To date the observations substantiate the concept of the relationship between 

 growth rate and quahty wood production. The current work includes a study of 

 trees artificially wounded. 



A marking scheme giving emphasis to stand improvement, maintenance of 

 balanced stand structure and ease of application was tried with promising results. 



Red and White Pine and White Spruce. The objectives of this work is to 

 evaluate various techniques for establishing regeneration and improve the growth 

 of pine. This is an important species to the lumbering industry of the area. 



Sample data from an underplanting and release experiment using these species 

 show striking differences in height development after nine growing seasons. 

 Released red pine were 700 per cent taller than unreleased trees on a fresh site 

 and only 160 per cent taller on a dry site. Current height growth of released red 

 pine is 1,700 per cent greater than unreleased trees on the fresh site and only 180 

 per cent greater on the dry site. Similar trends exist for white pine and white spruce, 

 although they have developed more slowly than red pine. 



Remeasurement of thinned plots in a stand of red and white pine showed 

 that ten years after treatment, diameter increment was greatest on the larger residual 

 stems. Stand growth was greatest where large trees made up the highest proportion 

 of the stand after treatment. 



Tube-grown Seedlings. The objective of this work is to develop a fast, inex- 

 pensive method of reforestation which could be useful in extending the planting 

 season and to provide stock on short notice for planting after wildfires. A pilot 

 scale planting of ten thousand red pine was made on various sites in a first effort 

 to develop production techniques. 



SOUTH WESTERN FOREST RESEARCH UNIT 



The program in this region has been concerned mainly with the development 

 of those species that have been regenerated artificially. 



Silver Maple Culture. Silver maple (and eastern cottonwood) were established 

 successfully following spring and fall planting on a cut-over silver maple-elm swamp. 

 The average annual growth for both species at one and two years after establishment 

 was approximately 2 feet. Weed competition appeared to be the most serious 

 single factor in hindering growth and increasing mortality for both species. 



Eighteen, high quality, silver maple phenotypes were budded in August on 

 nursery stock at the Orono Nursery. The successfully budded trees will be propo- 

 gated asexually and eventually established in plantations in those silver maple-elm 

 swamps which are being devastated by the Dutch Elm Disease. 



Silvicultural Treatments. The studies on the effects of thinning and of weather 

 on diameter growth of hard maple, American basswood, white ash, silver maple, 

 bur oak and red pine as measured by the dendrometer tapes were continued at 

 bi-weekly intervals during the 1963 growing season. A report covering five years 

 of diameter growth will be published in 1964. Spacing and pruning effects on 

 height and diameter growth were also evaluated in a red pine plantation, as well 

 as the effects of shearing lateral shoots on the growth of the terminal shoots of 

 white pine, red pine and white spruce. 



Red oak were established with acorns in a white birch nurse crop on a dry 

 site at the Research Experimental Plantation in East Gwillimbury Township. Red 

 oak and hybrid poplar which had been planted under cultivated conditions, are 

 now being assessed as to the effects of cultivation and of protection against rabbits 

 and frost in relation to growth and survival. 



Herbicides and Soil Sterilants. The effects of eight herbicides and soil stcrilants 



253 



