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CHAPTER IV. 



DETERMINATION AND REGULATION OF THE YIELD. 



As long as the owner of a forest is satisfied with inter- 

 mittent returns, the regulation of the yield is chiefly governed 

 by sylvicultural considerations, that is to say, every wood is 

 cut over when it is just ripe according to the objects of 

 management, while thinnings are made when they are neces- 

 sary. If the owner demands a sustained annual yield of equal, 

 or nearly equal, quantity and yet the forest is not in a normal 

 state, the various cuttings may have to be made at other times. 

 All such deviations demand certain sacrifices on the part 

 of the owner, which differ according to the actual condition 

 of the forest and the objects of management. 



These sacrifices are due to the fact that the final cuttings 

 must be made at an age other than the normal age as 

 determined by the objects of management ; even thinnings 

 may have to be postponed instead of being made when the 

 condition of the wood demands such cuttings. This state of 

 affairs may be brought about by a surplus or deficiency of 

 mature woods, or by their being so situated that they cannot 

 be cut over at the proper time from consideration for the 

 adjoining woods. 



The task of the forester is, in such cases, to secure a 

 sustained annual yield, and yet to lead the forest gradually over 

 into the normal state as defined in Part III. of this Volume, 

 with the smallest possible loss to the owner. Many different 

 methods have been elaborated with the view of achieving that 

 task, which approach the subject from various points of view ; 

 the degree of success differs however considerably. It is not 

 proposed to describe here all methods, but only those which 



