produce hardwoods. This is accomplished by measuring the 

 yield of fully stocked upland hardwood stands and estimat- 

 ing the growth throughout the age of the stand by stem- 

 analysis techniques. 



FOREST ECONOMICS 



The purpose of this unit is to advise on the economic aspects 

 in the planning of forest research projects and to participate 

 in the research requiring economic analysis. A comprehen- 

 sive paper on the various aspects of Soviet forestry was pre- 

 pared, and a library research conducted on the theory of the 

 sustained-yield principle. 



TREE NUTRITION 



A report on fertilization of jack pine was published, showing 

 results after six years. Growth and cone production were 

 increased. 



One-year growth of poplar hybrids. 



Two years after fertilizing red pine on a sand plain, results 

 showed that growth of larger trees had increased, apparently 

 at the expense of the smaller trees. 



A fertilization program of black spruce in the Clay Belt is 

 under study. Urea was applied from aircraft at the rate of 111 

 lbs. and 222 lbs. per acre. 



Various methods of analysis for determination of N, P, K, 

 Ca and Mg have been tested for the purpose of selecting 

 the most accurate and economical techniques. 



SEED RESEARCH 



Studies continue in relating seed size and density to germi- 

 native capacity and subsequent seedling survival and 

 growth. 



It has been determined that for high density seed, ger- 

 mination was slightly lower for largest and smallest size 

 classes, and this relationship became more pronounced as 

 seed density was reduced. 



Seedlings have been planted out for determination of 

 future growth rate. 



Various forms of seed treatment, prior to sowing, have 

 been tried to improve germination, and these studies are 

 continuing. 



ECOLOGY 



Studies continued on the regeneration and reforestation of 

 pine and spruce and on the quality development of pre- 

 ferred species, especially sugar maple, in the tolerent hard- 

 woods of southern Ontario. 



Models have been developed to express the relationship 

 of tree growth rate to environmental factors and tree 

 attributes. 



Current analysis of this data involves relating the results 

 of the cultural isolation work to wound attributes (such as 

 size, age, rate of healing, etc.) to whole-tree attributes 

 (growth rate, age, etc.) and the type and amount of stain 

 and decay associated with the wound. 



DEVELOPMENTAL 



The work of this unit has been to improve the techniques 

 and equipment used in the tubed seedling programs. 

 Laboratory work to eliminate frost heaving is in progress. 



FIELD UNITS 



NORTHERN ONTARIO 



The main objective is to conduct a program that will pro- 

 vide information for the efficient silvicultural management 

 of the spruce-fir forest in northern Ontario. 



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