RRGIONAIv VOLUME TABLE 73.i 



Table 9. — Comparative Errors of Site Class and General Tables. 



CONCLUSIONS 



The foregoing detailed discussion of the work performed shows 

 quite clearly why the division was made on lines of site quality in- 

 stead of sub-regions. In addition it should be noted that while it 

 would perhaps have been possible to have grouped the data geograph- 

 ically and thereby to have obtained apparently satisfactory tables, 

 the dividing lines between such sub-regions would have necessarily 

 been arbitrarily chosen, and decidedly dubious until a vast number 

 of additional data had been collected. The writer's previous experi- 

 ence furthermore had indicated that other species (notably Idaho 

 white pine) varied in form more with site within even a very small 

 region, than between similar sites which were geographically remote. 



The study indicates, therefore, that : 



(A) At least for the species in question a single table for a region 

 as large as California is inaccurate. 



(B) That separate tables based on site quality (this quality to be 

 determined by the height-index method) are both accurate and prac- 

 ticalile. 



(C) That if such tables are prepared they will apply accurately to a 

 large region and hence that local tables are unecessary. 



