Canadian Forests 109 



great northern forest which unites them all. The grass 

 plains extend northward into Canada, dividing the eastern 

 and Rocky Mountain forests as far north as the Saskatche- 

 wan river, but the Rocky Mountain and the Pacific coast 

 belts are not so completely separated. The desert of the 

 south does not reach Canada, but there is a "dry belt" 

 in southern British Columbia, lying between the Selkirks 

 and the Coast Range, which is in reality an extension of 

 the southern desert. This dry belt is not by any means 

 an open plain, much less a desert, but growth is less 

 luxuriant than it is either east or west of it, and some tracts 

 are almost treeless. Then, too, some of the species found 

 there are not found in the regions of more abundant rain- 

 fall. In the northern part of the province this separation 

 disappears, and the two belts merge into one great forest 

 stretching from the Rocky Mountains to the coast. This 

 is perhaps the greatest and most valuable block of timber 

 in the northern hemisphere to-day. 



At the extreme northern edge of forest growth only 

 spruce and tamarack are to be found. An irregular line 

 drawn from Fort Churchill on Hudson Bay to the mouth 

 of the Mackenzie river, and a similar line from the east 

 side of the bay at the same latitude to Ungava Bay, mark 

 this most northern limit, and leave only a comparatively 

 small part of the continent west and north of Hudson Bay 

 which is quite treeless. Next to these hardiest species, 

 the tree which grows farthest north is the canoe birch, 

 followed closely by the poplar and the jack pine. The 

 forest does not become densely wooded until we reach the 



