554 



ZONES AND REGIONS [Pt. Ill, Sect. II 



a dry winter and a rainy summer ; the climate bears the character of 

 a grassland climate, and natural steppe and meadow actually occur over 

 extensive areas. The feature in steppe districts that is specially hostile to 

 trees, the prevalence of strong dry winds in winter, is wanting here, for in 

 the winter the air is very calm. In Eastern Siberia, where but little rain 

 falls, tree-growth is consequently richer, in the prevailing form of dry thin 

 coniferous forests ; whilst grasslands and clumps of forest alternate with 

 one another near the Amur. What climatic or edaphic influences determine 

 the occurrence of either type of vegetation in this alternation is not yet 

 decided. 



ANNUAL PERIOD OF RAINFALL IN EXTRA-TROPICAL EASTERN ASIA. 



(After Hann, I, Bd. Ill, p. 223.) 

 The monthly figures are in percentages of the annual amount. 



SUMMARY. 



The conclusions which may be drawn from what has been stated in this 

 chapter may be summarized in the following paragraphs: — 



