12 



CIRCULAR- 21, U, S. DEPARTMENT OF AGRICULTURE 



The greater part of our forest, however, has been and still is 

 rreated as a mine rather than as a continuously productive resource. 

 About 125.000 square miles of it now lies idle and nonproductive as 

 a result of destructive lumbering and repeated fires. To restock this 

 land with valuable timber species will be a slow and costly process. 

 and even then it can not produce timber crops for several decades, 

 nor saw timber in less than half a century. More than 390.000 square 

 miles additional, which has been cut or burned over, is partially 

 restocked with timber varying in age from seedlings to mature trees. 

 Although some of this land is fairly productive, a greater propor- 

 tion bears for the most part inferior trees, or stands too open to give 

 high yields or to grow good timber. Such forests can not be brought 

 to full productivity within less than 50 years. The rest of our forest 

 area is occupied by old-growth timber, the growth of which is 

 approximately balanced by decay ; it can not add appreciably to our 



30 20 



BILLIONS OF BOARD FEET 

 10 O 10 20 30 40 





• Present] cut \ \ 



TOTAL FOR 





■"■f 







Present consumption 









Present \growth 







J 







Growth :\Crude forestry 







.w ] 



26 



1 

 Growth : intensive forestry 











eagiflBwaiW^HBBgiHH Hi ?n 



I. 







WESTERN UNITED STATES I EASTERN UNITED STATES 



Fig. 4. — Saw-timber cut consumption* and growth 



stock of timber until the old trees are cut and replaced by young 

 growth. 



It has been estimated that the forest land we now have, if it were 

 all stocked with trees and managed carefully with the object of con- 

 tinuous timber production, could yield annually about 27.000.000.000 

 cubic feet of wood, or about one-sixth more than our present con- 

 sumption of all kinds of woods. Something over half of this amount 

 would consist of 70.000.000.000 board feet of saw timber or one-third 

 more than we now require. It is more than four times the present 

 total growth and seven times the present annual increment of saw 

 timber. 



By the time our forests are brought to such a high state of produc- 

 tivity, which can not come about in less than several ^decades, and 

 probably not within a half century, there can be little doubt that all 

 of the wood will be needed. With the increase in population that is 

 likely to take place our needs will grow, even though the rate of con- 

 sumption per capita should fall almost as low as the present Euro- 



