14 



PBACTlOAL FORESTRY. 



Two-storied seed forest. — After a forest fire in Maine it frequently 

 happens that the first tree to cover the ground is the popple, or quak- 

 ing aspen. It is a slender, short-lived tree, intolerant of shade, with 

 a light crown. After the popple has grown for some years, spruce 





Fia. 7.— Beproduotion obtained by process shown in figure 6. Sihlwald, Switzerland. 



seedlings spring up under the friendly cover, and rapidly follow the 

 popple in height. There grows up in this way a forest composed of 

 an upper and a lower story of growth, in which, as so often happens, 

 the lower story is of more importance. 



The system of two-storied seed forest is useful when a tolerant tree 

 like the spruce is to be grown under the shade of an intolerant tree 

 like the aspen. In countries where forestry is well developed it is 

 usual to plant young trees of tolerant species under older intolerant 

 trees, to make a cover for the soil and to prevent the growth of grass 



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