Lebombo South | Nwaswitsontso and Nwanedzi River Gorges: Klipspringers Common

Location and Geomorphology

The Lebombo Mountains on the eastern side of the KNP form a physiographical unit of its own. Because of climatological reasons this range of mountains is divided into two landscapes. The area between the Crocodile River and Pumbe pan will be dealt with in this landscape. It is an undulating terrain with north/south running ridges and bottomlands. The geological formation is rhyolite and granophyre of the Lebombo Group, Sequence Karoo (Schutte 1982). The altitude varies between 360 metres in the south to 300 metres in the northern areas. The Lebombo Mountains are situated almost 100 metres higher than the adjacent basalt plains and sometimes form a low escarpment on the western slopes. All the large rivers and spruits that either flow through, or originate in the KNP, Break through the Lebombo Mountains at some stage to form deep incisions or gorges. Of these the Crocodile, Sabie, Fig. 64. Landscape 28. Acacia xanthophloea tree savanna – page 99 Fig. 65. Landscape 28. Hyphaene natalensis fringe around a Sporobolus consimilis grassveld. –page 99 Nwaswitsontso and Nwanedzi River gorges are certainly the best known. This landscape covers 765 km/2 or 4.8 percent of the area of the KNP.

Climate

The rainfall on the Lebombo Mountain diminishes from south to north. In the vicinity of the Crocodile River the average annual rainfall is probably close to 700 mm and it drops to 500 mm in the vicinity of Pumbe. According to Gertenbach (1980) the isohyets Turn northwards on the Lebombo Mountains which implies that the area is wetter than the adjacent basalt plains. The emperature on the western mountain side becomes extremely high in summer with no possibility of frost in winter.

Soil Pattern

The soils in the Lebombo Mountains can best be described as lithosols. Occasionally shallow soils from the Mispah and Glenrosa Forms can be expected, but this is the exception. The terrain is less undulating to the east of Muntche and deeper soils of the Swartland and Glenrosa Forms are present.

Vegetation

The vegetation of the landscape is divided by Coetzee (1983) into 12 associations (Fig. 66). The most common woody species are Combretum apiculatum, Boscia albitrunca, Acacia exuvialis, Dichrostachys cinerea subsp. africana, Cassia abbreviate, Albizia harveyi, Tephrosia sericea, Kirkia acuminate, Commiphora mollis, Securinega virosa, Croton gratissimus, Euphorbia confinalis, E. cooperi, Sclerocarya caffra, Lannea stuhlmannii, Ozoroa engleri, Grewia bicolor, G. flavescens, Sterculia rogersii, Pappea capensis, Manilkara mochisia, Tricalysia allenii and Pavetta catophylla. Under special circumstances a combination of the following species and those mentioned above may be found: Maclura africana, Ficus ingens, F. soldanella, F. sycomorus, Pouzolzia hypoleuca, Olax dissitiflora, Portulacaria afra, Erythrina humeana, Monodora junodii, Maerua rosmarinoides; Thalycium africanum, Albizia brevifolia, Acacia burkei, Afzelia quanzensis, Erythoroxylum emarginatum, Vepris reflexa, Commiphora harveyi, Iboza riparia, Acacia caffra, Ptaeroxylon obliquum, Rhus gueinzii, Hippocratea longipetiolata, Berchemia zeyheri, Dombeya cymosa, Ochna natalitia, Galpinia transvaalica, Elephantorrhiza burkei, Combretum zeyheri, Terminalia phanerophlebia, Strychnos decussata, S. madagascariensis, Hymenodictyon parvifolium, Kraussia floribunda and Vangueria infausta.
A community especially highlighted by Coetzee (1983) are the dry slopes where Acacia erubescens occur in association with Combretum apiculatum. The distribution of Acacia burkei is limited to the southernmost Lebombo Mountains near Komatipoort. In this case it is the sandveld variation of the species that occurs more commonly in Swaziland and Natal. East of Muntshe a short shrubveld of Pterocarpus rotundifolius and Acacia gerrardii (Fig. 67) occurs, with a dense stand of grass consisting of Themeda triandra and Digitaria eriantha var. pentzii, Terminalia phanerophlebia is a species which is virtually limited to the more mesic Lebombo Mountains,
Fig. 66. Landscape 29. Lebombo South. – page 101 Fig. 67. Landscape 29. Pterocarpus rotundifolius shrubveld east of Muntshe. – page 101 While Van Wyk (1973) maintains that Newtonia hildebrandtii occurs only in dry gorges in certain areas of the Lebombo Mountains. Adansonia digitata and Androstachys johnsonii like Newtonia hildebrandtii are restricted to the drier habitats of the Lebombo North (Landscape 31). Grasses common in the rocky surroundings are: Digitaria eriantha var. pentzii, Panicum maximum, Brachiaria xantholeuca, Enneapogon cenchroides, Aristida congesta subsp. barbicollis, Pogonarthria squarrosa, Heteropogon contortus, Themeda triandra, Schmidtia pappophoroides, Andropogon gayanus, Brachiaria nogropedata and Bothriochloa radicans. According to Coetzee (1983), the following forbs occur in the Lebombo Mountains: Pallaea calomelanos, P. viridis, Mariscus dregeanus, Kyllinga alba, Commelina africana, C. bengalensis, Aloe chabaudii, A. sessiliflora, Sansevieria hyacinthoides, S. desertii, Asparagus falcatus, A. minutiflorus, Dioscorea sylvatica, Pupalia lappacea, Archyranthes aspera, Kalanchoe rotundifolia, Indigofera vicioides, Acalypha indica, Jatropha variifolia, Cissus rotundifolia, C. quadrangularis, Cyphostemma subciliatum, Abutilon angulatum, A. ramosum, Hibiscus lunariifolius, H. micranthus, Adenia hastate, Sarcostemma viminale, Ipomoea albivenia, Paederia foetens, Coccinia rehmannii and Bidens ternata.

Fauna

The game which is most common in this landscape are kudu, impala, giraffe, buffalo bulls and waterbuck. Waterbuck move into the Lebombo Mountains during the rainy season when water is available. For the rest of the dry season they keep to permanent water points on the flat plains. Other species of game that occur less frequent are zebra, elephant breeding herds and warthog. Wildebeest occur only in the Pterocarpus rotundifolius shrubveld behind Muntshe. Reedbuck also occur in small numbers. Klipspringers are plentiful.