It’s no happy accident the Amazon rain forest has so many fruit and nut trees. According to a new study, 20 different species of fruit and nut trees originally cultivated by green–thumbed Amazon inhabitants over 8,000 years ago make up large parts of the region today.
The study grew out of previous research from 2013, when researchers from the Naturalis Biodiversity Center in the Netherlands performed a survey of forest plots dotting the Amazon. They discovered that half of the Amazon’s trees represented just 1.4% of the total number of native species in the Amazon. In other words, of approximately 16,000 Amazonian tree species, only 227 of these species accounted for half of all trees. The new study found that of those 227 species, 85 of them had physical traits indicative of full or partial domestication by native Amazonians before the Europeans arrived.
The team studied plant remains and DNA, finding that domestication likely started over 8,000 years ago. They also found that 20 domesticated fruit and nut tree species are the dominant trees in their respective regions, which is five times more than the number expected from nature taking its course.
Domesticated trees were most abundant near rivers and archaeological sites– places where ancient people would have gathered. The research team discovered this by overlaying data from the 2013 forest surveys on a map of over 3,000 Amazonian archaeological sites. They then analyzed forest composition at different distances from the sites, resulting in the first picture of how the entire Amazon region was shaped by ancient farmers.
“In the beginning, it was not easy to see clear patterns for the whole Amazonia,” study coauthor Carolina Levis of the National Institute for Amazonian Research in Manaus, Brazil, told Fox News. “But when we analyzed the data within Amazonian regions, we rapidly identified some very interesting patterns about the relationship between domesticated plants and archaeological sites.”
According to Levis, the periphery of the Amazon basin is where the domesticated plants originated, and from there spread to other regions via boat.
“The rivers were the roads [for] past societies,” she said, “[and] many seeds and clones were disseminated and exchanged with other societies. For example, cocoa trees native to western Amazonia were taken to Central America by past human societies, where seeds were used to produce a stimulant drink called chocolate.”
The team believes that Portugese and Spanish voyagers exploited these already–cultivated cocoa trees to establish their own plantations in Southwestern Amazonia back in the 17th century. When the Europeans arrived in South America, the Amazon was populated with countless tribes of highly–skilled farmers. Some of the larger tribes, such as the Arawak, were skilled and developed enough to intentionally alter some Amazonian forests.
“At the time of European conquest, there were probably between 8 and 10 million people in Amazonia, speaking at least 400 different languages, if not twice that,” study co–author Charles Roland Clement said. “This makes it difficult to say who was responsible for a given piece of pottery at a given archaeological site and archaeologists are consequently cautious about affirming who was where. Nonetheless, there is good evidence that 3 language families were (and still are) very abundant and were wide spread.”
The Arawak were the largest of these families. Tupi were the second largest group, followed by the Carib. There were also countless other tribes scattered across the Amazon, who these larger groups would have traded seeds with.
“There also were at least 6, maybe 10 language groups with intermediate numbers and distributions,” Clement explained. “Then there were hundreds of isolated, small language groups. As a general tendency, the major language groups occupied the major rivers, the intermediate groups smaller rivers, and the isolates even smaller rivers.”
The team is currently planning on working to associate specific kinds of domesticated forests with specific languages for a future report.
Their current study can be found in the March 3rd edition of the online journal Science.