The Succulent Karoo

The Succulent Karoo biodiversity hotspot covers 116 000 square kilometres of desert. The Succulent Karoo biodiversity hotspot extends from the southwest through the northwestern areas of South Africa into southern Namibia. 

The Succulent Karoo was the first only arid region to be recognised as a Biodiversity Hotspot. The hotspot is home to over 6000 plant species,of which 40 percent are endemic, found nowhere else on earth. Succulents, known as "vetplante" in Afrikaans, make up 29 percent of all plant species, as the region supports the richest succulent flora on earth. 

 In addition to the rich plant life, this area is also a centre of diversity for reptiles and various invertebrate groups, and supports a variety of mammals and many of South Africa's endemic birds.Tortoises, lizards, mole rats, monkey beetles, bee flies, bees, wasps and scorpions. Mammals such as bat-eared fox, aardwolf, steenbok and duiker, and reptiles are abundant. Brant’s whistling rat is responsible for the burrow systems in sandy areas, which provide ideal conditions for seed germination. Of importance in the area are heuweltjies, raised mounds of calcium-rich soil, which support distinctive plant communities. It is thought that these were created by termites.

Despite the global importance of the Succulent Karoo Hotspot, in 2001 less than 3.4 percent of the region existed in formal protected areas. In 2008 6.3 percent of the region has been increased to formal protected area expansion.

The terrain in the region varies from coastal sandy flats to mountain ranges of diverse geological formations- granite, gneiss, quartzitic sandstone, lava, quartzite, dolomite, conglomerate and shale. The mild temperatures during winter and summer remain remarkably constant as a result of the influence of the cold Benguela Current of the Atlantic Ocean.

In summer temperatures can reach in excess of 40 degrees celsius. Rain borne on cold fronts falls during winter, and is on average less than 400 mm a year. Fog is common nearer the coast. The rainfall in Namaqualand is remarkably reliable and this is the fundamental explanation for its unparalled diversity of leaf succulents, bulbs, high numbers of minute succulents and the regular displays of spring flowers.

Annual plants, mainly of the daisy family, are largely responsible for the impressive field of colour during spring. These annuals are a result of human interference with the environment: they reclaim the ploughed wheatfields. Within this, dwarf succulent shrubland, leaf succulents dominate, of which most of these species are in the Mesembryanthemaceae ( more than 2000 species) and Crassulaceae families. Most of the succulents are small and compact, and as a result there is much space and habitat available in which to develop, which is why succulent species are so diverse in this biome.

Small stock (sheep and goats) are ranched in the Succulent Karoo. Mining for limestone, gypsum, diamonds and zinc results in the destruction of the vegetation and leaves heaps of unvegetated soil, which cannot be rehabilitated to its former glory. Fruits are grown along the river valleys and ostrich farming is practiced in the south of the region.   

The hotspot's biodiversity is under pressure from a  range of human impacts, especially mining, crop agriculture, ostrich farming, overgrazing, illegal collection of fauna and flora, and anthropeogenic climate change. An estimated 100 000 kilometres of the region is used for communal or commercial grazing. Although this land-use can be compatible with the maintenance of biodiversity, overgrazing has severely degraded as much as two-thirds of this area. 

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