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Wildfire on warming planet requires adaptive capacity at local, national, int’l scales

In some parts of the world, “fire adaptive communities” have learned to live compatibly with wildfire — in some cases for centuries or millennia.

Industrialized nations that view wildfire as the enemy have much to learn from people in some parts of the world who have learned to live compatibly with wildfire, says a team of fire research scientists.

The interdisciplinary team say there is much to be learned from these “fire-adaptive communities” and they are calling on policy makers to tap that knowledge, particularly in the wake of global warming.

Such a move is critical as climate change makes some landscapes where fire isn’t the norm even more prone to fire, say the scientists in a new report published in a special issue of the Philosophical Transactions of the Royal Society B.

“We tend to treat modern fire problems as unique, and new to our planet,” said fire anthropologist Christopher Roos, Southern Methodist University, Dallas, lead author of the report. “As a result, we have missed the opportunity to recognize the successful properties of communities that have a high capacity to adapt to living in flammable landscapes — in some cases for centuries or millennia.“

One such society is the ethnically Basque communities in the French Western Pyrenees, who practice fire management to maintain seasonally flammable grassland, shrub and woodland patches for forage and grazing animals. But the practice is slowly being lost as young people leave farming.

Additionally, Aboriginal people in the grasslands of Western Australia use fire as part of their traditional hunting practices. Children begin burning at a very young age, and the everyday practice is passed down. These fires improve hunting successes but also reduce the impact of drought on the size and ecological severity of lightning fires.

Social institutions support individual benefits, preserve common good
Fire-adaptive communities have social institutions in place that support individual benefits from fire-maintained landscapes while preserving the common good, said Roos, whose fire research includes long-term archaeological and ecological partnerships with the Pueblo of Jemez in New Mexico.

“These institutions have been shaped by long-histories with wildfire, appropriate fire-use, and the development of social mechanisms to adjudicate conflicts of interest,” said Roos, an associate professor in the SMU Department of Anthropology. “There is a wealth of tried and tested information that should be considered in designing local fire management.”

The authors note that globally, a large number of people use fire as a tool to sustain livelihoods in ways that have been handed down across many generations. These include indigenous Australians and North Americans, South Asian forest dwellers, European farmers, and also hunters, farmers and herders in tropical savannahs.

Global Warming will likely bring new fire problems, more flammable landscapes
Global Warming will likely bring new fire problems, such as making some landscapes more flammable, Roos said. More effort will be required to balance conflicting fire management practices between adjacent cultures. Currently most fire-related research tends to be undertaken by physical or biological scientists from Europe, the United States and Australia. Often the research treats fire challenges as exclusively contemporary phenomena for which history is either absent or irrelevant.

“We need national policy that recognizes these dynamic challenges and that will support local solutions and traditional fire knowledge, while providing ways to disseminate scientific information about fire,” Roos said.

The authors point out that one of the greatest policy challenges of fire on a warming planet are the international consequences of smoke plumes and potential positive feedbacks on climate through carbon emissions. Most infamously, wildfire smoke plumes have had extraordinary health impacts during Southeast Asian “haze” events, which result in increased hospitalization and mortality in the region.

Not all fire is a disaster; we must learn to live with and manage fire
Carbon emissions from wildfires can be as much as 40 percent of fossil fuel emissions in any given year over the last decade. Although only deforestation fires and land conversion are a net carbon source to the atmosphere, the contribution of wildfires to global carbon emissions is non-trivial and should be a formal component of international climate dialogs.

“It is important to emphasize that not all fire is a disaster and we must learn how to both live with as well as manage fire,” said co-author Andrew Scott, earth sciences professor at Royal Holloway University of London.

The report, “Living on a flammable planet: interdisciplinary, cross-scalar and varied cultural lessons, prospects and challenges,” was published May 23, 2016 by The Royal Society, the U.K.’s independent scientific academy.

Authors call for holistic study of fire on Earth
The authors are from the United States, Great Britain, Canada, Australia, South Africa and Spain. The synthesis emerged from four days of international meetings sponsored by the Royal Society – the first of its kind for fire sciences.

The authors advocate for greater collaboration among researchers studying all aspects of fire.

