Geography and Environment

 

                                                                      General

 

1. The core of the Central Andean Culture Area encompasses roughly the central third of the western portion of South America, although at certain times other regions to the north and south were brought politically and economically within its sphere.

 

2.  This area comprises modern Peru and Bolivia between 4 Degrees and 18 Degrees South of the Equator (roughly 1000 miles N-S), and extends from the eastern Andean slopes to the Pacific Ocean (roughly 200 miles E-W). The area is circumscribed by the ocean in the west by equatorial rain forest to the north and east and by the Atacama Desert to the south.

 

3.  This entire region except the in the extreme east falls within the Pacific climatic zone.  It is consequently much dryer in general than the equatorial forest regions to the east, and encompasses a very different ecological pattern

 

4.  In terms of human settlement, there is a greater tendency toward permanently-sedentary, agricultural society than in the forests to the east where hunting and gathering remains strong and agriculture is of the more mobile “swidden” type.                               

 

5.  The central Andean area is one of great contrasts.  Moving inland from the Pacific shoreline, zones of coastal desert, highland, and forest run from north to south down the western side of the South American continent, all within a 200 mile E-W span.   This overall pattern brings with it extreme contrasts of heat and cold, rainfall and altitude, thus creating a great diversity of ecological zones in a relatively small area.

 

6.  Compounding the dramatic volatility of the area, the Andes constitute one of the most active tectonic zones in the world and earthquakes, tidal waves, and volcanic eruptions all occur fairly frequently.

 

7.  These general factors play important roles in shaping the physical (subsistence, settlement, technical) and mental (political, religious) domains of Andean people’s   experience.  

 

 

                                                                         Specific

 

                                                                 Coastal Ecology

 

Coastal shores 

The coastal environment is formed by the conjunction of two forces – oceanic and terrestrial.

The cold inshore current the Humboldt Current washes the western side of the continent with its greatest effect along the Peruvian coast.  In conjunction with the prevailing climatic and topographic conditions this plays a major role in shaping the distinctive coastal environment.

 

1.  The Humboldt Current removes the warm inshore water and allows its replacement by upwelling of cold water from the deeper ocean.

2.  The cold water carries nutrients to the surface (especially phosphates and nitrates).

3.  These nutrients feed vast quantities of microscopic marine plants and organisms.

4.  These in turn feed small fish, especially anchovy.

5.  Larger fowl, fish, and sea mammals feed on the smaller animals creating one of the most abundant marine resources in the world.

6.  Finally Man exploits the entire food chain.

 

Inland coastal desert

1.  Warm southern trade winds blow over the cold Humboldt Current, causing condensation and dense clouds.

2.  The wind blows the clouds over the warm equatorial landmass whose heat causes the air to expand and hold the large moisture content until the clouds hit the high western facing slopes of the Andes Mountains, where they precipitate rain.

3.  However, there is no rain along the level coastal plains.  These constitute one of the most arid deserts in the world.

4.  The rain runs back down to the coast in the form of numerous coastal rivers that traverse the coastal desert.

5.  Thus the coast presents a distinctive combination of small but extremely fertile river valleys separated by wide stretches of desert.

6.  At times of El Nińo this normal climatic regime reverses, the cold ocean current recedes, the normal marine fauna are displaced, and the coastal climate becomes rainy leading to catastrophic floods and great damage to the economic and social infrastructure.

 

Coastal Diversity

1.  Within this coastal pattern there is diversity with coastal valleys in the north being larger and closer together and supporting greater irrigation agriculture potential and population intensity than in the south where valleys are more widely separated, indented and carry less water.

2.  This provides greater northern potential for:

- agricultural development.

- population.

-economic integration.

- political integration.

3.  Consequently the North Coast of Peru was one of the two centers of pre-European cultural and social florescence.

 

 

                                                             Highland Ecology

 

General

1.  The Andes Mountains run N-S in two parallel ranges with altitudes commonly exceeding 20.000 ft, enclosing intermountain basins and high altitude river valleys that commonly reach 10-12,000 feet of altitude.

2.  There is consistent rainfall permitting rain-fed agriculture throughout the Andes

3.  The steep slopes necessitate terracing to prevent soil erosion.

 

 

The Vertical Archipelago

1. Andean highland life was conditioned by dramatically diverse climates and topography.

2.  In order to obtain the full range of nutrients highlanders had to control various altitudinal zones, each producing a different set of crops and each with a distinct set of settlement qualities.

3.  Thus highlanders developed a way of life that extended their social as well as economic control over various zones extending across the entire sloes of the Andes from lowlands river valleys to high grassy plains of the altiplano where only specialized tubers grew and llama and alpaca herding was possible.               

4.  We will discuss the specific strategies used in this “archipelago” ecological adaptation in later lectures.

 

Highland Diversity

1.  In the north the mountains were of lesser height, received more rainfall and were broken by transverse ranges, making communication and integration difficult.

2. In the far south in the Titicaca Basin the two Andean ranges opened into a huge high grassland plain – the altiplano.  This region of southern Peru and adjacent Bolivia constituted a uniform environmental zone.  People of this region developed specialized subsistence, economic and political strategies shaped by the vertical archipelago to construct elaborate social and political integration.

3.  Thus the southern altiplano represented the second great center of Andean civilization.