Abstract

Three soil depths (0 to 5, 5 to 10 and 10 to 15 cm) were chosen at the study area and the soil seed bank was analyzed for the number of live and dead seeds for each of them. The analysis revealed the following: The seed bank density was higher in the upper soil depths (0 to 5 and 5 to 10 cm) as compared to the lower ones (10 to 15 cm). It was found that the seed density had decreased with increasing depth. The live seed density ranged from 1015 to 5371 seeds/m², whereas that of the dead seeds ranged from 3215 to 6957 seeds/m². The dominant plant species to which the live seeds belonged were grasses includingSchoenefeldia gracilis, Brachiaria spp., Dactyloctenium aegyptium and Aristida spp. The dominant species to which the dead seeds belonged were mixed life- forms including Panicum turgidum, Euphorbia aegyptiaca and Cyperus rotundus.

Key words: Seed bank, density, species composition, semi-arid environments, rainfall variability, dispersal, viable seeds and dead seeds.