic Edward Clements coined biome in a lecture on December 27, 1916. At that time he used the word even as a short synonym for biotic community ( biocenosis ). In this sense it was used in 1932 for the classification of biological communities.

So the original biome concept still had no direct relation to the substantive plant formation. This connection between plant formations and biome was only seven years later. A biome called henceforth the biocenosis of the climax vegetation, named after its plant formation (→ Potential natural vegetation):

"The biome or plant- animal formation is the basic community unit, did is, two separate communities, plant and animal, do not exist in the same area. The term biome ..., as here employed, is Regarded as the exact synonym of formation and climax When synthesis are used in the biotic sense. "

" The biome or plant -animal formation, is the basic unit of the community. It follows that two distinct communities of plants and animals not found in the same region of the world. The concept of ... biome, as used here, is regarded as the exact synonym for formation and Klimax [ company ], if these terms are used in their biological meanings. "

The biotic biome concept of 1939, which targeted only on the ecosystem of the climax vegetation, was quickly recognized and remained in use for decades. However, pioneered since the 1960s to a conceptual shift in content. It was initiated by the German - Russian Plant ecologists Heinrich Karl Walter. He wrote in 1960 that the biome - term would be content not strictly defined. Thus, the tight binding of biome - concept had been broken at the biocenosis. Against this background, published ten years later, the American plant ecologist Robert Harding Whittaker biome its definition:

" A major kind of community, Conceived in terms of physiognomy, on a continent givenName is a biome or formation. ( Formation is used When the concern is with plant communities only, biome When the concern is with Both plants and animals ....) A biome is a grouping of terrestrial ecosystems on a givenName continent did are similar in vegetation structure or physiognomy ... Biome The concept is most Widely Applied to land ecosystems but can therefore be Applied in aquatic environments. "

" One of the outstanding form of community that is recognized by their appearance, situated on a given continent a biome or formation. ( Formation is used when only plant communities are taken into account, biome if both plants and animals are considered ... ) A biome is a grouping of land-based ecosystems on a given continent, which is building its vegetation or in their looks the same ... The biome concept is most often used for terrestrial ecosystems, but can be used equally for aquatic environments. "

Whittaker biome definition began biotic ( "kind of community" ) and ended ecologically ( " Widely Applied to land ecosystems " ): After Whittaker a biome called a composite of ecosystems, which can be summarized because of their biological communities to the same end. Thus it has departed from biotic biome - term. Since at least the 1970s until the 1990s, were both the old biotic, as well as the new ecological biome - term in use. These were used conceptual uncertainties. They were cleared in 1995 by the German geographer Heinz Nolzen tentatively:

" For every type of climate and climatic soil type with characteristic plant and animal communities. Such characteristic ... plant and animal communities of a climatically uniform habitat are as Bioformationen ( plant and animal formations ), referred to as their habitats biomes, large living rooms or macro ecosystems. The biomes are the ecological macro structure of the [ eco ] sphere. "

Nolzen suggested it, again neatly separate the two biome terms of each other. For the biotic biome concept he wanted a hand Bioformation return to the original word formation. Biome itself should be reserved solely for the ecological biome - term on the other hand from now on. His proposal did not sit through. On the one hand he had to let him merely print in a handbook for geography teachers. On the other hand, the word Bioformation had now received a new bioscience importance. Instead, just put the new ecological biome - term by more and more, while the old term was biotic resistant less used:

" [ Biome Means ] a regional ecosystem with a distinct assemblage of vegetation, animals, microbes, and physical environment reflecting Often A Certain climate and soil. "

" [ Biome called ] a regional ecosystem with a particular combination of plants, animals, micro-organisms and inanimate environmental characteristics that reflect the often specific climate and soil conditions. "

According to the new definition of terms joined biome and the abiotic environment ( Physio System) with a. By the end of the 1990s the original, pure biotic biome concept had been replaced by the modified, ecological biome - term. The younger term view makes today biome but synonymous with two other words: ecoregion or ecozone. Unlike biome both terms not of organic, but of geoscientists were minted. Content, but there are similarities between them and the ecological biome - term. With few exceptions, the ecological biome concept has now yet fully replaced the biotic biome - term.

