Altitudinal Zonation

Applied primarily in Latin America, this term refers to the differentiation of distinct environmental regions characterized by specialized agricultural production, based on elevation. Each elevation layer or “zone” is marked by a unique, or nearly unique, set of agricultural products suited to the growing conditions at that particular altitude. This structure is most pronounced in countries in the Caribbean, Central America, and tropical South America where the local topography is characterized by coastal lowlands that rise abruptly into mountainous regions in the interior. The various zones of production are typically referred to by the Spanish terms tierra caliente (hot land), tierra templada (temperate land), tierra fria (cold land), and, if the elevation reaches above 12,000 feet, teirra helada (frozen land). Some scholars identify yet another zone in Andean South America, the tierra nevada, which stretches from roughly 15,000 feet to higher elevations, and which is generally unoccupied by humans.

The tierra caliente is located between sea level and approximately 3,000 feet in elevation. It experiences warm, humid temperatures year round, and frequently receives abundant rainfall, in some places exceeding 60 inches a year. Naturally occurring vegetation in this region is typically tropical rainforest, or in somewhat drier areas, tropical savanna. Population densities here are typically high where the land is being cultivated. The climate provides an ideal setting for the commercial production of tropical specialty crops, many of which are exported northward to the large North American market. Bananas, sugar cane, tobacco, various tropical fruits, including mangoes, papaya, plantains, and others are raised on large plantations, as well as various staple crops such as wetland rice and corn. Within the zone there is some altitudinal layering as well: bananas, rice, and sugar are raised in the lower elevations, while tobacco, corn, and sometimes coffee are planted on the higher reaches of the slopes. In areas where the soils are less productive or there is insufficient rainfall to support the plantation crops, commercial livestock, primarily cattle and pigs, are raised. The tierra caliente is a region of intensive cultivation in most instances, and for some countries, especially Caribbean islands that lie at lower elevations and that depend largely on the production of a single crop (sugar cane in Haiti, for example), represents the only commercial agricultural region.