Results 



The areas of the timber growing bases of the 

 six National Forests as estimated in the pre- 

 vious inventory and as revised in this study are 

 compared in table 1. This reveals very clearly 

 how misleading such information can be if land 

 suitability for timber use, land capability, and 

 land availability are not adequately considered. 

 It is well to remember, though, that land use 

 intentions change and they have changed in re- 

 cent years. For that reason, the earlier data re- 

 flects in some cases outdated thinking relative 

 to use expectations. 



The specific reasons for the decline in the 

 timber base on each National Forest are shown 

 in table 2. As mentioned earlier, factors that 

 cause reduction of the timber growing base dif- 

 fer from place to place. However, one con- 

 sistent result of careful reexamination was the 



elimination of areas from timber production 

 plans because other uses and values are more 

 important than timber yields and timber pro- 

 duction. In many cases this conflict is based less 

 on the actual cutting than it is on the roads 

 made necessary by the cutting. 



LOW PRODUCTIVITY 



If forest land is to be considered part of the 

 timber growing base, it must be capable of 

 growing at least 20 cubic feet per acre per year; 

 this is a longstanding Forest Service standard. 

 One may properly ask whether this is the best 

 standard for all places. It probably isn't, but we 

 have not tried to solve that problem in this 

 study. Rather our attention has been directed 

 to the question of how well this existing stand- 

 ard has been applied (fig. 3). 



Table 1. — Comparison of timber growing base areas by study unit, 

 previous inventory, and 1969 inventory 









1969 study 







Study unit 



Previous inventory 



inventory 



Difference 





Year 





— Thousand acres 





Percent 



Lolo area,' R-1 



1966 



745.2 



629.1 



116.1 



-16 



Arapaho N.F., R-2 



1958 



668.4 



399.6 



268.8 



-40 



Coconino N.F., R-3 



1961 



'793.5 



568.6 



224.9 



-28 



Boise Area,* R-4 



1964 



385.3 



273.3 



112.0 



-29 



E. Klamath W.C., R-5 



1968 



420.1 



372.3 



47.8 



-11 



Gifford Pinchot N.F., R-6 



1960 



3 1,041.2 



921.6 



119.6 



-11 



Total 





4,053.7 



3,164.5 



889.2 



-22 



^Portion of National Forest. 



^ 731.8 thousand acres classed as operable; 61. 7 thousand acres classed as nonoperable. 

 ^Area adjusted to correct for adjustment made in total area estimate for the Working Circle. 



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