CHAP, ix.] Tending of Woods 199 



treated, after the lapse of twenty years natural regeneration 

 will generally be found to have been effected spontaneously, 

 the standard trees will be of good marketable dimensions and 

 excellent quality, and the seedling growth will vary from 

 about 3 to 1 5 feet in height. Blanks left by the removal of 

 the standards can easily be most advantageously filled up by 

 planting with Pine, Oak. Larch, Ash, Maple, &c. 



Of course, an essential condition for the success of this 

 measure is that the crops are still in active vitality and capable 

 of being stimulated to quantitative and qualitative increments. 

 The operation would be useless in the case of trees already 

 entering, even prematurely from injudicious treatment or any 

 other cause, into the stage of senile decay. With reference to 

 the relative and the absolute increment on individual stems 

 after partial clearance, Behringer l gives some interesting and 

 instructive data, which are exhibited in tabular form on the 

 two following pages. 



Measurements made at the same time showed that the rate 

 of growth in height had been sensibly diminished in con- 

 sequence of the greater amount of growing-space afforded after 

 the partial clearance. But as the operation was not performed 

 until after the most active period of growth in height had been 

 completed, this diminution was of comparatively little technical 

 or financial importance. 



So far as these experiments go they prove not only that, 

 owing to the larger growing-space, each of the standards was 

 stimulated to produce more than double the increment in 

 cubic contents which it had before the partial clearance took 

 place, but also that, whilst in regard to the Spruce the enhanced 

 increment culminated within the first decade after this opera- 

 tion, the culmination was delayed in the cases of the Scots 

 Pine and the Silver Fir until the second decade had been 

 entered on. This had also previously been found by Konig to 

 be the case in Beech woods. 



1 Op. cit., pp. 59, 60. 



