20 



FORESTRY BRANCH BULLETIN NO. 33 



In pine stands, where the average diameter is usually smaller than in spruce 

 stands, there is ordinarily left a larger number of trees. However, . a uniform 

 result over the whole area of a pine stand is usually unfavourable, no matter what 

 proportion of the trees are left. Pine reproduction is obtained most favourably on 

 ground entirely cleared, while under the shade of a fairly dense cover of trees it is 

 difficult for the seedlings to develop, and surface conditions are not usually favourable 

 to the germination of the seeds. Where logging opens up the stand sufficiently to 

 make conditions favourable to reproduction, if the area opened up is a large one, 

 there will be effective distribution of seed only at the edges. In the centre of the 

 area itself, which is out of reach of the seed that may be supplied by the trees at 

 the edge, the trees left are too few to furnish the requisite amount of seed, and they 



Photo T. W. Dwight. 

 Plate 5 Logged-over area showing Spruce and Pine Seed-trees. 



are exposed to wind-fall and sun-scald. When enough trees are left to make sure of 

 plenty of seed being distributed over the entire area and to avoid any serious wind- 

 fall, there is too much shade on the ground for proper development of young growth, 

 and the ground cover is too little disturbed by the logging operations to give oppor- 

 tunity for the germination of a sufficient number of seeds. The only favourable 

 middle ground is where fairly dense groups or small stands are left distributed 

 in heavily cleared areas. This result may be obtained in stands where the average 

 diameter varies considerably from one part of the stand to another, but actually 

 is procured on only a small proportion of the cut-over areas. 



The effect of logging on the condition of the surface of the ground is important. 

 Of advantage to both spruce and pine is the exposure of bare soil resulting from the 

 uprooting of trees and dry stubs during felling, from the skidding of the logs and 

 from the construction of roads and trails. Of more particular interest to spruce, 

 since pine seeds germinate with difficulty on any kind of covering over the soil, is 



