Soil Seed Bank Longivity Of 4 Desert Plant Species Under Field Burial Conditions

The soil seed bank plays a vital role in the vegetation's occurrence, succession, renewal and restoration. Studying the soil seed bank of desert grasslands, especially the dormant seed buried in the soil, is a useful approach to understand renewal and the dynamic of succession, reconstruction and restoration of the vegetation.The research was conducted in Reaumuria soongorica - Cleistogenes songorica grassland in the Alax desert of Inner Mongolia, China. Four species were studied: Reaumuria soogorica, Cleistogenes songorica, Bassia dasyphylla and Corispermum mongolicum. Dynamics of seeds' viability were monitored in one year's storage beneath the soil. The results showed that:1. The viability of seed bank in the four kinds of plants dropped remarkably. After one year's burial in the field, the percentage of Reaumuria soongorica, Cleistogenes songorica and Bassia dasyphylla seeds remained viable were 9%, 9% and 7%, respectively; Compared with them, 80% seeds of Corispermum mongolicum remained viable. During burial period, most seeds of Reaumuria soongarica (82%), Cleistogenes songorica (90%) and Bassia dasyphylla (93%) germinated in the field and the germination mainly occurred in the rainy season.2. According to Thompson's method, Reaumuria soongorica, Cleistogenes songorica, and Bassia dasyphylla could be assumed as transient soil seed bank, but Corispermum mongolicum is persistent soil seed bank.3. Although most seeds of Reaumuria soongorica and Cleistogenes songorica germinated in the field, no seedling was observed in the plot. It indicated that the propagation of these two species were mainly through asexual reproduction other than seeds. For Bassia dasyphylla, most seeds germianted when the condition is favorable; and Corispermum mongolicum persisted in the soil seed bank and kept dormant.