Natural Regeneration Capacity of Vitellaria Paradoxa (Shea Tree) on the Hills of Bassar (North-Togo)

Abstract

As the consequence of anthropic pressure along with climatic factors, the vegetation of the hills of Bassar is degrading day after day and a regression of many woody species is observed. Vitellaria paradoxa is a highly valued multi-use species, but it is threatened with extinction in the area. The "bell" and "L" shapes of the diameter class distribution histograms reflect aging and/or disturbed populations. Stand disturbance is illustrated by the low proportion of large diameter class individuals. The "L" shape reveals an advanced state of degradation characterized by a near absence of large diameter trees. The study of the natural regeneration of Vitellaria paradoxa on the hills of Bassar shows that the density of regeneration by seedlings, shoots and suckers depend on the diameter of the individual stem. The larger the diameter increases, the higher the density of seedlings becomes. However, plantlets stemming from seedlings are higher, and weaker from suckers and shoots. The density of Vitellaria paradoxa seedlings is lower in shrub savannahs than in tree savannahs. The analysis of variance showed that whether under the crown or outside the crown, there was a significant difference between individuals from regeneration in all the formations studied. In the inventory plots, the densities of young trees are equally variable under the crown and outside the crown as those of large trees.