Biodiversity Hotspots - Karoo

The Succulent Karoo of South Africa and Namibia boasts the richest succulent flora on earth, as well as remarkable endemism in plants, with 69 percent as endemics. Reptiles also show relatively high levels of endemism in the region. It is also one of only two entirely arid ecosystems to earn hotspot status, and is home to the mysterious tree-like succulent, the halfmens, as well as many unique species of lizards, tortoises and scorpions.

Grazing, agriculture and mining, especially for diamonds and heavy metals, threaten this fragile region. Fortunately, low population levels have allowed for greater preservation in the Succulent Karoo when compared to other more densely populated regions.

Hotspot Original Extent (km ²)	102,691
Hotspot Vegetation Remaining (km ²)	29,780
Endemic Plant Species	2,439
Endemic Threatened Birds	0
Endemic Threatened Mammals	1
Endemic Threatened Amphibians	1
Extinct Species†	1
Human Population Density (people/km ²)	4
Area Protected (km ²)	2,567
Area Protected (km ²) in Categories I-IV*	1,890

†Recorded extinctions since 1500. *Categories I-IV afford higher levels of protection.

overview

Stretching along the Atlantic coast of Africa, from southwestern South Africa into southern Namibia, the Succulent Karoo hotspot covers 102,691 square kilometers of desert. Some pockets of this hotspot are scattered within the Cape Floristic Region Hotspot, which borders it to the south. In fact, the Succulent Karoo exhibits a particularly strong floristic affiliation with the Cape Floristic Region, to the point that some have argued convincingly for the region’s inclusion as part of a greater Cape Flora.

The Succulent Karoo, which consists primarily of winter rainfall desert, is one of only two hotspots that are entirely arid (the other is the newly recognized Horn of Africa). The region is commonly divided into two zones. The first, Namaqualand, extends along the west coast of South Africa and southern Namibia. It is a winter rainfall desert with a mild climate moderated by cold Atlantic Ocean currents. The mild climate has contributed to the evolution of a rich array of endemic species. The second zone, the Southern Karoo, experiences peaks of rainfall in spring and autumn and has more extreme climate variations than the Namaqualand desert.

Dwarf shrubland dominated by leaf succulents is found throughout the hotspot. These drought-adapted plants have thick, fleshy leaves or stems for water storage. In the Succulent Karoo, there are about 1,700 species of leaf succulents, and this dominance is unique among the world's deserts. The recent and explosive diversification of the Mesembryanthemaceae, the largest group, has been described as an event unrivaled among flowering plants. Stem succulents are also found here (around 140 species), as are seasonal bulbs and annuals that display magnificent spring blooms in the open spaces between the shrubs, particularly during the spring in the Namaqualand. Hilly areas in the southern Karoo are dotted with evergreen shrubs and tall aloes.

Overview | Unique Biodiversity | Human Impacts | Conservation Action

The rare Aloe pilansii enhances the beauty of the Succulent Karoo landscape.

Threatened Species

Species Database

Related Links

References

Glossary

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