tation has been concluded for the present, although information on this subject is 

 still being supplied to co-operators. 



' 



RODUCTIVITY ECOLOGY OF RED SPRUCE 



Red spruce has characteristics which make it very useful in improving the pro- 

 ductivity of derelict tolerant hardwood and mixed wood stands. This study is 

 Kxpected to elucidate the silvics and silviculture of this species and provide defin- 

 ;ive information of growth potential for planting programmes. 

 The study is designed to measure growth and productivity of red spruce in 

 ure and mixed stands on a complete range of physiographic sites across its range 

 in Ontario. It is hoped to provide explanations of differences in spruce growth as 

 related to nutrient uptake from forest soils. In addition, total productivity (dry 

 weight production), specific gravity, regeneration and ground flora relationships 

 are being investigated. 



By using computer techniques, it is intended to construct a mathematical 

 model not only for describing, explaining and predicting the foregoing relationships, 

 but also in studying other spruce species and populations. Comparative measur- 

 ments are already being made on white and black spruce when these species occur 

 in association with red spruce. 



Work is also proceeding on the racial variation in spruce in order to find the 

 best ecological characteristics. The relationships of genetic variation on nutrition 

 and growth in spruce are being investigated by measurement and analysis of differ- 

 ent provenances and species on the same and different sites. Several species are 

 being considered. Early indications are that natural or artificial hybrids between 

 red and black spruce, while possibly possessing some hybrid vigour, are not nearly 

 as desirable as the parent trees. The hybrids are exceedingly rough and limby. 



A large-scale experimental underplanting has been established, and is being 

 re-measured this year. Assistance to the Timber Branch on the establishment of 

 seed production areas is continuing. 



Tree Nutrition, Forest Disturbance and Regeneration. Studies are under way 

 on the effects of prescribed burning and scarification on nutrient release in the soil 

 and uptake of these nutrients on the growth of tree seedlings on different land types. 



NORTHERN FOREST RESEARCH UNIT 



Black spruce, the principal source material of our pulp and paper industry, 

 is the chief concern of research in this Region. There have been, over the years, 

 numerous studies made by many investigators into the regeneration and rate of 

 growth of the species, both of which have been unsatisfactory, particularly on 

 lowland areas. 



This unit has had two objectives. The first, to determine the cause of poor 

 regeneration and find means of correcting it; the second, to ascertain the reasons 

 for the slow growth of spruce and learn how the rate of growth can be accelerated. 



We do not have the answers. Nevertheless, the past year has been one of 

 accomplishment and it appears that methods of attaining our objectives on the 

 lowland sites can soon be described. 



Experimental work indicates that sphagnum moss is the major competitor to 

 spruce both in its initial and later stages. We have found conclusive evidence 

 of the growth of sphagnum on open areas, growth so prolific that it tends to 

 swamp any spruce regeneration which may have originated there. It is assumed 

 that this acceleration in growth of sphagnum is the reason our spruce cut-overs 



are not regenerating satisfactorily. 



i 



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