Abstract: Research on the functions of vegetation for reducing wind-sand disaster through field test was conducted. The results indicate that plants can obviously increase the surface roughness of different dunes, which provides mechanism of wind-preventing and sand-controlling. With the vegetation coverage increasing, the sand transporting amount and sand erosion (accumulation) and dust drops amount significantly reduced. Based on the analysis on sand transport rate of the different dunes, we can see that the rate separately drops 93.6% in fixed dune and 59.8% in semi-fixed dune. Comparing with the newly cultivated sandy land the wind-erosion status only has 32.6% in fixed dune and 73.4% in semi-fixed dune in the month of highest wind-erosion status. There is a common regularity. The dust amount concentrates in April, May and June, and biggest in April, accounting for 1/4~1/2 of the total; the dust amount changes significantly on horizontal or vertical gradient in each month.

Key words: natural vegetation, wind erosion, dust amount