JONSON ABSOLUTE FORM QUOTIENT o87 



scientific research it will be found a great help when direct measure- 

 ments for precise form determination cannot be made. 



The form point method is now always used in Scandinavia. My 

 work with it here in America gives me reason to believe that the 

 method is universal, at any rate as regards the temperate zone. 



APPLICATION OF THE ABSOLUTE FORM QUOTIENT METHOD ON A SURVEY 



I will assume that it is being applied to my present cruising method, 

 realizing that there are many modifications in cruising due to local 

 conditions and personal preference. 



Timber Estimate of an Individual Stand 



The trees are tallied in say two-inch diameter size classes, also sub- 

 divided into sound and unsound, or even dominant and subdominant 

 trees if desired. Simultaneously or subsequent to the tallying, comes 

 the taking of readings for securing special information on "sample 

 trees." The larger the stand the smaller the percentage of trees neces- 

 sary to obtain reliable average figures and curves. Even for small 

 stands of, say, 15 to 20 acres in dense forests, sample tree readings 

 taken on every hundredth tree would give fair results. Using a 

 suitable blank form, or even plotting the points directly on a special 

 sheet, one enters for each sample tree, the height (measured say 

 with a Christens or fractional hypsometer) the relative location of 

 the form point, the exact diameter, and the bark thickness at breast 

 height. If age and growth were required the boring would be done 

 simultaneously. The taking of these readings should only take two 

 or three minutes per tree. 



It is very important to remember that in all timber estimating, in 

 fact, in the applying of figures to any of nature's work, we must 

 always go by average results. The individual variation and exceptions 

 may be considerable but should not be allowed to have but very lim- 

 ited influence on averages. Consequently, 'many trees taken with or- 

 dinary care are much more likely to give exact results than few trees 

 taken with minute precision. 



While the Jonson method will often work for individual trees, its 

 application is intended for homogenous groups of trees and gives 

 average results. The single tree readings should be plotted on squared 

 paper, using d.b.h. as abcissa for all curves, to determine: (1) The 



