Habitat diversity in Western Africa ranges from semidesert and savanna to tropical forests, mangroves, freshwater lakes and rivers, and inland and coastal wetlands. The Upper Guinea forest, which extends from western Ghana through Côte d'Ivoire, Liberia, and Guinea to Southern Sierra Leone, is a biologically unique system that is considered one of the world's priority conservation areas because of its high endemism (Conservation International, 1999). Nearly 2000 plants and over 41 mammals are endemic to the ecosystem. Species diversity is also high, with more than 20,000 butterfly and moth species, 15 species of even-toed ungulates, and 11 species of primates.
The richness of Western Africa's biological resources has constituted the basis of survival of the sub-region's indigenous societies. The local human populations have developed knowledge systems and practised traditions which have protected and conserved plants, animals, water resources and other components of their life support systems. In Ghana, sacred groves protect biodiversity in three different ways: by protecting particular ecosystems or habitats, by protecting particular animal or plant species, and by regulating the exploitation of natural resources (Ntiamoa-Baidu 1995). Many plant species are also used in Ghana in traditional herbal medicines (Mshana, Abbiw, Addae- Mensah, Adjanouhoun, Ahyi, Ekpere, Enow-Oroc, Gbile, Noamesi, Odei, Odunlami, Oteng-Yeboah, Sarpong & Tackie 2000), and the Kakum National Park in Ghana, with its canopy walkway, attracts thousands of visitors a year, helping to boost the economy as well as awareness of environmental issues.