Study: Amazonian Regions were Agricultural Landscapes Some 10,000 Years Ago

Far from being a rainforest and vast wilderness, certain Amazonian areas were cultivated by people for crop-growing. An international team of scientists has discovered that humans residing in remote regions of now present-day Bolivia were planting crops such as cassava, squash, and maize. Inhabitants also developed thousands of "forest islands" which are small mounds of lands, and where there is proof of plant cultivation.

One of the most relevant results of the end of the last ice age almost 12,000 years ago was a change in the lifestyles of early civilizations. Nomadic hunter-gatherers started to live permanently, and they cultivated plants for food. The Holocene epoch was a relatively warm period after the ice age that saw the increase in human activity.

Researchers have discovered evidence that early civilizations cultivated crops for food in four primary locations: China produced rice, grains were grown in the Middle East, maize in Central America and Mexico, and potatoes and quinoa in the Andes region. Scientists now claim that the Llanos de Moxos, the southwestern part of Amazonia, should be identified as the fifth.

This area in Amazonia is a savannah but is dotted with around 4,700 forest islands where humans once lived. These are raised areas of land that are now covered with trees, and approximately 70 meters in diameter. These areas are flooded during the year's rainy season, but these small mounds of land remain above the waters.

The region's inhabitants developed these small islands. The people would drop their rubbish in these areas, and over time they have grown, according to the lead author from the University of Bern - Switzerland, Dr. Umberto Lombard.

Waste is extremely rich in nutrients, and as these mounds grow, they slowly become higher than the flood level during the rainy months. These became excellent places to settle with fertile soil, so people come back to these areas most of the time.

Scientists have examined 30 of these forest islands to search for evidence of crop cultivation. They have discovered fragments of silica called phytoliths, which are little pieces of glass that develop inside plant cells. Depending on which plants they come from, the shape of the glass fragments varies.

The researchers were able to determine evidence of cassava, yucca, and squash more than 10,000 years ago, while maize appeared more recently, almost 7,000 years ago.

Dr. Lombardo said that this turned out as a surprise because people have always regarded Amazonia as a virgin, untouched forest. However, unearthed evidence proves that people were living in the region some 10,000 years ago, and these inhabitants practiced cultivation. Researchers also believe that people who lived at this period most probably ate sweet potatoes, peanuts, fish, and large herbivores for sustenance.

The researchers also believe that their study is an illustration of the global impact of environmental changes, particularly the warming up of the world at the culmination of the last ice age.

This study confirms once more that domestication and plant cultivation began at the onset of the Holocene period, where a pivotal change in world climates and temperatures started, and where the ice age ended.