Steppe
A steppe (from Russian степь, "step′‘) in physical geography refers to a biome region characterised by grassland plain without trees apart from those near rivers and lakes. The prairie (especially the shortgrass and mixed prairie) is an example of a steppe, though it is not usually called such. It may be semi-desert, or covered with grass or shrubs or both, depending on the season and latitude. The term is also used to denote the climate encountered in regions too dry to support a forest, but not dry enough to be a desert.
Steppes are characterized by a semi-arid and (usually) continental climate. Peaks can be recorded in the summer of up to 40 °C (104 °F) and in winter -40 °C (-40 °F). Besides this huge difference between summer and winter, the differences between day and night are also very great. In the highlands of Mongolia, 30 °C (86 °F) can be reached during the day with sub-zero °C (sub 32 °F) readings at night.
Also, the mid-latitude steppes can be summarised by hot summers and cold winters, averaging 250–500 mm (10-20 inches) of precipitation per year. Precipitation level alone is not what defines a steppe climate, potential evapotranspiration must also be taken into account.
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Two types of steppe
Two types of steppe can be recorded[1]:
- the temperate steppe, the "true" steppe, found in continental areas of the world; it can be further subdivided; as seen here.
- the subtropical steppe, a similar association of plants that can be found in the driest areas with a Mediterranean-like climate; it has usually a short wet period.
Peculiar types of steppe include Shrub-steppe and Alpine-steppe.
Locations
Cold steppe
The world's largest zone of all steppes, often referred to as "the Great Steppe", is found in southwest Russia and neighbouring countries in Central Asia, stretching from Ukraine in the west through Turkmenistan, Uzbekistan and Kazakhstan to the Altai, Koppet Dag and Tian Shan ranges. The vast Eurasian Steppe, as it is called, is bordered in the north (on the eastern side of the Urals) by the forested West Siberian Plain taiga, extending nearly as far as the Arctic Ocean.
The inner parts of Anatolia in Turkey, Central Anatolia and East Anatolia in particular and also some parts of Southeast Anatolia, are cold steppe.
The Pannonian Plain conforms another steppe climate in South Eastern Europe.
Another large steppe area (prairie) is located in the central United States and western Canada. The shortgrass prairie steppe is the westernmost part of the Great Plains region. The Channeled Scablands in Southern British Columbia and Washington State are an example of a steppe region in North America outside of the Great Plains.
Patagonia is another land dominated by a steppe. Relatively small steppes can be found in the inner part of the South Island of New Zealand, and in Hungary (the Puszta).
Subtropical steppe
In Europe, some Mediterranean areas have a steppe-like vegetation, such as central Sicily,parts of Greece in the southern Athens area [2] ,and central-eastern Spain, especially the southeastern coast (around Murcia), and places cut off from adequate moisture due to rain shadow effects such as Zaragoza.
In Asia, a subtropical steppe can be found in semi-arid lands that fringe the Thar Desert of the Indian subcontinent; in Australia it can be found in a belt surrounding the most severe deserts of the continent and around the Musgrave Ranges.
In North America this environment is typical of transition areas between zones with a Mediterranean climate and true deserts, such as Reno, Nevada, and the inner part of California. In South America the most important zone with a warm steppe is the Pampa.
Tropical grasslands and shrublands similar to steppe
Other zones dominated by grasslands and shrublands similar to steppe can be found in tropical areas of the world. In these locations, necessary rainfall to separate steppes from true deserts may be half as much again due to greater evapotranspiration. These include transition zones between savanna and severe desert such as the Sahel that fringes the true Sahara.
Another significant "tropical steppe", noteworthy for not grading into desert, is the Sertão of northeastern Brazil.
See also
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References
Notes
Sources
- Ecology and Conservation of Steppe-land Birds by Manuel B.Morales, Santi Mañosa, Jordi Camprodón, Gerard Bota. International Symposium on Ecology and Conservation of steppe-land birds. Lleida, Spain. December 2004.ISBN 84-87334-99-7
External links
- "The Steppes". barramedasoft corporation. 1998-2008. http://www.barrameda.com.ar/ecology/the-steppes.htm. Retrieved 2008-04-04.