48 Forestry Quarterly. 



the climate grows, especially in winter, when the large lakes of 

 Finnland and Sweden, as well as a large number of the harbors 

 of the Baltic Sea, are frozen over and the moderating influence 

 of these waters on the climate is eliminated. The warm season 

 of the year, therefore, shows a mild sea climate, similar to the 

 German climate. 



The mountain group in the western part precipitates a large 

 per cent, of the precipitation coming from the ocean. Only the 

 west coast as far north as Gotenburg is open and receives a rela- 

 tively high precipitation (70-75 cm) similar to the Norwegian 

 coast. The greater part of Sweden, however, lies in the shadow 

 of the Scandinavian Divide, so that most of the recorded precipi- 

 tations in the interior and coast land fall below 50 cm. This 

 is especially true of the timbered Norrland, which only gets 

 40-45 cm. annually. The mountain ridge also protects Sweden 

 against western storms. Winds are quite limited, especially in 

 summer; and the number of calm days is large. This is of great 

 significance in the straight symmetrical development of the pine. 



The sources of warmth during the summer months differ very 

 little from those in Germany. As far as the amount of heat, 

 which favors vegetation is concerned, the longer hours of the 

 day equalize the lower degree of intensity of the sun's rays, so 

 that our cereals and even species of turnips ripen in the central 

 Norrland. 



The greatest change in climatic respect is brought about by 

 the cold season. In central and northern Sweden, the timbered 

 sections, the lakes freeze over during November, beginning with 

 those farthest north. In Wermland the lakes are usually frozen 

 by November 20th, in Dalekarlien by November loth to 15th. 

 Actual thawing does not start in till the latter part of April. 



The lakes of Dalekarlien are free from ice about May loth 

 but farther north the ice does not break up before June. In 

 central Sweden snow covers the ground from 90 to 130 days, in 

 northern Sweden for 200 days on an average of a number of 

 years. The harbors of the Baltic Sea are closed several months 

 during winter, unless they are artificially kept open as the harbor 

 of Stockholm and several others south of it are. Navigation 

 usually closes down in December, beginning again in May. 

 For trade and traffic, therefore, the harbors of Norrland are 

 handicapped. 



