Ancient Amazonians lived sustainably – and this matters for conservation today
Our colleague, the archaeologist Santiago Rivas, recently made a remarkable discovery. On a small plateau above the outskirts of Iquitos, a town in the northern Peruvian Amazon, he found a layer in the soil which contained small pieces of ceramic pottery, that were around 1,800-years-old. Digging deeper, he found another layer of soil, this time containing pottery that was about 2,500 years old.
This is the archaeological site at Quistococha which has been occupied for at least the past 3,000 years. The pottery fragments are beautifully decorated, sometimes with subtle geometric scratch marks or boldly painted with bright red patterns. Not all of the fragments are small: erosion revealed the rim of a large cooking pot that would have been 40cm across when it was intact. Large pots were supported on an open fire by "elephant feet": small clay pot rests also found in the archaeological layers.
As a place for people to live, Quistococha would have had many advantages. It is located on a terrace above a fertile floodplain of the Amazon which is ideal for growing maize, while the surrounding palm swamp provides fruits and fibres. Just below the terrace, fresh water flows out of a spring.
Researchers know that indigenous communities have had profound and complex relationships with Amazonian forest landscapes for thousands of years. However, it is still far from clear just how much deforestation took place before European colonisation in the 16th century.
Quistococha is an ideal place to search for answers – and we recently published a research article based on our work there. The site has an unusually good record of past environmental change thanks to a nearby floodplain lake and swamp. These preserve the remains of plants that grew there, and the charcoal from fires lit by people – both in the prehistoric period as well as during the expansion of Iquitos over the past two centuries. This combination allowed us to explore the relationship between ancient people and the extent of the surrounding forest.
Charcoal in the sediment core from the nearby lake – an indicator of fire use – was abundant from about 2,500 years ago until the 1800s: people were, therefore, continuously present at that time. However fossil pollen from smaller trees that make up "secondary forest" growing on deforested land only became abundant over the past 150 years, when the nearby city expanded. Prior to that, for thousands of years, indigenous communities apparently had little impact on forest cover.
Such new knowledge about ancient Amazonians is highly relevant for conservation today. For indigenous groups it provides historical context to their fight for land rights and recognition. Studies like ours also show that traditional uses of the landscape should be valued highly, and that Amazonian communities can support themselves without extensive deforestation. This philosophy is the basis for the work of our partners, the Instituto de Investigaciones de la Amazonia Peruana (IIAP), which promotes sustainable management of these floodplain forests. Last but not least, these discoveries are an opportunity to engage with the expanding urban populations of Amazonia: an important voice in the decision-making process.
Iquitos is the largest city in the world not connected to a national road network. Recently, the Peruvian Congress has declared an ambitious range of road building projects in Amazonia as national priorities. The planned connection between Iquitos and the rest of Peru promises lower prices for food and other imports.
But activists who warn of the adverse consequences of poorly planned development are struggling to be heard. The new road would represent a "first-cut" through indigenous territories and the most diverse and carbon-rich forests of Amazonia. And as these are issues of low importance to the urban majority, the only way to challenge it would be by engaging city dwellers in debates about the implications of future transport networks and of other options for land use.
Locals and tourists alike throng to Quistococha on hot weekends to swim in the lake and relax in waterside cafes. Above and in sight of all of them, but now silent, there is a site that records thousands of years of humans living in a continuously forested landscape. The landscape and the stories it tells are an opportunity to reflect on how we might choose to continue the relationship between people and forests in the future.