human impactsThe vegetation of the Succulent Karoo is in somewhat better shape than in other hotspots. A sparse human population of only 300,000 people and the fact that more than 90 percent of the hotspot is used for natural grazing (a form of land use that is, theoretically, compatible with maintenance of biodiversity) have eased the conversion pressures on this region as compared to the other hotspots. It is difficult to arrive at accurate estimates of the amount of vegetation remaining intact, but at least five percent has been irreversibly lost to mining and agriculture, and around two-thirds of the land has been seriously overgrazed, especially in Namaqualand. Consequently, only an estimated 30,000 km, or 29 percent, of the hotspot remains in a relatively pristine state.Diamond mining has had a very heavy impact on the Namaqualand coastline and alluvial terraces of the lower Orange River Valley. Approximately two-thirds of the South African coastline, and almost all the Namibian coastline in this hotspot, has been mined for diamonds. This mining is now supplemented by the large-scale extraction of heavy minerals, including gypsum, marble, monazite, kaolin, ilmenite, and titanium, which threatens to vastly increase the impact of mining on the region's biodiversity. Farming in the Succulent Karoo hotspot depends on irrigation infrastructure, like dams, that transform the natural habitats of river valleys. The cultivation of grapes, citrus, tobacco, alfalfa, and vegetables is practiced throughout the hotspot in areas that get as little as 150 millimeters of annual rainfall. Several dam projects and new irrigation schemes have been proposed for the last remaining wild rivers in the Succulent Karoo. Dryland farming also accelerates desertification as fragile soils are blown away during the dry season without the natural flora to keep them in place. Furthermore, the rise of the ostrich farming industry has resulted in the degradation of thousands of hectares of veld in the Little Karoo.Finally, the illegal collection of succulents and bulbs is an increasing problem throughout the area. Spectacular diversity, including miniature succulents and many flowers, attract unscrupulous plant collectors who harvest without regard for the integrity of this unique ecosystem. The problem is likely to grow as the public knowledge of the region's spectacular plant diversity increases.
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© Conservation International, photo by Haroldo Castro
The scarlet paintbrush (Crassula falcata) from the Little Karoo region typifies the hotspot's unique plant diversity, which is at risk due to invasive species, habitat loss, and climate change.
© Conservation International, photo by Haroldo Castro
Diamond mining near Richtersveld National Park, South Africa impacts the biodiversity of the Succulent Karoo.
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