470 REARING OF THE ESTABLISHED CROP. 



ARTICLE 1. 



ORDINARY THINNINGS. 



The object of ordinary thinnings is to give to the individuals 

 forming the principal part of a crop increasing expanding room 

 both in the soil and in the atmosphere above, in proportion to 

 their increasing requirements, the grand result being the improved 

 vegetation and enhanced growth of the individual trees as well as 

 of the forest collectively. 



Even if a forest were left to itself, the strongest individuals 

 would in time prevail by gradually hemming in or suppressing and 

 ultimately killing out all the rest. But this victory would be the 

 result of a more or less prolonged struggle, during which they 

 could not themselves escape suffering a certain amount of check, 

 if nothing worse. It is to prevent this undesirable consequence 

 that thinnings are made. Thinnings are thus operations intended 

 principally to favour the stronger individuals and to help them to 

 get rid of their rivals before these can do them any harm. The 

 word "principally " has been used advisedly, for it not unfrequently 

 happens that the stronger individuals are neither the most promis- 

 ing nor the most valuable or desirable as regards species, and must, 

 therefore, be made to yield the place to their weaker neighbours. 



I. Advantages offered by thinnings. 



Thinnings offer the following important advantages : 

 (a) By opening out the leaf-canopy, they stimulate the growth 

 of the individual trees as well as of the crop as a whole. It has 

 been established by direct experiment that a certain minimum 

 number of well-developed stems per unit of area, the number 

 varying with the different conditions of growth, contains absolutely 

 more wood than a larger number of stems standing closer together 

 and, therefore, possessing less vigour of growth. 



(&) They give us the most practical and effective means of re- 

 gulating the growth ot the forest and the formation of the boles of 

 the trees according to our requirements. Their influence on the 

 length, diameter and shape of the bole increases both the quantity 

 and the usefulness of the timber in each tree. 



(c) By strengthening the trees, they redue the extent of damage 

 caused by violent or hot or cold winds and by the weight of super- 

 incumbent snow. 



(d) By removing all dead, dying, unhealthy and unsound 

 trees and inducing a sound healthy growth, they diminish the se- 



