Ecozone

From Free net encyclopedia

Ecozones are global divisions which have their own characteristic interplay of climatic factors, morphodynamics, soil-forming processes, living conditions for plants and animals, and production potentials for agriculture and forestry. Correspondingly, they are distinguished by different climates, landforms, soil units, plant formations and biomes, and land use systems. In the (hierachical) systems of natural regions, whose basic unit is the ecotope, the term ecozone represents the highest class heading. A few of the ecozones are subdivided into comparatively independent subregions or ecoregions, such as the Polar subpolar zone, which is divided into the glacier-covered regions (ice deserts), the frost debris regions and the tundras. Some of these ecorgions are further subdivided into eco-provinces and eco-districts (in this hierachical order).

According to Schultz (1988, 2000, 2002 and 2005) nine ecozones can be defined:

1. Polar subpolar zone 2. Boreal zone 3. Temperate (or Humid) midlatitudes 4. Dry (or Arid) midlatitudes 5. Subtropics with winter rain (or Mediterranean-type subtropics) 6. Subtropics with year-round rain (or Humid subtropics) 7. Dry tropics and subtropics (or Tropical/subtropical arid lands) 8. Tropics with summer rain (or Seasonal tropics) 9. Tropics with year-round rain (or Humid tropics)

These ecozones occur in bands, often fragmentated because of the distribution of the continents and oceans, from the poles to the equator. Nearly all are present in both the Northern und Southern Hemispheres (see below; or see map in www.wikipedia.de: Ökozone).

The classification system of ecozones in the manner described can aid in establishing a kind of orientation guide which

- allows immediate listing of several important characteristics of any area on earth;

- and is suitable as a basis for further detailed investigation (starting with the question: in what way does a certain area in an ecozone differ from the overall characteristics of the ecozone in which it is found?).

References:

• Schultz, J.: Die Ökozonen der Erde, Ulmer Stuttgart, 3rd ed. 2002 (1st ed. 1988). ISBN 3-8252-1514-8

• Schultz, J.: Handbuch der Ökozonen, Ulmer Stuttgart 2000. ISBN 3-8252-8200-7

• Schultz, J.: The Ecozones of the World, Springer, Berlin Heidelberg New York, 2n ed. 2005. ISBN 3-5402-0014-2 und ISBN 3-5402-0014-7

Image:Global Ecozones kl.png

Image:Mergefrom.gif It has been suggested that Biogeographic Region be merged into this article or section. ([[{{{2|: talk:Ecozone}}}|Discuss]])

A biogeographical realm or ecozone is a biogeographical and ecological land classification system of the world first formally proposed by Miklos Udvardy in 1975 for conservation purposes. Arguably, biomes are better suited for conservational purposes.

8 biogeographical realms with unifying features of geography, fauna and flora are defined.

Image:Ecozones.png

Nearctic 22.9 mil. km² (including most of North America)
Palearctic 54.1 mil. km² (including the bulk of Eurasia and North Africa)
Afrotropic 22.1 mil. km² (including Sub-Saharan Africa)
Indomalaya 7.5 mil. km² (including the South Asian subcontinent and Southeast Asia)
Australasia 7.7 mil. km² (including Australia, New Guinea, and neighbouring islands)
Neotropic 19.0 mil. km² (including South America and the Caribbean)
Oceania 1.0 mil. km² (including Polynesia, Fiji and Micronesia)
Antarctic 0.3 mil. km² (including Antarctica)

Udvardy originally further divided the biogeographic realms into 203 biogeographical provinces (floral "regions" and faunal "provinces").

Intensive regional analyses of biodiversity patterns across five continents and biogeographical realms have been used by the World Wildlife Fund to define the boundaries of terrestrial ecoregions for the Global 200.

The biogeographic realms are also supporting current natural World Heritage sites.

Among zoologists, Nearctic and Paleartcic together make up the Holarctic zone, as these two zones have often been connected by the Bering land bridge and thus have very similar mammal and bird fauna.

[edit]