222 THE NORMAL AOK CI,ASSES. 



the cleared areas, which are to l)e naturally regenerated, must 

 1)6 situated to the leeward of the seed-hearing trees, as, for 

 instance, under the strip system with regeneration by seed 

 fallen from trees standing on the adjoining area. 



Large cJearingH in one place are generally objectionable, 

 because the soil is liable to dry up, and damage by frost is 

 more likely to occur : hence, in extensive forests the area to be 

 cut annually may have to be divided into a number of small 

 coupes situated in different parts of the forest. 



Inserts and fire are likely to be most injurious, when several 

 cuttings made in consecutive years adjoin each other, because 

 the former wander from one coupe to the next, while fire 

 spreads more rapidly in young woods, than if they are 

 interrupted by older woods. 



These circumstances demand in many cases, and especially 

 where clear cutting is practised in coniferous woods, that a 

 second cutting should not be made in any locality, until the 

 first coupe has been successfully re-stocked. This leads to the 

 splitting up of a working section, or a series of age gradations, 

 into several sub-divisions, which are called cutting series. 

 Supposing, in a forest worked under a rotation of 20 years, it 

 was considered necessary, not to cut in the locality adjoining 

 a previous cutting except after a lapse of 4 years, the series 

 of age gradations would be divided into four cutting series, of 

 which each would comprise five coupes. (See Fig. 49.) 



Cutting 



Series 



A would comprise the coupes now 20, 1(), 12, 8, 4 years old. 

 B „ „ „ „ ., 19, 15, 11, 7, 3 ,, „ 



C „ „ ,, ,, ,, 18, 14, 10, 6, 2 „ „ 



D „ ,. ,. ., ., 17, 13, 9, 5, 1 „ „ 



As a general rule, a careful distribution of the age classes 

 over the area of the forest is of special importance in the case 

 of species, which are easily thrown by wind, liable to attacks 

 by insects, to danger from fire or frost, and also those Avhich 



