SILVICULTURAL METHODS OF REPRODUCTION 51 



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

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

 500,000 board feet on the whole area, can be removed each dec- 

 ade. 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 



J 



Fig. ii. The hardwood type. A stand containing mature timber marked for selection 

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

 of many trees. 



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. 



B. THE CLEAR-CUTTING METHODS. 



Where such a large proportion of the trees is cut that the 

 remainder does not influence the growth of reproduction, it is 

 called a "clear cutting." The clearing may be done in one or a 

 series of operations but is usually accomplished in twenty years 

 at most. While selection is best adapted for many virgin forests 



