FOREST, FISH AND GAME COMMISSION. 



n 



The volume of the stem of a tree without the branches is less than that of the 

 corresponding cylinder, hence the form factor for the stem alone is less than i. If 

 the branches are added, the form factor is sometimes greater than i, especially 

 when the tree is young. 



Form factors may be, 



1. Stem form factors, which refer only to the volume of the stem above 

 ground. 



2. Tree form factors, which refer to the volume of the stem and branches, 

 excluding the root wood. 



3. Timber form factors, which exclude all material except those parts that make 

 timber, whether stem or branches. 



The diameter is measured at breast height of an ordinary man, about 4 ft. 3 in. 

 The height of the ideal cylinder is equal to the height of the tree. Since the 

 measurements are taken at a constant height, the form factors of two trees of the 

 same shape but differing in height cannot be the same. Therefore, in using form 

 factors for calculating the volume of trees, the height of the trees must be taken 

 into consideration. 



European tables, based upon the measurements of numerous felled trees, have 

 been prepared, which give the form factors for different species, heights and ages. 

 The following table shows the form factors for four species: 



HEIGHT 



OR 

 LENGTH. 



TIMBER ONLY, DOWN 



TO 3 IN. DIAMETER. 



WHOLE TREE EXCLUSIVE OF ROOT WOOD. 



FEET. 



SCOTCH 

 PINE. 



SPRUCE. 



SILVER 

 FIR. 



BEECH. 



SCOTCH 

 PINE. 



SPRUCE. 



SILVER 

 FIR. 



BEECH. 



20 



0.14 



0.18 



0. 27 



0.13 



0.83 



0.88 



0.83 



0.63 



30 



0.32 



0.31 



0.38 



0.21 



0.68 



0.77 



0.77 



0. 62 



40 



0.45 



0.41 



0.51 



0.30 



0.62 



0.69 



0.68 



0.62 



50 



0.48 



0.47 



0-53 



0.40 



0-57 



0.64 



0.65 



0-59 



60 



0.47 



0.48 



0-53 



0-45 



0-53 



0.61 



0.63 



0-57 



70 



0.46 



0.49 



0.52 



0.47 



0.51 



0-59 



0.60 



0.56 



80 



0.46 



0.49 



0.52 



0.48 



0.50 



0-57 



0-59 



0.56 



90 



0-45 



0.48 



0.50 



0.50 



0.50 



0-55 



0.56 



0-57 



100 



0-45 



0.47 



0.51 



0.51 



0.49 



0-53 



0-55 



0.58 



liO 



0.44 



0.46 



0.52 



0.52 



0.49 



0.51 



0.52 



0-59 



120 



43 



0.44 



0.52 



0.52 



0.48 



0.49 



0.51 



0.60 



