THINNING OF ADVANCED PINE PLANTATIONS. 161 



least affected of any. Of all forest-trees, the Scots 

 pine is the most impatient of any artificial interference, 

 and suffers more from thinning than any other species. 

 In this case, after thinning, the trees lost their natural 

 dark -green colour, and assumed a faint light -green. 

 The leaves became shorter, and presented a clustered 

 appearance. Some foresters, on giving their opinion 

 upon the plantation, said it required more thinning 

 that the crop was too great for the poor gravelly soil. 

 Some thought it blighted by some atmospheric influ- 

 ence ; and others said it had come to maturity, and 

 ought to be cut down as having attained it. 



After weighing all arguments, and duly examining 

 the whole case, I came to the conclusion that thinning, 

 and thinning alone, had done the mischief. From a 

 very wonderful provision in nature, the branches of a 

 tree are so spread out as to shade the surface of the 

 ground underneath where the delicate tender roots are 

 spread, and thus keep them uniformly moist and cool, 

 and never at any time scorched or unduly heated by 

 the direct rays of the sun. A plantation, therefore, 

 like that under consideration, which had grown up till 

 about forty years old without ever receiving a regular 

 thinning, may well be understood to have so far adapted 

 itself to its circumstances of life as to be seriously and 

 injuriously affected by any change such as thinning 

 would produce. The trees including stem, branch, 

 and root were what may be termed acclimatised, or 

 rather habituated, and therefore thinning produced a 

 severe change upon them equivalent to removal to 

 a different inferior soil and climate. 



There is much said about acclimatising of plants, 

 which applies only to that part above ground, but 

 there is little or nothing said about the roots of the 



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