IMPROVEMENT OF THE FOREST 191 



an advance tree is more or less isolated, it really consti- 

 tutes an integral part of the crop, and is allowed to stand. 



In reproducing a forest naturally, the species most 

 desired often dk> not establish themselves as quickly as the 

 poorer kinds, or, during early youth, the inferior species 

 may be the more rapid growing. If the stand is left 

 untouched, a large number of the most promising trees 

 may thus be killed or crippled, and the value of the crop 

 may be much reduced. A good illustration of this 

 condition is found in New England. After a pine stand 

 is cut, the first species to spring up are hardwoods. 

 Later on, young pines creep in abundantly under the 

 hardwoods, but many of the pines are killed in the com- 

 petition. A cleaning would release the best pines, and 

 thus maintain the species in the next crop. 



The application of this method may be seen also in 

 the mountains of Europe, where beech and spruce in 

 mixture are reproduced naturally. The two species come 

 up together in the reproduction, but the beech grows 

 the more rapidly, overtopping and injuring the spruce. 

 The latter is maintained in proper proportion only by 

 cleanings in which those beeches which are likely to in- 

 jure the spruce are cut back. 



In hardwood regions one of the problems is to pro- 

 tect young seedling trees from sprouts. The latter grow 

 very rapidly during early youth, and in some cases over- 

 top seedling trees which are of special value. This is 

 illustrated where pine is planted after the clear-cutting of 

 hardwoods. There are inevitably a certain number of 