Because biomes based on the general appearance of their climax vegetation - so using their " plant formation " - are reported, plays the exact species composition not matter to them: If it does not biomes are plant communities. This causes a transcontinental identifiability.

A forming same appearance - a same plant formation - with different species inventory is the result of an analogous evolution: Different species that are not necessarily closely related to each other, have evolved similar shapes due to similar environmental conditions. Therefore let same formative similarities also the conclusion to be resembling environmental conditions.

Biomgröße

One difficulty of the biome - concept based on the fact that the biological community with this one word - or ecosystems - different sized areas of the ecosphere can be named.

• Biome as Zonobiom: The Zonobiom names the biological community - or the ecosystem - a Erdraums zonal ( erdumspannender ) expansion, its location is oriented mainly to the climate zones. Although the number between the authors fluctuates slightly less than 30 Zonobiome worldwide but always reported. It was on such a small number can be detected when an author uses the term biome for Zonobiome. Zonobiome are also called Hauptbiome, larger biomes or biome types.

• Biome as Eu - biome: Each Zonobiom can be further subdivided. Such subdivisions form the actual ( Eu ) biomes. The Eu - biome names the biological community - or the ecosystem - a Erdraums regional expansion. While the global market is only a handful Zonobiome, several hundred Eu - biomes can be recognized worldwide. It was on such a large number can be detected when an author uses the term biome for Eu - biomes.

Biome by Walter and Breckle: Zonobiome, Orobiome, Pedobiome

"We understand [ under Eu - biome ] a gear or landscape unit, eg in the climatic series of the central European deciduous forests or in the deserts, the Sonoran Desert ... There are hundreds of Eu - world biomes. "

In German-speaking countries, the system of biomes according to Heinrich Karl Walter and Sigmar -Walter Breckle could establish. Your biomes do not have a pure biotic, but rather an ecological character. So the biomes not only certain vegetation formations, but also certain soil types are mapped. Although the somewhat rigorous soil type mappings of the two authors can be questioned. Nevertheless, includes soil formation often interactions between living things and inanimate lithosphere.

It follows that the biome - term ecological owns shares by Walter and Breckle. Elsewhere their biomes are even referred to as " habitats ". The references to the abiotic environmental features give these biomes ecological importance contents. They move so close to the ecoregions or ecozones.

Walter and Breckle distinguish three rows of biomes - Zonobiome, Orobiome and Pedobiome. The terms were invented by Heinrich Karl Walter and was first published in 1976.

• Zonobiome: A Zonobiom summarizes landscapes that have greater similarities in the studied characteristics climate, vegetation, wildlife and soils. The most important distinguishing factor here is valid and Walter Breckle the climate. The spatial orientation of the Zonobiome addressed accordingly in the first place according to the climate zones. Therefore Zonobiome lay quite similar climates, like a belt around the earth, from the tropics to the two polar regions. In this context, the system of Zonobiome joins the geozonalen models of biogeography.

• Orobiome: Orobiome form the mountain -related ( orographic ) In addition to number of biomes. They differ in their mountainous character of the surrounding Zonobiomen. Orobiome form narrow belt running around the mountains roam dependent on altitude (→ height levels). The Orobiome be divided according to their location in three groups: Unizonale Orobiome: Orobiome that lie within a single Zonobioms, for example, Tibesti, Kilimanjaro.
• Multizone Orobiome: Orobiome, extending through several Zonobiome, such as the Urals. For each intersected Zonobiom own sub- Orobiom is reported.
• Interzonal Orobiome: Orobiome that lie on the line between two Zonobiomen and separate them as an effective climate divide from each other, such as the Alps.

