220 A MANUAL OF FORESTRY. 



7. Execution of Thinnings. 



The advantages of thinnings can only be fully 

 realized if the operation be conducted in a careful 

 and judicious manner; in other words, it must be at- 

 tended to by a competent forester and not left to the 

 wood-cutters. 



In young woods, which have as yet a large number of 

 trees per acre, thinnings should generally be carried out 

 in the presence of a competent forester ; only where the 

 wood is absolutely uniform throughout, a sample may be 

 prepared as a guidance for the workmen, and this only if 

 the latter are thoroughly reliable and competent. In the 

 more advanced stages of life, each tree to be removed 

 should be marked separately and in the forester's pre- 

 sence, and this must be done while the trees are in leaf, 

 so that the effect of the removal may be properly judged. 

 Special care is necessary where valuable timber trees are 

 to be produced, where dominant trees are to be removed, 

 and where a proper mixture of species is to be preserved. 



The exposed edges of a wood should be thinned where 

 the trees must be trained to withstand strong winds. If 

 the wood be subject to the effects of raw cold, or dry 

 hot winds, the exposed edge should be kept as dense as 

 possible, and an additional strip some distance from it 

 may be kept in a similar condition. 



The best time for the execution of thinnings is winter, 

 but local circumstances demand deviations from this rule. 

 In high mountains they must be done in summer, as the 

 localities are generally inaccessible during winter. 



