28 



A PKIMER OF FORESTRY. 



SELECTION FOEEST. 



When a stand of aspen dies away from a young crop 

 of spruce, the ground is no longer completely shaded. 



Fig. 15. — Young growth of spruce under older growth of popple. Colorado. 



and there is light and room for other kinds of trees to 

 come in. Thus, birch and maple seeds may be blown 



