Northern Unit 



The former Mid- Western and Northern units are joined for the present, with 

 headquarters at Port Arthur. The studies of the silvicultural characteristics of the 

 main species in northern Ontario were continued in 1965-66. The work is 

 described below under Northwestern Ontario and Northeastern Ontario. 



NORTHWESTERN ONTARIO 



In 1965-66 emphasis was placed on a study of methods to obtain natural 

 regeneration, on comparative growth rates of species, and on several projects 

 relating to artificial regeneration. Much time was spent during the year on the 

 establishment of a new research headquarters at Port Arthur which now provides 

 good office, laboratory and greenhouse facilities. 



Natural Regeneration. Studies were pursued of the effects on regeneration of 

 mechanical scarification before logging and of the scarification effects following 

 mechanical logging on 1,000 quadrats established in 1960 in a 50-acre experi- 

 mental block in the Caramat area. This study included also the effects of leaving 

 seed trees in a mixed white spruce-balsam fir cut-over (with the object of favouring 

 spruce). 



Growth Study. The study was continued to compare the growth rate of white 

 spruce and balsam fir growing in mixture on upland sites. On these sites white 

 spruce has grown faster than balsam fir. This appears to refute the idea that 

 balsam always grows faster than spruce. In 1965 one hundred samples of older 

 regeneration were added to provide an adequate statistical base. 



Artificial Regeneration. A re-examination was made of three seeding trials 

 established in 1959-60. Two studies were made in co-operation with the Thunder 

 Bay nursery, one of summer planting of white spruce and the other on germination 

 problems of black spruce. 



NORTHEASTERN ONTARIO 



Forest research has been concerned for a number of years with the failure 

 of black spruce to regenerate and grow subsequently at a sufficiently rapid rate on 

 lowland sites. 



There has been a progressive degradation of sites following cutting and there 

 has been a continuous study made on a number of permanent sample plots, 

 established in the early 1920's on the lowland sites of the Cochrane Clay Belt. 

 The purpose of the study is to find out why and how this degradation takes place, 

 and, if possible, suggest measures to overcome it. 



It has been found that the removal of the merchantable-size black spruce in 

 logging operations is followed by a considerable rise in the water table resulting 

 in much more rapid growth of sphagnum moss. Successive layering of the moss 

 has created a condition which eliminates germination of the spruce and causes a 

 marked retardation in the advance growth left after logging. 



Experiments in drainage, initiated in 1930, were continued in 1965. In 

 addition, a number of experiments have been undertaken, commencing in 1963, 

 to determine the correlation between poor drainage and the undesirable growth 

 of sphagnum moss, as well as the effect of this on spruce and balsam fir 

 regeneration. 



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