THE MANAGEMENT OF PLANTATIONS. 



47 



leaf canopy over the whole area covered by the crop. This may 

 be termed the ideal crop, and, it is needless to say, is scarcely 

 ever realised in practice. For, on looking through the planta- 

 tion, we shall find that the dominant trees stand thicker in one 

 part than in another. Differences of soil and situation will cause 

 the struggle for existence to be short and sharp in one quarter 

 and slow and protracted in another. In the latter case the trees 

 will probably be weakened and drawn, and possess slender stems 

 and small crowns. In other places, again, we may find one or 

 two dominant trees which have met with little or no opposition 

 from their neighbours, and are, in consequence, in possession of 

 heavier crowns than is desirable. Such irregularities 'may not 

 be universal, but are sure to occur more or less in plantations 

 left entirely to themselves. It is to remedy these defects that 

 artificial thinning is necessary, and, although greater differences 

 of opinion exist on this branch of forestry than on any other, we 

 cannot pass it by altogether. The aim of thinning, in my 

 opinion, should be the provision of a certain number of dominant 

 trees in those parts where, as we have seen, they do not already 

 exist in sufficient numbers, and thus bring the crop nearer its 

 ideal condition. This is not a rule-of-thumb operation, such as 

 the removal of every other tree, or leaving the distance between 

 the trees equal to one-third of their height. These ancient rules 

 have simplicity in their favour, it is true, but they ignore the 

 fact that trees differ as much in their habit and rate of growth 

 as any other class of animal or vegetable, and should be treated 

 accordingly. Thinning, therefore, with the already mentioned 

 object in view, should consist in giving the necessary number of 

 trees an advantage over their neighbours, and this can only be 

 done by removing or weakening the latter. The trees selected 

 for becoming part of the main crop should, of course, be perfectly 

 healthy, with straight stems, and sufficiently vigorous to enable 

 them to continue the normal growth which the overcrowding 

 threatens to interfere with. The exact mode of operating should 

 depend upon circumstances. We are accustomed to regard 

 thinning as cutting so many trees out of a wood, but in reality a 

 plantation may be thinned without cutting a single tree. For 

 we must remember that it is the crowns of the trees which alone 

 necessitate thinning, and if we can give our selected trees the 

 necessary space by cutting back the branches of, or beheading 



