Diversity and structure of vegetation in relation to subarid, hydromorphic and vertisol soils of the Kadzel sub-watershed (Lake Chad Basin, Niger)

This study was conducted in the Sahelian zone of the Kadzel sub-watershed (Lake Chad Basin, Niger). The objective of this study was to characterize the flora across different soil types. A total of 23 composite soil samples were collected at a depth of 0 to 20 cm. Phytosociological and dendrometric data were collected using the Braun-Blanquet sigmatist method and the forest inventory method for characterizing woody and herbaceous vegetation. Soil chemical characteristics (electrical conductivity, organic matter, carbon, and available phosphorus) differed significantly (P value = 0.005) across soil types. The floristic characteristics of each soil type were identified. Subarid soils are characterized by high density (83.45 individuals/ha), height (8.4 m), and diameter (34.21 cm), while species diversity is high on Hydromorphic-Vertisols. The horizontal structure of trees is characterized by a predominance of young individuals on subarid soils, with a near absence of individuals with small and large diameters on Hydromorphic-Vertisols.