Effects of different topsoil covering modes on seed bank vitality

  Objective  The aim of this study was to investigate the characteristics of seed bank vitality under different covering modes in topsoil stockpiles, and to provide technical basis for vegetation reconstruction of coal mine damaged land in desert area.

  Method  The method of combining field topsoil stacking with seed bank germination test was adopted, and two common topsoil covering modes, dense mesh covering and color strip covering, were used to analyze the effects of soil temperature, seed water content and buried depth on seed vitality under different topsoil covering modes, and monitor the loss of seed bank.

  Result  The seed viability of Caragana korshinskii, Artemisia desertorum, Hedysarum mongolicum and Hedysarum scoparium decreased after 4 months of storage, and the seed viability of Caragana korshinskii and Artemisia desertorum under dense mesh net coverage was significantly higher than that under color strip cloth. There was no significant difference between Hedysarum mongolicum and Hedysarum scoparium seeds under the two coverage modes; temperature, seed water content and buried depth were important factors affecting the decline of seed viability. The effect of buried depth on seed germination rate was reflected as the highest germination rate in the surface layer, then the deepest layer and the lowest germination rate in the middle layer; the initial soil seed bank of topsoil was mostly annual plants, and the seed bank density was 335 seed/m². After 4 months of topsoil stacking, the soil seed bank density decreased significantly. The seed bank density under dense mesh coverage was 192 seed/m², and the seed bank density under color strip coverage was 249 seed/m².

  Conclusion  The storage of topsoil will reduce the seed vitality. The difference of temperature, seed water content and buried depth will lead to different degrees of seed vitality decline. From the storage of topsoil in winter to spring, the density of soil seed bank under the color strip covering method is lower than that under the dense mesh covering mode. During this period, the color strip covering mode can be considered as the topsoil covering mode.