Grasslands of the World.pdf - Disasters and Conflicts - UNEP

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Grasslands of the world
Plate 3.1
Kalahari: The arid savannah occurs in the northwestern portions of South Africa
and southern Botswana, and is associated with the sands of the Kalahari system.
The vegetation comprises a woody layer of mainly single-stemmed deciduous
shrubs, and a ground layer of grasses and forbs.
grasslands. The major urban, mining and agricultural activities take place
in the central high-veldt, which lies at 1 600–1 700 m above sea level.
• The great Karoo basin lies at 1 400–1 600 m and contains the steppe-type
vegetation associated with fertile aridosols of a semi -arid region.
• The Kalahari region, bordering on Namibia and Botswana, also represents
a very important extensive livestock producing area. The region is the
southern part of the continental-scale basin, which is covered by sands of
varying depth (sometimes >200 m). Deep boring technology has enabled
commercial graziers to become permanently established in the region and
to optimize livestock production off arid grasslands. The vegetation is an
arid savannah (Plate 3.1), with a carrying capacity of 30 to 40 ha per Livestock
Unit (LSU).
South Africa is thus characterized by a high interior plateau, surrounded
on three sides by the Great Escarpment and the Drakensberg mountains,
which provide the physical barriers that largely determine the climate and
vegetation . The plateau is intruded by several mountain massifs, with the
highlands of Lesotho exceeding 3 000 m in places. The northern and western
sections of the plateau contain two large basins, namely the Kalahari and the
Transvaal Bushveldt (Partridge, 1997). Adjacent to the Great Escarpment lies
a coastal plinth that varies in width from 50 to 200 km. This plinth is incised
by deep riverine gorges.
A.R. PALMER