Parataxonomy, perceived dynamics and diversity of uses of two Detarium species in Benin (West Africa)

The contribution of species providing non-timber forest products to the livelihoods of local communities is well established. However, this contribution may be limited by the existence of confusion while dealing with close relative species. This is particularly the case for Detarium microcarpum Guill & Perr. and D. senegalense J.F.Gmel. The objectives of this study were to (1) identify the criteria used by local communities to differentiate D. microcarpum and D. senegalense, (2) determine local communities’ perception of the past dynamics of the two species and (3) assess the diversity of uses of both species. Data on differentiation criteria, perceived variation in the species abundance, and the different uses were collected using individual semi-structured interviews (n = 914 informants). The relative frequency of citation and the use-value were calculated. The Chi-square test, correspondence analysis and generalized linear model were used for statistical analyses. Informants used fourteen criteria to differentiate the two species. The predominant criteria were the shape of the seed (87.86%) and the shape of the fruit (67.86%). Most of the informants reported that the populations of D. microcarpum (61.80%) and that of D. senegalense (60.12%) have regressed. In total, 168 use-reports were enumerated for the two species with 19 shared use-reports. We concluded that local communities use a variety of criteria to differentiate both species, the most popular being morphological traits of the fruits. Both species shared several use-reports (11.31%). However, their populations have declined. The documented uses for both species provide preliminary information for their future food uses and drug discovery.