For researchers and historians, the Lost City of the Amazon continues to drive an intoxicating passion. This pre-Columbian archaeological site is located deep in the Upano River Valley of eastern Ecuador. A new study, led by Mark Bush from the Florida Institute of Technology and Crystal McMichael from the University of Amsterdam, reveals insights into the changing landscapes of this area, which is home to over 7,000 hidden structures buried beneath dense forests. This research provides a comprehensive examination of how human activity and climate change have shaped the region over the last 2,700 years.
Scientists retrieve sediment cores from Lake Cormorán to reveal the landscape’s transformation over time. Our study connects those changes to a sequence of human occupation and environmental change. These results directly counter long-held scientific theories on why the Upano civilization abandoned the area. Rather, they argue, the decline happened slowly over centuries, rather than quickly as a response to a volcanic ashfall event from the nearby Sangay volcano.
Insights from Lake Cormorán
To carry out their research, Bush and McMichael used a detailed analysis of microfossils recovered from sediment cores in Lake Cormorán. This approach yielded a rich chronological record showing the dynamic shifting environments of the Upano River Valley. Radio-carbon dating indicates that the Upano civilization had started to settle down in the valley by 750 B.C. Yet they flourished for more than 1,000 years before beginning a slow decline around A.D. 250. By A.D. 550, this urbanized civilization had entirely disappeared from the region.
“Our study provides an improved timeline of human activity in the valley, as we see people moving in and out of the landscape and different styles of cultivation coming and going,” – Mark Bush
The study finds that following the downfall of the Upano civilization, a second wave of settlers were arriving by around A.D. 1500. These colonizers developed a sophisticated agrarian lifestyle, including intensive cultivation of corn, until their abandonment of the region around A.D. 1800. The forest was left with a stunning legacy of unexpected recovery. It today features high, shaggy palms and an exotic landscape that hasn’t existed there for thousands of years.
The Role of Climate Change and Human Impact
These virgin forests in the vicinity of Lake Cormorán are now protected by Sangay National Park. This park has been at the forefront of this battle to preserve this spectacular ecological tapestry. Further, the researchers contend that climate change and anthropogenic effects have played important roles in determining how these contemporary forests were established. This has resulted in a landscape that has been as we know it for only about 200 years.
McMichael emphasizes the significance of understanding historical patterns to appreciate contemporary ecosystems:
“This work highlights the importance of looking into the past to understand the present,” – Crystal McMichael
This study’s findings serve as a reminder of just how destructive and impactful climatic shifts can be on our ecosystem. At the same time, anthropogenic activities have played a key role in shifting land use and vegetation patterns across Earth’s history.
Reassessing Historical Narratives
The new study challenges assumptions that have long been accepted about the reasons behind what is thought to be the abandonment of the Upano civilization. This perspective moves the focus from attributing the blame to one dramatic disaster. Rather, it focuses on the cumulative, often subtle, environmental and social changes that made their decline inevitable. This new perspective is changing the way archaeologists and historians have understood human habitation in the Amazon.
As researchers continue to explore these ancient landscapes, they uncover not only the remnants of civilizations long gone but valuable lessons on resilience and adaptation in the face of changing environmental conditions.