176 INTERMEDIATE CUTTINGS THINNINGS 



the thinnings, because the material removed averages of 

 larger size and better quality than in the ordinary method - 

 except for the heaviest grade of thinning. A comparison of 

 the crown classes removed in each of the two plainly indicates 

 this. 



(c) Any light admitted through the openings in the main 

 stand is utilized by the overtopped trees which are able to 

 continue growth, slowly producing cordwood as the principal 

 product. Under the ordinary method any light admitted 

 after a heavy thinning tends to stimulate a growth of grass, 

 weeds and shrubs. 



The principal disadvantage of the method, but not a serious 

 drawback, is the fact that the overtopped trees left standing 

 are a hindrance in the work of felling and transporting from 

 the area the material cut. 



Thinnings according to the French method should not be 

 started until around the thirtieth year when the period of 

 most rapid height growth is past and the stems have been 

 cleared by natural pruning. The heavy thinning if made 

 before natural pruning was well started would result in mak- 

 ing the final crop trees too wide spreading and branchy with 

 short clear boles. 



The overtopped trees prevent the production of epicormic 

 branches on the main stems and continue to some extent the 

 natural pruning. 



If the stand requires thinning before the French method 

 can be started, a thinning on the ordinary method may be 

 made. 



The French method can be applied successfully in either 

 pure or mixed stands. Undoubtedly the best combination 

 from the standpoint of the greatest yield in quantity and 

 quality is found in a stand where the final crop trees are of a 

 light demanding species, while the overtopped stand is formed 



