Geography of Cape Verde - Flora

Flora

Cape Verde is the driest archipelago of the ecoregion of Macaronesia. That with a greater influence of African species due to its geographical location near the African mainland of the Sahel. At first, the islands of Cape Verde housed an extensive savanna and dry forest cover, but mostly it was removed to convert to agricultural land, which, together with the arid climate and rugged terrain, has led to a soil erosion and desertification widespread. However, the archipelago can be divided into four broad ecological zones (arid, semiarid, subhumid and humid), according to altitude and average annual rainfall ranging from 200 mm in the arid areas of the coast to more than 1 000 mm in the humid mountain. Mostly rainfall precipitation is due to condensation of the ocean mist. Today much of the forest cover comprises relatively immature agroforestry plantations, in which are used non-native species such as Prosopis juliflora, Leucaena leucocephala and Jatropha curcas. The native laurel forest species are in wet area only in mountainous areas.

On the lower and drier islands the vegetation before human colonization consisted of savanna or steppe vegetation, with the flattest inland portion supporting semi-desert plants. At higher altitudes, a form of arid shrubland was also present. Once this islands were covered with savanna on the plains and arid shrubland on the mountainsides, but over 500 years of human habtitation, since colonisation by the Portuguese in the 15th century, nearly all the original vegetation has been cleared by widespread agriculture including the grazing of goats, sheep and cattle and the planting of imported crop species. There are some remaining patches of dry forest high on steep mountainside including a number of endemic plant species, but these are inaccessible and hard to study.

On the higher islands and somewhat wetter islands, exclusively in mountainous areas, like Santo Antao island, the climate is suitable for the development of dry monsoon forest, and laurel forest as this vegetation is believed to have been present in the past. However, most vegetation has now been converted to agriculture and forest fragments are now restricted to areas where cultivation is not possible, such as mountain peaks and steep slopes. The demand for wood has resulted in deforestation and desertification.

Of particular note is the endemic type of humid subtropical laurel forest of macaronesian laurisilva, found on several of the Macaronesian islands of the North Atlantic and Macaronesian African mainland enclaves, namely Madeira Islands, the Azores, Cape Verde Islands and the Canary Islands, a relict of the Pliocene subtropical forests, supporting numerous endemic species.

This laurisilva forests are found in the islands of Macaronesia in the eastern Atlantic, in particular the Azores, Madeira Islands, and western Canary Islands, from 400 m to 1200 m elevation. Trees of the genera Apollonias (Lauraceae), Ocotea (Lauraceae), Persea (Lauraceae), Clethra (Clethraceae), Dracaena (Ruscaceae), and Picconia (Oleaceae) are characteristic. The Madeira Islands laurel forest was designated a World Heritage Site by UNESCO in 1999.