Briar savannah

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Thorn bush savannah in Namibia

The thorn bush savannah is also known as thorn bush savanna , thorn tree savannah , thorn savanna or thorn bush steppe . Depending on the perspective, it is an ecozone , a zonobiom or a vegetation zone of the tropics and is characterized by open vegetation ( grassland ) and bushes standing at relatively regular intervals.

Spread

The thorn bush savannah occurs in the transition area between the arid trade wind zone and the tropical rainforest climate. Accordingly, the vegetation zone of the thorn bush savannah lies between the vegetation zones desert and semi-desert on the one hand and dry savannah and wet savannah on the other. The natural thorn bush savannahs belong to the region of the tropical arid areas and are not part of the humid tropics . Thorn bush savannahs are particularly widespread in Africa , but they also occur in Australia and in the northern part of South America . In Africa, a belt of thorn bush savannas stretches in a semicircle through the continent and is found mainly in the Sudan and Sahel zones of West Africa. Together with the cactus deserts, the areas of the thorn bush savannah make up about 5% of the land area.

climate

Climate diagram Zinder ( Niger )

The thorn bush savannah is called "V 4" in the climate classification by the climate researchers Troll / Paffen , and in Köppen as "BSh climate".

The dry season in the thorn bush savannas lasts about 8 to 10 months, the annual rainfall is usually between 200 and 500 mm. The climate is arid or semi-arid and has a clear evaporation deficit, where the potential evaporation is higher than the real precipitation . The soil of the thorn bush savannah is predominantly stony or sandy and poor in organic material. The loose topsoil is endangered by wind erosion, which can lead to the formation of dunes. Accumulations of secondary carbonate are common.

Flora and fauna

The flora and fauna in the thorn bush savannah are adapted to the climatic conditions. Due to the long dry season, trees in the thorn bush savannah can only survive sporadically, but there is an extensive thorn forest in certain regions (Central America, Central and Northeastern Brazil: called Caatinga ). Only plants that can store water, such as thorn bushes, can survive in this region. There is no closed grass cover as in the moist savannah , typical plant families are xerophytes such as succulents , geophytes and ephemers .

The animal world such as insects , small reptiles , arachnids , birds and mammals are usually temporal specialists , i.e. predominantly either nocturnal or crepuscular, also in order to keep the loss of fluid as low as possible.

swell

  • Dictionary of general geography. Edited by Hartmut Reader (1996)

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