The Thinning of Woods. 



295 



crop does not attain its maximum ; and, on the other hand, 

 if the crop be not tended in a proper manner the productivity 

 of the soil is prejudiced, and consequently the capital value 

 of the land sinks. There is only one way of ensuring the 

 requisite conservation of the productive capacity of the soil 

 against the deteriorating effects of sun and wind, and this 

 consists in the maintenance of a complete and effective leaf- 

 canopy. Woods consisting of light-demanding kinds of 

 trees, like Oak, Ash, Larch, or Scots Pine, whose normal 

 density of canopy is of itself insufficient to ensure conserva- 

 tion of the soil, can therefore only be grown economically 

 along with shade-bearing densely foliaged trees like Beech 

 ■or Spruce, or by being underplanted with such soil- protecting 

 genera. To discuss this matter would, however, lead too far 

 from the question of thinnings, with which the present article 

 is more particularly concerned. 



To utilise in the most thorough and advantageous manner 

 the productive capacity of the soil, it is essential that the 

 stock should be maintained in close canopy from the thicket 

 stage of growth onwards, until it has passed through the 

 more energetic period of its growth in height. It is only by 

 such means that the formation of a clean straight bole can 

 be attained. If more than the requisite individual growing- 

 space be afforded, then there is an immediate tendency to 

 dissipate the vegetative energy in ramification and in the pro- 

 duction of twigs, in place of having the crowns of foliage 

 drawn up so as to obtain the maximum length of stem 

 possible under the existing conditions of soil and situation. 

 To allow plantations to become overcrowded, by leaving the 

 individual stems to struggle on till they are dominated and 

 finally suppressed and killed by their stronger neighbours in 

 the struggle for existence, is uneconomical in a degree. In 

 the first place, the dominfited stems gradually languish, and 

 then fall into a sickly condition predisposing them to attacks 

 from noxious insects and parasitic fungi,which may spread and 

 finally overrun the whole plantation. Secondly, when the stems 

 are becoming suppressed it is better to cut and utilise them 

 rather than to allow them to decay and lose any marketable 

 value they may have. And thirdly, if left in situ longer than 

 is necessary for the maintenance of the leaf-canopy, they inter- 



