VOLUME INCREMENT ON CUT-OVER PULPWOOD LANDS 



Bv E. F. McCarthy and W. M. Robertson 



Connnission of Conservation, Ottai^'a 



There are few systems of cutting in spruce and balsam fir forest 

 which have not already had a practical trial. 



Cuttings of every degrees of intensity, on every type, have been 

 made and a sufficient period has since elapsed to show the effect on 

 reproduction, mortality of the remaining stand, fire risk, and accelera- 

 tion of growth. Studies of such cut-over land will furnish facts 

 which cannot be secured from virgin lands, and the lessons so learned 

 may be applied either to similar types of virgin forest or to the cut- 

 over area which is increasing in Eastern Canada at the rate of over 

 a million and a half acres annually. 



The problem is two-fold : the study of cut-over land to determine 

 the influence of such cutting, and the study of virgin land to determine 

 maturity, that is, the time when profitable growth is no longer accruing 

 in the virgin forest. 



The study of volume increment in many-aged stands has been dis- 

 cussed in various phases by Cary (1), Chandler (2), Chapman (3), 

 Fernow (4), Moore (5), and Stetson ((i), but in nearly all instances 

 the stand under consideration was virgin in character and the methods 

 do not consider the several agencies of destruction which, after cut- 

 ting, practically offset growth for a period of years. This discussion 

 presents a method of study of cut-over land which takes cognizance 

 of present growth and mortality, and from these suggests a method of 

 volume regulation. 



SELECTION OF THE AREA 



Many stand > in the northern forest are adapted to management by 

 selection or shelterwood systems for the continuous production of 

 pulpwood. Where the softwood has a good representation in all size 

 classes and is free from serious interference by the tolerant hard- 

 wood-, it needs only protection and conservative cutting to yield a 

 good second crop. Such stands may be found in the swamp and flat 

 land types of the tolerant hardwood belt and in all parts of the north- 



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