Abstract: This paper studied the effects of different sand burial depths (0, 1, 2, 3, 4, and 5 cm) of Achnatherum inebrians seed on its germination and seedling growth under a constant temperature regime, aimed to approach the proliferation mechanism of A. inebrians population and to supply theoretical basis for the control and exploitation of A. inebrians. Sand burial depth of A. inebrians seed had significant effects on its seedling emergence percentage, date of first emergence, seedling height, and biomass allocation (P<0.001). The seedling emergence rate was the highest (92%) when the seed was buried at the depth of 2 cm, but the lowest (58.7%) when the sand burial depth was 5 cm. The seed
ling height reached the maximum (10.8 cm) when the sand burial depth was 3 cm, but was the shortest, being 6.3 and 7.1 cm when the seed was buried at the depths of 0 and 5 cm, respectively. The above and below ground biomass of A. inebrians was the maximum at the sand burial depth of 2 cm, but the minimum at the sand burial depth of 5 cm; and the root was the longest (nearly 5 cm) at sand burial of 2-3 cm and the shortest (1 cm) at sand burial of 5 cm. It was suggested the optimum sand burial depth of A. inebrians seed for its seedling emergence and growth would be 2-3 cm.

Key words: Songnen plains, Degenerated grassland, Leymus chinensis population, Reproductive module, Reproductive allocation