Practical Sylviculture 143 



thinnings is looked forward to in the final crop rather than 

 in the wood that is removed during thinning operations. 



TIME OF THINNING 



It will be understood in this discussion that the term 

 thinning is applied to any operation that tends to remove 

 from the woodlot any undesirable material, either living or 

 dead, at any time, or any desirable and valuable trees in 

 overcrowded stands at such times as seem best for the 

 woodlot. This definition of thinning is not the one 

 adhered to strictly by the forester, but is used here in a 

 broad and general sense. 



As to the time of thinning the woodlot, it is a difficult 

 matter in a treatise of this kind to give anything other 

 than general advice, since conditions are so variable. 



It is a good rule to commence thinning early in the life of 

 trees, and this time is best indicated when there is a begin- 

 ning of active crowding between individual trees. In the 

 vigorous-growing natural stands or in the planted grove, 

 this crowding usually begins at about twelve to eighteen 

 years. At this time only such trees should be removed 

 as interfere with one another or with other and better 

 trees that will eventually be suppressed and stunted. 

 Such a thinning should be light and the operator should 

 look to the crown of each tree rather than to the number of 

 trees on any particular area. The prime object is to 

 give each tree crown space and yet to maintain a thinned 

 but even canopy over the entire woodlot area. 



The woodlot owner doubtless will object to this kind of 

 an operation, since the material removed cannot be 

 expected to defray the incurred expense or to net any 



