Though the Pacific Ocean provides food from plant life in the sea, fish, birds, and sea mammals, on land, the coast is a desert-like climate where it is difficult to grow food. The Andes are high, rugged mountains, that have cold snow capped peaks, as well as fertile river valleys, and plateaus that are good for agriculture. Although, prone to earthquakes living in the mountains can be unpredictable. 

The rainforest in the Amazon River Basin is a humid place with this vegetation. It is good for growing tropical crops, but large-scale agriculture is difficult in the rainforest.

This system, called a “vertical economy,” has many advantages in the harsh Andean climate. First, it gives a community access to a wide variety of foods and other products. Second, it protects them against the impact of harsh and unpredictable weather conditions—if frost or drought destroys the crop at one elevation, the community can fall back on the harvest in another ecological niche. Andean farmers also plant several (sometimes dozens) of varieties of one crop like potatoes in a single field so that at least some plants will survive the season’s unpredictable temperature and rainfall.