PROTECTION AOAINST EXmANEOUS CAUSES OP INJURY, 461 



after-fellings according to the gronp method. In executing these 

 special local fellings we must not of course neglect thefinterest of 

 the parent crop as a whole, and large old trees should accordingly 

 be removed in preference to younger ones. 



General Remaeks. — Treated thus advance growth will furnish 

 most valuable material with which to form the future crop. It is 

 a free gift from Nature, which we ought thankfully to accept and 

 turn to the best use. It helps regeneration operations to a 

 wonderful extent, conduces to the desired mixture of species, and 

 is equally useful whether we adopt natural or artificial regenera- 

 tion. If neglected, the most promising advance growth will be- 

 come stunted and bushy and will later on prove no sUght impedi- 

 ment to natural regeneration by seed. 



ARTICLE 2. 

 Protection against extraneous causes of injury. 



These causes are frost, excessive insolation, winds, weeds, includ- 

 ing grass, animals and parasites. 



Frost. — Where regeneration is effected under cover, a certain 

 number of the parent or nurse trees must be preserved beyond the 

 period that they would be kept if it were only a question of admit- 

 ting the seedlings to a sufficient enjoyment of light and other bene- ' 

 ficial atmospheric influences. Considered from a purely sylvicul- 

 tural point of view, these trees should belong to species possessing 

 light folHage ; but as it may often happen that there are in the 

 upper crop a number of trees of the more valuable species which 

 are still growing and to which a slight increase of diameter would 

 give a considerably enhanced money-value, the trees to be preserv- 

 ed as nurses are selected on other than mere sylvicultural grounds. 

 Ecoiiomical have to yield to cultural considerations only in so far 

 as that, if the individuals to be maintained have broad and thick 

 crowns, their number must be limited. Where the coppice system 

 is employed, stores must be kept, even if only firewood is required, 

 and the rotation ought to be long enough to enable the coppice to 

 get up well above the height reached by the severest frost. In all 

 naturally regenerated crops scattered individuals of fast-growing 

 hardy species should be encouraged to push ahead. In stocking 

 complete blanks with a delicate species, a nurse crop of one or more 

 hardy species should be raised in advance, or some hardy, very 

 quick-growing species should be mixed. In the former case, if 

 artificial means continue to be employed, the preliminary species 



