62 BULLETIN 55, U. S. DEPAKTMENT OF AGEICULTURE. 



SILVICULTURAL SYSTEMS OF CUTTING. 



Upon the methods of cuttmg adopted in spruce stands will depend 

 whether the future forest will be chiefly spruce or balsam or whether 

 there will be future growth at all. In discussing these methods the 

 economic limitations and specific conditions which may affect their 

 application are not considered. These must necessarily differ for 

 each particular forest tract. In a general discussion of the silvicul- 

 tural system adapted to spruce and balsam it is possible to lay down 

 only general principles. 



Natural reproduction may be secured in spruce-balsam fii' stands 

 by two methods: (1) Clear cutting and (2) gradual cuttings. 



CLEAR CUTTING WITH NATURAL REPRODUCTION. 



In clear cuttmg, natural reproduction from stands adjoining the 

 cuttmg must be relied upon to restock the area. The size and form 

 of the clear-cut areas are therefore factors in the success of the repro- 

 duction. If natural reproduction is desired, the greatest width of the 



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Fig. 6. — Results secured by logging on the leeward side of balsam fir-spruce stands. The youngest stands 

 are found on the windward side and deflect the wind upward, preventing windfall among the older 

 trees. 



area to be cut clear in spruce-balsam fir stands should not exceed 

 double the height of the adjoining stand from which reseeding is 

 expected. For example, if the average height of a spruce and 

 balsam-fir stand is 75 feet, then the width of the area which is to be 

 cut clear should not be greater than 150 feet. The length of the area 

 does not affect the natural reproduction and should depend, there- 

 fore, upon the amount of timber to be cut, convenience of logging, 

 and similar considerations. In general, then, clear cutting with 

 natural reproduction in spruce-balsam fir stands should take the 

 form of long narrow strips. 



Since both spruce and balsam are shallow-rooted trees and there- 

 fore subject to windfall, logging operations should as far as possible 

 always begin on the leeward side of the mature timber, and proceed 

 against the wind. If logging were to begin on the windward side 

 there would always be danger from windfall in the stands adjoining 

 the logged area. When the entire forest is cut over in this way, 

 the youngest stands will be on the windward side, their tops forming 

 a gradual ascending plane (fig. 6). The wind is thus deflected 



