CLIMATOLOGY OF THE PERUVIAN ANDES 149 



lar development of the cold timber line. It also permits the full 

 use of the pasture belt above the timber (Fig. 97), hence perma- 

 nent habitations exist but little below the snowline and a group 

 of distinctive high-mountain folk enjoys a wide distribution. 

 There is a seasonal migration here, but it is not wholesale ; there 

 are pastures snow-covered in the southern winter, but, instead of 

 the complete winter burial of the Alpine meadows of our western 

 mountains, we have here only a buried upper fringe. All the rest 

 of the pasture belt is open for stock the year round. 



This climatic distinction between the lofty grazing lands of the 

 tropics and those of the temperate zones is far-reaching. Our 

 mountain forests are not utilized from above but from below. 

 Furthermore, the chief ways of communication lead around our 

 forests, or, if through them, only for the purpose of putting one 

 population group in closer touch with another. In the Peruvian 

 Andes the largest population groups live above the forest, not be- 

 low it or within it. It must be and is exploited from above. 



Hence railways to the eastern valleys of Peru have two chief 

 objects, (1) to get the plantation product to the dense populations 

 above the forest and (2) to bring timber from the montana to the 

 treeless plateau. The mountain prospector is always near a habi- 

 tation ; the rubber prospector goes down into the forested valleys 

 and plains far from habitations. The forest separates the naviga- 

 ble streams from the chief towns of the plateau ; it does not lead 

 down to rich and densely populated valley floors. 



Students in eastern Peru should find it a little difficult to 

 understand poetical allusions to silent and lonely highlands in con- 

 trast to the busy life of the valleys. To them Shelley's descrip- 

 tion of the view from the Euganean Hills of northern Italy, 



" Beneath is spread like a green sea 

 The waveless plain of Lombardy, . . . 

 Islanded by cities fair," 



might well seem to refer to a world that is upside down. 



There is much variation in the forest types between the moun- 

 tains and the plains. At the top of the forest zone the warm 



