Floodplains Shingwedzi, Bububu, Mphongolo & Phungwane Rivers. Lions and Leopards Occur Regularly
Salvadora angustifolia Floodplains … Location and Geomorphology
This landscape occurs along the lower Shingwedzi, Bububu, Mphongolo and Phungwane Rivers.
As a result of the alluvium deposited on the banks of the above-mentioned rivers over the years, floodplains have developed that are periodically under water. However, what is important is that the material from the surrounding area is carried to the rivers and deposited on the banks before reaching the actual stream. The floodplains are flat to slightly concave. The landscape is situated between 240 and 300 metres a.s.l. and it covers 133 km/2 or 0.7 percent of the area of the KNP.
This area receives between 450 and 500 mm of rain per year. The long term average for Shingwedzi, which falls in this landscape is 472 mm per year. Due to the concave topography, moisture is more available than what is indicated by the rainfall. Temperature data for Shingwedzi is given in Table 6.
As a result of the accumulation of salts in the alluvium, the soils of this landscape are usually brackish. Dominant soil Forms are Valsrivier, Sterkspruit and Oakleaf. White salt deposits are sometimes detectable on the surface of the soil.
The vegetation of this landscape is unique in the respect that it is the only river system along which it occurs. It is a high tree savanna with a well developed shrub layer (Fig. 78). The field layer is very sparse and in some parts completely absent. The woody component of this landscape is dominated by Colophospermum mopane trees and shrubs and Salvadora angustifolia shrubs of +/- three metres high. Other woody species which occur are Adenium obesum, Euclea divinorum, Ximenia Americana, Commiphora glandulosa, Thilachium africanum, Acacia tortilis, Grewia bicolor, Dichrostachys cinerea subsp. africana, Capparis tomentosa, Grewia monticola, Salvadora persica, Combretum mossambicense and Hyphaene natalensis.
The field layer is weakly developed and bare patches frequently occur. Grass species which do occur are: Urochloa mosambicensis, Panicum maximum, Sporobolus fimbriatus, Dactyloctenium aegypteum, Chloris virgata, Aristida congesta subsp. barbicollis, Tragus berteronianus, Chloris roxburghiana, Bothriochloa radicans, Schmidtia pappophoroides, Brachiaria xantholeuca, Enneapogon cenchroides, Oropetium capense and Chloris mossambicensis.
Fig. 78. Landscape 35. Salvadora angustifolia Floodplains. – page 118
Forbs are very common in this community and the following are worth mentioning: Commelina bengalensis, Abutilon guineense, Ruellia patula, Cyathula crispa, Cyphocarpa angustifolia, Phyllanthus pentandrus, Portulaca kermessina, Hibiscus sidiformes, Neuracanthus africanus, Abutilon austro-africanum, Sansevieria hyachinthoides, Amaranthes thunbergii, Pharnaceum elongatum, Ocimum americanum, Pupalia lappacea, Justicia flava, Elytraria acaulis, Asparagus plumosis and Portulaca quadrifida.
The banks of the rivers are overgrown with high trees of which Diospyros mespiliformis, Colophospermum mopane, Croton megalobotrys, Lonchocarpus capassa and Xanthocercis zambesiaca are the most important. The conspicuous absence of Trichelia emetica in the Shingwedzi/Mphongolo-complex deserves mentioning.
This landscape is the home of large herds of impala and a browse-line is often perceptible in the vegetation as a result of the presence of this game species. Waterbuck, kudu, buffalo and elephant are commonly found and even roan antelope are seen from time to time, usually on route to water. Quite a few herds of wildebeest stay on the bare patches in this environment and zebras are generally present. Baboons and monkeys are to be found along the rivers and carnivores such as lions and leopards occur regularly. Steenbok, duiker and nyala are present, while hippo and crocodile occur frequently in the rivers.