Patterns in tree species richness as a test of the glacial extinction hypothesis

摘要: IT is well established that Europe has far fewer tree species and genera than either eastern North America or Asia1–3. Fossil evidence shows west-central had a much richer flora during the Upper Tertiary (25–2 Myr BP), with many which now survive only in temperate regions of Asia3. These trees seem to have been eliminated from cold, dry glacial periods Pleistocene Era (2–0.001 BP). Their failure recolonize may be due reach potential refugia phase2,3. Alternatively, present-day climates, rather purely historical effects extinction suvival refugia, explain observed contrasts richness between regions. Currie Paquin4 showed number Britain Ireland corresponds American areas similar climate, without need invoke explanation. Here we report differences three northern regions, Europe, Asia, can mainly explained terms climatic factors. Similarly, despite its long period isolation flora, New Zealand closely same relationship climate richness. By contrast, greater (compared America) found some parts Asia cannot readily accounted for present lower rates phases.