Posts on pyrogeography
Native bison hunters on the northwestern Great Plains used fire to manipulate bison grazing patterns and increase the success rates of communal hunts. In so doing, they leveraged climate opportunities to burn, ultimately amplifying the effects of climate on prairie fire activity.
Using geoarchaeology and landscape archaeology, my colleagues and I document this sophisticated fire use between 1100 and 1650 CE associated with the use of stone demarcated drive lanes and jumps to harvest bison en masse. Bison prefer to graze recently burned patches. When climate conditions were right, indigenous hunters burned prairie near the mouth of these drive lanes to lure bison herds in. Once within the gathering basin of a drive line complex, the hunters could initiate a stampede and funnel the bison towards the jump. By using climate conditions in their decision making, Native hunters were amplifying the impact of climate variability on prairie fire activity.
Roos, Christopher I., María Nieves Zedeño, Kacy L. Hollenback, and Mary M. H. Erlick (2018) Indigenous Impacts on North American Great Plains Fire Regimes of the Last Millennium. Proceedings of the National Academy of Sciences 115:8143-8148.
We often ask the wrong question: how do we stop wildfires? The real question should be: what kinds of fire can we live with?
Environmental archaeology can be valuable here because we can learn from the successes and failures of past societies to live in fire-prone settings. This is what my colleagues and I have been doing in partnership with the Pueblo of Jemez in northern New Mexico. How did Jemez people live in fire-adapted ponderosa pine forests so successfully for centuries when we are in danger of losing this forest type to mega-fires today?
I recently had an opportunity to chat about these issues with my old schoolmate, Maya Lilly. She has made a video from that chat for her environmentally conscious lifestyle channel, Gungho Eco. Check it out.
I have a new paper out today in the International Journal of WIldland Fire. This paper was a collaboration with geologist Andrew Scott from Royal Holloway University, in which we compare charcoal reflectance between samples from crown and surface fire contexts in northern New Mexico.
Our analysis indicates that charcoal produced by surface fires is statistically distinguishable from charcoal produced by crown fires. This is an important methodological development, as it suggests that reflectance of stratified soil and sedimentary charcoal may be used to infer changes in fire severity over time.
Roos, Christopher I. and Andrew C. Scott
2018 A Comparison of Charcoal Reflectance between Crown and Surface Fire Contexts in Dry Southwest US Forests.International Journal of Wildland Fire 27:396-406. [PDF] [LINK]
What is pyrogeography? In a nutshell, it is the holistic study of fire on earth from its earliest beginnings more than 400 million years ago to the present. Fire has influenced the evolution of biota, including our lineage, for millions of years. Human fire-use was a multi-purpose tool that facilitated our migrations across the globe. Today, human communities and our surrounding environments face a number of challenges to cope with wildfire. Some of these problems are novel, whereas others have historical precedent. For example, as human settlements have encroached upon fire-prone forests in the Western US (and elsewhere), we are struggling to cope with the reality that fire and smoke are an inevitable part of these settings. Living with wildfire, however, is something that our ancestors dealt with as a fact of life. We can learn a lot from our ancestors.
For example, we can learn how ancient societies lived with fire and smoke, used fire as a tool on the landscape, and made “fire-wise” communities through their wood-use practices. My research group at SMU is tackling these very issues in places as varied as the forested Jemez Mountains of New Mexico, the prairies of northern Montana, and tropical dry forests of Viti Levu, Fiji. You can find out more on my research and publication pages. My group also published a magazine for the general public on our work in New Mexico via Archaeology Southwest that can be found here.
Undergraduate and graduate students are involved in this research as research assistants and several have taken elements of these projects to develop senior theses in Environmental Studies or PhD dissertations in Anthropology. Additionally, I have recently developed two new courses on pyrogeography at SMU. ANTH 3370 – Fire on Earth is a fall semester course that introduces students to the holistic field of pyrogeography, with components on the geology, ecology, history, and anthropology of fire. ANTH 3373 – Living with Fire is a course that I developed specifically for our beautiful SMU-in-Taos campus. Taught in the May term, this course focuses on political and ecological history of the contemporary wildfire problem in the Western US. Taking advantage of the location of the SMU-in-Taos campus in fire-prone pine forests and taking a day-long field trip to the Jemez Mountains, this class uses place-based experiential learning to give students a platform to explore lessons from the past for the future of human communities in fire-prone landscapes.