548 



ZONES AND REGIONS [Pt. Ill, Sect. II 



atmospheric humidity in winter is considerable, so that its average for the 

 whole of winter is not low. 



Even during summer, excessive atmospheric dryness offers a climatic 

 element that is unfavourable for tree-growth. Despite the prevalence of 

 the west wind, investigators agree that when the weatJier is fine, the air of 

 the steppe at summer time is extremely dry, and during this season high 

 temperatures prevail, involving vigorous transpiration. 



It follows from what has been said, that the climate of the Russian steppe 

 district has by no means the character of a forest climate, but rather that of 

 a grassland climate, including as it does dry winter, moist spring and early 

 summer {June), and a mild temperature with frequent precipitations during 

 the vegetative season. The drought in late summer and autumn comes 

 at the close of the vegetative season, and is therefore without injurious 

 effects. 



Central and Northern Russia have a less pronounced forest climate than, 

 for instance, the Atlantic territories of North America, and accordingly 

 possess a much less luxuriant forest growth. The precipitations are far 

 less abundant, especially during the winter; but the unfavourable influence 

 of this is to some extent mitigated by the prevalence in the Russian forest 

 district, in contrast with the steppe, of west winds which, even during 

 winter, do not possess the destructively desiccating action that characterizes 

 the east winds. It is also of advantage to the Russian forest district that 

 its climate is unfavourable to grassland, because the early summer is 

 relatively poor in rain and the precipitations fall chiefly in late summer and 

 autumn. 



DIRECTION OF THE WIND IN THE STEPPES OF CENTRAL AND 



SOUTHERN RUSSIA BETWEEN 53 AND THE BLACK SEA. 



(After Woeikof, Bd. II, p. 159.) 



