50 A MANUAL OF FORESTRY 



develops in this country the selection forest will gradually be 

 supplanted by even-aged stands managed under one of the other 

 methods. In the application of this system the whole stand may 

 be cut through every year, or the stand is divided into blocks 

 each of which is cut over periodically. In this case the interval 

 between cuts is called the cutting cycle. Under ideal conditions 

 this would be about ten years. Care must be taken always that 

 trees of all ages be maintained, otherwise a time will come when 



I 3 4 5 6 7 8 12 14 15 16 17 18 20 21 



Fig. 10. The selection system in a stand of spruce and hardwoods. 



I. First cutting.^ 



II. Ten years later. Reproduction has started in the openings, and the stand is marked for 

 a second cutting. 



the cut must be reduced and the revenue correspondingly 

 diminished. If the whole stand is cut over annually the amount 

 removed should correspond with the annual growth of the whole 

 stand. If it requires ten years to get through the forest the 

 equivalent of the growth of ten years would be removed at each 

 cutting. Thus, in one of our white pine forests having an area 

 1 In this and succeeding diagrams, trees to be cut are indicated by dashes. 



