Soil seed bank characteristics in relation to different shrub species in
semiarid regions
Abstract
Little information is available about the effects of different species
of shrubs on the composition of the soil seed bank (SSB) in semiarid
regions. We determined the role of three dominant shrub species on SSB
characteristics and evaluated their potential for their possible use in
rangeland restoration projects. Fifteen sites, each containing three
shrub species (Amygdalus scoparia, Daphne mezereum and Ebenus stellata)
and a herbaceous patch (control) in close proximity, were sampled and
their SSB density, species richness and diversity at 0-10 cm depth were
determined. The results showed that the density of the SSB was highest
under A. scoparia (1133 seeds per m2) and lowest in herbaceous
vegetation (110 seeds per m2). Species richness and diversity of the SSB
was significantly greater under E. stellata than under the other shrubs
and control. This study revealed that the extent to which vegetation
affected SSB characteristics did not only depend on the presence of
shrubs, but also on the species of shrub. These different roles of
different species of shrubs on SSB are advised to be considered in the
restoration of degraded areas through planting of shrubs in semiarid
regions. Planting and the extension of E. stellata cover in degraded
sites could be of priority due to its prominent role in herbaceous SSB
reservoir and species diversity and richness.