Pyrogeography — the holistic study of fire on Earth , “may be one way to provide unity to the varied fire research programs across the globe,” the authors write.

“Fire researchers across disciplines from engineering, the natural sciences, social sciences and the humanities need to develop a common language to create a holistic wildfire science,” said Roos. “The magnitude of the wildfire challenges we face on a warming planet will demand greater collaboration and integration across disciplines, but our job won’t be done unless we are also able to translate our research for policymakers, land managers, and the general public.”

Other co-authors on the scientific paper include Andrew C. Scott, Claire M. Belcher, William G. Chaloner, Jonathan Aylen, Rebecca Bliege Bird, Michael R. Coughlan, Bart R. Johnson, Fay H. Johnston, Julia McMorrow, Toddi Steelman, and the Fire and Mankind Discussion Group. — Southern Methodist University

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Culture, Society & Family Earth & Climate Fossils & Ruins

Long-term daily contact with Spanish missions triggered collapse of Native American populations in New Mexico

New evidence shows severe and rapid collapse of Pueblo populations occurred in the 17th century and triggered a cascade of ecological effects that ultimately had consequences for global climates

A detailed map of the Southwest Jemez Collaborative Forest Landscape Restoration Project that provided the LiDAR data for the published study (map by the USDA Forest Service, Santa Fe National Forest).
A detailed map of the Southwest Jemez Collaborative Forest Landscape Restoration Project that provided the LiDAR data for the published study (map by the USDA Forest Service, Santa Fe National Forest).

New interdisciplinary research in the Southwest United States has resolved long-standing debates on the timing and magnitude of American Indian population collapse in the region.

The severe and rapid collapse of Native American populations in what is now the modern state of New Mexico didn’t happen upon first contact with Spanish conquistadors in the 1500s, as some scholars thought. Nor was it as gradual as others had contended.

Rather than being triggered by first contact in the 1500s, rapid population loss likely began after Catholic Franciscan missions were built in the midst of native pueblos, resulting in sustained daily interaction with Europeans. The indirect effects of this demographic impact rippled through the surrounding forests and, perhaps, into our atmosphere.

Those are the conclusions of a new study by a team of scientists looking for the first time at high resolution reconstructions of human population size, tree growth and fire history from the Jemez Mountains of New Mexico.

“Scholars increasingly recognize the magnitude of human impacts on planet Earth, some are even ready to define a new geological epoch called the Anthropocene,” said anthropologist and fire expert Christopher I. Roos, an associate professor at Southern Methodist University, Dallas, and a co-author on the research.

“But it is an open question as to when that epoch began,” said Roos. “One argument suggests that indigenous population collapse in the Americas resulted in a reduction of carbon dioxide in the atmosphere because of forest regrowth in the early colonial period. Until now the evidence has been fairly ambiguous. Our results indicate that high-resolution chronologies of human populations, forests and fires are needed to evaluate these claims.”

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Standing walls at the ruins of an Ancestral Jemez village that was part of the published study. (Roos, SMU)
Standing walls at the ruins of an Ancestral Jemez village that was part of the published study. (Roos, SMU)

A contentious issue in American Indian history, scientists and historians for decades have debated how many Native Americans died and when it occurred. With awareness of global warming and interdisciplinary interest in the possible antiquity of the Anthropocene, resolution of that debate may now be relevant for contemporary human-caused environmental problems, Roos said.

Findings of the new study were published Jan. 25, 2016 in the Proceedings of the National Academy of Sciences, “Native American Depopulation, Reforestation, and Fire Regimes in the Southwest U.S., 1492-1900 C.E.”

The researchers offer the first absolute population estimate of the archaeology of the Jemez Province – an area west Santa Fe and Los Alamos National Lab in northern New Mexico. Using airborne remote sensing LiDAR technology to establish the size and shape of rubble mounds from collapsed architecture of ancestral villages, the researchers were able to quantify population sizes in the 16th century that were independent of historical documents.

To identify the timing of of the population collapse and its impact on forest fires, the scientists also collected tree-ring data sets from locations adjacent to the Ancestral Jemez villages and throughout the forested mountain range. This sampling framework allowed them to refine the timing of depopulation and the timing of fire regime changes across the Jemez Province.

