SYSTEMS OF CLEAR-CUTTING 119 



The design is to leave scattered over the cutting area 

 trees which are thrifty, capable of producing abundant 

 seed, and capable of living through a second rotation. 

 Suppose that a stand is cut when 100 years old. Selected 

 reserves are left standing, and these restock the ground. 

 The reserves, then, are designed to stand during the 

 entire rotation of the new crop. If this new stand is cut 

 at 100 years of age, there will be scattered throughout it 

 a certain number of trees about 200 vears old. The re- 

 serves will have stood for fully half a century practi- 

 cally isolated, and for another half century as the leaders 

 in the stand. With the advantage of full light they will 

 have made a maximum growth. With a rotation for 

 the stand of only 100 years, a certain amount of timber 

 of large size and high grade will be produced. 



Selection of the Standards. — The trees selected to 

 remain standing are from among the dominant trees of 

 moderate development. The aim is to select trees of as 

 little present commercial value as will meet the require- 

 ments of reserves. The trees must, however, be from 

 the dominant class. Suppressed trees and ordinary inter- 

 mediate trees would not be suitable for purposes of re- 

 production or growth. The trees must be wind-firm, 

 since they will stand isolated for man}- years. They 

 must have thrifty crowns capable of responding to the 

 new conditions of light and space, and capable of produ- 

 cing rapid growth. They must be likely to develop 

 into good seed producers, even if they are not so at pres- 

 ent. Ordinarily, their crowns should take up at least 35 



