EFFECTS OF ITS REMOVAL. 611 



the low vitality of the trees renders them liable to become stag- 

 headed if the litter be removed. It should also be remembered 

 that an old wood is the precursor of the future young genera- 

 tion, for which it has, as it were, to prepare the way ; in mature 

 woods, therefore, the soil-covering should be as carefully 

 preserved as in young woods. 



The stage of young pole-woods is that of the greatest heighi.- 

 increment, which experience shows is greatly reduced when the 

 soil deteriorates. There remain only the stages of high-poles, 

 and of trees which have attained their full height, when the 

 dense standing crop raises the fertility of the wood most 

 markedly by preserving moisture in the soil and enriching it 

 with dead leaves ; these are the only periods in which a moderate 

 removal of litter is admissible, because the locality is then most 

 able to afford the drain on its resources. 



(0 Condition of the Standing Crop. 



The remark has already been frequently made that vigorous 

 dense woods in favourable localities can withstand the removal 

 of litter far better than those under opposite conditions. Re- 

 moval of litter is therefore most pernicious in all decadent, 

 open and stunted woods. This applies to woods which have 

 been devastated by insects, snow, frost, or abnormal drought ; 

 also, after any regular forest operations have been effected, 

 such as thinnings, fellings preparatory to natural regeneration 

 by seed, selection-fellings, &c. : woods are then more endangered 

 by the removal of litter than at other times. 



(//) Amount of Litter Eemoved. 



It is obvious that the removal of litter is the more injurious 

 the more frequently it recurs on the same area. The interval 

 between two successive removals may be termed close-time. 



The period during which the forest is closed to the removal 

 of litter should evidently vary in different woods and at different 

 ages of the same wood, if the amount of damage done is not to 

 be excessive. The length of the close-time should depend on 

 the quality of the locality, species of tree and age of the wood. 

 The more susceptible a wood to danger from the removal of 



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