Abstract: Soil seed bank is a potential reserve of plant diversity, which could influence the revegetation and ecological restoration of mining areas. Through field investigations and experiments, we examined the characteristics of soil seed banks in typical coal mine restoration areas and control areas (undamaged) in the Qilian Mountains Nature Reserve at different altitudes and explored the relationship between species composition of soil seed banks and soil factors. The results showed that the density of soil seed banks in the restoration and control areas increased with altitude. The density of soil seed banks in the restoration areas was significantly lower than that in the control areas at the same altitude (P<0.05). Margalef richness index, Shannon diversity index, and Simpson diversity index of soil seed bank in the restoration areas were significantly lower than those in the control areas at altitudes of 2510 and 2630 m (P<0.05). The Sorenson similarity of species composition between aboveground vegetation and soil seed banks in the restoration areas decreased with altitudes. Results of the redundancy analysis showed that soil factors such as soil organic matter, total nitrogen, soil bulk density and soil water content were significantly correlated with species composition of the soil seed bank (P<0.001). Collectively, there is a significant difference in soil seed bank characteristics between the coal mine restoration areas and the control areas in the Qilian Mountains Nature Reserve, especially in the sites of 2510 and 2630 m altitudes. Other measures (such as artificial seed addition and improvement of soil properties) are needed to consolidate the restoration effects.

Key words: Qilian Mountains Nature Reserve, coal mine restoration, soil seed bank, soil factor