Conclusions
AGV in the present study area suffers from human activities as over grazing and collection of plants for medicinal purposes. This may lead to habitat degradation and vegetation destruction in some part of the area. Knowledge of the SSB and its temporal and spatial variation is a useful tool for conservation and restoration efforts. This study showed that shrubs played an important role in restoring of herbaceous seeds under their canopies. However, the extent to which shrubs affects SSB characteristics is dependent on the species of shrub and the type of SSB characteristics. These different roles of shrubs on SSB are advised to be considered in restoration of areas through conservation of native shrubs in the semiarid regions. Highest SSB density under the canopy ofA. scoparia with its potential in medical and grazing uses increase the priority of using for degraded site restoration by this shrub species. In addition, although E. stellata has a low or intermediate palatability for grazers, it can be of priority for rangeland improvement if plant diversity conservation is of priority for the manager.