ABSOLUTli FORM QUOTIENT 35T 



Finally, these figures were evened off by curves and the final volume 

 table read off. 



The principle used in making this table is, we believe, correct, but it 

 might be better to have a larger number of trees to work on and make a 

 separate curve for the large d.b.h. sizes, medium sizes, and small sizes. 



By the same method a volume table for Sitka spruce on Queen 

 Charlotte Island was worked out. This table seems rather high, how- 

 ever, but this was probably due to the fact that it was based on trees 

 without much root swelling and therefore of better form than the 

 average. One objection to the use of a farm class table based on total 

 height on the Pacific Coast is that the trees are often so high that the 

 tops are hard to see. Therefore, a merchantable height classification is 

 more suitable. 



Also, the determination of the average form class, whether by [on- 

 son's form point method or by occular estimate, is more or less difficult. 

 However, what we have tried to prove with our investigations so far is 

 that the absolute form quotient expresses the percentic taper of a con- 

 iferous tree and that conifers with the same form quotient or of the 

 same form class are formed according to the same model, at least in the 

 merchantable portion of the tree. Judging from our present material, 

 we believe that such is the case. The difficulty is to estimate the form 

 class of a standing tree or the average form class of a stand, but, as 

 explained above, we believe that a little practice will overcome this. 



The form class method is no doubt best adapted for use in second- 

 growth stands, especially if they are even-aged, but it can also be used 

 to great advantage in preparing local volume tables in virgin stands of 

 very large timber. 



The form point method of determining form class was briefly men- 

 tioned in the article about the absolute form quotient in the May, 1918, 

 number of the Journai, ok Forestry. 



For those who might be interested in this subject we would refer to 

 Bulletin No. ()-8, 1918, of the Swedish Institute of Experimental For- 

 estry, which contains an article, "The Form Point as an Expression of 

 the Trunk Form," by Sven Petrini, of \Ahicli artic'e a summary is 

 given in English. 



