Effects of different sand burial depths on seedling growth of three psammophytes

Effects of sand burial depth on seedling growth of three dominant annual herbaceous plants in Horqin Sandy Land were studied. Nine treatments of sand burial depth were designed, growth characteristics including survival rates, seedling height, total biomass and its allocation were measured. The results showed that shallow burial depth stimulated the survival rates of three species, however, severe sand burial is fatal to plants. The upper threshold limit of Setaria viridis and Corispermum macrocarpum seedlings to sand burial stress is 100% of their height, Agriophyllum squamosum seedling has the strongest adaptability to sand burial, can even survive when the burial depth reached to 10 cm higher than its height. The response of seedling height and biomass among three species is different, contrary to Corispermum macrocarpum, seedling height of Setaria viridis and Agriophyllum squarrosum were stimulated in shallow depth. Compare with the other two species, Agriophyllum squarrosum allocated more to roots, this may be one of its adjustment mechanism to sand burial.