The Thinning of Woods. 



299 



Judiciously carried out, and with a favourable market, 

 thinnings are often very remunerative in themselves, besides 

 having an important effect in enhancing the rate of incre- 

 ment in the remaining trees and the future technical and 

 monetary value of these latter. The larger growing-space 

 thus afforded to the crowns usually results in the formation 

 of much broader annual rings till the crop forms close canopy 

 again. When the growth in height has been practically com- 

 pleted, the thinnings can be made heavier, so as to enable 

 better crowns of foliage to be formed with a view to improving 

 the shape of the bole and to increase it in top-diameter relative 

 to the diameter near the base of the tree. This latter operation, 

 indeed, now forms a special feature of Continental forestry in 

 the treatment of light-demanding trees like Oak and Larch. 

 The thinning is carried out to the extent of a partial clearance 

 (over 15 per cent, of the basal area of the stems forming the 

 crop being removed), and is combined with natural regenera- 

 tion in the case of shade-bearing trees, or else with the under- 

 planting of light-demanding trees like Oak, Larch, and Pine. 

 After such a partial clearance the trees are allowed to stand for 

 a considerable number of years in an almost isolated position 

 with a view to the stimulation of their rate of increment be- 

 fore being felled and brought to market. This measure is, 

 however, only advisable on good soils where underwood 

 below such standards can be provided without much outlay 

 for the protection of the soil against sun and wind. 



J. NiSBET. 



