21. SOUR LOWVELD BUSHVELD

Synonyms:

Lowveld Sour Bushveld (A8); Lowveld Sub-humid Mountain Bushveld, Malelane Mountain Bushveld; Gemengde Bergbosveld, Vaalboom/Sekelbosveld.

Statistics:

19 662 km²; ± 76% transformed; 9.65% conserved.

Locality & Physical Geography:

Found on the lower eastern slopes and foothills of the Drakensberg, from the Soutpansberg in Northern Province, through Mpumalanga and into Swaziland. The landscape is undulating, at an altitude between 550 and 800 m.

Climate:

The summer rainfall varies from 600 to 1 000 mm per year. Temperatures range between 2C and 43C with an average of 22C.

Geology & Soil:

This bushveld is found on deep, predominantly sandy to sandy loam soils in the uplands, to clayey soils with a strong structure in the bottomlands. These are derived from granites and gneisses.

Vegetation:

This open tree savanna is dominated by Silver Clusterleaf Terminalia sericea, Bushwillow Combretum collinum, Paperbark Thorn Acacia sieberiana, Parinari curatellifolia, Pterocarpus angolensis, Acacia caffra, Ficus thonningii and Strychnos madagascariensis. The shrub layer is characterised by Sickle Bush Dichrostachys cinerea, Large Sourplum Ximenia caffra, Camel's Foot Piliostigma thonningii, Antidesma venosum and Maytenus heterophylla. The grass constituent is tall, tufted and relatively dense, and the common species are Yellow Thatching Grass Hyperthelia dissolute, Wire Grass Elionurus muticus, Common Thatchgrass Hyparrhenia hirta, Setaria sphacelata, Melinis nerviglumis, Cymbopogon excavatus and Heteropogon contortus.

Key Environmental Parameters:

The higher rainfall and frost-free climate allow a lush vegetation to develop. Acocks considered the climax of this area to be forest, which still occurs in the kloofs along the escarpment. However, fires prevent forest from developing in this vegetation type. Grazing by cattle and game also helps to prevent forest encroachment.

Economic Uses:

Cattle and game farming, ecotourism, cultivation of subtropical fruit, and forestry.

Conservation Status:

Well conserved in Blyde River Canyon Nature Reserve, Entabeni State Forest, Barberton Nature Reserve, and other game farms and conservation areas.

Key References:

Van der Schijff (1957), Van der Schijff & Schoonraad (1971), Gertenbach (1983), Van Wyk (1984), Deall et al. (1989).

Authors:

Noel van Rooyen & George Bredenkamp.