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Steppe |
In physical geography, a steppe (German1, from Russian: степь - Russian pronunciation: [sʲtʲepʲ] "a flat and arid land", Ukrainian: степ - /stɛp/, Mongolian: тал - tal, Kazakh: дала - /dɑlɑ/), pronounced in English as /stɛp/, is a grassland plain without trees (apart from those near rivers and lakes). The prairie (especially the shortgrass prairie) can be considered a steppe. 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.
Steppe are characterized by a continental and dry climate. Peaks can be recorded in the summer of up to 40 °C and in winter -40 °C. 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 can be reached during the day and sub-zero temperatures at night.
Also, the mid-latitude steppes can be summarized by hot summers and cold winters, averaging 250-500 mm (10-20 inches) of rain or equivalent in snowfall per year.
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Two types of steppe can be recorded2:
Peculiar types of steppe include Shrub-steppe and Alpine-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 to the Ural Mountains and the Caspian Sea. To the east of the Caspian Sea, the steppes extend 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.
Another large steppe area is located in the central United States and western Canada. The High Plains steppe is the westernmost part of the Great Plains region.
Patagonia is another land dominated by a steppe. A relatively small steppe can be found in New Zealand, in the inner part of the South Island and in Hungary (the Puszta).
In Europe, some Mediterranean areas have a steppe-like vegetation, such as central Sicily and central-eastern Spain, especially the southeastern coast (around Murcia), central Anatolia, 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.
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.
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