University of Colorado Boulder: Indigenous Fire Management Buffered Climate Impacts for Centuries

Devastating megafires are becoming more common, in part, because the planet is warming. But a new study led by Southern Methodist University and coauthored by CIRES suggests bringing “good fire” back to the United States and other wildfire-prone areas, as Native Americans once did, could potentially blunt the role of climate in triggering today’s wildfires.

The age-old Native American tradition of “cultural burning” appears to have previously weakened – though not entirely eliminated – the link between climate conditions and fire activity for roughly 400 years in the southwestern United States.

Studying a network of 4,824 fire-scarred trees in Arizona and New Mexico, where the Apache, Navajo and Jemez tribes lived, SMU fire anthropologist and study lead author Christopher Roos and other researchers found that the typical climate-fire pattern from 1500 to 1900 reflected one to three years of above-average rainfall – allowing vegetation to grow – followed by a fire-fueling year of significant drought.

But the pattern was broken when Native American tribes performed traditional burning practices, according to the group’s study published today in Science Advances.

The researchers compared tree-ring fire records with paleoclimate reconstructions and extensive information on Native American land-use patterns and practices. Scientists like paper coauthor Christopher Guiterman, CIRES researcher working in NCEI, rely on tree rings not only to calculate a tree’s age, but also to determine wet and dry weather patterns of moisture and drought. “Tree rings give us a wealth of information, including centuries of active fire activity,” said Guiterman.

“What’s remarkable is that this impact of Native American fire management was evident across hundreds of square kilometers,” said lead author Roos. “That is across entire mountain ranges.”

Roos said the findings suggest we can learn from Native Americans how to make our forests less vulnerable to fires we’re facing now. “Native American or Indigenous fire practices have shown us how people living in fire-prone places can positively coexist with wildfire in sustainable ways by actively engaging with it,” he said.