中国种子植物物种丰富度的大尺度分布格局及其与地理因子的关系

Distribution patterns of species richness of seed plants in china and its relationship with geographical factors

地理因子对物种多样性空间分布格局的影响具有重要意义。文章利用大尺度的物种分布数据以及地理信息,结合GIS和数理统计方法,探讨了中国种子植物物种丰富度的空间分布格局及其与地理因子的关系。结果表明,从南到北,研究区域内物种丰富度总体上呈递减趋势;在经度梯度上,从东到西,物种丰富度呈递增趋势,这可能与其它地理因子的影响有关;在排除其它因子影响的情况下,物种丰富度随着面积的增加,呈递增趋势。但在其它地理因子的综合影响下,面积的影响作用被掩盖或弱化。物种丰富度随着海拔变幅的增加,呈显著递增趋势;物种丰富度与纬度变幅、经度变幅之间不存在显著的(偏)相关性。总体上,纬度、面积和海拔变幅均显著影响物种丰富度的分布格局,但相对而言,面积和纬度起着更为重要的影响。相对海拔变幅而言,海拔变幅与纬度之比值能更好地反映"生境异质性"效应,说明,海拔梯度的"纬度效应"值得关注。

The effects of geographical factors on spatial patterns of species richness were one of key topics in the field of biodiversity science. In this paper, spatial patterns of species richness of seed plants in China and its relationship with geographical factors were investigated based on flora lists in large scale and geographical information, coupled with GIS and statistic methods. The results showed that species richness decreased against the latitudinal gradients. Species richness increased against the longitudinal gradients, which maybe resulted from effects of other geographical factors. When other factors were controlled, species richness increased with the increase of area, and the effects of area were probably hidden by other factors. With the increase of altitudinal variation, an increasing trend was observed on species richness. Latitude, area and altitudinal variation all significantly affected the spatial patterns of species richness, but latitude and area played much stronger roles. No significant correlation was observed between species richness and latitudinal or longitudinal variations. The significant positive correlation was observed between species richness and the ratio of altitudinal variation to latitude. Compared with altitude, the ratio of altitudinal variation to latitude may reflect habitat heterogeneity more effectively.