The Kalahari Desert stretches across an area of 900,000 square kilometers, in the three African countries of Botswana, Namibia and South Africa. Up to 70% of the land in Botswana, the eastern third of Namibia, and the northernmost parts of South Africa are all occupied by this desert. The Kalahari, unlike a true desert, has a semi-arid climate that supports vast tracts of sandy savanna, and a considerable diversity of flora and fauna lives therein. The landscape of the Kalahari is mostly flat, with an average elevation of around 1,000 meters above sea level in most parts of the desert. The Boteti River, in Botswana, is the only permanent surface water source in the desert.
Scientists estimate that the Kalahari Desert was formed between 65 and 135 million years ago in the Cretaceous Period. Since then, the desert has faced both periods of higher precipitation and greater aridity than the present prevailing conditions. It is possible that the dry riverbeds of the Kalahari and the Makgadikgadi Depression were formed during such periods of higher precipitation. Historical evidence proves that the San Bushmen of Africa were the ancient occupants of the Kalahari Desert region. The Bantu people, including tribes like the Tswana, the Kgalagadi, and the Herero, are currently residents of the desert along with the traditional San people, and these others arrived much later, towards the end of the 18th Century. In 1849, David Livingstone, a Scottish medical missionary, and William C. Oswell, an English explorer, were the first Europeans to cross the Kalahari Desert. In more recent years, Europeans arrived in the Kalahari primarily for commercial purposes, and only a single European settlement (in the Ghanzi District) existed in the region as late as the 1890’s.
Presently, the Kalahari Desert serves as the homeland for Bantu-speaking African tribes and the Khoisan-speaking San people. The vast stretches of savanna in the region allow the locals to rear cattle and goats for meat and milk. Corn, sorghum, and pumpkins are also cultivated by most households in the region. The Kalahari Desert is home to large deposits of precious metals and diamonds. The first diamond mine was opened here in Orapa in 1971. Tourism also adds to the economy of the region. Besides the economical significance of the Kalahari, the desert is also extremely significant from the ecological and environmental points of view. The sands of the desert are packed with cyanobacteria which can fix atmospheric carbon dioxide, thus acting as a natural carbon sink for much of the world. The desert also houses some rare and endangered animals in its game reserves, including the Central Kalahari Game Reserve, the Khutse Game Reserve, and the Kgalagadi Trans-frontier Park.
Habitat and Biodiversity
While the southwestern half of the Kalahari meets the requirements to be qualified as a desert, the northeastern portion of it receives a significant amount of precipitation, and thus cannot qualify as a true desert. There are great diurnal and seasonal variations in temperature throughout the Kalahari. While in summers day temperatures range between 43° and 46° Celsius, and night temperatures fall to between 21 degrees and 27° Celsius, in winters night temperatures can be as low as -12° Celsius. The arid areas of the southwestern Kalahari Desert support very little plant life, and are covered by vast stretches of xeric savanna comprised by xerophytic plants like savanna grasses, grey camelthorn, shepherd’s trees, and silver cluster-leafs. Several species of acacia grow in the less arid, central Kalahari region as well. The more humid northern parts of the desert, however, have large woodlands, palm trees, and even forests with evergreen and deciduous trees. Lions, cheetahs, giraffes, zebras, elephants, leopards, meerkats, and antelopes are just some of the mammalian species found in the northern Kalahari Desert. Several species of reptiles and birds are also to be found here. In the arid southern parts of the desert, animal species like gnu, hartebeest, oryx, eland, kudu, and steenboks can be spotted as well.
Environmental Threats and Territorial Disputes
Large scale cattle farming in the Kalahari Desert poses the greatest risk to the desert habitats there. Overgrazing by cattle leads to loss of vegetation cover on land, and increased desertification as a consequence. The erection of fences and the clearing of land by farmers for agriculture also deprives the native wildlife of their food, thus reducing their chances of survival. A large number of carnivorous species, especially wild dogs and jackals, are killed by cattle ranchers every year to protect their cattle from such predators. Mining of metals like diamonds also damages the ecological balance of the desert, removes surface vegetation, displaces native populations of human and wildlife, and also extracts large quantities of water from the already water-scarce habitat. Territorial disputes also exist among the diamond miners and the native Bushmen over the land, with the native complaining about the forceful occupation of tribal land by the mining companies.