SILVICULTURAL CHARACTERISTICS 55 



It is less particular in regard to the character of the soil or 

 moisture than the sugar maple, but is less tolerant of shade than 

 that tree. In second growth stands it is a fairly rapid grower, 

 but under virgin conditions the growth is similar to that of maple 

 and it hves to equally advanced age. Like all birches this 

 species is a very proHlic seeder, and as the seed is very light it 

 is blown long distances. Birch seed germinates particularly well 

 on burned-over land where the mineral soil is exposed. Openings 

 in spruce forests caused by windfall or lire or camp clearings 

 frequently grow up to a dense stand of seedUngs either of pure 

 yellow birch or of this mixed with other species. This tree has 

 no serious natural enemies and is little damaged by fire. 



Paper Birch (Betula papyrifera). 



The range of the paper birch extends across the continent to 

 the Rocky Mountains but not very far south. It occurs through- 

 out New England but only occasional specimens are found in 

 Connecticut and Rhode Island. 



This tree thrives best on a fresh, well-drained soil, being fond 

 of moisture but not of swampy land. Although frequently found 

 on dry slopes it does not prosper there as well as the yellow birch. 

 Paper birch is one of the most intolerant trees and is often killed 

 out, for lack of hght, by slow-growing but more tolerant spe- 

 cies, which started under its protection but finally caught up 

 with it in old age. Although rapid growing in youth, it is com- 

 paratively short hved, trees over one hundred years old being 

 uncommon. Specimens over eighteen inches in diameter and 

 seventy-five feet high are scarce. 



It produces an abundant supply of seed, but on account of 

 its intolerance of shade reproduction is only successful under 

 favorable light conditions such as those obtained on burned 

 areas. . These also furnish the bed on which the seed germi- 

 nates best because the bare mineral soil is exposed. When 

 cut at an age of less than sixty years the stumps sprout pro- 

 lifically and these sprouts grow even more rapidly for forty or 

 fifty years than trees grown from seed. 



