modate environmental change. A specific objective has been 

 to produce a stable reproductive strain of the brook trout x 

 lake trout hybrid which will mature at age II or III and have 

 the ability of the lake trout parent to inhabit deep water. 



PARASITOLOGY UNIT 



A general survey of fish parasites has been completed in 

 Lakes Erie, Huron and Ontario and in Algonquin Park 

 lakes. A comparable survey of Lake Superior fish parasites 

 will require further work. These studies have defined a 

 number of specific parasite problems which are of 

 considerable concern to fish management and which may 

 require special research and/or control action. 



PRODUCTIVITY UNIT 



After ten years of application, a re-evaluation of the 

 morphoedaphic index is underway. This index was devised 

 as a convenient method of estimating fish yield from a 

 broad range of lakes. The evaluation of the index, its 

 inherent significance, criteria for use and new information 

 pertaining to its validity was presented at a seminar at the 

 University of Toronto in January, 1972. 



TECHNICAL STUDIES UNIT 



PubUshed literature concerning a number of environmental 

 contaminants, including mercury, PcB's, heat, oil, D.D.T. 

 and copper, was assembled and assimilated. 



CO-OPERATIVE RESEARCH 



Co-operative research projects were conducted in conjunc- 

 tion with the following Universities: Toronto, Guelph, 

 York, Montreal and Waterloo, and with Royal MiHtary 

 College, Atomic Energy of Canada, Freshwater Institute 

 FRBandUN,FAO. 



FORESTRY SECTION 



Efforts are made to anticipate and work towards solution 

 of the major forestry problems of the Timber Management 

 and Environmental Protection Branches. Priorities and 

 preparation of long-term plans have been determined 

 co-operatively. Programs of the Section and of the Great 

 Lakes Forest Research Centre were reviewed by the 

 Canada-Ontario Joint Forestry Research Committee. 



SITE UNIT 



Research continues to deal with relationships between 

 environmental factors and productivity within ecosystems. 

 Older programs are being finalized with the publication of 

 landtype maps and a report on site classification. 



FOREST ECOLOGY UNIT 



Problem areas currently under consideration deal with 

 optimization of the growth and development of established 

 yellow birch regeneration, and with characterization of 

 sugar maple defect, especially with regard to factors which 

 regulate defect syndrome development. Preliminary studies 

 of defect development of hybrid poplar were initiated. 



ENVIRONMENTAL PHYSIOLOGY UNIT 



The main area of concentration is the determination of the 

 varying degrees of frost hardiness and dormancy of our 

 native coniferous species throughout the year, and the 

 development of methods to determine these conditions. 



TREE BREEDING UNIT 



Work concentrated on two major projects: poplar breeding 

 and spruce breeding. New selections of hybrid poplars were 



made, and propagation initiated. Larger scale propagation 

 of previously selected hybrid poplar and native poplar 

 clones continued. Progress was made on the co-operative 

 poplar pulpwood production project, and a new co-opera- 

 tive project for aspen veneer production was initiated. The 

 spruce program to produce genetically superior trees 

 through breeding, hybridization, selection and vegetative 

 propagation continues, and active work has started on seed 

 orchards. 



SEED UNIT 



Seed characteristics, seed source and seed production are 

 the three main fields being examined by the Unit. The aims 

 are to determine seed factors which contribute to better 

 survival, rapid establishment of seedlings, and subsequent 

 growth and yield, and to determine the best management 

 systems for seed production areas. 



TREE NUTRITION UNIT 



Growth changes and foliar nutrient levels were recorded in 

 a number of experiments with red pine and sugar maple. 

 Foliar nutrient levels were measured in aspen, hybrid 

 Cottonwood and white spruce — the latter in relation to the 

 possibiUty of increasing seed production through 

 fertilization. 



FORESTRY ECONOMICS UNIT 



This program is concerned primarily with the extension of 

 services internally to other units, and externally to industry 

 and other agencies, both federal and provincial. It aims at 

 assembling, analysing and developing economic information 

 which may be combined with biological findings in 

 subsequent practical implementation. 



MENSURATION UNIT 



Data were collated from field experiments for the 

 preparation of growth and yield tables for poplar, red pine, 

 white spruce and southern hardwoods. 



FIRE CONTROL UNIT 



A program was initiated to evaluate forest fire suppressants 

 and retardants and methods of their application. Methods 

 of assessment and test procedures were developed for 

 various wetting and viscous agents used for forest fire 

 control. 



MIDHURST RESEARCH UNIT 



This Unit is now well established at Midhurst Forest 

 Nursery with an outplanting area in Vespra Township. 

 Plantings were established at Vespra, Larose Forest and at 

 locations in Parry Sound and Pembroke districts. 



SOUTHWESTERN FOREST UNIT 



The Unit is developing methods of establishing the clones 

 and progeny of high quality, fast growing, hardwood 

 phenotypes of several selected tree species in plantations on 

 a variety of lowland and upland sites. Emphasis is being 

 placed on the selection of multi-purpose species which will 

 not only satisfy the wood requirements, but also serve a 

 wide range of environmental functions, such as water and 

 soil conservation, protection of native plant ecosystems, 

 establishment of favourable wildlife habitats, and improving 

 the aesthetics of impoverished forest sites. 



SOUTH-CENTRAL FOREST UNIT 



Work was continued collecting growth data from hard 

 maple and other associated species in order to predict 

 better the response of trees in a variety of stand conditions 

 to different intensities of cuttings. 



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