45. Afro Mountain Grassland

Synonyms:

Themeda-Festuca Veld (A58); Monocymbium ceresiiforme-Tristachya leucothrix Grassland.

Statistics:

15 894 km²; ± 32% transformed; 0.00% conserved.

Locality & Physical Geography:

This grassland type is found on the moist, cool, steep Drakensberg mountain plateaux and slopes, at altitudes between 1 700 and 2 500 m, and higher. It occurs in Lesotho and the adjacent KwaZulu-Natal mountains. The rugged topography creates a variety of habitats, and consequently a large number of plant communities can be recognised within this type.

Climate:

The summer rainfall varies considerably over short distances, ranging from 575 mm to more than 1 000 mm per year, with snow frequent in winter. Temperatures vary from -8°C to 30°C, with an average of 14°C.

Geology & Soil:

The soils are shallow, rocky and leached. The geology is sandstone capped with basalt.

Vegetation:

The most prominent grass species are Wire Grass Elionurus muticus, Weeping Lovegrass Eragrostis curvula, Common Thatchgrass Hyparrhenia hirta, H. pilosissima, Themeda triandra, Heteropogon contortus, Aristida junciformis, A. congesta, Cymbopogon marginatus, C. dieterlenii, Festuca caprina, Rendlia altera, Koeleria capensis, Digitaria sanguinalis, Harpochloa falx. Prominent among the forbs are Helichrysum pilosellum and H. cephaloideum. Other typical species include the forbs in the genus Helichrysum (Everlastings): H. cerastioides, H. oreophilum, H. aureonitens, H. spiralepis, H. subluteum, H. acutatum, H. pilosellum, as well as: Haplocarpha scaposa, Euphorbia striata, Rhus discolor, Selago galpinii, Berkheya cirsiifolia, B. echinacea, Anthospermum herbaceum, Acalypha schinzii, Clutia monticola, Sebaea sedoides,'Senecio coronatus and Indigofera dregeana, and the geophytic Star Lily Hypoxis obtusa. The high altitude plateau contains the following endemic species which may be considered as diagnostic of the higher reaches: grasses - Stiburus alopecuroides, Blackpatch Lovegrass Eragrostis caesia, Merxmuellera spp. and Toothbrush Grass Rendlia altera; forbs - Three-leaf Pea Lotononis eriantha, Selago compacta and Syncolostemon concinnus. Under heavy grazing many dwarf shrubs of Karoo affinity encroach into the grassland, and may become dominant in places. These include Ghombos Felicia filifolia, Anchorkaroo Pentzia incana, Broom Karee Rhus erosa and Chrysocoma ciliata.

Key Environmental Parameters:

This vegetation type is considered to be climatically suited for succession into either forest or savanna woodland. Grassland is maintained by fire and grazing, and it is therefore considered as a fire climax. The pressure of increased human settlement on woody vegetation, together with drier climatic conditions, is also blamed for the absence of woody species. Although the frosty winters may be responsible for the persistence of grasslands on the exposed ridges, it appears that this grassland has been the climax for many centuries. Some forest encroachment does appear to be occurring locally.

Economic Uses:

Mainly grazing by livestock.

Conservation Status:

Not represented in any nature reserve.

Key References:

Killick (1978), Wieland (1982), Martin (1986), Mokuku (1991), Morris (1994).

Authors:

Ed Granger & George Bredenkamp.