关键词: 封育, 植被恢复, 荒漠植被, 防风作用, 固沙效益

Abstract: With wind profiler and sand sampler we have measured the wind-breaking effect of single plant, wind velocity and sand flux near ground at different succession stages of vegetation. At the same time we have investigated into the plant community and coverage, and the physo-chemical characteristics of soil. The configuration of Hedysarum scoparium and Artermisia sphaerocephala are nondense tuft, the Caragana korshinskii configuration is mid-dense tuft, and the A. ordosica configuration is dense tuft. The wind-breaking and sand-preventing effect in 0~50 cm near ground layer is A. ordosica > Artermisia sphaerocephala > Caragana korshinskii > Hedysarum scoparium. In the processes of progressive succession, Hedysarum scoparium, Caragana korshinskii, and Artermisia sphaerocephala decayed gradually, even disappeared at the stage of climax community; whereas, Artermisia ordosica continuously increased and finally formed the single predominant community. From the initial stage (mobile sands) to the developing stage and to the relatively stable stage, the roughness length of near ground changed form 0.003 cm to 6.039 cm and to 17.726 cm due to changes of predominant community. When the wind velocity at height of 2 m on the mobile sand dunes reached 6.5 m·s-1, there was no wind erosion at dune relatively stable stage, and the sand flux at dune developing stage was only 1.83 g·cm-1·h-1, occupying 3.2% of the moving dunes. When the wind velocity at height of 3 m was the same, the wind velocity near ground of the developing stage was reduced by 54.29% compared with that of the initial stage; the thickness of sand crust accumulated up to 1~3 mm, making up 91% of the total area, which can basically play a role of desert control. The wind velocity near ground of the relatively stable stage was reduced by 83.68% compared with that of the initial stage; the thickness of sand crust accumulated up to 5~6 mm, making up 98% of the total area, which can effectively play a role of desert control.

Key words: enclosure, progressive succession, desert vegetation, wind-breaking effect, sand-fixing effect