IMPROVEMENT OF THE EOREST 191 



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

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



In reproducing a forest naturallv, the species most 

 desired often do not establish themselves as quickh'asthe 

 poorer kinds, or, during earh' \outh, 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 foLind 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 manv 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 mav 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 gro\\s 

 the more rapidh', overtopping and injuring the spruce. 

 The latter is maintained in proper proportion onlv b\ 

 cleanings in which those beeches v.'hich are likelv to in- 

 jure the spruce are cut back. 



In hardwood regions one of the problems is to pro- 

 tect voung seedling trees from sprouts. The latter grow 

 very rapidlv during earlv vouth, and m some cases over- 

 top seedling trees which are of special \'a!Lie. This is 

 illustrated where pine is planted after the clear-cutting of 

 hardwoods. There are inevitnbl\- a certain number of 



