THE OUTLOOK FOR TIMBER SUPPLIES 



113 



projected cut. These residual cuts were allocated 

 between the North and South on the basis of 

 prospective timber supplies in these sections. 



LAND USE AND MANAGEMENT 

 ASSUMPTIONS 



In projecting timber growth and inventories it 

 is apparent that assumptions as to areas available 

 and levels of protection and other management 

 activities will have major impacts on the timber 

 supply outlook. 



Gains and Losses of Forest Land 

 Assumed To Balance by 2000 



During the past few decades the area of com- 

 mercial forest land has increased slightly, as 

 pointed out in the section on Forest Land and 

 Timber Resources. Additional net increases in 

 forest land areas in the near future also are indi- 

 cated in a recent U.S. Department of Agriculture 

 study of projected land-use requirements.^^ This 

 study concluded that approximately 50 million 

 acres of cropland may be retired from agricultural 

 production by 1980. Possibly several million 

 acres of this land might be planted to trees or 

 revert naturally to forest, with the remainder 

 devoted to other uses. 



In contrast to such gains in forest area, con- 

 tinuing diversions of forest to other uses such as 

 residential areas, industrial sites, highways, air- 

 ports, reservoirs, and transmission lines will be 

 necessary to service the Nation's rapidly growing 

 population. Thus, possible gains in forest area 

 in the next two decades appear likely to be offset 

 by losses of forest in the latter part of this century. 

 It was therefore assumed for the purpose of devel- 

 oping growth projections that the Nation will 

 have approximately the same amount of com- 

 mercial forest area in 2000 as in 1962. 



Continued Effectiveness 

 of Fire Control Assumed 



In long-range projections, the regeneration rate, 

 i.e., the number of trees from both natural and 

 planted sources growing into the 2-inch diameter 

 class each year, is an important growth factor. 

 Much of the recent improvement in timber growth 

 has been due to high regeneration rates since the 



AREA BURNED AND 

 FIRE CONTROL EXPENDITURES 



20 





 160 



Area 







V 







X 



\ 







V^" 



V 



Expenditures 

 ,20 (1957-59 Dollars) 



million dolla 



I ■!>. CD 



^^^ 



y^-^ 



















50 1955 I960 1965 



^^ U.S. Department of Agriculture. Land and Water 

 Resources. Washington, D.C. May 1962. 



Figure 49 



1930's resulting from both increased fire protection 

 and tree planting. 



Outstanding progress has been made in recent 

 years in extending fire protection and reducing 

 the area burned annually (table 76 and fig. 49). 

 Areas burned in 1960-62, for example, averaged 

 about 3.9 million acres a year, or 0.51 percent of 

 the total forest area. 



This reduction in area burned greatly increased 

 the regeneration rates and the number of seedlings 

 that survive to grow into the 2-inch diameter 

 class each year. This increase in sapling ingi'owth 

 due to high natural regeneration rates has ac- 

 counted for a large part of the improvement in 

 timber growth since the 1950's. In projecting 

 timber supplies, it was assumed that protection 

 efforts would continue at approximately recent 

 levels. 



