Silvicultrue in Canada 21 



Hence, early attention should be given to finding out the best 

 materials and methods of planting. 



The Jack Pine Problem 



Large areas of sandy soils are covered with a dense growth of 

 pure Jack pine, standing so dense that each tree has little chance 

 for development, hence the individual development is extremely 

 slow. By reducing the number per acre, i. e. by thinning, as it is 

 technically called, the remaining stand can be given opportunity 

 for better development. 



The problem is to find out at what time of the life of the stand 

 to thin and how many trees to the acre promise the most satis- 

 factory result. 



The most valuable use of the Jack pine is for railroad ties, and 

 it would, therefore, be desirable to grow tie trees. For this pur- 

 pose, there is no need of freedom from knots, hence branchiness 

 is no objection, and the increase in increment due to fully devel- 

 oped crowns that can develop in open stand may be secured with- 

 out injuring quality. That means an early and severe opening 

 up is indicated, only taking care not to expose the soil too much 

 at a time. 



The Jack pine is a rapid grower when young, but not persistent, 

 hence this tendency should be utilized by giving it a chance to 

 develop its rapid rate early. This may, perhaps, be done by 

 reducing the number in the stand early to say, 300 or 400 trees 

 per acre or perhaps even less. 



The narrow-minded manager will object that the operation 

 would not pay because, perhaps, he could not dispose of the 

 material coming from the thinnings profitably, but if it could be 

 shown that instead of having to wait 80 to 90 years for a 5-tie 

 tree to develop, a full crop of railroad ties, 1500 to the acre, could 

 be produced in 40 to 50 years, the profitableness of the operation 

 might justify its inauguration even without the possibility of 

 disposal of the thinnings. Experiments, then, for determining 

 the most satisfactory density of these stands should be under- 

 taken at once. 



The possibility of shortening the time of production of sizeable 

 materials by a rational thinning practice has even in Germany 

 been fully realized only dtuing the last 30 years, and now, not only 

 are from 25 to 50 and more per cent of the final harvest crop 



