NORMAL FORKST 137 



f . The growth of 5600 cubic feet is the growth of ripe timber ; 

 it is made by sixty acres of growing trees and each acre makes or 

 is assumed to make 5600/60 = 93.3 cubic feet, the average yearly 

 growth of ripe timber on one acre. This distinction of growth of 

 "ripe timber'' is made because the growth of the material taken in 

 thinnings is omitted in this consideration. 



g. Yearly cut of 5600 cubic feet from this sixty-acre forest 

 forms a definite portion of the growing stock which may be ex- 

 pressed in per cent : 



Cut as percent of Growing vStock = 5600 X 100/168000 = 3.3%, 

 i. e., each year 3.3% of the Growing Stock is cut, and we can also 

 say that the average growth of this growing timber is 3.3% in 

 Volume. This conception was used by Hundeshagen in his Method 

 of Regulation. 



h. The Cut of 5600 expressed as a fraction of the Growing 

 stock is : 



Cut = Growing Stock / Vi the years in rotation = 2G/r = 

 168000/30^=5600, which is a useful conception applied in Von 

 Mantel's Modification of Hundeshagen's Method of Regulation. 



i. A glance at the Diagram Fig. 7 shows that if all of the 

 sixty acres were stocked with forty-year old timber, the growth 

 would he greater than it now is (forty-year old stuff being in the 

 age of most rapid growth), and the amount of growing stock would 

 be greater than in the regulated forest but it would not be ix)ssible 

 to have a yearly cut, until the forest were again regulated to its 

 present condition of Age Classes. Again the sixty acres might have 

 all timber eighty or 100 years old and so a very large amount of 

 growing stock and capital and yet have a small amount of growth, 

 and be unable to furnish a yearly cut without considerable sacrifice. 

 This merely illustrates that it is only in the Regulated forest that 

 Growth. Cut and Capital are properly balanced to supply best yearly 

 cut and income. 



5. Perfect regularity in matter of Age Classes, growth and 

 Growing Stock is probably never attained in any forest. On the 

 other hand it is quite surprising how perfect the regularity of Age 

 Classes is coming to be on larger State forest properties of Europe 

 and how readily and steadily this regularity maintains and perfects 

 itself under well planned management. 



