A new study of fire-scarred trees in the American Southwest has documented extensive fire management practices by Western Apache people that significantly reduced the climate’s influence on fire activity across their homeland and increased resiliency in their home ecosystems.

CIRES researcher Chris Guiterman worked with colleagues at other institutions to analyze 649 fire-scarred trees from pine forests in Western Apache traditional territory in Arizona. They looked for evidence of fires that occurred from 1600 to 1870 and compared the fire-scarred trees to several thousand unburned trees from the broader Southwest region. 

The findings show that despite being a small, mobile population, the Western Apache had significant control over fire patterns across the landscape at different times of the year, much more than scientists previously thought possible. Their burning practices improved foraging for game animals and enhanced wild plant resources, which brought people back to these locations and led to additional burning cycles. 

Notably, the study found fires occurred more frequently in Apache territory than elsewhere in the region for centuries before the establishment of Indian reservations. Most fires occurred disproportionately in late April and May, when Apache people devoted significant time to subsistence activities in pine forests.

"The fire frequencies were so different in Western Apache homelands that they stood out like a neon light," said Christopher Roos, environmental archaeologist at Southern Methodist University and lead author of the new study. "This was a small group of foragers who were basically taking control of the fire regime. And we were able to show this clearly through tree rings.”

The findings challenge common assumptions about Indigenous fire management, which often focus on larger, more sedentary populations, according to Roos. The Western Apache were primarily mobile forager-gardeners who practiced limited gardening. But the tree ring evidence shows they maintained systematic control over fire patterns across the landscape.

The research has implications for current fire management approaches. Rather than conducting extensive burns to meet acreage goals, the study suggests that many small, fragmented burns create more effective firebreaks and reduce hazards near human communities. 

Read more about this research in a press release from Southern Methodist University.