Spatio-temporal variation in a seed bank of a semi-arid region in northeastern Brazil

► Spatio-temporal variation in a seed bank of a semi-arid region was investigated. ► The seed bank is rich in herbaceous species. ► The seed density and taxa richness are low in the litter when compared with soil. ► Vertical space and precipitation explained 44% of the seed bank's richness. ► Vertical space and precipitation explained 43% of the seed bank's density.