42. Moist Upland Grassland

Synonyms:

Highland Sourveld (A44a), Dohne Sourveld (A44b); Hyparrhenia hirta Tall Grassland.

Statistics:

45 688 km²; ± 60% transformed; 2.52% conserved.

Locality & Physical Geography:

These sour grasslands occur at altitudes of 600 to 1 400 m above sea level, most commonly in the Drakensberg foothills of Eastern Cape and KwaZulu-Natal. They extend to the Amatola - Winterberg Mountains in the western region. This grassland occurs adjacent to Afromontane Forest, which is common in the valleys and kloofs at these altitudes.

Climate:

These areas are moist, cold montane grasslands with rainfall of 650 to 1 000 mm per year and little snow except on the tops of mountains. Rainfall occurs mainly in summer in the east and less seasonal in the west. Temperatures vary between -3°C and 40°C, with an average of 16°C.

Geology & Soil.

The soil is often shallow, rocky and leached, derived from Karoo Sequence sediments and dolerite. Where deep, the soils may be leached due to the high rainfall and are fairly erodible forming large dongas in some parts.

Vegetation:

This vegetation type is a dense, sour grassland with Redgrass Themeda triandra, Speargrass Heteropogon contortus, Hairy Tridentgrass Tristachya leucothrix, Eragrostis curvula and Elionurus muticus as some of the dominant species. The tall-growing Common Thatchgrass Hyparrhenia hirta and Catstail Dropseed Sporobolus pyramidalis are often prominent in the north. Diagnostic species include hardy forbs such as Walafrida densiflora, Spiky Cucumber Cucumis zeyheri, Wild Cucumber C. hirsutus, Berkheya onopordifolia, Spermacoce natalensis, Kohautia cynanchica, Tephrosia macropoda, T multijuga, Conyza obscura, Corchorus confusus, Phyllanthus glaucophyllus, Richardia brasiliensis, Gomphrena celosioides, Aster bakerianus, Alysicarpus rugosus, Helichrysum coriaceum and H. rugulosum. Trees and shrubs that occur on sheltered sites, rocky hills and ridges, include Common Spikethorn Maytenus heterophylla, Small Knobwood Zanthoxylum capense, Buffalo Thorn Ziziphus mucronata, Rhus rehmanniana and Acacia sieberiana in the north. Overgrazing encourages unpalatable Wire Grass Elionurus muticus and herbaceous weeds such as Staggersweed Senecio retrorsus and Doll Rose Helichrysum argyrophyllum. In fire-protected areas the incidence of other species increases, including forest pioneers such as Cape Beech Rapanea melanophloeos, and Fynbos species, such as Cliffortia spp., Heaths Erica spp., Blombos Metalasia muricata and Jakkalsstert Anthospermum aethiopicum.

Key Environmental Parameters:

This vegetation type is often evident on disturbed, ploughed or heavily overgrazed and degraded sites, indicating the secondary status of many of the representative plant communities. Poor grazing management of these grasslands encourages unpalatable grasses and the invasion of herbaceous weeds. Control of grassy Fynbos and weedy elements is effected by summer burning. In the absence of fire, Afromontane Forest and Grassy Fynbos may invade these grasslands.

Economic Uses:

The area is mainly used for grazing, though crop-farming (maize) and forestry are also important economic activities. Hiking trails are popular in Eastern Cape.

Conservation Status:

Poorly conserved - the Coleford and Himeville Nature Reserves in KwaZulu-Natal are the major conserved areas of this grassland. The high-altitude areas of middle Eastern Cape are well maintained outside of forestry plantations. It is heavily overgrazed in the Transkei region of Eastern Cape.

Key References:

Lubke et al. (1986, 1988).

Authors:

George Bredenkamp, Ed Granger, Roy Lubke & Noel van Rooyen.