A new study has shown that tree species domesticated and distributed throughout the Amazon basin by indigenous peoples before 1492 continue to play an important role in modern-day forests. These new findings strongly refute the idea that Amazonian forests have been largely untouched by humans.
Published in the journal Science, the study has been developed by an international team of ecologists and social scientists, including a researcher from The University of Nottingham.
It was led by Carolina Levis, a PhD candidate at Brazil's National Institute for Amazonian Research (INPA) and Wageningen University and Research Center in the Netherlands. She said: "For many years, ecological studies ignored the influence of pre-Colombian peoples on the forests we see today. We found that a quarter of Amazonia's domesticated species are widely distributed in the basin and dominate large expanses of forest. These results clearly indicate that the Amazonian flora is in part a surviving heritage of its past inhabitants."
The team made the discovery by overlaying data from more than 1,000 forest surveys of the Amazon Tree Diversity Network, including some supplied by Dr Geertje van der Heijden, Anne Mclaren Fellow in the School of Geography, on a map of more than 3,000 archaeological sites across the Amazon.
By comparing forest composition at varying distances from archaeological sites, their analysis generated the first Amazon-wide picture of how pre-Colombian peoples influenced Amazonian biodiversity.
The study focused on 85 tree species known to have been domesticated by Amazonian peoples for food, shelter, or other uses over the last several thousand years. Researchers found that throughout the Amazon basin these species were five times more likely to be common in tree surveys than non-domesticated species. Domesticated species were also found to be more common and more diverse in forests closer to archaeological sites. These 85 domesticated trees include well-known commercial species, such as cacao, açaí and Brazil nut.
Hans ter Steege, Coordinator of the Amazon Tree Diversity Network, said: "This finding promises to heat up a long-simmering debate among scientists about how thousands of years of human occupation in the Amazon basin have influenced modern-day patterns of Amazonian biodiversity, and challenges the view many of us ecologists had and still have of this huge area."
Posted on Friday 3rd March 2017