D1. Combretum-Terminalia woodland

Vegetation type D1 is characterised by fire-tolerant, sandy soil species (e.g. Terminalia sericea) and bears a close resemblance to other high grass-woodland vegetation types such as the Burkea-Erythrophleum woodlands of western Zambia and the Chipya woodlands of the Bangweulu region (Trapnell et al., 1950). The common herbaceous indicators of lake basin Chipya, Aframomum alboviolaceum, Smilax anceps and Pteridium aquilinum are not a feature of this habitat, but like Chipya woodland (Lawton, 1978), it is probable that vegetation type D1 is maintained by the fierce dry season fires which sweep through the valley every year. Combretum-Terminalia woodland is found in close association with thicket (B1/B2), both vegetation types occupying a belt of deep, sandy soil running parallel to the Luangwa river. The relationship between thicket and woodland is not clear, but it is possible that the two vegetation types are components of a fire-induced succession. In certain (western) areas of the park, Combretum-Terminalia woodland intergrades with hill miombo woodland (C2). Combretum-Terminalia woodland covers large areas of the valley floor over elevations ranging from 650m to 700m a.s.l. It is generally associated with flat terrain where relief is only up to 10m.

Soils associated with this vegetation type are deep, light brown to orange and are mildly acidic to neutral (pH 6.4-7.0). These soils are characterised by a very high sand content (70-90%) and are probably colluvial (or old alluvial) and derived from Karoo sandstone.

Combretum-Terminalia woodland takes the form of open 1-2 storeyed deciduous woodland. Canopy species may be up to 20m tall. The grass layer is tall and well-developed. The tall trees found in this habitat are dominated by Terminalia sericea (up to and above 15m high), Pseudolachnostylis maprouneifolia, Pericopsis angolensis, Burkea africana, Erythrophleum africanum and Amblygonocarpus andongensis. Common small trees and shrubs are Combretum molle, Combretum collinum subsp. gazense, Combretum zeyheri, Bridelia cathartica, Crossopteryx febrifuga and Baphia massaiensis. On the deep soils of this type, the grass layer is well-developed with both tall and short grasses. Common tall grasses are Andropogon schirensis, A. gayanus, A. chinensis, Hyparrhenia anemopaegma, Hyparrhenia filipendula, Pogonarthria squarrosa and Tristachya superba. Shorter species are Aristida scabrivalvis, Digitaria gayana, D. acuminatissima, Heteropogon contortus and Sporobolus festivus. Characteristic subshrubs include Senna petersiana, Cissus cornifolia and Euphorbia matabelensis. The herb component is dominated by ground creepers of the family Vitaceae and includes Cyphostemma gigantophyllum, Cyphostemma hermannioides, Cyphostemma viscosum and Cissus nigropilosa. Other typical herbs are Polycarpaea corymbosa, Hypoestes forskaolii, Tricliceras spp. and Phyllanthus spp.