| Mu Us sandland is an ecotone and one of the serious desertification areas. The natural shrubs, such as Sabina vulgaris , Artemisia ordosica, Slix psammophila, are important to keep the stability of the ecosystem and to control the extension of the desertification. It was studied on structure characteristics, photosynthesis, transpiration, roots distribution, root number, generation of adventitious roots, natural regeneration, regenerate setting, clonal growth pattern and soil characteristic of Sabina vulgaris community with field experiment. And the stability of Sabina vulgaris community was discussed.The height and the coverage of the natural Sabina vulgaris community were 30~ 100cm and 40%~85% respectively. The community structure was made up of shrub and herbage synusias. The biodiversity index was high in early succession of community, then declined in upper succession of community and came into being pure shrubs. The ratio of photosynthesis biomass was high in shrub edge. The growth quantity of shrub edge was 3~4 times that of shrub center. Sabina vulgaris community extended its shrub range by infinitely clonal growth of the stolon and moved other areas by the spread of seeds. The internode length and branching angle decreased, while branching intensity increased gradually from inside to outside within the range of 3m from the edge of the shrub to its center along the stolon, and they changed with an exponential model. The characteristics of clonal growth and resources sharing were important to keep stability of community. The transpiration and the stomatal conductance of stolon with and without adventitious roots were same. But the water potential of stolon without adventitious roots was higher than that with adventitious roots. The transpiration of Sabina vulgaris on top of sand dune was lower than that on grassland. After the stolon was severed from the superior stolon, the stolon could maintain life by the adventitious roots absorbing resources, but the physiological characteristics were restrained obviously. After a week of severing, the transpiration was only 45% that of control and the differences of chlorophyll fluorescence characteristics between them were significant (p<0,05) . The ratio of biomass between stolon and adventitious roots was an important index of injured degree. The soil nutrientswere heterogeneously distributed. It has shown an evident phenomenon of "island of fertility" . The medium-fine soil particles(0.25~0.02cm) in Sabina vulgaris shrubs were 9% higher than that in Artemisia ordosica area. The nutrients except available P showed the enrichment oppositely under the layer of 20cm.The ground with Salix cheilophila shrubs was a protector of seedlings and a feasible microenvironment of regenerate Sabina vulgaris. There were 30-50 seedlings per square metre on this ground. The seed density of Sabina vulgaris was 770 seeds per square metre, but the seeds could not bourgeon because of water deficit in topsoil. The succession began on grassland and ended on fixed sand dune in Mu Us. The mode of succession was from Salix cheilophila or protect plants to Salix cheilophila + Sabina vulgaris to Sabina vulgaris + Salix cheilophila to Sabina vulgaris to Artemisia ordosica.The high coverage and concentrative sheet distribution of Sabina vulgaris enhanced anti-jamming and maintained stability of community because of its characteristics, such as high efficiency of water using, the structure of leave fighting a drought, the high content of fine roots and clonal growth.
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