Introduction 



Between 1952 and 1969, total timber har- 

 vested in tiie West showed an increase of 35 

 percent. In this same period, timber cutting on 

 the National Forests of the West showed a dra- 

 matic 154 percent increase, from 3,855 million 

 board feet to 9,798 miUion. From a significant, 

 but somewhat secondary place in the Western 

 timber supply picture, the National Forests 

 have moved to a dominant role. 



As long as the level of timber harvested on 

 National Forests was relatively low, the ques- 

 tion of how much wood the Forests could pro- 

 duce within a program of sustained yield was 

 neither immediate nor critical. However, as the 

 rate of cutting has increased, the question of 

 upper limits of cut has become a current 

 issue — often a crucial one. This question has 

 become especially critical on those National 

 Forests where increasing the annual cut means 

 harvesting timber in more difficult areas of ter- 

 rain, the capabilities of which are yet to be ade- 

 quately determined. These areas tend to be 

 physically and biologically more complex and 

 much more information about them is required 

 to plan acceptable usage of them. 



Even under the best circumstances this ques- 

 tion of proper cutting levels would be hard to 

 answer; and it has now been greatly aggravated 

 by the increase of other demands on the Forest. 

 Today, more watershed protection is required, 

 recreation use is mounting, and there is greater 

 interest than ever before in maintaining scenic 

 quality, fish and wildlife habitat, and other 

 values. It is apparent that all of these other re- 

 quirements of management are going to have a 

 greater impact on timber yields — at least in the 

 next few decades — than had formerly been 

 anticipated. 



In recent months the allowable cut esti- 

 mates on some National Forests have been re- 

 duced because of second thoughts about the 

 size of the harvest that could be sustained. On 

 other National Forests there has been public 

 clamor to reduce cutting levels which are al- 

 leged to be too high for sustained yield. There 

 are counterclaims, of course, that National For- 

 est harvest levels are quite reasonable. Certainly 

 on many Forests if more intensive management 

 were applied, the cut could be substantially in- 

 creased in time. 



Throughout this report we have used the 

 term "timber growing base" when referring to 

 forest land suitable and available for timber 

 growing. To many this term "timber growing 

 base" is synonymous with "commercial forest 

 leind" and even the standeird Forest Survey defi- 

 nition of "commercial forest land" is forest 

 land suitable and available for timber growing. 

 However, in some circles "commercial forest 

 land" includes any forest land from which tim- 

 ber may be cut. Therefore, since this study is 

 concerned with identification of only the for- 

 est land suitable and available for timber grow- 

 ing, the term "timber growing base" is used to 

 avoid confusion. 



Since allowable cut levels and management 

 plans are functions of the assumptions under- 

 lying them, the principal effort of this study 

 has been directed to reexamining the stated and 

 implicit assumptions with regard to forest land 

 stratification on the National Forests. The pro- 

 cedures for implementing the assumptions have 

 also been examined. 



The most recent timber growing statistics 

 for the West (excluding Alaska and Hawaii) re- 

 veal that there are 109 million acres of forest 



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