A SUMMARY OF THE TIMBER RESOURCE REVIEW 



71 



PLANTABLE 

 AREA 



'00,000 acres 



. RIVATE 



PUBLIC 



400,000 acres in 1952 



Figure 34 



to relate the proportion of recently cut lands in 

 the upper productivity class of the current survey 

 with the combined proportions of "high order," 

 "good," and possibly half of the "fair" practice 

 levels of cutting in the Reappraisal. The Forest 

 Service has made a careful study of possible com- 

 parisons but has drawn none, because it believes 

 that any comparisons that might be made would 

 be highly questionable for many reasons. 



Productivity Index — A New Concept in 

 Appraising Forest Condition 



Essential to an understanding of results of the 

 survey of recently cut lands is a clear grasp of 

 the "productivity index" which was used to class- 

 ify recently cut lands into various groups. A 

 rating system with indexes ranging from 1 to 100 



was developed. This was based on consideration 

 of several individual elements. An index rating 

 of 100 for a recently cut area did not mean it was 

 the best attainable. On the contrary, it only 

 meant that forest condition, i. e., productivity of 

 recently cut lands, was at a standard or level con- 

 sidered reasonably attainable for the particular 

 locality, site, and forest type under current and 

 average operating situations. This is very im- 

 portant and is one of the main reasons why such 

 a large area of recently cut lands qualified for the 

 upper level of productivity. An index of 100 is a 

 higher standard than what might have been 

 adopted as reasonable or practical several years 

 ago; it is a lower standard than what might be 

 reasonable or practical at some future time. The 

 standards are not related to the maximum growth 

 possible nor were they geared to the growth that 

 would result from the most intensive forestrv 



