Structure and Spatial Distribution of the Abundance of <i>Spondias mombin</i> L. Populations in the Subequatorial Zone of Benin (West Africa)

Abstract

Conservation and sustainable use strategies for reliable management plans of valuable species are lacking due to the gap in basic scientific information on their structure and status. The objectives of this work were to study the structural characteristics and the spatial distribution of the abundance of <i>Spondias mombin</i> L. populations in the subequatorial zone of Benin. The data collection was based on the tessellation of study zone with ArcGIS analysis tools. The grid cell used was a square of 100 m side (1ha of surface). The occurrence of species in each grid was obtained using GBIF database. One hundred and seventy-five (175) trees of <i>S. mombin</i> were sampled through the four Phytodistricts of study zone. The main dendrometric variables measured from these individuals were diameter at breast height (1.30 m above ground level) and height. The parameters such as density, mean quadratic diameter, basal area and mean Lorey height were calculated. To study the spatial abundance distribution of <i>S. mombin,</i> we used Inverse Distance Weighting (IDW) interpolation method to realize abundance map from the occurrences. The results of structure showed a density of 3 trees/ha. The basal area was 1500 cm²/ha and the mean quadratic diameter was 25.10 cm. The mean of Lorey height obtained was 12 m<i>.</i> The diameter structure showed a predominance of bell-shape distribution with a relative abundance of young individuals. The low numbers of individuals in some diameter classes, the erratic distribution and the presence of old population of <i>S. mombin</i> indicate the strong anthropogenic pressure on the species. The abundance map showed that the species was present in all the phytodistricts and covers 93% of the study area’s municipalities. The conservation strategies, including both the species and its habitat, need to be developed to allow sustainable use of <i>S. mombin</i>.