Abstract: Nebkhas was widely distributed in the arid region of northwest China. More researches on the sand-pile and sandbags stage of nebkhas have been done in recent years, but few have been conducted on the shadow dune originated from the plants. Therefore, in this study, the morphological parameters of shadow dunes of three plant species,Halostachys caspica,Tamarix ramosissima and Suaeda glauca,were studied at dry lakebed of Taitema Lake. The morphological characteristics of shadow dunes and sand trapping capability of three plant species were compared and analyzed by the approaches of least significant difference, correlation analysis and regression analysis. The results indicate that the length, width and height of three kinds of shadow dunes presented a significant correlation(P<0.01)with the correlation coefficients ranging from 0.392 to 0.995. There was a better correlation between the height and horizontal scale of shadow dunes(R>0.6). The vertical development of the dunes was faster than the horizontal expansion. The morphological parameters of shadow dunes were correlated with the morphological parameters of their plants. But the correlation between different plants and their shadow dunes were different. This difference was mainly influenced by the biological nature of the plant. In the same area, the sand trapping capability of individuals of three plants was shown as Tamarix ramosissima > Halostachys caspica > Suaeda glauca, the amount of sand trapped by on average unit crown volume of the plant was Suaeda glauca > Halostachys caspica > Tamarix ramosissima. The amount of deposited sand trapped by Halostachys caspica and Suaeda glauca kept a quadratic relationship with plant height. The sand trapped by Tamarix ramosissima dune was mainly influenced by the windward area of the shrub. The result of this paper was of great significance for understanding the interaction between plants and sand-blown activities, and evaluating the sand trapping capability of plants.

Key words: morphological character, shadow dunes, sand trapping capability, dry lakebed