CHAPTER XVIII 



ALASKA 



Climate and Topography. — As a preliminary to a description 

 of the timber distribution in Alaska an understanding of the 

 climatic factors is desirable. In the first place it is necessary to 

 correct the general impression that low temperatures preclude 

 all tree growth. This probably arises from a failure to understand 

 that Alaska is 1400 miles long. In other words, it would reach 

 from Cape Cod to Key West if set down on the Atlantic Coast. 

 Hence the southern third is outside the Arctic Circle. Sitka, the 

 capital, for example, has an average annual temperature equal to 

 that of Philadelphia. This is true even tho Sitka is in the same 

 latitude as northern Labrador because of the warm winds which 

 blow off the Pacific Ocean. These are also responsible for the 

 heavy precipitation of southern Alaska where 80 inches per annum 

 is not uncommon. The northern or continental part of Alaska 

 has an entirely different climate, however. This part may be 

 said to consist of a basin, the Yukon and Kuskokwim river val- 

 leys with the Alaska Range on the south and the Endicott Range 

 on the north. The former is particularly rugged, running up to 

 15,000 feet above sea level in many places and attaining the mag- 

 nificent altitude of over 20,000 feet in Mt. McKinley the highest 

 peak in North America. This means that many of the mountains 

 are too high to permit tree growth on them. 



The Endicott Range while not so lofty is, however, high 

 enough to also have considerable areas above timber line. In all, 

 approximately one third of the territory is so far above sea level 

 that tree growth is out of the question. Another third of the 

 land area is also treeless but for another reason. This is the so 

 called " tundra " upon which tree growth cannot exist because of 

 the short growing season. To this category belong the slopes 

 draining into the Arctic Ocean and Behring Sea. The glaciers 

 and snowfields are also without tree growth. 



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