A preliminary study of temporal dynamics of seed rain and seed production of Agropyron michnoi population

The temporal dynamics of seed rain and the characteristics of sexual reproduction of Agropyron michnoi in the semifixed dune and the fixed dune of Hulun Buir desertification grassland were studied in this paper. Results showed that the seed rain of A.michnoi lasted 45 days from August 8 to September 22. There was a linear regression between the seed rain intensity fluctuation of A.michnoi and the maximum wind speed. Among different habitats, the seed rain intensity of A.michnoi in the semifixed dune was always significantly higher than that in the fixed dune. The panicle length, panicle width, per panicle weight, the number of spikelets per panicle, and 100 grain weight of sexual propagules of the semifixed dune were significantly higher than those of the fixed dune. The ratio of seed rain number and seed production were 29% and 10% respectively in the semifixed dune and the fixed dune. Sand microhabitat changes do not affect the spread period and fluctuation of A.michnoi seed rain, but have a significant impact on morphological features of its sexual propagules.