32 FORESTS AND MANKIND 



the vanquished trees become dwarfed, sickly and die. Of all 

 the trees that may begin in this race for life on an acre of forest 

 soil sometimes a hundred thousand at the very start only a 

 very few, perhaps only two or three, survive to form a part of 

 the mature forest. 



So trees battle against one another in a life and death 

 struggle for sunlight and moisture. Yet they help one another 

 too, in affording mutual protection from wind and storm and 

 from breakage by heavy wet snows. In keeping the ground be- 

 neath them moist and soft they create conditions favorable to 

 tree growth and tree reproduction not only for themselves, but 

 for their neighbors. And always, so far as man is concerned, 

 this close association of trees in the forest with its necessity for 

 rapid height growth serves the useful purpose of crowding the 

 trees so that early in life their lower branches are cut off from 

 light and die. Trees of the forest are often free of limbs for 

 a hundred feet above the ground. The tree that grows alone 

 and receives light from all sides is usually shorter than its 

 forest-born neighbor. It produces knotty lumber, it is bushier, 

 and its trunk is thicker just above 'the roots and tapers more 

 rapidly. 



Although more picturesque, open grown trees are of little 

 use for lumber. Our forest tree, competing with its neighbor in 

 an everlasting search for sunlight grows tall to escape being 

 overshadowed and killed and so produces a long straight trunk 

 that gives man his most valuable timber. 



The forest types of the world differ enormously. They differ 

 in rate of growth, in size, density, species, and in a dozen 

 other ways. We have one kind of forest here and another there, 

 changing as the climate, altitude and soil changes. We have as 



