G12 JOURNAL or" FORKSTRV 



ern forest region where white birch and aspen constitute the hardwood 

 element of the forest. On such sites, spruce and balsam will respond 

 favorably to selection methods, with a severity of cutting determined 

 by the exposure and the soundness of the timber. 



Intensive study of large areas of cut-over land is impracticable for 

 the same reasons that intensive cruising methods have not found favor 

 where the yield per acre is low and cost of logging high. It is neces- 

 sary to limit the study, therefore, to a sample area of sufficient size 

 to give good average results and later apply the results to a more 

 extended area of similar character. The area selected for study should 

 have been cut at least ten years previously ; and if parts of it have 

 been cut heavily twice, additional information concerning mortality 

 and growth can be acquired. 



Such a study of the cut-over land was made during the summer of 

 ]i»20 in two townships in the Algoma district of Ontario. The results 

 obtained are to be used in regulating the cut of eleven other townships 

 in the same (Goulais River) watershed. Data were obtained by a 

 o-per-cent strip survey on about 13,000 acres of cut-over land. This 

 was sufihcient to give good arithmetical averages for all tables without 

 the construction of curves, The same methods were applied to the 

 study of certain areas in New Brunswick, and the illustrative data are 

 taken from this latter study. 



ESSENTIAL DATA 



Determination of volume increment 1)y this method requires stand 

 tables, volume tables, a record of mortality and measurement of 

 diameter growth. The study of the amount of advanced growth and 

 reproduction is not necessary to determine the volume increment for 

 the period elapsing before the next cut, but it is essential to determine 

 the character of the forest which will be left following the next cut, 

 as well as to show whether the opening of the forest has been favor- 

 able to regeneration of the softwood type. 



Uniformity in classification of all data is required so that the results 

 obtained in stand tables, volume tables and increment borings may be 

 combined for computation of volume increment. The study of any 

 average area of northern forest becomes a group of separate studies 

 as numerous as the distinct type associations or recognized sites. 



Any attempt to learn the natural laws controlling growth and repro- 

 duction, rather than the average facts for the area as a whole, will 



