54 FORESTS AND MANKIND 



problem of wood supply. Rainfall, stream flow, humidity and 

 temperature all seem to be adversely affected by deforestation. 



Each year the world cuts about fifty-six billion cubic feet 

 of wood. Of this a little less than half is of the size and quality 

 that make it suitable for sawing lumber the lumber we use 

 for building and for general construction. The rest more than 

 half is small, inferior material cut chiefly for firewood. North 

 America produces half of the wood cut in the world, and the 

 conifers or softwoods supply about three-fourths of the sawing 

 timber. It is the conifers, then, whose perpetuation is essential 

 so that the world may continue to be kept in timber. 



How much wood is grown each year in the world's forests ? 

 That is a hard question to answer. We believe that it is much 

 less than the amount consumed and it is certainly much less 

 than could be grown if the forests were properly handled. In 

 the virgin forests of the world such as the great forests of 

 the Amazon and of north Russia, the amount of wood that 

 grows each year is balanced by death and decay. So far as 

 adding to the world's wood supply, these forests produce noth- 

 ing. They are not creating great reserves of timber against our 

 future need they are merely holding their own. 



Foresters estimate that about thirty-eight billion cubic feet 

 is grown yearly. They believe that if all the forests of the world 

 were placed in a condition of ideal growth, they could prob- 

 ably be made to produce as much as three hundred and fifty 

 billion feet. But the world's forests will never reach the max- 

 imum production for even though scientific forestry may some- 

 day greatly increase the rate of growth of valuable species the 

 area of forest is bound to decrease. In the face of this certain de- 

 crease of forest area throughout the world it becomes an in- 



