STRUCTURE DES PEUPLEMENTS DES ESPECES POURVOYEUSES DESPRODUITS FORESTIERS NON LIGNEUX (PFNL) DES UNITES DOCCUPATION DES SOLS SUIVANT UN GRADIENT AGRO-CLIMATIQUE DU CENTRE-SUD DU NIGER

NTFPs play a major socioeconomic role for rural populations, particularly as food and medicinal sources.Their intensive exploitation leads to a reduction in the populations of the woody species concerned.This study analyzes the structure of these populations according to agroclimatic zones and land use units in the Maradi region, in south-central Niger.A total of 260 floristic surveys were conducted according to land use units.Plots of 2,500 m were used for fields (continuous crops, tree/shrub parklands), 1,000 m for pastures and reclaimed sites, and 500 m for riparian barriers.For each tree, the DBH, total height,and both crown diameters were measured.Individuals with a diameter < 2 cm were considered regeneration. Marked differences appear between the zones.In the southern Sahel, the CR and SR regions display the highest densities (180 and 227.5 individuals/ha, respectively) and average diameters (up to 41.06 cm in CR).In the north, the highest densities are observed in the PA (172 individuals/ha) and SR regions (190 individuals/ha), but with smaller diameters (8 11 cm).Coverage is highest in the southern CR regions (35.28%) and the northern PA regions (31.72%).Basal area reaches 3.65 mha in the northern PA regions and remains high in the southern CR regions. The density of adult trees follows a similar trend.Differences between units are significant (p < 0.05).In the north, regeneration shows a low overall density, with no significant variation between units (p > 0.05).The lowest rate is recorded in SR regions (23.23 plants/ha), reflecting limited natural regeneration.