Varying characteristics of soil seed banks during the succession process of Nitraria Tangutorum vegetation in an arid desert area

The seed bank is the collection of viable seeds present on or within the soil at any given time. Soil seed bank is an important indicator in response to changes in land utilization and climate, and also forms the basis for desert vegetation restoration and development. In recent decades, Nitraria vegetation in the oasis-desert ecotone has been seriously degraded due to the rapid decrease of the groundwater table caused by agricultural over development. Using the method of substituting space for time, the species composition, distribution pattern and quantitative variation of soil seed banks of N. Tangutorum, nebkhas in initial, stable, degraded and severely degraded stages were studied in the lower reaches of the Shiyang River. Results showed that the soil seed bank of N. Tangutorum nebkha in the lower reaches of the Shiyang River was composed of 18 species, belonging to 9 families.