Research and Collections Center, Illinois State Museum, 1011 East Ash Street, Springfield, Illinois 62703 USA.
Am J Bot. 2002 Nov;89(11):1818-25. doi: 10.3732/ajb.89.11.1818.
The taxonomic richness of seed plants at different taxonomic levels was compared between temperate East Asia and North America at both continental and semi-continental scales. In each comparison, land area and latitude range were adjusted to a comparable level between the two continental regions. East Asia is significantly more diverse than North America. In general, differences in taxonomic diversity arise at and below the genus level. At the continental scale, East Asia has 1.3 and 1.5 times as many genera and species, respectively, as North America. The northern part of East Asia has 1.1 times as many species as the northern part of North America. At the genus level, the northern part of East Asia is less diverse than the northern part of North America by a factor of 0.94. This pattern indicates that the diversity bias between the two continental regions results from the flora of southern East Asia. The diversity differences between East Asia and North America are not homogenously distributed across different plant groups. At the species level, East Asia had significantly more species than expected in magnoliids, alismatids, Liliidae, ranunculids, and rosids and had significantly less species in the Commelinidae, Caryophyllidae, and euasterids than North America.
在大陆和半大陆尺度上，比较了东亚热带和北温带不同分类水平的种子植物的分类丰富度。在每一次比较中，都将陆地面积和纬度范围调整到两个大陆区域可比的水平。东亚的多样性明显高于北温带。一般来说，分类多样性的差异出现在属级以下。在大陆尺度上，东亚的属和种分别比北温带多 1.3 倍和 1.5 倍。东亚北部的物种比北温带北部多 1.1 倍。在属级水平上，东亚北部的多样性比北温带北部少 0.94 倍。这一模式表明，两个大陆区域之间的多样性偏差是由东亚南部的植物区系造成的。东亚和北美的多样性差异在不同的植物群中分布不均。在种级水平上，东亚的木兰类、泽泻类、百合类、毛茛类和蔷薇类的物种明显多于预期，而石竹类、藜科和真双子叶植物的物种明显少于北温带。
