THINNING 37 



Plantations above the 800-foot contour line 

 should, as a rule, be treated in this way, unless 

 there are special advantages of soil or situation. 



In larch plantations which at fifty to sixty 

 years of age still show a vigorous growth, the 

 density of the crop should be removed as soon 

 as the height- growth is seen to be approaching 

 the end. At that period the density has done 

 its work and is of no more use. An effort should 

 be made to produce that growth in diameter 

 which makes the trees of considerable value. 



By the removal of all the inferior trees the 

 plantation should be thinned until each of the 

 remaining trees stands clear of its neighbours. 

 For fear of damage by windfall this partial 

 clearance may be effected by two thinnings. 

 The removal of the density of the crop should 

 not be delayed until height-growth has ceased, 

 for at that time there is a reduction of vigour 

 in the trees and they cannot then produce as 

 large a diameter growth as they would have 

 done if full light and air had been admitted into 

 the plantation a few years previously. 



During this last stage in the growth of a 

 larch plantation the soil will, in most cases, be- 

 come covered with a growth of broad-leaved 

 plants. Under favourable circumstances the 



