Mechanical Section from plans published by other workers, for the direct deter- 

 mination of negative sap pressures (moisture stress) in the seedlings. The 

 introduction of this equipment promises to be of considerable value to the Ontario 

 programme of studies in water-tree growth relations. 



In the soil nutrient work, much of the effort in the past year was devoted to 

 the preparation of two papers summarizing investigations over the previous decade 

 concerning the calcium release from parent soil materials. In addition, laboratory 

 work was done for a variety of projects, such as: 



— Chemical and physical analyses of a number of soil samples from various 



sites for the Northeastern Forest Soils Conference. 

 — pH (acidity scale) ratings of soil samples required by a number of Districts 



for their tubed seedling programme. 

 — Chemical and physical analyses of a number of soils for the Reforestation 



Research Unit. 

 — Routine analyses were continued to provide additional quantitative data for 

 the Site Research programme in general. 



LAND PRODUCTIVITY RESEARCH 



The objective of land productivity research is to rate the potential of physio- 

 graphic land classes for various uses, such as the production of farm, timber and 

 wildlife crops and for recreational activities. 



This was the field of greatest activity of the members of the Site Unit during 

 1965-66. Much of the work was carried on in cooperation with the Canada Land 

 Inventory Program under ARDA (Agricultural Rehabilitation and Development 

 Act). Accordingly this programme has dual objectives, (i) the provision of infor- 

 mation for the land resource managers practising in Ontario, (ii) establishing 

 principles and methods for obtaining statistical data, such as the location and 

 acreages of land classes of varying potential for forestry, wildlife and recreation. 

 Seven classes are established independently for each type of land use. Two systems 

 are used, one to meet the requirements of the resource managers of Ontario and 

 the second to meet the more general requirements of a nation-wide inventory. 



Measurements of forest growth on specific physiographic site continued in 

 Southern and Northeastern Ontario. One of the Site staff spent most of the field 

 season measuring tolerant hardwood plots in Site Region 6E and in classifying 

 sites for the ARDA project in which Professor D. Love is directing a study of 

 economic production of red pine, white spruce and hard maple in southern Ontario. 

 Prof. Love and a Site member prepared a manuscript report of their joint findings. 



The leader of the Site Unit spent a considerable portion of the field season 

 in directing a pilot study to determine the significant physiographic features defining 

 the various levels of capability of shoreland, water, marsh and upland units for 

 specific types of recreation such as: 

 (i) Family bathing and group camping 

 (ii) Swimming, boating and other deep shore water activities 

 (iii) Lodging (cottages, lodges, etc.) 

 (iv) Viewing 

 (v) Skiing 

 (vi) Hunting 



This work was summarized in two reports entitled "Definition of Capability 

 Classes and Benchmark Sites for the Recreational Land Inventory" and "Ranking 

 the Recreational Potential of Land Units by Gradient Analysis" which have been 

 prepared in mimeographed form. 



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