SILVICULTURAL SYSTEMS 



19 



wise a time will come when 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 the application of 

 the system in one of our white pine forests having an area of 100 

 acres and with an annual growth of 500 board feet per acre and 



timbtr marked for selection 



Fig. 4. — The hardwood type. A stand (cMiiaininL; mature ^^ .«. -^ 



cutting. (The marked trees are blazed.) Note overmature and unhealthy condition 

 of many trees. 



a cutting cycle of ten years, 5000 board feet per acre, or 500,000 

 board feet on the whole area, can be removed each decade. If 

 the rotation in this forest, or the length of time required to mature 

 the crop, is one hundred years, the area cut over annually, with 

 a cutting cycle of ten years, would be 10 acres, and the annual 

 cut from this area would amount to 50,000 board feet. In our 

 virgin forests where there is a great range of age classes, all 

 mature trees are grouped in the oldest-age class and the first 

 cuttings will tend to eliminate them, so that in the forests of 

 twenty years hence we shall have comparatively few trees over 

 one hundred years old. 



