Life Zones 179 



be covered by rain forest and the summit by snow. As you climb 

 upward you emerge from the dense vegetation of the tropical forest 

 and pass progressively through life zones of savannah, deciduous 

 forest, and coniferous forest. Higher up you reach a belt of dwarf 

 pine, fir and alder. Above this a life zone of grasses, lichens, and 

 mosses exists, corresponding to the tundra and giving way finally to 



TABLE 13 



Outline of Plant Communities in the Uinta Basin and Their Relation 

 TO Altitudinal Life Zones (Graham, 1937) 



bare rocks, snow, and ice. Altitudinal zonation on the slopes of 

 mountains in the temperate region is often equally striking but may 

 not be as extensive. The report by Graham (1937) of the Uinta 

 Basin of Utah and Colorado contains a detailed study of the life zones 

 at different altitudes with many excellent photographs of representa- 

 tive plant communities ( Fig. 5.20 and Table 13 ) . 



