cook: vegetation in southern peru 293 



the extent to which the presence of man has modified the original 

 conditions of the environment along the eastern slopes of the 

 Andes. 



AGRICULTURE AT HIGH ALTITUDES 



Corresponding with the wide range of altitude there is great 

 diversity in the forms and habits of the wild vegetation and in 

 the agricultural arts of the native inhabitants. In the lower 

 valleys where corn is the principal crop the method of clearing 

 the land and the relation of agriculture to the native vegetation 

 are much as in Central America. 



The high plateaus of Peru, where the native agricultural 

 population is now chiefly centered, are unlike any part of Central 

 America, the nearest approach being found in the tablelands 

 of Guatemala. In Central America cultivation is hardly carried 

 above 8000 feet; whereas in Peru potatoes and other Andine 

 crops are commonly grown at 13,000 feet and in some places at 

 14,000 feet. Moreover, it is in these elevated districts that the 

 native system of agriculture attained its highest development 

 and was least disturbed by the Spanish •' conquest. 



conclusions 



The native agriculture of southern Peru is self-limiting. 

 Cultivation may be maintained for longer periods on the table- 

 lands and higher slopes, but when the soil is once exhausted and 

 removed by erosion there is less prospect of renewal through 

 reforestation than at the lower elevations. Although under 

 the high altitude conditions the accumulation of soil goes on 

 to a certain extent in open grass lands, without the aid of forests, 

 such gains evidently do not make good the losses incidental to 

 cultivation. Large areas of the higher slopes that appear to 

 have been cultivated intensively in former times are now com- 

 pletely sterile and abandoned. 



Thus Peru may be said to afford even more striking evidence 

 than Central America of the fact that the primitive agricultural 

 civilizations were not permanent, but of limited duration. 

 Eventually the soil became unsuited to cultivation by the native 

 methods. 



