There may be more than 10,000 undiscovered pre-Columbian sites in the Amazon basin, research suggests, highlighting the profound impact ancient societies had on the region's ecology and underlining the need for its conservation and sustainable management. A new study estimates that more than 10,000 pre-Columbian archaeological sites remain undiscovered across the Amazon. This study uses remote sensing data and predictive spatial modeling to reveal the potential impact of early societies on the Amazon.
"The vast number of archaeological sites and extensive human-modified forests in the Amazon are critical to accurately understanding the interactions between human society, the Amazon forest, and Earth's climate," the authors write.
For more than 12,000 years, indigenous societies have called the Amazon their home, creating ancient earth and stone structures and domesticated landscapes that have had a long-lasting impact on the makeup of modern forests. However, little is known about the scale and scale of settlement and landscape transformation in the Amazon - these sites are remote and often obscured by dense vegetation. As a result, pre-Columbian sites throughout the Amazon basin have never been comprehensively surveyed.
Airborne lidar (light detection and ranging), a remote sensing technology that can map subtle changes in surface topography beneath forest canopies, has been used to uncover many previously unknown pre-Columbian structures and earthworks at heavily forested sites in Central and South America.
Here, Vinicius Peripato and colleagues searched 5,315 square kilometers of lidar survey data and discovered 24 unreported human-made earthworks across the Amazon Basin, including fortified villages, defensive and ritual buildings, mountaintop settlements, and other landscape features. However, lidar survey data only covers 0.08% of the total area of the Amazon.
To better understand where and how numerous undocumented pre-Columbian sites might be, Peripato et al. combined data from their small basin-wide survey, as well as data from other previously discovered sites, with a predictive spatial distribution model. According to the model, between 10,272 and 23,648 large pre-Columbian structures remain to be discovered, especially in the southwestern Amazon.
Additionally, the authors determined the relationship between predicted probabilities of earthworks and the occurrence and abundance of domesticated tree species and found significant correlations, suggesting that active pre-Columbian indigenous forest management practices had long shaped the ecology of modern forests in the Amazon. "The Amazon forest is clearly worth protecting not only for its ecological and environmental value, but also for its high archaeological, social and biocultural value, which can teach modern societies how to sustainably manage natural resources," Peripato et al wrote.
Reference: "More than 10,000 pre-Columbian earthworks still hidden throughout the Amazon"
DOI:10.1126/science.ade2541
Compiled source: ScitechDaily