Over 10,000 Years Ago, Ancient Humans Created Forest Islands In Amazonia Grasslands

• Photos taken by Umberto Lombardo, a geographer from the University of Bern, showed forest islands littered across the savannah of Amazonia.
• A new study proves that these forest islands were not wild, but were cultivated by early humans.
• Evidence of human settlement, including burned clay, food scraps, and burial sites were found in 4,700 of the 6,643 forest islands.
• They also mapped them out using Google Earth based on the aerial shots taken by Lombardo.

Researchers revealed that 10,800 years ago, early humans cultivated crops and planted trees in the Amazonia grasslands, as proven by the strange mounds of forest islands photographed in the Llanos de Moxos region in South America.

The photos were taken by Umberto Lombardo, a geographer from the University of Bern in Switzerland. They showed aerial views of the vast savannah littered with tree-covered mounds along the Andes Mountains and the Amazon rainforest in northern Bolivia.

“They are like islands in a sea of savannah,” says Lombardo, author of a study published in the May issue of Nature. He said that he was puzzled about the tree-filled islands since he first came in 2006 because grassland regions are typically wet, low-lying areas filled with swamp grasses, sedges, bunchgrass, or carpet grasses.

One theory suggested that ranchers carved away at some portions of rainforest and created pastures over the past few centuries. However, experts were at a loss about why the trees, which were supposed to be remnants of a once-existing rainforest, were on higher grounds.

Because of the unusual plant terrain, Lombardo and his colleagues pieced together a theory that these forest islands were human-made. Their study put these Amazonia forest islands as domesticated plots that are almost as old as the oldest known domesticated plants in the Middle East 12,000 years ago.

Along with Lombardo, José M. Capriles, study co-author and archaeologist at Penn State launched excavations in 2012. Together, they probed and found archaeological debris made by ancient people in 64 of the 82 mounds they tested. Three of the mounds also housed debris from burned clay, food scraps, and human burials between 2,300 to 10,800 years old.

Professor Jose Iriarte from the University of Exeter and one of the study authors, said:

Genetic and archaeological evidence suggests there were at least four areas of the world where humans domesticated plants around 11,000 years ago.

This research helps us to prove South West Amazonia is likely the fifth. The evidence we have found shows the earliest inhabitants of the area were not just tropical hunter-gatherers, but colonizers who cultivated plants. This opens the door to suggest that they already ate a mixed diet when they arrived in the region.”

Further probes also revealed that ancient humans cultivated crops and trees in the Amazonia grassland. In particular, Lombardo’s team found microscopic plant remains, proving that Amazonia was among the first places on Earth where people domesticated wild species.

They identified traces from the oldest-known crops like squash and tuber cassava in Amazonia. There were traces of a 7,000-year-old corn plant domesticated in Mexico 2,000 years earlier, proving that ancient people passed seeds from one community to another between Central and South America.

Using the aerial shots, Lombardo mapped all 6,643 forest islands, including the 4,700 that were found to be man-made ones, using Google Earth. He said the mapping felt like “a Zen activity” as he surfed and clicked at the map’s various points.

Based on their findings, scientists now believe south-western Amazonia to be the “fifth area” of the world where the earliest domestication of plants began, alongside China (rice), the Middle East (grains and pulses), Mesoamerica (maize, beans and squash) and the Andes (potatoes and quinoa).

Lombardo’s research suggested an 8,000-year gap between the start of cultivation and the full-blown agricultural developments in Amazonia. He plans to probe further to explain why the developments took more time in Amazonia than in other areas, which progressed within 1,000 years.