28. SHRUBBY KALAHARI DUNE BUSHVELD

Synonym:

Kalahari Thornveld (A16).

Statistics:

37 434 km²; ± 55% transformed; 19.45% conserved.

Locality & Physical Geography:

This bushveld covers most of the Kalahari Gemsbok National Park and the Gordonia area to the north of Upington, and eastward to Olifantshoek and Van Zylsrus, in Northern Cape. The landscape comprises gently undulating dunes, but pans can be found scattered throughout this vegetation type. The altitude is between 1 000 and 1 100 m.

Climate.

The average annual rainfall for the area is about 200 mm, which fails mainly from November to April (summer to autumn), with a peak in March. Temperatures vary between -10C and 45C, with an average of 20C.

Geology & Soil:

Deep aeolian sandy soils, underlain by calcrete.

Vegetation:

Characterised by scattered shrubs of mainly Grey Camel Thorn Acacia haematoxylon, with a few individuals of Camel Thorn Acacia erioloba and Shepherd's Tree Boscia albitrunca. The shrub layer is poorly developed and individuals of Bastard Roughleaf Raisin Grewia retinervis and Kalahari Currant Rhus tenuinervis occur as widely scattered individuals. The grass layer is well developed and gives the impression of a grassland. Grasses such as Kalahari Coach Stipagrostis amabilis, Lehmann's Lovegrass Eragrostis lehmanniana, Giant Stick Grass Aristida meridionalis and Centropodia glauca are conspicuous on these plains.

Key Environmental Parameters:

Grazing by game and livestock in a low rainfall zone on sand dunes.

Economic Uses:

Ecotourism in the Kalahari Gemsbok National Park, with livestock and game farming in neighbouring areas.

Conservation Status:

Well conserved in the Kalahari Gemsbok National Park.

Key References:

Leistner (1967), Bothma & De Graaff (1973).

Authors:

Noel van Rooyen & George Bredenkamp.