JON SON ABSOLUTE FORM QUOTIENT 591 



such possible misplacements, fairly accurate information is available 

 for individual stands. 



ACCURACY OF THE ABSOLUTE FORM QUOTIENT VOLUME TABLES, TAPER 

 TABLES, AND FORM POINT DETERMINATION OF FORM QUOTIENT 



The question natural!}' comes up in many minds, "Does this system 

 apply to American conditions as well as it does to European condi- 

 tions ?" 



Generally speaking, the system consists in classifying trees accord- 

 ing to the shape of their stem, and, so far as the form point is con- 

 cerned, this shape seems designed to resist lateral wind stress. 



Speaking of the temperate zone, there is no apparent reason why 

 trees in any one part of the world should differ in their general form 

 from those in any other part, that is, that there should be different 

 sets of '*stem forms." especially when one considers that trees of any 

 one species have the same general appearance in any country. Per- 

 sonally, I have been impressed with the fact that, barring marked 

 local features, forests are remarkably similar wherever I have seen 

 them. Trees have similar shapes and appearance everywhere ; they 

 are subject to the same general natural phenomena, some of which 

 favor their development, some of which are detrimental; the forces 

 of nature such as wind, gravity, etc., are the same. When visible 

 characteristics of trees and nature's laws are the same, would there 

 be more reason for indirectly visible features like stem form to be 

 variable? It is not likely. 



This reasoning gave me hopes that the Jonson system could in a 

 broad way. be directly applied in America. Comparison with official 

 publications on the form of different species showed a surprisingly 

 close agreement. My actual use of the Jonson system in northeastern 

 forests on extensive cruises I have carried on and the testing of form 

 point observations with stem analysis work have also given verv exact 

 results. 



Comparison of the Jonson Form Quotient Tables zvith American Data 



Taking data given by Raphael Zon in Bulletin No. 55 on Balsam 

 Fir, we can pick out two examples at random : 



Balsam on hardwood slope and flat : 



D.b.h. 9 inches, height 50 feet, total volume 0.119 cords. 



One cord for such a tree contains 95.925 cubic feet. 



Total volume is therefore, 11.36 cubic feet. 



