Floristic diversity of plant populations sheltering Detarium senegalense in the Dahomey Gap (West Africa)

Abstract

The identification and characterization of the natural habitats of D. senegalense is a prerequisite for any action aimed at better conservation of the species. The present study carried out in the Dahomey Gap aims to investigate the floristic diversity of the natural habitats of D. senegalense. Data is collected using phytosociological surveys in 1000 m² plots. A total of 103 surveys were carried out and 81 species were inventoried. The ordination carried out using factorial correspondence analysis then ascending hierarchical classification to evaluate the vegetation groups made it possible to discriminate three floristic groups in each phyto-district, i.e. twelve plant groups throughout the study area. Species richness varied from 22 to 40 species. The values of the Shannon diversity index were between 2.25 and 2.98 bits and those of Pielou equitability were low (0.36 to 0.51) reflecting phenomena of the dominance of few species in the groupings and the high level of habitat degradation. The main families are Caesalpiniaceae, Fabaceae, Sapotaceae, Sterculiace et Anacardiaceae. The value of the Sorensen index varies from 0.30 to 0.58 reflecting low to medium similarity. Each type of natural habitat of D. senegalense is a unit whose management will require its own principles. Other studies should to be undertaken to improve the conservation status, valorization and sustainable use of D. senegalense.

Keywords: Diversity, population, natural habitat, Detarium senegalense, plant group, Dahomey Gap