TWO-STORIED HIGH FOREST. 103 



(I. Effi'il upon Ihe Factors of the Locdliti/. 



Directly, the effect is the same as that of the principal 

 system. Indirectly, the system acts l)eneficially, as it obviates 

 the adoption of very high rotations, where limited quantities of 

 specially large timber are wanted. 



8. Tico-storicd Hh/It Forest. 



a. Or i (J ill mill Character. 



In the life of most woods, especially if they consist of light 

 demanding species, a time arrives when the cover becomes 

 interrupted, so that they can no longer preserve the factors 

 of the locality. In the case of species where this time arrives 

 at a comparatively early age, a second crop can be introduced, 

 generally by sowing or planting, which is allowed to grow up 

 into high forest with and between the older crop, so that 

 practically two distinct even aged woods exist on the same 

 area, both high forest, the difference in age ranging from 

 15 — 60 3'ears, according to species and circumstances ; hence 

 the name of two-storied high forest. The two crops are 

 cut over at the same time, when the whole process is 

 re-commenced. 



It is usual to thin the older crop heavily, either before or 

 after the introduction of the second crop, by removing all 

 diseased and badly shaped trees, leaving those which promise 

 to develop into fine sound timber trees. 



The older crop should, in all cases, consist of light demanding 

 and the younger crop of shade bearing species, or else the 

 latter is not likely to thrive. 



I). External UaiKjers. 



The older crop may be subject to damage by storms, but 

 generally only for a short period. Damage by frost or drought 

 in the case of the vounger wood is excluded. 



