ABSTRACT 



The area of forest land now considered suitable and available for 

 sustained timber management on six western National Forests is a- 

 bout one-fifth less than previously reported. The reduced area is 

 not greatly different from the area used as a basis for allowable cut 

 calculations. 



The reduction in area estimates reflects more precise consideration 

 of land productivity, land instability, isolation of small stringers and 

 patches of forest land, and impacts of improved multiple use plan- 

 ning. Revised classifications of forest land in terms of planned use 

 contributed most to the reduction of areas classed as commercial 

 forest land. This in turn largely reflects an improved data base and 

 procedures for multiple use planning. 



Adequate information is not available to determine how much the 

 reduction of the timber growing base area will reduce the allowable 

 cut of timber on the six Forests studied. However, the impact on 

 allowable cut will be less than the reduction in area. On many 

 Forests, adjustments have been made for various constraints on tim- 

 ber harvesting and allowable cut estimates have been calculated for 

 only the more accessible and productive forest areas. 



This study emphasizes the need for resource inventory work that 

 will describe and update timber and other resources in relation to the 

 land, land-use status, and other factors that affect forest develop- 

 ment and use. Timber and other resource inventories must be coor- 

 dinated and related to land characteristics and other current factors 

 that are significant in the multiple use management of these public 

 for'^st lands. 



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