中文摘要：

流动沙丘区的丘间低地的土壤种子库大,种类丰富,但其对流动沙丘植被恢复的作用尚不清楚。以科尔沁沙地为研究对象,在靠近丘间低地的下风向裸沙段设置沙障,研究了其对土壤种子库、幼苗出土与植物定居的效应。结果表明：沙障处土壤种子库物种数和密度都显著大于对照处（P〈0.05）,5～10cm深度种子密度达到土壤种子库密度的60%,而对照处低于50%;沙障内的沙生植物出土和定居幼苗密度都显著大于对照处（P〈0.001）,沙障处与对照处的非沙生植物出土幼苗密度低于1株.m-2,建植幼苗密度低至0.1株.m-2;对照处种子数与幼苗出土和定居的相关性相对于沙障处的更强,沙生植物种子数与幼苗出土和定居的相关性相对于非沙生植物的更强;对照处种子库与幼苗出土和定居的物种组成相似性较沙障处大,沙生植物种子库与幼苗出土和定居的相似性较非沙生植物大。可见,沙障截留来自丘间低地的种子增加了流动沙丘的土壤种子库种类和密度,改变了土壤种子库的空间格局;沙障的设立提高了沙生植物幼苗的出土和物种定居的水平,但没有显著提高非沙生植物幼苗的萌发和建植。

英文摘要：

Interdune lowlands of mobile sand dunes have big soil seed bank rich in species,but the significance of this soil seed bank in vegetation restoration is little known.In this study,willow branch sand-barriers were settled on the windward slope of mobile sand dunes near the interdune lowlands in Horqin Sand to investigate the effects of the sand-barriers on the soil seed bank,seedling emergence,and plant establishment of the lowlands.In the plots within sand-barriers,the species number and density of soil seed bank were significantly higher,the seed density at the soil depth 5-10 cm accounting for 60% of the total,while that in control plots being less than 50%.The seedling emergence and establishment rates of psammophytes in the plots within sand-barriers were also significantly higher than those in control plots.Both in the plots within sand-barriers and in control plots,the seedling emergence of non-psammophyte was less than 1 seedling·m-2,and the plant establishment was as low as 0.1 seedling·m-2.The correlations of seed density with seedling emergence and establishment were higher in control plots than in the plots within sand-barriers,and higher for psammophytes than for non-psammophytes.In the same,the similarity coefficients of the species numbers of soil seed bank and the seedling emergence and establishment were higher in control plots than in the plots within sand-barriers,and higher for psammophytes than for non-psammophytes.This study suggested that sand-barrier could intercept the seeds in interdune lowlands,increase the species richness and seed density of soil seed bank,and alter the spatial pattern of soil seed bank.The establishment of sand-barrier could improve the seedling emergence and establishment of psammophytes but not of non-psammophytes.