DIVERSITE FLORISTIQUE ET ESPECES BIOINDICATRICES ET ACCUMULATRICES DE METAUX LOURDS AUX ABORDS DU PARC A RESIDUS MINIER DE SABODALA (SENEGAL)

This study was conducted in the Sabodala mining area to characterize floristic diversity and assess metal contamination around the tailing s storage facility. A roving floristic survey was carried out, and samples of rhizospheric soils, roots, and leaves were collected from each recorded specimen. The samples were digested and analyzed by ICP-OES to determine trace metal concentrations and their bioavailability. In total, 37 species were recorded, belonging to 29 genera and 17 families. The dominant families were Combretaceae, Malvaceae, Fabaceae,and Lamiaceae. Biological spectra revealed the predominance of mesophanerophytes (40.54%) and microphanerophytes (37.84%), reflecting a flora typical of Sudanian Guinean zones. Rhizospheric soil analysis showed that arsenic and antimony were mainly confined to the residual fraction, indicating low bioavailability, whereas nickel and cadmium exhibited partial mobility. Mean concentrations followed the order Ni > Sb > As > Cd. Bioaccumulation varied among species: Cd accumulated primarily in roots, while Ni was translocated to leaves in certain species. Hexalobusmonopetalus stood out with high Ni concentrations ( 247 ppm in leaves and 132 ppm in roots), with bioconcentration and translocation factors greater than 1. These results suggest a strong potential of this species for the phytoremediation of nickel-contaminated soils. They also provide a useful baseline for the ecological management of mining sites and for the identification of bioindicator and accumulator species.