Forest Mensuration 



PARAGRAPH LXXXI. 



SECTION ANALYSIS. 



The section-method is a complete tree analysis by sections. The entire 

 bole is divided into a number of sections, preferably of even length, at 

 both ends, or, better, in the midst of which the periodical increment of 

 the sectional area is ascertained (compare Paragraph XL). 



In the latter case, multiplying such sectional areas (in square feet) 

 as belong to the same age of the tree by the length (in feet) of the sec- 

 tions, the volumes (in cubic feet) of the different sections at given ages 

 are obtained. 



The "top pieces," however, must be figured out separately, their length 

 differing from the even length of the sections. These top pieces are 

 usually considered as cones, and their volumes are ascertained as one-third 

 height times basal area of top piece. The basal area of the top piece is 

 identical with the upper area of the uppermost full section of a given age. 



EXAMPLE FOR HUBER-SECTIONS TEN FEET LONG. 



The volume of the top pieces forms in the older age columns an insig- 

 nificant part of the total volume. 



If the logs as cut in the woods are used as sections, then each section 

 has a separate length and its volume must be separately ascertained for 

 every decade of age of tree. 



REMARK : It is wise to first ascertain the full age of the tree, allowing 

 for stump years. It is further wise to throw off that number of years 

 which exceeds full decades e. g., in case of a tree 117 years old, 7 years. 



