TENDING OP OPEN WOODS. 223 



more thinnings follow, as required by the extension of 

 the crowns of the trees. 



The underwood can be established in a variety of 

 ways, such as by sowing or planting, by natural seeding, 

 or by coppicing a portion of the overwood. In some 

 cases the underwood itself is allowed to grow into 

 timber-trees (two-storied high forest) ; in others it 

 remains a soil-protection wood. \ 



The procedure differs considerably according to 

 species and the objects of management. To meet the 

 special requirements of each case, a considerable number 

 of modifications have been elaborated. Some of these 

 commence with the isolation in early growth, while others 

 during the greater part of the rotation follow the system 

 described in the last section, and reserve to its latter 

 part the isolation of the more valuable trees. 



Although the treatment has been recommended for 

 almost all species, it is easy to perceive that thinly- 

 crowned species, which are generally light-demanding, 

 are better adapted for the method than those with a 

 dense crown, as the underwood has a better chance of 

 thriving under the former, and doing justice to the task 

 which it is called upon to perform. In Britain the 

 Oak, Larch, and Scotch Pine have, in a rough way, 

 been treated according to this method for a long time 

 past. On the Continent, the treatment has been 

 elaborated in comparatively recent times. 



2. Principal Forms of Treatment. 

 These may be enumerated as follows : 



