TENDING OF WOODS DURING EARLY YOUTH. 197 



on to the area (as Poplars, Willows, Birch), or carried 

 1h ore by animals, as Sweet Chestnut, Oak, Hazel, and 

 others. Often Spruce, Scotch Pine, Lime, Alder, and 

 Elm also appear where their cultivation was not 

 intended. 



It would, however, be a mistake to remove all such 

 additions without distinction. Frequently they are very 

 welcome in filling up otherwise thin woods ; hence they 

 should only be removed where they interfere with the 

 principal, species or individuals. 



It is often desirable to make several cleanings, 

 especially where the undesirable growth occupies a 

 considerable portion of the area, and where its removal 

 at one time would leave blanks. In some cases it may 

 even be judicious to accept a portion of the accidental 

 growth as a constituent of the final crop, in others it 

 may serve as a shelter wood. 



4. Preservation of a proper Mixture. 



This difficult subject must receive special attention 

 while a wood is young ; much can be done towards 

 realizing it during the operations of recruiting and 

 cleaning which have just been described, by plant- 

 ing into blanks those species which are otherwise 

 deficient in number, or by removing an excess in other 

 places. 



Again, where one species is threatened by another, 

 the latter can be checked either by lopping off its side 

 branches, by topping, ringing, or removing some of 

 the trees. 



