Guiera senegalensis (GS) est une espèce soudano-zambézienne sempervirente au port arbustif ou buissonnant rencontrée sur les latérites et les sols sableux. La floraison a lieu de mai-juin à aout, la fructification s’étale d’aout à décembre.
In Sub-Saharan Africa, trees and shrubs are intentionally cultivated with crops for multiple ecological and socioeconomical benefits [1-3]. Agroforestry systems are important for improving crop productivity, maintaining ecosystem integrity, and limiting capital resources depletion such as water, nutrients and soil [4,5]; mitigating the effect of global climate changes due to permanent tree cover that stores terrestrial carbon [6-9]; and reducing forest destruction by providing wood and non-timber products for human wellbeing [10]. Classically, agroforestry systems have been classified into six categories in which the woody plant component has the central role in the functioning of the agroforestry systems. These systems include crops under tree cover, agroforests, agroforestry in a linear arrangement, animal agroforestry, sequential agroforestry and minor agroforestry techniques [11]. The systems of crops under tree cover include all combinations of trees and crops in which the woody component creates an upperstorey covering the crops.
We assessed a restoration treatment (planting tree seedlings and sowing grass seeds as nurse plants in waterharvesting half-moon pits) on degraded, compacted soils with surface crusts in Niger. Height and above-ground biomass of herbaceous plant species, tree stem circumference, and relative cover of erosive crust, gravel crust, bare ground, rock, litter, and total vascular plants were assessed at three sites with similar environmental conditions but different treatment periods (3, 5, 7 years). Species richness, evenness and Shannon-Weaver index were lowest at the 7-year site and highest at the 5-year site. Above-ground biomass of herbaceous plants and percent plant cover were lowest at the 3-year site and highest at the 7-year site.