Included here are the forests of the Atlantic coast of Africa from southwestern Gambia to eastern Ghana. The moist semi-deciduous forests of Upper Guinea are structurally similar to the rainforest but show a greater degree of deciduousness, and in fact, between October and April many of the trees in the emergent and upper canopies lose their leaves. They are situated in the slightly dryer zones north of the rainforest. However, between the two there is a large transition zones known as the Lophira-Triplochiton association. This forms a belt some 10 to 30 miles broad and commonly includes Daniella ogea, Lophira alata, Triplochiton scleroxylon and the endemic or near endemic Hymenostegia afzelii (Fabaceae). This eventually gives way to a Celtis-Triplochiton association, which is considered to be the climatic climax of the semi-deciduous zone. Here Celtis species, such as C. adolfi-frederici, C. mildraedii and C. zenkeri become more abundant and the near endemic Cyclodiscus gabonensis (Fabaceae) makes its appearance, while other emergent or upper canopy species include Cola gigantea var. glabrescens, Nesogordonia papaverifera, Pterygota macrocarpa and Sterculia oblonga.  These forests make up about half total area of forest within this area. At the northern limit of deciduous forest is a transition zone to dryer habitat known as the Antiaris-Chlorophora forest association, which eventually gives way to savannah woodland. Togoland forest is included in this association. Although Celtis and Triplochiton remain common, Antiaris africana and Chlorophora excelsa become more frequent here than in any other part of the forest. The understory commonly includes the two endemic or near endemic trees Chidlowia sanguinea (Fabaceae) and Talbotiella genti (Fabaceae), while other endemic or endemic trees include Anopyxis klaineana (Rhizophoraceae), Terminalia ivorensis (Combretaceae) and the oil palm Elaeis guineensis (Arecaceae).

References

Boughey, A. S. 1957. Ecological studies of tropical coastlines I. The Gold Coast, West Africa. Journal of Ecology, 45: 665-687.

Brenan, J. P. M. 1978. Some aspects of the phytogeography of tropical Africa. Annals of the Missouri Botanical Garden, 65: 437-474.

Foggie, A. 1947. Some ecological observations on the tropical forest type in the Gold Coast. Journal of Ecology, 34: 88-106.

Hall, J. B. & Swaine, M. D. 1976. Classification and ecology of closed-canopy forest in Ghana. Journal of Ecology, 64: 913-951.

Kolongo, T. S. D., Decocq, G., Yao, C. Y. A., Blom, E. C. Rompaey, R. S. A. R. van. 2006. Plant species diversity in the southern part of the Tai National Park (Côte d’Ivoire). Biodiversity and Conservation, 15: 2123-2142.

Poorter, L., Bongers, F., Kouame, F. N. & Hawthorn, W. D. 2004. Biodiversity of West African Forests. CABI Publishing.

Taylor, C. J. 1952. The vegetation zones of the Gold Coast. Forestry Department Bulletin No. 4. Accra.

Taylor, C. J. 1960. Synecology and silviculture in Ghana. Thomas Nelson & Sons Ltd

White, F. 1983. The Vegetation of Africa. UNESCO.