40 



FORESTRY BRANCH BULLETIN NO. 33 



comparatively unimportant. However, second-growth stands of spruce regularly 



show a minor proportion of alpine fir trees, since the conditions which result in 



spruce reproduction also favour alpine fir, although the latter species is at a dis- 

 advantage. 



WHITE SPRUCE. 



This species reaches the southwestern limit of its range on the east slope of the 

 Kockies. It is found mixed with Engelmann spruce at the lower elevations, and 

 does not usually ascend the higher slopes. It occurs, especially, in the larger river- 

 valleys and in the stands of spruce near the prairies. It forms but a small per- 

 centage of the large bodies of spruce timber and from a commercial or silvicul- 

 tural standpoint does not need to be distinguished from Engelmann spruce, as the 

 form and size of the tree, the quality of the timber, and the habits of growth and 

 reproduction do not differ to any practical extent. 



Photo A. Knevhtel. 

 Plate 11 Whitebark Pine (dwarfed by exposure to winds and frost' . 



LIMBER AND WHITE-BARK PINES. 



These two species of pine are found as scrubby trees on the poorest sites. 

 Owing to their infrequent production of cones and the difficulties involved in dis- 

 tinguishing them, the exact occurrence of the two species was not determined. It 

 is probable that white-bark pine alone occurs on the higher ridges in the mountains 

 proper, and that limber pine is mainly confined to the higher elevations in the foot- 

 hills. Neither species reaches merchantable size except occasionally, nor is of great 

 importance from the standpoint of forming a soil-cover on poor sites, since they 



