祁连山4种杜鹃在不同海拔梯度上的株丛特征

以分布于祁连山东段的头花杜鹃(Rhododendron.Capitatum)、千里香杜鹃(R.thymifolium)、烈香杜鹃(R.anthopogonoides)和陇蜀杜鹃(R.przewalskii)为对象,研究了其株丛特征与海拔梯度间的关系。随着海拔升高,头花杜鹃、千里香杜鹃和烈香杜鹃的冠基呈降低趋势。随着海拔升高,头花杜鹃与千里香杜鹃的重要值增加,并显著大于其他物种。在海拔3 100m处,杜鹃灌丛群落物种组成和多样性均处于较高水平。随着海拔升高,杜鹃灌丛总盖度逐渐降低。千里香杜鹃的分盖度在海拔3050m较小。头花杜鹃的分盖度在各海拔梯度上均较大。头花杜鹃和千里香杜鹃的植株高度随着海拔升高而逐渐降低。

The plant characteristic of four Rhododendron species at different altitude gradient in Qilian Mountain

Four Rhododendron shrubs (Rhododendron capitatum ,R.thymifolium,R.anthopogonoides ,and R.przewalskii)were chosen as indicators to study the relationship between plant characteristics and altitude gradients in the Qilian Mountain in the eastern Qinghai-Tibetan Plateau.The results revealed that the crown width of R.Capitatum,R.thymifolium and R.anthopogonoide decreased with altitude increasing.The spe-cious important value of Rhododendron.capitatum and R.thymifolium increased with the altitude increasing, and was significantly higher than that of other species.The species composition and diversity reached the high-est level at the 3100 m altitude.The total coverage of Rhododendron shrubs gradually decreased with altitude increasing.The sub-coverage of R.thymifolium reached the lowest level at the 3050 m altitude.The sub-cov-erage of R.capitatum was higher than that of other species.The height of R.capitatum and R.thymifolium gradually decreased with altitude increasing.