190 A NATIONAL PLAN FOR AMERICAN FORESTRY 



milling practices have, from the standpoint of engineering and me- 

 chanics, become much more efficient. It has become, therefore, in- 

 creasingly feasible to log more remote areas. At the same time, 

 knowledge of the adaptability of the less desirable species for special 

 purposes has grown and the trend has been toward the utilization of 

 the less desirable species. In view of such developments, it would 

 be unsafe to prophesy as to the proportion of existing timber stands 

 that may ultimately prove to be economically available. It seems 

 reasonable to believe, however, that competing or substitute materials 

 for wood, which already have become a powerful factor, will prevent 

 the indefinite pushing back of the limits of availability. 



REGIONAL AVAILABILITY OF SAW TIMBER 



The economic availability of saw timber, as estimated very roughly 

 by regions, will give concrete evidence of the wide divergence that 



Approximate Stand 



Having Positive 

 Conversion Value 



Estimated Total 

 Stand 



500 1000 1500 2000 



Billion Board Feet 



FIGURE 9. Approximate stand of saw timber in the United States having a positive conversion value on 

 the basis of 1925-29 lumber prices (mill) and operating conditions, in comparison with total saw-timber 

 stand. 



may exist between stand and availability in any estimate of national 

 timber supply. 



NEW ENGLAND, MIDDLE ATLANTIC, LAKE, AND CENTRAL REGIONS 



The combined saw-timber stand of these four regions amounts to 

 about 155 billion board feet or less than one tenth of the national 

 supply. Hardwoods make up two thirds of the total. Old-growth 

 saw timber comprises less than 60 billion board feet. The bulk of it 

 is confined to the more remote and sparsely settled sections with poor 

 transportation facilities. Many of these old-growth stands have been 

 so heavily culled that the remaining overmature and defective timber 

 cannot be marketed profitably. The fact that there are any old- 

 growth stands left in these four regions, which contain 67 percent of 

 the population of the United States, but furnish only 15 percent of 

 the total lumber cut, indicates that the bulk are relatively inaccessible, 

 scattered, or of poor quality. 



Much of the second-growth saw timber, largely as the result of 

 fires and of cullings for the more desirable timber, consists of little 

 more than scattered trees that barely meet the minimum requirements 



