西藏地区种子植物多样性分布格局和多样性分化特点

以大尺度的植物分布信息为基础,结合地理信息系统和统计学分析,对西藏地区的种子植物多样性地理分布格局和多样性分化特点进行了探讨.结果表明,从种到科,植物多样性和区系分化强度的数据集离散度呈递减趋势.与科相比,种、属的植物多样性的空间变异程度更为明显,这可能与种、属和科所代表的不同时期的地质历史有关.相对中部和北部而言,无论是在种、属水平,还是在科水平,西藏地形更为复杂的南部尤其是东南部拥有更高的植物多样性.种子植物的区系分化强度与表征地形复杂度的海拔高差存在显著的正相关关系,这说明复杂的地形可能有利于区系的分化.区系分化强度对研究区域植物多样性的地理分布格局存在明显的影响,这可能与西藏地质历史上地层的差异性抬升引起的气候变迁有关.

The Spatial Patterns of Species Diversity of Seed Plants and Its Differentiation in Tibet

The geographical patterns and differentiation of species diversity of seed plants in Tibet were investigated based on large-scale plant distribution information through combination with geographic information system and statistical analysis.The results showed that the discreteness of datasets of plant diversity and flora differentiation decreased from species to families.Compared with that of families,the spatial variability of species and genus was more apparent,which may be because that species,genus and families represent different periods of geological history.Compared with central and northern regions,the southern Tibet with more complex topography,especially the east southern Tibet,had more diverse plants whether on the species or genus level.There was a significant positive correlation between the flora differentiation of seed plants and altitudmal variation,indicating that complex topography might be beneficial for flora differentiation.The flora differentiation had obvious influence on the geographical distribution of plants in the researched area.This may be related to the climate change caused by differential uplift of stratums in the geological history of Tibet,