44. South-eastern Mountain Grassland

Synonyms:

Themeda-Festuca Alpine Veld (A58), Stormberg Plateau Sweetveld (A59), Karroid Merxmuellera Mountain Veld (A60); Mountain Mixed Grassveld.

Statistics:

22 676 km²; ± 32% transformed; 0.33% conserved.

Locality & Physical Geography:

This mixed grassland type is found on the upland of the Karoo and inland margins of the Great Escarpment of Eastern Cape in the Barkley East-Steynsburg and Cradock-Middelburg areas. Altitude varies from 1 350 to 2 150 m.

Climate:

Rainfall typically ranges from 450 to 600 mm per year, but reaches 1 900 mm at the highest altitudes. Temperatures vary from -13°C to 40°C, with an average of 15°C. During winter severe frosts occur, but little snow falls.

Geology & Soil:

Volcanic soils of the Stormberg Plateau and doleritic peaty soils predominate, with some sandstone. Soils are shallow and often rocky.

Vegetation:

In the northern regions (north of Queenstown) on volcanic soils of the Stormberg Plateau the sweet grassland is dominated by Redgrass Themeda triandra, Bullgrass Pennisetum sphacelatum and Robies Cocksfoot Tetrachne dregei. Along the Winterberg Range and in the higher mountains of the Karoo, Mountain Wiregrass Merxmuellera disticha is common, especially on the more rocky, sandstone sites or locally in over-utilised areas, although Redgrass Themeda triandra and Robies Cocksfoot Tetrachne dregei are conspicuous on doleritic, black, peaty soil. Other grass species are Common Ehrharta Ehrharta calycina, Staggers Grass Melica decumbens, Purple Danthonia Karoochloa purpurea, Helictotrichon hirtulum, Pentaschistis spp. and Bromus leptoclados. Dicotyledonous forbs are well represented and include: Longspur Diascia capsularis, Sutera macrosiphon, Wild Pink Dianthus caespitosus, Othonna auriculifolia and Euphorbia epicyparissias. In higher rainfall areas a short dense grassland dominated by Redgrass Themeda triandra, Tussock Fescue Festuca costa, Munnik Fescue F scabra along with Wire Grass Elionurus muticus occurs. Dry grassy Fynbos patches are also evident with Water Heath Erica caffra, Cliffortia spp. and Restio spp. as conspicuous species. Rocky areas are often quite bare, with a sparse, succulent vegetation. Karroid species such as Bitterbush Chrysocoma ciliata and Ghombos Felicia filifolia may also be invasive.

Key Environmental Parameters:

This sweet to mixed grassland type, is important stock land owing to suitable winter grazing. However, injudicious, selective grazing can convert it to sourveld or result in the invasion of karroid or Fynbos elements.

Economic Uses:

Mainly grazing for sheep and cattle.

Conservation Status:

Poorly conserved, but good examples of this type occur in the Mountain Zebra National Park. Although some farming areas are overgrazed, other areas are fine examples of well-conserved private land.

Key References:

Lubke et al. (1986, 1988).

Authors:

Roy Lubke, George Bredenkamp & Noel van Rooyen.