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BULLETIN 544, U. S. DEPARTMENT OF AGRICULTURE. 



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The use of strips up to 300 feet wide or more will reduce the cost of 

 logging but will delay the cutting of the second half of the area until 

 the trees on the first half become large enough to furnish the neces- 

 sary seed for reproducing it when 

 cut over. This will delay the sec- 

 ond cut to between the sixtieth 

 and seventy-fifth year and require 

 a rotation for each half of the stand 

 of from 120 to 150 years. Com- 

 plete stocking on the entire 300 

 feet of clearing could hardly be 

 expected short of 3 and possibly 4 

 seed years; that is, from 15 to 18 

 years. Birch, aspen, beech, maple, 

 and other hardwoods, and rasp- 

 berries and other perennials will 

 almost surely come in during the in- 

 terval, whether the area is burned 

 over or not. Spruce, however, will 

 seed in beneath; and while that 

 which comes in first where the 

 cover crop is dense will be retarded, 

 that which comes in later will find 

 conditions favorable to its rapid de- 

 velopment, so that when the over- 

 wood thins out, this understory of 

 spruce will develop largely as an 

 even-aged stand. (See Fig. 2a.) 

 The most desirable of the hard- 

 woods as a nurse tree for spruce is 

 the aspen. It also reaches such a 

 size as to enable it to be cut at a 

 profit within from 40 to 50 years. 

 Its coming in, therefore, should be 

 encouraged. This can best be ac- 

 complished by the broadcast burn- 

 ing of the brush in the early spring 

 following the logging. The seed 

 of fire cherry is dispersed in the 

 summer and of beech, paper birch, 

 and sugar maple in the fall and 

 winter, while that of the aspen is 

 dispersed in the early spring. Broadcast burning in the spring, there- 

 fore, as soon as the brush is dried out enough to burn readily, will 

 destroy the duff and the seeds and spring germinates of the other 



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