Karoo

The Karoo ( ; likely from Khoikhoi (also known as Khoekhoegowab/Namagowab or Hottentot language) word Karo (Korana for 'hard, dry, desert')) is a semidesertnatural region of South Africa. No exact definition of what constitutes the Karoo is available, so its extent is also not precisely defined. The Karoo is partly defined by its topography, geology and climate, and above all, its low rainfall, arid air, cloudless skies, and extremes of heat and cold. The Karoo is also known for the exposure of fossiliferous rocks of the Karoo Supergroup, which record in detail ecological changes in the region when it formed part of southern Pangaea from the Middle Permian to the Early Jurassic, around 270 to 200 million years ago.

The Karoo formed an almost impenetrable barrier to the interior from Cape Town, and early adventurers, explorers, hunters, and travelers on the way to the Highveld unanimously denounced it as a frightening place of great heat, great frosts, great floods, and great droughts. Today, it is still a place of great heat and frosts, with an annual rainfall of between 50 and 250 mm (2.0–9.8 in). On some of the surrounding mountains it can be 250 to 500 mm (9.8–19.7 in) higher than on the plains. However, underground water is found throughout the Karoo, which is tapped by boreholes, making permanent settlements and sheep farming possible.

The xerophytic vegetation consists of aloes, mesembryanthemums, crassulas, euphorbias, stapelias, and desert ephemerals, spaced 50 cm (20 in) or more apart, becoming very sparse going northwards into Bushmanland and, from there, into the Kalahari Desert. The driest region of the Karoo, however, is its southwestern corner, between the Great Escarpment and the Cederberg-Skurweberg mountain ranges, called the Tankwa Karoo, which receives only 75 mm (3.0 in) of rain annually. The eastern and north-eastern Karoo are often covered by large patches of grassland. The typical Karoo vegetation previously supported large game, sometimes in vast herds.

Today, sheep thrive on the xerophytes, though each sheep requires about 4 hectares (9.9 acres) of grazing to sustain itself.