Lands use impact on the floristic diversity in the Néma watershed in sudano-sahelian zone (Senegal, West-Africa).
Akpo L. E., Coly I., Sarr D., Ngom D., Ndao S.
Author Affiliation: Département de Biologie végétale, Faculté des Sciences et Techniques, Université Cheikh Anta Diop BP n. 5 005 Dakar, Senegal.
Journal of Agriculture and Environment for International Development 98 : 165-180
Abstract : Three types of lands use in the Néma watershed were identified, defined and characterized from air photos; they are a forest gallery, a zone of grazing areas and fields. The flora contains 84 species distributed in 65 genders and 28 families. In the forest gallery 62 species were listed, 35 in fields and 24 in the range. The ligneous place setting and the basal area are more important in the forest gallery. The density is raised in the range. Typically sudanian species like Detarium senegalense, Elaeis guineensis and Saba senegalenis, who are still present along the stream indicate better climatic conditions in the past. These species do not meet themselves more either in fields in the range. In the forest gallery, the plantations of fruit trees (Anacardium occidentale, Mangifera indica) and/or of wood of work (Eucalyptus camadulensis) or the presence of species looked for by the populations (Pterocarpus erinaceus, Adansonia digitata, Zizyphus mauritiana, ...) contribute to amplify the pressure of the populations on the environment. In the Nema site, the determined impact index for fields is the weakest. The pressure in this environment can be then defined from the forest gallery towards the zone of fields by way of the range. In the forest gallery, the anthropological pressure becomes more and more remarkable.