Deserts and Semideserts of Southern Africa

Southern Africa is ecologically a region of steep climatic gradients and vegetation contrasts. The dry corner of the broad spatial heterogeneity is formed by extensive deserts and semideserts that occupy the western and southwestern portions of the subcontinent. The region is home to three continental biomes of deserts, of which the iconic coastal-fog Namib Desert is the largest and best-researched. The smaller Gariep Desert continental biome was recognised only in 2006, whereas the smallest Tankwa Desert continental biome is recognised for the first time in this book. The semideserts are more extensive and varied (in bioclimatic and floro-genetic terms), although only two continental biomes have been recognised, namely Nama-Karoo and Succulent Karoo. All these deserts and semideserts, except the exclusively South African Tankwa Desert, are shared between South Africa and Namibia. Only the Namib Desert and Nama-Karoo also extend beyond the MBSA study area into Angola. The five continental biomes and their 18 constituent regional biomes are described. The continental biome Succulent Karoo is the richest in regional biomes within the zonobiome S2 Hot Arid Zone in the MBSA area.