Terrestrial ecosystems

Central African vegetation is distributed globally from south to north depending on the climate. Savannah covers most of the territory and dense forest is limited to the southwestern and southeastern regions of the country.

Central African vegetation is distributed globally from south to north depending on the climate. Savannah covers most of the territory and dense forest is limited to the southwestern and southeastern regions of the country. Boulvert (1986) estimates that the Central African forest covers 92,500 km2 or 15% of the national territory, of which 27,000 km2 exploitable for the production of timber is found in the west, while in the south-east, it is t is an area made up of dense humid forest, dry forests and gallery forests covering 38,200 km2 in the Guinean zone and 6,500 km2 in the Sudanian zone .

It is also important to remember that in the far north, there is steppe vegetation composed of bushy shrubs such as Bauhinia rufescens , scattered clumps of grasses and stunted shrubs (Ndjendole, 2007).

From a phytogeographical point of view, Boulvert (1986) subdivided the country into the following five areas:

• Congo-Guinean domain to which belongs the sector of the dense humid forest which is classically subdivided into dense ombrophilic forest of which all the species are evergreen (south of Nola) and dense tropophilic forest, comprising secondary species including Terminalia superba and Triplochiton scleroxylon . This area is part of the Congo Basin and is characterized by the Guinean forest climate covering the entire southwestern and southeastern part of the country. There are generally 9 months of rainy season and 3 months of dry season. The average annual rainfall for this area is over 1600 mm.

• Sudano-Oubanguian domain, to which belongs the sector of peri-forest savannahs made up of forest-savannah mosaics or wooded savannahs and dense dry forests. The climate presents a variant with an average of 7 to 8 months of rainy season and 4 to 5 months of dry season.

•  Sudano-Guinean domain, fairly well characterized by development in the ligneous stratum with Burkea africana , Lophira lanceolata and Daniella oliveri and in the herbaceous stratum with Andropogon gayanus , Hyparrhenia spp ., H. familiaris. It covers nearly half of the Central African territory, ie 290,000 km2, including 130,000 km2 in the west and 160,000 km2 in the east of the country. Within this domain, there are nearly 38,000 km2 of dense semi-humid forests and gallery forests. The Sudano-Guinean climate or humid tropical type occupies a band which goes from Baboua to the Cameroonian border, to Yalinga in the east. It is characterized by 6 months of rainy seasons, 3 months of dry season and 3 months of off-season. The height of precipitation varies from 1200 to 1500 mm/year.

• A mid-Sudanian domain, it covers more than a third of the Central African territory, ie nearly 170,000 km2, including 106,000 km2 in the west and 64,000 km2 in the east. Within this domain, 7,000 km2 are covered with dense dry forests and gallery forests. The climate is a subtype of the Sudano-Guinean climate with a rainfall index of 6-1-5.

• The Sudano-Sahelian domain, which is located at the north-eastern extremity of the country above 8º30' N, covers 58,000 km2. This area is subdivided into two sectors, one Sudano-Sahelian in the south and the other Sahelo-Sudanian which extends beyond 10º N comprising, on the one hand, a sandy expanse "goz" where reigns a steppe to thorny with palm groves with Borassus eathiopium and Hyphaena tebaeca , and on the other hand, more or less sparse wooded and shrubby savannahs. This zone is a Sudano-Sahelian subclimate with an index of 4.3.5 and the Sahelian type with an index of 4.2.6. rainfall varies between 800 and 1100 mm.

Finally, the Central African forest is subject to the influence of the length of the rainy seasons for its vegetative period which ranges from 304 days in Salo in the south to 132 days in the extreme north in Birao (Boulvert, 1986).