FOREST RESOURCES OF THE PONDEROSA PINE REGION 



The Timber Supply 



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fails to emphasize the urgency of the forest problem. 

 For example, similar calculations made by unit 

 and by species groups show an indicated life of 

 ponderosa pine supply for the region of only 73 

 years, while, for example, in the heavy-producing 

 Deschutes River and Klamath Plateau units the 

 hypothetical life of ponderosa pine is but 60 and 

 65 years, respectively, and for communities such 

 as Bend and Klamath Falls the time must be 

 halved or quartered. 



Privately owned timberlands, however, are being 

 cut over much more rapidly than the average. 

 The one-third of the region's ponderosa pine saw 

 timber that is in private ownership is suffering about 

 70 percent of the pine depletion. In addition the 

 rate of depletion has accelerated rapidly since 

 1936. For example, if cutting continued at the 

 1937 rate, the region's privately owned pine would 

 be completely exhausted in 21 years. 



Sustained- Yield Capacity 



The Region as a Whole 



A far more rational analysis of the forest resource, 

 anticipating timber harvest under a forward-look- 

 ing plan of management, involves computation of 

 sustained-yield capacity, i. e., the volume of 

 timber that could be cut annually without interrup- 

 tion or substantial future reduction. 



If future curtailment is to be avoided, the current 

 regional cut from ponderosa pine types should be 

 limited to 930 million board feet annually. This 

 is the estimated cut that these types can sustain 

 over an initial cutting cycle (based on 95 percent 

 volume removal per acre on privately owned lands 

 and 75 percent on lands of other ownerships) 

 without reducing their future productivity. This 

 sustained-yield cut for the pine types is 74 percent 



VITALLY important to forest industries and 

 communities is the timber supply upon which 

 both depend. Appraisals of the adequacy of 

 this primary resource for maintaining flow of tim- 

 ber have in many instances resulted in conflicting 

 conclusions. Discrepancies have arisen both from 

 variation in method of analysis and from differ- 

 ences in statistics employed. The forest survey 

 eliminated inconsistencies in basic data, but con- 

 siderable variation in interpretation of these data 

 persists. 



Relation of Timber Cut to Timber Supply 



In the past, forest industry has generally been 

 migratory, the life of the principal operation in 

 each locality being determined largely by the avail- 

 able stand of virgin timber. Based on a system of 

 liquidation, the duration of forest industry has 

 frequently been estimated simply by dividing total 

 timber stand by annual production. For example, 

 it would be computed that this region's present tim- 

 ber supply, subjected to an annual depletion equal 

 to the average cut of saw timber for the period 

 1925-36, would endure for about 101 years. 

 Such crude calculation disregards entirely the 

 effect on timber supply of depletion by agencies 

 other than cutting on one hand and effect of growth 

 on the other. It ignores the fact that a portion of 

 the timber supply is economically inaccessible 

 owing to remote location, undesirable composition, 

 or poor quality, and also that approximately two- 

 thirds of the timber resource is in Federal and 

 Indian ownership and not available for unrestricted 

 cutting. Furthermore, such a calculation fails to 

 reveal the maldistribution of timber with respect 

 to established communities. 



An average figure such as 101 years for the life 

 of the timber supply is grossly misleading and 



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