Comparison of Erodibility on Four Types Biological Crusts in Gurbantunggut Desert from Wind Tunnel Experiments

1 Abstract: Experiments of wind erodibility on four types biological crusts (moss crust, lichen crust, algal crust and algal-lichen crust) obtained from Gurbantunggut Desert were conducted in wind tunnel. The results showed that biological crusts and its destructive percentage had considerable influences on surface erosion. There was no sand grain movement and ground surface erosion occurred on the four types biological crusts even wind speeds reached to 25 m s -1 while the relative wind erosion rate (WER) on bare sand reached 1214.82 g m -2 sec -1 . Under the same destructive percentage, the threshold wind velocity (TWV) over the moss crusts was the highest, followed by lichen crusts, algal crust and algal-lichen crusts was the lowest. The WERs increased exponentially with increasing of destruction percentage of crust cover and wind velocity.