Evaluation of the viable seed potential of degraded dune soils in Gouré (south-eastern Niger)

The revegetation of degraded dunes may depend on its seed potential, so that a better understanding of this may help find solutions for the problem of the discontinuity of the herbaceous cover of fixed sites. Control germination tests using soil horizon (0-5 cm) from 32 degraded dune buildings in the Department of Gouré (Niger) proved that they contained viable seeds. Their quantity depends on the type of dunes, and the topographic position on the dune. Thus, the best germinations are obtained on "isolated dunes" (DI) with 79% germination, and on the slip face topographical position with 98% of germinated plants, respectively for the type of dunes, the level of degradation and the topographic position on the dune. The biological spectrum consists of 9 herbaceous species distributed mainly in four families dominated by the Poaceae with six species. Of these nine species, Cenchrus biflorus alone accounts for 80% of all sprouting seeds.