27. THORNY KALAHARI DUNE BUSHVELD

Synonym:

Kalahari Thornveld (A16).

Statistics:

2 286 km² ; area transformed unknown; 99.76% conserved.

Locality & Physical Geography:

This type occurs on deep sand in the Kalahari Gemsbok National Park in Northern Cape, at about 1 000 m altitude. The area is characterised by parallel dunes with dune valleys (streets).

Climate:

The average annual rainfall is about 200 mm which mainly falls from November to April (summer to autumn) with a peak in March. Temperatures vary between extremes of -1OC and 45C, with an average of 20C.

Geology & Soil.

Mainly on sands and loamy sand of aeolian origin, underlain by calcrete.

Vegetation:

This bushveld vegetation type is characterised by sparsely scattered trees of mainly Camel Thorn Acacia erioloba, but also including a few individuals of Belly Thorn Acacia luederitzii and Shepherd's Tree Boscia albitrunca. Silver Clusterleaf Terminalia sericea is conspicuous on some dune crests. The shrub layer is poorly developed and individuals of Honeythorn Lycium bosciifolium, Bastard Roughleaf Raisin Grewia retinervis and Kalahari Currant Rhus tenuinervis occur as widely scattered plants. The grass layer is moderately developed depending on the amount of rainfall. Grasses such as Lehmann's Lovegrass Eragrostis lehmanniana and Sour Bushmangrass Schmidtia kalihariensis are conspicuous in the dune valleys and Kalahari Coach Stipagrostis amabilis is abundant on the dunes.

Key Environmental Parameters:

This bushveld occurs in and areas which are grazed by game.

Economic Uses:

Ecotourism is the major land use.

Conservation Status:

Within South Africa this type is almost totally contained within the Kalahari Gemsbok National Park.

Key References:

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

Authors:

Noel van Rooyen & George Bredenkamp.