关键词: 植物种选择, 沙地引种, 坝上高原

Abstract: From the existing vegetation survey and experiments on species introduction and planting of sand fixing plants, it is considered that the succession of sand vegetation in Bashang has experienced three stages in general: ①stage of eroded scabland as well as spotted shifting sand; ②stage of fixed and semi fixed sandy land; ③stage of zonal vegetation. Also, it is pointed out that there are 9 species suitable for sand fixing afforestation in the studied region. Among them, those with stronger adaptability are Hedysarum fruticosum Pall., Larix principis-rupprechtii, Pinus sylvestris var. mongolica, Hippophae rkmnoides and Salix gordejevii; those with middle adaptability are Caragana microphylla, Salix psammophila and Hedysaram scoparium. The dry cold climate in Spring and Winter of Bashang is greatly disadvantageous to plants overwintering. The suitable areas for species introduction are the sandy lands in steppe zone where the annual average air temperature is less than 6 5℃ and the annual precipitation is under 450 mm. In Bashang region, Hulumbuir Desert, Otindag Desert, Horqin Desert and Northern Mu Us Desert are in the range. Whether success or failure of species introduction not only has relation with the ecological similarity between original place and planting site, but with plant's own physiological and ecological properties. For example, although Salix psammophila and Sabina vulgaris are all from Mu Us Desert, the fomer grow well and the latter does not. The survival rates of introduced species at the introducing year depend on the precipitation amount of the year and its distribution, sapling quality and planting techniques, besides the adaptability to new babitats. So, the judgement to a specie's adaptability is not easy and must after experimental observation for many years.

Key words: Species selection, Introduction for sandy land, Bashang high plain