Zonal models of biogeography

from Wikipedia, the free encyclopedia

The generic term zonal models of biogeography can be used to summarize the zonal models of the bio- and geosciences , which divide the earth's land surface into delimited, largely coherent large-scale landscapes with various combinations of ecological characteristics.

Basics

The basis are the climatic zones , which lie like belts around the earth from the tropics to the two polar zones. In most cases, they are the primary cause of the earth's different ecosystems. Against this background, it is basically possible to delimit similar landscapes in a meaningful way, so that a manageable number of biogeographical zones of the earth is created, the arrangement of which roughly reflects the sequence of the climatic zones. However, the altitude levels of the mountains and other extrazonal flora break through the zonal structure, so that in the literature one speaks more often of plant formations or biogeographical regions ( biomes ) instead of zones : Biogeographical models that have no direct relation to the climate (e.g. the flora or fauna kingdom ) are not zonal models.

Background and demarcation problems

The delimitation of zonal landscapes or altitudes is considered a complex undertaking; Many researchers have dealt with it (especially since the 18th century). In the process, a number of scientific models were created (attempts to represent the real conditions in a greatly simplified manner, as clearly as possible and yet as precisely as possible). Some have only a few parameters; others very many. If the scale of a model is very large, as is the case with the large global zones, the presentation of the results becomes more and more similar despite the different number of parameters used, also in the comparison of maps of vegetation zones, zonobiomes or eco-zones.

On the other hand, there are the differences that can be determined when looking at different maps of the same model : Although the authors themselves determine which number of zones makes sense to them, it is also crucial that the transitions between the zones in reality rarely have one correspond to the sharply drawn border. The boundaries are therefore relatively arbitrary; depending on the subsequent author or application area, they differ slightly.

Most models depict a potential state of the earth that would occur if human activities since the beginning of industrialization - which have a massive impact on natural conditions - did not exist. The two geobotanists Walter and Breckle pointed out at the beginning of the 1980s that the zonal structure of the earth in some areas that were used over long periods of time can only be deduced from relics of natural vegetation; The ongoing destruction of nature means that it will soon be difficult to reconstruct the original conditions. Global warming had and is a particularly big influence . In addition to classic models, there are modern concepts that use satellite data and that also depict anthropogenic landscape societies and characteristics.

For the origin and delimitation of the various geozonal terms, see also: Geozone

Systematics

There is a wide variety of terms that are often used interchangeably. As in any science, it happens that a term has more or less different meanings in different technical languages, that different professors grasp a term narrower or broader and that terms are reinterpreted or redefined over time.

Examples:

Shift in the biogeographical zones due to climate change

Animation: Predicted shift of the climate zones according to the "worst case scenario" of the IPCC . Legend and explanations in the main article → Consequences of global warming

The man-made global warming that is currently taking place will undoubtedly lead to a shift in the climatic zones and thus also in the landscape zones over the coming decades. As a rule, it will be a north shift (or elevation shift of the elevation steps ). According to information from the BMBF in 1990, an increase in temperature per degree Celsius will shift the climate zones by 100 to 200 km.

It is very likely that important habitats such as wetlands , tundras , high alpine and island biotopes will be lost. In the boreal and tropical forests , a significant increase in forest fires is to be expected. The water balance in many landscape zones will change. The deserts will continue to expand. Heat-loving microbes in the tropical and subtropical landscape zones will spread to the north, so that z. For example, diseases such as Q fever or malaria can be expected in Central Europe in the future .

It depends on the speed at which climate change takes place whether and how well communities can adapt. A rapid rise in temperatures of several degrees Celsius will have consequences for most ecosystems; these are difficult to predict because of the complexity of the systems. It is certain that the extinction of animal and plant populations will increase.

Example: FAO Ecozones

The FAO map shown below is a clear example of the division of the earth into biogeographical zones ( Ecozones is not synonymous with the German term eco-zones : The FAO model is rather an independent attempt to combine many vegetation zones into a more manageable number.)

Ecozones of the Earth , design by the FAO

. (largely equal-area Eckert VI map projection )

Polar u. Boreal Moderate Subtropical Tropical
Desert u. Semi-desert (and ice)    Desert u. Semi-desert    Desert u. Semi-desert    Desert u. Semi-desert   
 Tundra  steppe  steppe  Shrub savannah
 Forest tundra  Continental forest     Dry forest  Dry forest
 taiga  Ocean forest  Wet forest  Moist forest and savannah
 Rainforest
 Mountain vegetation     Mountain vegetation  Mountain vegetation     Mountain vegetation


Note : The different mountain vegetations vary greatly from deserts to forests; even within the same climates!

literature

  • Dieter Heinrich, Manfred Hergt: dtv atlas on ecology. 3rd edition, Deutscher Taschenbuch-Verlag (dtv), Munich 1994, ISBN 3-423-03228-6
  • G. Grabherr: Color Atlas of Earth's Ecosystems . Ulmer, Stuttgart 1997. ISBN 3-8001-3489-6
  • Jürgen Schultz: Handbook of the eco-zones. Ulmer, Stuttgart 2000. ISBN 3-8252-8200-7
  • W. Frey, R. Lösch: Textbook of Geobotany . Gustav Fischer, Stuttgart 1998. ISBN 3-437-25940-7

Individual evidence

  1. ↑ a b Heinz Nolzen (Ed.): Handbuch des Geographieunterrichts, Vol.12 / 2, Geozonen. Aulis Verlag Deubner & Co. KG, Cologne 1995
  2. ↑ http://www.biosphaere.info/biosphaere/index.php?artnr=000192 Extensive information and sources on www.biosphaere.info
  3. ↑ The world has to sweat for at least 1000 years. In: Spiegel Online. January 27, 2009, accessed December 2, 2014 .