Analysis of Soil Seed Banks for Different Degraded Stages of Seriphidium transillense Desert Grassland

Different degraded Seriphidium transillense desert grasslands were selected to study their soil seed bank characteristics using the seed-emergence method to guide ecological restoration of degraded ecosystems in arid and semi-arid regions.Results showed that there are 14 species belonging to eight families in soil seed banks of Seriphidium transillense desert grassland.The densities of soil seed banks decreased from 684 seeds·m-2 to 443 seeds·m-2 from non-degraded stage to heavy-degraded stage.However,the density of soil seed banks reached 758 seeds·m-2 in over-degraded stage.Soil seed bank density decreased with increased soil depth,with about 67% of total seeds gathered at the surface layer of soil.The species richness and diversity indices of soil seed banks varied little between different degraded stages.However,the evenness index showed a downward trend after rising at first.The similarities among soil seed banks of different degraded stages became lower with farther distance between degradation degrees.Jaccard similarity index between soil seed bank and above-ground vegetation varied from 0.11 to 0.21.