Current knowledge and future directions on West African wild palms: an analytical review for its conservation and domestication in the context of climate change and human pressures

Abstract

Palms constitute vital species for local people’s well-being, especially in West Africa. This analytic review aims at providing an overview of West African palms flora diversity, uses, ecology, and conservation. Scientific papers related to palms in West Africa were searched on electronic databases Google Scholar, Web of Science, and general web search on Google using the names of palms occurring in West Africa. From 108 scientific articles, we extracted relevant information after a critical reading. Papers were published between 1930 and 2019 and most of the studies focused on biochemistry, ethnobotany, and population structure. We identify in the literature 25 species belonging to 12 genera, 32% of them growing in dry areas. Five growth forms were identified among West African palms species. Erect and solitary stem forms were the most representative. Concerning leaf forms, most west African palms (84%) have pinnate leaves. Sexual systems of palms were represented by monoecy, dioecy, and hermaphrody, with the predominance of monoecy (44%). The pleonanthic species are the most represented reproductive feature (76%) and only Raphia palms are hapaxanthic. As far as uses are concerned, there is a link between used parts and uses categories. According to the relative importance index, the four first palm species in West Africa, namely Borassus aethiopum Mart., Elaeis guineensis Jacq., Borassus akeassii Bayton, Ouedr. & Guinko, and Hyphaene thebaica Mart. grow in dry areas. Rattans have a low relative index value due to their non-consumed organs. Critical analysis was presented in the focus of population structure, distribution, and propagation aspects. The review highlights a research gap in carbon sequestration, phenology, and called for more research effort in semi-arid and arid areas. Such investigations would help in planning better sustainable management and conservation of palm in West Africa.