中文摘要：

滇西北地区是我国三大特有物种分化中心之一.作者利用地方植物志资料,结合数值高程模型（DEM）数据,研究了云南丽江地区种子植物物种丰富度的垂直分布格局,并分析了面积和中间膨胀效应（mid-domain effect）对该格局的影响.研究结果表明：随着海拔的升高,各海拔段面积呈先增加后下降的分布格局;物种丰富度、物种密度和中间膨胀效应的物种丰富度预测值在海拔梯度上均呈单峰型变化格局.面积和中间膨胀效应对丽江地区物种丰富度的垂直分布格局有着显著的影响.其中,面积起主要作用,对物种丰富度的变异解释百分率达80.2%,而中间膨胀效应的影响作用相对较小,仅占11.3%.

英文摘要：

Based on regional flora and a Digital Elevation Model （DEM）, we investigated altitudinal patterns of seed plant richness in Lijiang, Yunnan. The results indicated that species richness, species density, available area, and the species richness predicted by the mid-domain effect increased first and then decreased after reaching their maximum, showing a unimodal pattern against elevation. There was strong correlation between species richness, available area and mid-domain effect. The area was a much more important factor, explaining 80.2% of the pattern of species richness, whereas the influence of the mid-domain effect was relatively weak, explaining only 11.3%.