Chapter 4 Phytogeography of Northeast Asia

the Korean Peninsula, and Hokkaido Island (Japan). We determined the species richness of Northeast Asia at various spatial scales, analyzed the floristic relationships among geographic regions within Northeast Asia, and compared the flora of Northeast Asia with surrounding floras. The flora of Northeast Asia consists of 971 genera and 4953 species of native vascular plants. Based on their worldwide distributions, the 971 gen-era were grouped into fourteen phytogeographic elements. Over 900 species of vascular plants are endemic to Northeast Asia. Northeast Asia shares 39 % of its species with eastern Siberia-Mongolia, 24 % with Europe, 16.2 % with western North America, and 12.4 % with eastern North America. Species richness and floristic relationships among different regions within Northeast Asia were discussed. The northernmost (Arctic) region shares 64 % of its genera and 9 % of its species with the southernmost (warm temperate) re-gion. The geographic setting, climate, vegetation, and endemism of each of the eighteen regions of Northeast Asia were described and characterized. The geographic distributions of the 53 most important tree species in Northeast Asia were mapped