中文摘要：

以科尔沁沙化草地的裸斑为研究对象,布设种子捕捉器监测生长季传播到裸斑的种子数量、物种组成,并人工播种监测裸斑中出苗情况,研究可获得种子数量和出苗对裸斑植被恢复的制约。结果表明：沙生植物3种,种子数为71～623粒·m-2,非沙生植物9种,种子数为73～410粒·m-2;裸斑中沙生植物的出苗数（9.3～22.3株·m-2）高于非沙生植物（0～3.4株·m-2）;沙生植物在裸斑的出苗率最高为沙蓬（12.2%～34.1%）,其次是乌丹蒿（4.5%～10.3%）,小叶锦鸡儿（0～0.5%）,非沙生植物狗尾草出苗率为0～6%,蒲公英为0～0.4%,其余植物种出苗率为0;沙生植物裸斑出苗数（9.3～22.3株·m-2）高于植被区（7.7株·m-2）,而非沙生植物在裸斑的出苗数（0～3.4株·m-2）低于植被区（4.5株·m-2）。可见,裸斑植被恢复中,沙生植物的可获得种子量制约高于出苗制约;非沙生植物的可获得种子量制约与出苗制约相当。

英文摘要：

Taking the bare patches in Horqin desertified grassland as test objects,seed traps were installed to investigate the amount and species composition of the seeds diffused on the patches during growth season,and artificial seeding was conducted to monitor the seedling emergence on the patches,aimed to understand the relative limitation between seed availability and seedling emergence on the vegetation restoration on bare patches.Of the seeds diffused on the bare patches,an amount of 71-623 grains·m-2 came from three psammophyte species,and of 73-410 grains·m-2 came from nine non-psammophyte species.The seedling emergence of psammophytes（9.3-22.3 plants·m-2） was higher than that of non-psammophytes（0-3.4 plants·m-2）,and the emergence rate of psammophytes Agriophyllum squarrosum,Artemisia wudanica,and Caragana microphylla was 12.2%-34.1%,4.5%-10.3%,and 0-0.5%,respectively,whereas that of non-psammophyte Setaria viridis was 0-6% and of the rest non-psammophytes was null.The seedling emergence of psammophytes on bare patches（9.3-22.3 plants·m-2） was higher than that on vegetation-covered patches（7.7 plants·m-2）,while the seedling emergence of non-psammophytes on bare patches（0-3.4 plants·m-2） was lower than that on vegetation-covered patches（4.5 plants·m-2）.This study suggested that during the vegetation restoration of bare patches in degraded grassland,the limitation of psammophytes seed availability was more important than that of seedling emergence,but for non-psammophytes,the importance of seed availability limitation was equivalent to that of seedling emergence limitation.