黄土区蔡家川流域河岸林物种多样性研究

Diversity of riparian vegetation in the Caijiachuan Watershed of the Loess Plateau,southwestern Shanxi Province,northern China

河岸带植被是陆地和水生生态系统过渡区环境变化的敏感指标。利用样方法对黄土高原山西吉县蔡家川流域主沟道中部海拔1020～1240m范围内的河岸带植被进行了调查,结果表明:该区域内河岸带植被的乔木层和灌木层结构较单一、物种丰富度较低,而草本层的物种丰富度相对较高,且长势良好;植物总的丰富度和乔木层的物种丰富度随海拔升高而呈现出显著的下降趋势,而灌木层却随海拔高度的变化呈现出较复杂的变化趋势;乔木层的均匀度也随海拔的变化而呈现出波浪式变化。

Riparian vegetation in the transition zone between terrestrial and aquatic ecosystems is sensitive to environmental changes. The riparian vegetation was sampled using a transect approach across an altitude gradient （1 020-1 240 m） in the Caijiachuan watershed of the Loess Plateau in Jixian County,Shanxi Province of northern China. The results showed that：1） the structure of tree and shrub layers was simple and the species richness was low. However,herbaceous richness was relatively high; 2） total plant richness and tree species richness were both negatively correlated with altitude,while species richness of shrubs didn＇t have clearly trends along the altitude; 3） overstory distribution also fluctuated along the altitude gradient.