物种分布宽度对种子植物物种丰富度垂直分布格局及“中间膨胀效应”的影响

Effects of altitudinal range on species richness patterns and mid-domain-effect along the altitudinal gradients

物种丰富度的垂直分布格局是生态学研究的重要课题之一。文章以云南楚雄地区为例探讨物种分布宽度对种子植物物种丰富度垂直分布格局及"中间膨胀效应"的影响。利用大尺度的物种分布数据建立物种分布数据库,同时结合地形信息,分析了研究区域内物种丰富度的海拔分布格局以及"中间膨胀效应"对该格局的影响。在此基础上,探讨了物种分布宽度对楚雄地区种子植物物种丰富度垂直分布格局及"中间膨胀效应"的影响。结果表明,随着海拔的升高,物种丰富度先增加,后下降,呈单峰分布格局。物种分布宽度的相互重叠,即"中间膨胀效应"对物种多样性的垂直分布格局具有显著影响。随着物种分布宽度的增加,"中间膨胀效应"以及各物种组对物种丰富度垂直分布格局的影响均呈显著增加趋势,这说明"中间膨胀效应"和物种丰富度的垂直分布格局更多地取决于分布宽度较大的物种。

Altitudinal patterns of species richness is one of hot topics in the field of Ecology. This paper aims to examined the effects of altitudinal range on species richness patterns and mid-domain-effect along the altitudinal gradients in Chuxiong, China. A database was built based on distribution information of seed plants in large scale. Coupled with topographical information, altitudinal patterns of species richness and the effects of mid-domain-effect on the patterns were probed. Further more, effects of range size on the altitudinal patterns and mid-domain-effect were also explored. The results showed that species richness were increased, and then decreased against altitudinal gradients. Mid-domain-effect played a significant role in the altitudinal patterns of species richness. With the increase of altitudinal range size, mid-domain-effect and the effects of the altitudinal patterns of species richness for each species group on overall species richness patterns became much stronger, indicating species with larger range sizes playing much stronger roles on mid-domain-effect and the altitudinal patterns of species richness.