320 REPORT OF THE FOREST, FISH AND GAME COMMISSIONER. 



4. Valuable young growth is often left under severe pressure overhead- 

 or in other cases prematurely exposed. 



5. Seed years are not used to full advantage. 



The normal possibility, from the economic standpoint, cannot be 

 expressed by volume; it must be expressed in dollars and cents. It is 

 that sum of money which yields annually the expected or desired interest 

 on all capitals engaged in the forestal production. In other words, it is 

 the yield of a forest when in financial equilibrium. In that case, no wood 

 works at a lesser rate than at the proper indicating percentage adequate 

 to its age. 



The ratio between annual cut and stumpage at hand reads, in the 

 normal forest : 



sustained yield r i 2 ™ - 2 



1 he factor — 



normal growing stock r 2 i r 



2 



is called the utilization percentage. It expresses the fact that a short 

 rotation allows, when the growing stock is given, of a larger possibility than 

 a long rotation. Short rotations are handicapped by silvicultural draw- 

 backs and the production of small trees only, the demand for which is 

 restricted (firewood, spokes, axe-handles and railroad ties). The utilization 

 percentage, since it is the ratio of volumes only, has little economic 

 importance. 



3uMtvtston;s of a Forest 



The subdivision of a forest into minor units of management is based 

 on local conditions and on local needs. 



A large forest is usually subdivided into 



Working circles, 



Working sections, 



Compartments and blocks. 



