:o5 



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, although 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 Ijeing made when the 

 condition of the woods demand such cuttings. This deviation 

 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 out of consideration for the safety 

 of adjoining woods. 



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

 sustained annual yield and yet to lead the forest, with the 

 smallest possible loss to the owner, gradually over into the 

 normal state, as described in Part III. of this volume. Many 

 different methods have been elaborated with the view of 

 achieving that task, which approach the subject from various 

 points of view. All the older methods started by considering, 

 in the first place, the forest as a whole, determining the yield 



