157 



CHAPTEE VI. 



EFFECTS OF THINNING ON ADVANCED PINE PLANTATIONS. 



It is often asked what rule can be given, and how it 

 may be known when either individual trees or planta- 

 tions have the proper quantity of branches upon them. 

 The rule for this is, as far as any rule can be given, to 

 maintain a due proportion of girth to the height of the 

 tree, and these proportions, as already stated, are girth 

 in inches to feet in height, measuring immediately 

 above the swell of the roots. For example, a tree 12 

 feet high should girth a little above the swell of the 

 roots 12 inches ; a tree 24 feet high, 24 inches ; and 

 so on up to 30 feet in height, to a corresponding num- 

 ber of inches in girth. When trees have attained the 

 above height, thinning should be discontinued ; and it 

 should frequently not be prolonged after the trees are 

 from 20 to 25 feet in height, but allowed to grow un- 

 disturbed (except by cutting down dead or decaying 

 trees) till ripe for finally cutting and clearing. 



That there is a danger of trees having too many as 

 weU as too few branches, is fully admitted, but there 

 is no danger of very young trees having too many; and 

 if the rule given be observed, there will be neither 

 superabundance nor deficiency of branches at any time, 

 for if the proportional girth is too great, it can soon 



