METHOD OF THINNINGS. 43 



wholesale any particular species while the forest is 

 yet young, an operation that is always a mistake, as 

 each kind of tree is useful in its own special way. 



By means of thinnings valuable produce is brought 

 into the market which would otherwise have been 

 entirely lost. This produce is generally equal in 

 quantity to a fifth or a quarter, sometimes to a half 

 of that yielded by the regeneration cuttings, and 

 with some species, may equal the latter. 



Lastly as thinnings deal principally with suppressed 

 and sickly trees, they tend to prevent the propaga- 

 tion of wood-devouring insects, which attack such 

 trees by choice, and sometimes threaten the 

 destruction of certain kinds of trees, particularly the 

 conifers. 



But we cannot repeat too often that if these 

 advantages accrue from a thinning carefully carried 

 out, an injudicious thinning may compromise the 

 future of the forest ; much better would it have been 

 in that case, not to have made one at all. 



Now if we compare the relative importance of 

 cleanings and thinnings, we shall see that the former 

 are necessary, while the latter are only useful. For, 

 in point of fact, cleanings ensure the very existence 

 of the valuable trees, while thinnings merely improve 

 their growth, and in consequence the quality and the 

 usefulness of their timber. 



