Fire-scarred ponderosa pine (Source: Wikimedia Commons)

The ecological importance of Indigenous burning and fuel management has been much debated, particularly in dry forests of western North America where lightning fire frequencies are high. Using an extraordinary collection of nearly 5000 fire-scarred trees across dry forests and three in Arizona and New Mexico, my colleagues and I were able to assess the impacts of Indigenous fire management by Diné (Navajo), Hemish (Jemez), and Ndée (Apache) people on fire-climate relationships. We show that Indigenous fire management weakened the impact of climate on fire activity at local (stands of a few acres) and landscape scales (100s sq mi).

Fragmentation of fuels by anthropogenic pyrodiversity (a mosaic of many small burn patches) may have weakened the influence of climate on fuel production and drying for fire spread even if the particular cultural and economic purposes of burning that created the pyrodiversity varied across the three different cultural groups. This shows that #goodfire can reduce the impact of climate on fire activity – it did so for centuries in the SW, particularly under Indigenous management.

This study would not have been possible without collaborations with Diné, Hemish, and Ndée communities and scholars. My co-authors and I acknowledge that tribal elders describe deep connections to traditional territories since time immemorial for Diné, Hemish, and Ndée people. Although archaeology and history document varying intensities and locations of land use and settlement, we recognize that Diné, Hemish, and Ndée connections to their traditional territories extend deep in the past and are ongoing.

The original study:

Roos, Christopher I., Christopher H. Guiterman, Ellis Q. Margolis, Thomas W. Swetnam, Nicholas C. Laluk, Kerry F. Thompson, Chris Toya, Calvin A. Farris, Peter Z. Fulé, Jose M. Iniguez, J. Mark Kaib, Christopher D. O’Connor, and Lionel Whitehair
2022    Indigenous fire management and cross-scale fire-climate relationships in the Southwest United States from 1500 to 1900 CE. Science Advances  8:eabq3221. [PDF] [LINK]

Press coverage can be found here:

In Science magazine: https://www.science.org/content/article/indigenous-americans-broke-cycle-destructive-wildfires-here-s-how-they-did-it

In Popular Science magazine: https://www.popsci.com/environment/indigenous-burn-practices-southwest-wildfire/.

In Axios magazine: https://www.axios.com/2022/12/07/wildfires-indigenous-cultural-burning

In Courthouse News Service: https://www.courthousenews.com/native-americans-managed-wildfire-risk-with-controlled-burns-for-hundreds-of-years/