82 FORESTRY IN NEW ENGLAND 



intermediate. As a general rule dominant and the better co- 

 dominant trees are favored in thinnings, while the other three 

 classes are cut out. Just what is taken out depends mainly on 

 the heaviness of the thinning, which may range from an extremely 

 light cutting to one as heavy as a reproduction cutting. The 



Fig. 32. — A stand of beech and oak iu Europe, 40 lo 50 years of age. A light thinning has 

 just been finished. 



following live classes of thinnings are recognized, depending on 

 the heaviness of the cutting: 



Grade A. — Light thinning; removing dead and suppressed 

 trees. 



Grade B. — Moderate thinning; removing dead, suppressed, 

 and the poorer intermediate trees. 



Grade C. — Heavy thinning, removing dead, suppressed, inter- 

 mediate and a few codominant trees. 



Grade D. — Very heavy thinning, removing dead, suppressed, 

 intermediate and codominant trees. 



Accretion Cutting. — Any thinning heavier than Grade D. 