• Lithobiome: Pedobiome hardly weathered bedrock, such as lava flows.
• Psammobiome: Pedobiome on sand, as sand dunes.
• Halobiome: Pedobiome of saline soils, such as the Etosha Pan.
• Helobiome: Pedobiome the swamps, such as the Sudd.
• Hydrobiome: Pedobiome of waterlogged soils, for example, on the soil types Dy, sapropel and gyttja.
• Peinobiome: Pedobiome the nährsalzarmen soils, such as the Cerrado.
• Amphibiome: Pedobiome on temporarily flooded soils, for example, in watts or mangroves.

Each of the Zonobiome and sub- Zonobiome, Orobiome and Pedobiome in turn composed of Eu - biomes. In this way, a global biome mosaic of several hundred Eu - biomes. The division of the earth into biomes corresponding to the attempt to divide the extremely diverse spaces of the earth on the basis of some criteria legs reaching out far into larger spatial units. A big problem here is the fact that there is only smooth transitions and no clear borders drawn in nature in most cases. Walter and Breckle solve the problem by recruiting transitional spaces between the clearly definable core areas of biomes, which they described as ecotones. In such areas, the gradual passing from one to the next biome ( " ecological voltage compartments " ) are a wide variety of ecological niches. Consequently, a relatively large number of animal and plant species occur. So the subalpine altitudinal zone is considered ecotone between the Orobiomen the montane and alpine altitude level.

• The ecotones between Zonobiomen be called Zonoökotone or Zono - ecotones. Typical Zonoökotone example, the forest-tundra between the boreal and polar Zonobiom and the forest-steppe between the boreal and continental Zonobiom.

The concept of ecotones in 1988 taken in exactly the same meaning in the then newly developed concept of ecozones, the content does not differ much from Zonobiomen. However, more ecotones are explicitly represented as the ecozones cards published to date on current Zonobiom cards.

Tabular overview

Map

The Zonobiome after Heinrich Karl Walter and Sigmar -Walter Breckle been adopted by many authors in their own textbooks. They were, however, often simplified or were merely the most widespread or very distinctive biomes singled out. Above all, the Zonobiome each dominant vegetation were no longer makroklimatologisch named, but used directly for the designation.

Biomes according to Whittaker and Haggett: biome types and Landbiome

The breakdown by Zonobiomen goes back at least to the year 1976, and was introduced almost simultaneously in the English -speaking world. There, however, three years and five years earlier two other layouts for larger biomes had been published. From 1972 came the division of the British cultural geographer Peter Haggett and in 1970 those of the U.S. plant ecologists Robert Harding Whittaker.

Biome types

Robert Harding Whittaker has made ​​25 biome types. Compared with the Zonobiom outline which is almost three times as many major biomes. The striking numerical difference is due to the fact that Whittaker identified some ecosystems as a separate biome types that are merely classified by Walter and Breckle than Oro or Psammobiome within the larger Zonobiome. Harding's textbook was published in two editions, and had some influence. Ins German however, it was not transmitted.

Landbiome

The Zonobiome of Walter and Breckle and the biome types of Whittaker remain in a physio- geographical, a scientific point of view. The viewing angle covers the macro climate, the ecosystem on the basis of vegetation and possibly still the predominant soil type. Here Peter Haggett goes on. Because Haggett also has the action and economies of people in mind. He points to each of its twelve Landbiome traditional forms of agriculture and average population densities. He also tries - as in a similar way a decade later also German geographers - to close by the environmental structure of Landbiome on the natural area potential. To this end, he determined their productivity classes:

Peter Haggett expanded the biome concept to cultural geography content. However, his approach was even among geographers far less attention than the purely scientific Zonobiome or as the newer and with the Zonobiomen content congruent concept of ecozones.

Anthrome

From the composite term " anthropogenic biomes " the two American geographer Erle C. Ellis and Navin Ramankutty created the term " Anthrom " that they use in their 2008 published biome model. Here the focus is on the influence of human land use, as the humanity now consumes about one third of terrestrial net primary production and affects more than 75 % of the ice-free land surface more or less characteristic.