i2 4 FORESTRY 



of the number of stems by the volume of a single stem of 

 the respective diameter and height. The individual contents 

 are obtained from prepared volume tables. By addition of 

 the volumes of the several classes, the volume of the whole 

 wood is found. 



Where conditions make it unsuitable to make use of the 

 two methods just described, Draudt's treatment may recom- 

 mend itself. By it a certain proportion of the stems of each 

 diameter class are felled as sample trees. The basal area 

 (sectional area) is measured as explained above, both for the 

 whole wood and for each sample tree. The volume of the 

 wood, V, is then obtained by multiplying the volume of the 

 sample trees, v 9 by the quotient of the standing crop's basal 

 area, and dividing by the sample trees' basal area 



The volume of the sample trees is usually reckoned from 

 the middle sectional area multiplied by length of stem. 

 Smaller split timber, as distinct from whole stems or logs, 

 is arranged in stacked measure, and to find its cubic contents 

 reducing factors must be employed. These are coefficients, 

 representing the proportion of actual wood to the space 

 occupied in the heaps. The converting factor -7 may be 

 accepted for stacked timber, and -2 for branchwood, when 

 estimating these in solid cubic feet. By Draudt's method an 

 advantage is gained in that the volume of the timber is 

 calculated in assortments in which it may be sold. Should 

 the prices obtainable be known, the total value of the forest 

 can at once be ascertained. To find this, it is only necessary 

 to replace v by the quantities of the respective assortments, 



c 



and to multiply by -. 



The best way of taking the age of a wood is to count the 

 number of annual rings upon the stool of a felled tree, adding 

 two to three years to the average age, the first few years' 

 growth not being always visible on the stool. 



