Broadleaved

Savannas occupy the northern two-thirds of the country. Large tracts of the southern parts are almost uninhabited. The population increases rapidly toward the north and the land is much more exploited for agriculture.

The Guinea savanna woodland extends over the area north of the closed forest and into the south-east of the country. This woodland is typically composed of short-statured trees, not usually forming a closed canopy and often very widely spaced. The ground flora is composed of a more or less continuous layer of grass. Some of the grass species attain a height of about 3.5 m. Most of the area lies within the "one peak" rainfall zone (August to September). Although annual precipitation is seldom less than 1 000 mm and may reach 1 250 mm, it is the intense dry season that is the limiting factor for vegetation. The true Guinea savanna woodland is a climatic climax. Though this is the case in the centre and north of the zone, there is a very large area in the south (the southern extremities of the northern region, north Ashanti, the African plains and the eastern Volta region) where this type of savanna woodland is considered to be a "derived savanna" brought about by human interference. Periodic grass fires (annual in many localities) sweep across the country from January to April. They are mainly set for hunting. Many of the trees are fire resistant and have thick bark.

Throughout the Guinea savanna woodland are Anogeissus schimperi, Butyrospermum parkii, Detarium senegalense and Parkia filicoidea. Daniellia oliveri is common in the south, and particularly so in the derived woodland savanna, where it is often associated with Entada sudanica. Acacia spp. are more frequent in the north. Combretum spp. and Terminalia spp. are numerous and often indicate areas of poor drainage. The savanna mahogany, Khaya senegalensis, is riparian.

Riverain woodland along the rivers in the northern area contains Anogeissus schimperi, Celtis integrifolia, Cola laurifolia, Cynometra vogelii, Lannea spp. and Parinari polyandra.

The Sudan savanna woodland is restricted to a small area in the extreme north-east of the country. This area has the highest density of rural population, which has resulted in settled farming. The zone has a very sparse tree cover and contains a sprinkling of Butyrospermum parkii, Parkia filiocoidea and Tamarindus indica, all of which provide an extra source of food for the local population.

last updated: Wednesday, October 6, 2004