Spatial structure of Xylopia aethiopica (Dunal) A. Rich., in the GuineoCongolean zone of Benin (West Africa)

Abstract

Xylopia aethiopica is a spice widely consumed in sub-Saharan Africa for the medicinal virtues of its fruits and seeds, whose distribution in  its natural habitat is compromised by anthropic pressure. The aim of this study was to characterize the spatial distribution of Xylopia  aethiopica plants and the possible interactions (attraction, independence, repulsion) that exist between them under the direct or indirect  influence of the environment in which they grow. Phytosociological surveys were carried out in habitats hosting Xylopia aethiopica in the  Guineo-Congolean zone of Benin. The geographical coordinates of adult plants and seedling individuals of Xylopia aethiopica were  collected in 50 m x 200 m rectangular plots. The results of the univariate analysis showed that the spatial distribution of adult plants and  seedlings was significantly aggregated in the fields. However, a random distribution trend was noted among seedling individuals, due to  anthropogenic environmental influences. In the semi-deciduous dense forest, adult plants were significantly aggregated, with a tendency  towards random distribution over certain distances, whereas seedling individuals had a significant exclusively aggregated  distribution. In the gallery forest, both adult plants and young individuals were significant aggregated. Bivariate analyses showed that in  the fields and the semi-deciduous dense forest, spatial associations were positive (attraction) and there was a strong independence of  seedling individuals from adult plants over certain distances. Moreover, spatial associations between adult plants and seedling  individuals in gallery forest were exclusively positive (attraction). The results of this study could be useful for policies aimed at the  sustainable conservation of vulnerable plant species in Benin.