浑善达克沙地植物群落主要类型与特征

浑善达克沙地植被在维护草原与沙地生态系统稳定、保护京津冀地区生态安全方面发挥着重要作用。因水分条件的不同，浑善达克沙地植被从东到西具有明显的地带性，物种组成和群落结构差异明显。本研究在野外样方调查的基础上，对浑善达克沙地不同降水条件下的植被类型进行了划分，分析了不同水分条件下群落的物种组成和多样性特征。结果表明：（1）浑善达克沙地植被类型丰富，可划分为5个植被型组、12个植被（亚）型、27个群系。（2）物种组成多样，共有维管植物46科149属256种，草本植物占75%以上。（3）东西部空间差异明显，由东部的疏林草原、中部的典型草原向西部的荒漠草原过渡。中东部优势科为菊科、禾本科、豆科等，西部的优势科为苋科和禾本科。

Types and characteristics of plant communities in the Otingdag Sandy Land

Vegetation in the Otingdag Sandy Land plays an important role in maintaining the desert-grassland ecosystem stability， promoting ecological security of the Beijing-Tianjin-Hebei region. Due to different water conditions， the vegetation in the Otingdag Sandy Land has obvious zonality from the east to the west， and the species composition and community structure are obviously different. On the basis of field survey， the vegetation types of the Otingdag Sandy Land under different precipitation conditions were classified， and the species composition and diversity characteristics of the community under different water conditions were analyzed. The results showed that： （1） There were abundant vegetation types in the Otingdag Sandy Land， including 5 vegetation type groups， 12 vegetation （sub） types and 27 vegetation groups， which has obvious zonal characteristics. （2） There are 256 species of vascular plants in 46 families， 149 genera， and more than 75% of them are herbaceous plants. （3） The community diversity varies greatly from east to west. The dominant families in the middle and east side are Asteraceae， Poaceae， Fabaceae， while the dominant families in the west side are Amaranthaceae， Poaceae. The results can provide basic data for vegetation protection and utilization in the Otingdag Sandy Land.