The Distribution and Phytogeographic Relationships of the Woody Plants of the Soviet Far East

The woody flora of the Soviet Far East is rich and diverse when compared to dendrofloras at similar latitudes of the world. The bulk of this region lies north oflatitude 46 degrees. This area includes the northernmost stations in eastern Asia for many genera, e.g., Abelia, Acer, Aralia, Carpinus, Corylus, Fraxinus, Hydrangea, Ilex, Juglans, Magnolia, Morus, Quercus, Phellodendron, Sasa, Schizophragrna, Schisandra, Skimmia, Syringa, Tilia, and Ulmus. The majority of the woody species native to the Soviet Far East do not occur elsewhere in the U.S.S.R. Many of the trees and shrubs are native to Japan, Korea, or China and extend into the Soviet Union, or are more closely related to temperate Asian taxa than to European or Siberian taxa. The woody species can be subdivided into seven major elements and from those elements four phytogeographic regions can be recognized in the Soviet Far East based upon the distribution of 311 species studied. The southern part of the region studied, along with most of Manchuria, serves as a refugium for taxa believed to have persisted from the Tertiary or to be at least derived from Tertiary ancestors.