Abstract
The synthesis of acquired published in this article focuses on the investigation of natural regeneration of tree in arid and semi-arid West Africa. The results showed that, even if the threat on ecosystems was ancient, research / actions in that were relatively recent. It was recognized that there was a regression of ligneous related to human activities (deforestation, overgrazing, bush fire) and weather conditions (drought). Current knowledge showed the multiple roles of natural regeneration of tree for services (soil fertility, anti erosion, shading ...) and outputs (timber, grazing, medicinal ...). There were, however, in some regions, a dynamic adaptation through the development of agroforestry systems in small and large scale farmers through the protection and management of spontaneous regeneration.