Abstract: Seed dispersal plays an important role in the natural regeneration of elm (Ulmus pumilaL.) in sparse woodlands. To explore the effects of wind on seed dispersal of elm, an individual based model was build to simulate wind-driven seed dispersal. The results showed that in all wind directions, seed number increased along with the increase of distance and reached the peak at the 3-4 steps (cells), and then seed number decreased. Furthermore, the seed dispersal distance and accumulation in seed number were almost the same in all wind directions. Our results suggest that individual based model is a useful tool to explore seed dispersal process and its influencing factors. Our results are helpful for understanding the regeneration of elm in sparse woodland steppe and thus providing basis for vegetation restoration in the Horqin Sandy Land.

Key words: arid region, groundwater, soil physical property, capillary rise., vadose zone