SYLVICULTURE 



croups. Where the age classes appear in bunches, each bunch can 

 be harvested at its proper age of maturity. No harm or little harm 

 is done to young growth during the logging season. 

 D. Disadvantages: 



I. Operations are scattering. 



II. Intricate system of permanent roads reqviii-ed. 



III. Groups surrounded by tall timber frequently act as " frost- 

 holes " where young growth suffers badly from early frosts and 

 late frosts in clear nights. 



IV. Thin barked trees surrounding the group suffer from sun 

 scald; flat-rooted trees suffer from storm. 



Paragraph XLVI. The cleared selection type. 



A. In this type, individual trees considered mature are selected 

 for removal, either absolutely singly, or in very small patches 

 formed by neighboring trees. 



The clearings made are so small that only shade-bearing species 

 will regenerate thereon, unless the soil be particularly strong. 



The cut is so scattering, that the soil is not sufficiently " plowed " 

 by the loggers. Hence it will not act as a ready seed-bed. 



In mixed woods composed of many species, only the most 

 valuable kind is usually withdrawn, and the small gaps made are 

 occupied by shade-bearing and often less valuable species. 



Beneath hypermature trees, the soil has frequently hardened 

 and defies any attempt of seedlings to establish themselves after 

 logging. 



The cleared selection type is almost invariably bastardized with 

 the shelterwood selection type and with the advance growth selec- 

 tion type. 



B. Actual application: 



In the tropics, Teak, Mahogany, Ebony, etc., are cut by selec- 

 tion, frequently regardless of the effect which logging will have 

 on regeneration. 



In Europe, the type is found in the Fir forests owned by farm- 

 ers; in parks; in protective forests at the headwaters of rivers; 

 on very steep slopes dotted with Larch, in the Tyrol. 



In America, Yellow Poplar, Walnut, Cherry, W^iite Oak, etc., 

 are cut by way of individual selection, — but with no regard to 

 reproduction. Also White Pine in the Spruce and Fir woods of the 

 Adirondacks where it never succeeds, withdrawn alone, to reproduce 

 its kind. 



105 



