Shrubs
Saxicoline shrub formations, belonging to the lowland "very dry continental" eco-floristic zone. This type of vegetation is found in the far north of the country, covering the sandstone cliffs of the Nano, Pana, Boumbaka and Dapaong region. The two massifs run more or less east-northeast to west-southwest and vary in altitude between 300 and 520 m, rising from the south toward the north and then falling in almost vertical cliffs to the plains of the far north, where the average altitude is 250 m. They cover only about 230 km2, i.e. 0.4% of the country. The climate of the region is Sudanian tropical in type, with a total average rainfall of 1 050 mm, spread over about 70 days. The harmattan has a very strong effect here, and the temperature on this rocky terrain rises very high in the dry season. Small pockets of vegetation protected by the rocks are sheltered from fires, but most of it is burnt off each year. Population density is high, with intensive grazing.
Given such difficult conditions for natural vegetation, these saxicoline formations are poor both in appearance and in floristic terms. The trees are mostly stunted and twisted, having suffered from fire, browsing herds and cutting. The most common species are Syzygium guineense, Terminalis glaucescens, Combretum glutinosum, Euphorbia spp., Acacia spp., Entada spp. and Sterculia setigera. Anogeissus leiocarpus, Butyrospermum paradoxum, Prosopis africana, Daniellia oliveri, Bridelia ferruginea, Khaya senegalensis, Vitex cuneata, Parinari excelsa and Diospyros mespiliformis are found on deeper soil.
Tree and shrub savannah with major inroads from cultivation, belonging to the lowland "very dry continental" eco-floristic zone. Situated roughly to the west of the Oti river in northern Togo, this region is the driest in the country, a feature exacerbated by two major factors the influence of the harmattan and human interference and its consequences. It is a very densely populated region. In addition to the very high occupation of land by crops (millet and cotton), it is also overgrazed by cattle, goats and sheep. The remaining trees are cut for firewood or for forage for goats and sheep. In densely populated areas, almost all the surviving species are protected because of their fruit or other products that can be eaten or otherwise used; these include Butyrospermum paradoxum (fruit and seeds), Tamarindus indica (fruit), Balanites aegyptiaca (fruit), Parkia biglobosa (flour from its pods) and Ficus spp. (fruit). The unprotected species (Acacia mellifera, Combretum spp. and Entada africana) often indicate a very degraded environment. The grassy cover tends to be steppe-like (pseudo-steppe), given the height of the grass and the space between clumps.
Shrub savannah, belonging to the medium-altitude (300 to 900 m) subhumid eco-floristic zone, with an annual rainfall of 1 400 to 1 700 mm. This type of vegetation is found at altitudes between 600 and 950 m, mainly on the Precambrian plateaux of Danyi, Akposso and Akebou in south-western Togo. The region has a moist montane tropical climate, with relatively low temperatures and evaporation, which means that it retains its humidity for the greater part of the year. Population density is fairly high at 20 to 40 persons per km2. The region is important for coffee and cocoa production. Taro and rice are the main food crops.
Two different environments can be distinguished on these plateaux mostly on the basis of soil conditions. The first has poor productive potential because of the shallowness of the soil and is covered by scattered shrub or grass savannah, while the second is post-forest savannah, with a considerable number of forest genera (Chlorophora, Antiaris, etc.), as well as savannah genera (Entada, Bridelia, Trema, etc.). Savannah derived from forest (on deep soil) would quickly develop into forest given the right ecological conditions so long as it is not already too degraded.
last updated: Tuesday, January 13, 2004
