浑善达克沙地榆种子扩散及成苗影响因素分析

Analysis on the Factors Affecting Seed Dispersal and Seedling Survival Rate of Ulmus pumila var. sabulosa in the Otindag Sandy Land

以浑善达克沙地榆为研究对象,以种子扩散规律及成苗率为主要研究内容,采用样线法调查了平沙地、沙丘迎风坡、丘间草地、稀疏灌木地、灌木地5种不同地表类型下沙地榆种子数量。分析种子分布数量与母树距离、地表状况、植被种类、盖度和高度及成苗率与土壤含水率的关系。结果证明:影响种子分布数量的主要因子是母树的距离,其他因子对沙地榆种子分布没有显著影响。影响种子萌发成苗的主要因子是6～8月的降水量以及由此导致的沙层含水率,其他因子影响不显著。

In this study,the seed dispersal pattern and seedling survival rate of Ulmus pumila var.sabulosa in the Otindag Sandy Land in Inner Mongolia were researched,the seed-dropping quantity of U.pumila var.sabulosa on 5 kinds of land surface including the flat sandy land,windward slope of sand dune,inter-dune lawn,sparse shruberry land and shruberry land was investigated using transect method,and the relationships between the distribution quantity of U.pumila var.sabulosa seeds and the distance from mothertree,surface conditions,vegetation types,coverage and height,and soil moisture content were analyzed.The results show that the distance from mothertree was the main factor affecting seed dispersal,and the effect of other factors was not significant.Precipitation and soil moisture content during the period from June to August were the main factors affecting seed germination and seedling survival rate,and the effect of other factors was not significant.