35. Moist Clay Highveld Grassland

Synonyms:

Turf Highveld (A52), Themeda triandra-Aristida bipartita Grassland.

Statistics:

10 265 km²; ± 79% transformed; 0.00% conserved.

Locality & Physical Geography:

Found in the Bethal-Standerton area in the southern parts of Mpumalanga, on flat to slightly undulating plains, at 1 500 to 1 700 m altitude.

Climate:

The rainfall is 650 to 750 mm per year, occurring in summer. Temperatures vary between -13°C and 37°C, with an average of 15°C.

Geology & Soil:

The predominating soils are very clayey, black vertic or near vertic, mostly of montmorillonitic clays.

Vegetation:

Redgrass Themeda triandra exclusively dominates areas which are not severely degraded. Characteristic species are Three-awn Rolling Grass Aristida bipartita, Blackseed Fingergrass Digitaria ternata, Largeseed Setaria Setaria nigrirostris, S. incrassata and Panicum coloratum. Other important species are Weeping Lovegrass Eragrostis curvula, Speargrass Heteropogon contortus, Golden Setaria Setaria sphacelata, Elionurus muticus, Microchloa caffra, Brachiaria serrata, Eragrostis plana with Feathered Chloris Chloris virgata, Couchgrass Cynodon dactylon and Tassel Bristlegrass Aristida congesta prominent at degraded sites. Dicotyledonous forbs are prominent and include Berkheya pinnatifida, Flower-in-a-cage Crabbea acaulis, Hairflower Chaetacanthus costatus, Salvia repens, Pseudognaphalium luteo-album, Abildgaardia ovata, Anthospermum pumilum, Chamaesyce inaequilatera, Bulbostylis contexta and Evolvulus alsinoides.

Key Environmental Parameters:

This vegetation type is restricted to very clayey soils of the high rainfall areas of the southern Mpumalanga highveld.

Economic Uses:

The clay soils are often not ploughed, and mostly utilised for grazing by cattle and sheep.

Conservation Status:

Although Moist Clay Highveld Grassland does not occur in any official conservation areas, well-managed private farms represent fine examples of this vegetation type.

Key References:

Breytenbach (1991), Breytenbach et al. (1993a,b,c)

Authors:

George Bredenkamp & Noel van Rooyen.