A2. Escarpment riverine forest

Escarpment riparian forest is found fringing the rivers and streams of the Muchinga mountains to the west of the Luangwa valley. Elevation ranges from 800m to 1300m and the terrain is deeply dissected with relief measured in hundreds of metres. The igneous/metamorphic geology of the Muchinga Escarpment means that many of its rivers pass through rocky terrain (granite, quartzite) and waterfalls are common.

Soils associated with this vegetation type are very variable in texture and tend to be alluvial on the valley bottoms and colluvial on the valley sides.

On the Muchinga Escarpment, rivers and streams are bounded by dense, usually 3-storeyed evergreen forest (known as Mushitu in CiBemba) which may extend to adjacent swampy areas. The canopy is closed and the trees from which it is formed may be 20m or more in height. Characteristic tall trees in this vegetation type include Syzygium cordatum, Breonadia salicina, Cleistanthus polystachyus, Syzygium guineense subsp. afromontanum, Uapaca lissopyrena, Uapaca sansibarica and Apodytes dimidiata. Other less frequent, but characteristic large trees include Parkia filicoidea, Sapium ellipticum, Tabernaemontanapachysiphon and Xylopia rubescens. Monopetalanthus trapnellii is locally common on the Mwaleshi river and can form extensive stands of forest in which it is the single dominant species. Characteristic understorey species are Antidesma vogelianum, Englerophyton magalismontanum, Craterispermum schweinfurthii, Faurea saligna, Garcinia smeathmannii and Bersama abyssinica. Shrubs include Diospyros natalensis, Rothmannia whitfieldii, Cremaspora triflora, Rhus longipes, Tricalysia coriacea, Lasianthus kilimandscharicus and Erythroxylum emarginatum. Climbers typical of this habitat are Carissa edulis, Sabicea laurentii, Smilax anceps, Phyllanthus muelleranus, Clematis welwitschii, Artabotrys spp. and Strychnos spp. Oxytenanthera bamboo is locally common on escarpment streams and rivers. Where A2 fringing forest is a narrow belt of riparian trees, grasses and herbs associated with dambo margins occur (see F3). Common grass species include Loudetia simplex, Trachypogon spicatus, Cleistachne sorghoides, Hyparrhenia spp., Pennisetum spp. and Setaria spp. Characteristic subshrubs and herbs are Acalypha chirindica, Urena lobata, Polygala exelliana, Phaulopsis imbricata, Droogmansia pteropus, Helichrysum spp., Tinnea spp. and Dissotis spp. Where riparian forest extends into seasonally flooded swamp forest, or Monopetalanthus forest, the forest floor is carpeted with moss, and ferns are common (Asplenium, Adiantum, Pellaea etc.). Epiphytes may also occur. Herbs in this habitat include Geophila obvallata, Schwartzkopffia lastii, Leptactina benguellensis and Biophytum spp. Sclerochiton vogellii is locally common in Monopetalanthus forest.