Native Americans were in New England for at least 14,000 years, but new research suggests their "ecological signal was essentially invisible," flipping our previous narratives about controlled fire burns and providing a possible blueprint for better land management in the region.
"We were a bit surprised by our results," lead author Wyatt Oswald, from Emerson College, told IFLScience. "The generally accepted view is that, before European colonization of New England, Native Americans cleared forests for agriculture and used fire to manage the landscape.
"This understanding of the past was popularized in the 1980s by William Cronon’s book Changes in the Land, and it has provided the rationale for using prescribed fire to manage open habitats on many conservation lands across southern New England."
However, their data reveals a different story – a landscape with old-growth, closed-canopy forests shaped largely by regional climate for eight millennia before Europeans arrived on the scene. They found a high level of fire activity between 10,000 and 8,000 years ago. After 8,000 years ago, when the climate became wetter and the modern forest composition became established, there was little fire on the landscape, even during peaks in human population. Around 400 years ago, the mature forests changed as deforestation, grazing by sheep and cattle, and the creation of pastoral landscapes became the norm.
"This paper is the first time that all of these sources of information are brought together in a way that is so comprehensive and mutually reinforcing," study author David Foster, director of the Harvard Forest, told IFLScience. "The way that the climate, vegetation, and cultural data agree in refuting the hypothesis of native burning, clearing and land management."
To reach this conclusion in Nature Sustainability, the team examined sediment cores from 21 lakes across southern New England, local pollen records, charcoal signals in lake cores, hydrology and archaeology data. They found Europeans set intentional and accidental fires, but other drivers of landscape change included tree-felling, animal grazing, mowing, and plowing. Prior to European arrival, significant use of human-set fire and forest clearance can’t be found.
"There’s a clear signal of European deforestation in the pollen records: pollen from tree species declines in abundance, while the pollen of weedy species, like ragweed, increases," said Oswald. The forests included species like beech in much greater abundance than seen after European settlement.
"Much to my surprise, we found that, even though we know that Native Americans were in New England for at least 14,000 years with, at certain times in history, fairly large population densities, the ecological signal was essentially invisible," said co-author Elizabeth Chilton, an archaeologist at Binghamton. "If one did not know there had been humans on the landscape, it would be almost impossible to detect them on a regional scale."
"These findings counter the prevailing theory that ancient humans had major ecological impacts on the landscapes in which they lived," added Oswald. "Our work should cause some New England conservationists to reconsider both their rationale and tools for land management."
To emulate pre-contact conditions, the team suggest land managers take advantage of the naturally reforested landscape, de-emphasize the role of human disturbance, and also anticipate climate-driven change. To maintain open-land habitats, colonial-era agricultural approaches should be applied, including grazing, mowing, and cutting woody vegetation.
The results may strike some as unusual. "What is so surprising to me now is the intense resistance to our results in many circles," said Foster. "In the absence of any contradictory archaeological or paleoecological data people continue to argue for active burning and open landscapes, claiming that our records miss the relevant evidence. But, where is the supporting evidence?"
"I want to underscore that Native peoples had and continue to have a rich and complex relationship with the land in New England and elsewhere," said Chilton to IFLScience. "The fact that we do not see a pre-European large-scale use of burning and clear cutting does not undermine either that complexity or the antiquity of their cultures and adaptations. Living in harmony with the environment does not imply a lack of sophistication or knowledge."