218 A MANUAL OP FORESTRY. 



valuable one, the former must be favoured from an early 

 age, so as to bring it to the highest possible develop- 

 ment, if necessary at the expense of the less valuable 

 species. As long as the valuable species is of quicker 

 growth than the other, the operation is comparatively 

 simple ; but if it is of slower growth, all individuals of 

 the secondary species which threaten to overtop it must 

 be cut away, until the principal species is secure. 



5. Thinning of Coppice Woods. 



These thinnings are conducted according to the same 

 principles as in high forest, whenever the number of 

 shoots is so great that there is not enough growing space 

 for all. More especially in Oak coppice the quality and 

 quantity of bark may be considerably influenced by 

 leaving on each stool only the two or three best shoots 

 and removing the others. Such thinnings are generally 

 made in the second half of the rotation. 



6. Principal Advantages of Thinning. 



The principal advantages of thinning are as fol- 

 lows : 



(a.) They afford the means of guiding the develop- 

 ment of a wood in accordance with the ob- 

 jects of management, either by producing 

 the greatest possible quantity, or the best 

 possible quality of produce; in many cases 

 both these objects may be combined. 



(b.) They afford the means of preserving a suitable 

 mixture in the case of mixed woods. 



(c.) Danger from insects, fungi, and fire is greatly 



