Toward the northern edge the trees grow farther apart, with 

 grasses, mosses and shrubs covering the ground between the trees. 

 The forests have a parklike appearance. Farther north there are 

 still fewer trees. Some of the trees such as the spruce, birch, and 



S E A 



\^ 



+ 



X) 



^ 



qS^, 



c^t 



&^ 



t>^ 



Figure 2-5. — The treeline. 



fir become dwarfed and stunted. More of the area is covered by 

 shrubs and thickets of willows and alders, especially the margins 

 along the rivers and lakes. North of the limits of true forest 

 growth these thickets of arctic willows and birches found in the 

 lowlands make summer overland travel very difficult. Farther 

 north these tangled masses of undergrowth die out, and are re- 

 placed by mosses and lichens. 



28 



