VALUATION OF PART OF A WOOD. 143 



SECTION II. VALUE OF A PART OF A WOOD. 



1. Value of Single Trees. 



The average value of a single tree is obtained by dividing 

 the value of the whole wood, whether it be the expectation, 

 cost, or utilization value by the number of trees. 



The special value of a certain tree can be ascertained by 

 estimating its utilization value, or according to the formula of 

 the expectation or cost value, by introducing the data referring 

 to the special tree in question, an operation which is beset by 

 considerable difficulties. 



2. Value per Unit of Volume. 



This is obtained by dividing the value of a wood (or tree) 

 by the number of units of volume contained in the wood (or 

 tree). 



3. Value of the Increment of One or More Years. 



The value of x years increment is equal to the value of the 

 wood x years hence less the present value of the wood. The 

 calculation can be made for x years forward or backward. 

 In either case the expectation, or cost value may be calculated. 



a. The, Expectation Value. 

 (1) Calculated for the year m + x : 



l' p r - (m+x) 

 _Y r +T n xl'op r - n +. . .-(S+E) (l'op r - m -l) 



l- op r-m 



v , _ (Y r +T H xl'ojT*+. . . + S+E}(l'op*-l) 

 \-of~ 



(2) Calculated for the year m : 



Valne = (Y r +T n xl'op r - n +. . . + S+E) (l-ops-l) 



