What Determine the Distribution and Richness of Wild Spices in the Sudano-Guinean zone of Benin, West Africa?

Abstract

In Benin, most of the spices used for food, medicine and ceremony are gathered from the wild as little attempt has been made so far for their domestication and cultivation. Consequently, many wild spices are prone to overexploitation and threatened by habitat loss. Also, little information is available regarding their occurrence areas and the factor determining their geographical distribution and richness. This study aimed at i) mapping the distribution and the richness of 14 wild spices, and ii) assessing the drivers of their distribution and richness patterns in the Sudano-Guinean zone of Benin. Data were collected during field exploration and from the database of the Global Biodiversity Information Facility. Species distribution was mapped, and a grid of 10 × 10 km cells and a circular neighborhood option with a radius of 10 km was used to assign points to grid cells, then species richness was mapped. The species were unequally distributed across the study area. High species richness occurs in Bassila and Zou phytodistricts. Three spice-rich areas are needed to capture all the wild spices at once. Interaction of mean temperature of driest quarter, altitude, and precipitation seasonality significantly shaped the distributional range of three wild spices (Aframomum alboviolaceum, Uvaria chamae and Zanthoxylum zanthoxyloides), while the same factors in addition to clay content between 5-15 cm, contributed significantly to create appropriate conditions for the cooccurrence of several species.