Thicket types:

Dune thicketValley ThicketXeric Succulent ThicketMesic Succulent Thicket Spekboom Succulent Thicket

8. SPEKBOOM SUCCULENT THICKET

Spekboom Succulent Thicket

Synonyms:

Spekboomveld (A25); Succulent Thicket; Karroid Succulent Thicket.

Statistics:

5 011 km² ; area transformed unknown; 1.76% conserved.

Locality & Physical Geography.

A thicket type of steep mountain slopes in Eastern Cape and the eastern parts of Western Cape, dominated by Spekboom Portulacaria afra. Spekboom is also common in Valley and Succulent Thicket types, so it merges into these in river valleys. It occurs in a belt of about 400 to 1 060 m above sea level.

Climate:

Rainfall is 250 to 300 mm per year, falling mainly in autumn and spring. Temperatures are moderate, although extremes may be experienced for short periods.

Geology & Soil.

Spekboom Succulent Thicket occurs on sandstone, quartzitic and shale substrata, which give rise to shallow soils.

Vegetation:

A dense scrub dominated by Spekboom Portulacaria afra with other shrubs. Spekboom can form pure stands. Other woody species include: Kerky Bush Crassula ovata, Large Honeythorn Lycium austrinum, Jacketpium Pappea capensis, Euclea undulata, Rhigozum obovatum, Grewia robusta, Aloe spp., Rhus spp. and Schotia afra. Many species of smaller Plakkies Crassula spp. as well as succulent herbs and grasses occur.

Key Environmental Parameters:

Locally Spekboom Succulent Thicket is confined to a narrow altitude range by temperature, rainfall and soil conditions. In some areas it is exploited by browsers such as goats, as most Spekboom is extremely palatable. A sour form identical to the sweet form is, however, never or rarely browsed by domestic or wild ungulates.

Economic Uses:

Mainly grazing - the backbone of the goat industry.

Conservation Status:

Spekboom Succulent Thicket is conserved in some reserves such as at Graaff Reinet and on higher altitude slopes.

Key References:

Cowling (1984), Palmer (1988).

Author.

Roy Lubke.