2. Application of Dybar granular soil sterilant to clear planting sites of 

 undesirable scrub trees and shrubs. 



Sap and syrup studies were continued. In the past year, particular attention 

 was given to the investigation of sap concentrations and syrup quality of five maple 

 species. Examinations were made to determine relations of site, thinning and genetic 

 differences. 



Southeastern Unit 



The Southeastern Unit is primarily concerned with the ecology of the tolerant 

 hardwood association, especially with the treatment of cut-over stands to improve 

 the quality of growing stock. The principal projects are prescribed burning and 

 the silvics of basswood. 



PRESCRIBED BURNING 



The purpose of this project is to determine the effects of burning on hardwood 

 regeneration and subsequent growth, related especially to yellow birch and hard 

 maple. Reduction of competition and seed-bed preparation are intended to produce 

 the desired results. 



Experiments in several areas during the past few years are revealing the 

 advantages and disadvantages between spring and fall burns, the number of 

 repetitions necessary and the length of time required for reaction. 



In one study area, planned for five successive fall fires, the 1965 burn was 

 not completed because of the weather conditions. 



In addition, a spring burn scheduled for 1965 was not made because of 

 insufficient fuel. In this case, previous fires had reduced the litter by causing 

 mortality to the standing trees. 



Burns on other study plots in the same area were not as successful as in 

 previous years due to adverse weather conditions. 



BASSWOOD 



A study of the silvicultural characteristics was started in 1962 to up-grade 

 the composition of hardwood stands, by studies of seed characteristics and planting 

 of nursery-grown basswood in clear-cut tolerant hardwood stands. 



The first stage of the studies, which was concerned with seed problems — fruit 

 collection, storage and germination — was completed in 1964. 



To the end of 1965 the survival rate of the basswood has been 93%. This 

 stock was supplied by the Provincial Nurseries, and planted in the Tweed District. 



Observations are continuing to determine the advantage of root-pruning and 

 top-pruning on the survival of planted stock. 



FROST-HARDINESS STUDIES 



The Southeastern Unit undertook a pilot study of the frost hardiness of tubed 

 seedlings — red pine, white pine, jack pine, black spruce and white spruce. More 

 advanced studies are planned for 1966. 



Tubed Seedlings 



The Research Branch carried out a series of trials in the winter of 1965-66 

 to develop techniques for a large-scale programme of growing and planting 



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