Their findings indicate that large-scale depopulation only occurred after missions were established in their midst by Franciscan priests in the 1620s. Daily sustained interaction resulted in epidemic diseases, violence and famine, the researchers said. From a population of roughly 6,500 in the 1620s fewer than 900 remained in the 1690s – a loss of more than 85 percent of the population in a few generations.

“The loss of life is staggering,” said anthropologist Matthew Liebmann, an associate professor at Harvard University and lead author on the PNAS article.

“Imagine that in a room with 10 people, only one person was left at the end of the day,” Liebmann said. “This had devastating effects on the social and economic lives of the survivors. Our research suggests that the effects were felt in the ecology of the forests too.”

Other scientists on the team include Josh Farella and Thomas Swetnam, University of Arizona; and Adam Stack and Sarah Martini, Harvard University.

The researchers studied a 100,000-acre area that includes the ancestral pueblo villages of the Jemez (HEY-mehz) people. Located in the Jemez Mountains of north central New Mexico, it’s a region in the Santa Fe National Forest of deep canyons, towering flat-topped mesas, as well as rivers, streams and creeks.

Today about 2,000 Jemez tribal members live at the Pueblo of Jemez.

The authors note in their article that, “Archaeological evidence from the Jemez Province supports the notion that the European colonization of the Americas unleashed forces that ultimately destroyed a staggering number of human lives,” however, they note, it fails to support the notion that sweeping pandemics uniformly depopulated North America.”

“To better understand the role of the indigenous population collapse on ecological and climate changes, we need this kind of high-resolution paired archaeological and paleoecological data,” said Roos. “Until then, a human-caused start to Little Ice Age cooling will remain uncertain. Our results suggest this scenario is plausible, but the nature of European and American Indian relationships, population collapse, and ecological consequences are probably much more complicated and variable than many people had previously understood them to be.”

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SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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The Guardian: Weatherwatch: Hotter, drier summers may mean more forest fires

The research of SMU fire anthropologist Christopher I. Roos was covered by the United Kingdom’s widely read newspaper The Guardian.

In his August 10 “Weatherwatch” column, “Hotter, drier summers may mean more forest fires,” science journalist David Hambling discussed the record-breaking megafires burning now in New Mexico and referenced new ancient fire research by Roos.

The study by Roos found that U.S. megafires in the U.S. Southwest region are unique and exceptional for the past 1,500 years.

Roos and co-author Thomas W. Swetnam, the University of Arizona, constructed and analyzed a statistical model that encompassed 1,500 years of climate and fire patterns to test, in part, whether today’s dry, hot climate alone is causing the megafires that routinely destroy millions of acres of forest.

The researchers found that even when ancient climates varied from each other — one hotter and drier and the other cooler and wetter — the frequencies of year-to-year weather patterns that drive fire activity were similar.

The findings suggest that today’s megafires, at least in the southwestern U.S., are atypical, say Roos and Swetnam. Furthermore, the findings implicate as the cause not only modern climate change, but also human activity over the last century, the researchers said.

Jump to the column.

EXCERPT:

By David Hambling
The Guardian

This year has been a bad year for forest fires in the US, with wildfires burning about eight hundred thousand hectares by the end of June. This is higher than average, in spite of the relatively low number of fires. But there may be worse to come.

The Wildland Fire Assessment System maps the ‘Dead Fuel Moisture Level’ in the US. This indicates how much flammable wood there is on the ground, a critical factor in how fire spreads. There are several grades of fuel involved, ranging from “one-hour” twigs, which dry out or absorb moisture rapidly, to “thousand-hour” logs which only burn after a long dry spell. As drought deepens, the amount of dry fuel on the ground is growing, just waiting to ignite.

A recent study of tree-ring scarring looking back 1,400 years at Southern Methodist University, Dallas, suggests the current spate of forest fires is unusual. The pattern has remained similar, with wet years of growth followed by dry years of increased fires, but the scale of fires has changed.

In previous centuries minor fires were common, burning grasses but leaving trees standing. Twentieth-century forestry management prevented small fires, so brushwood built up, leading to fewer but more intense fires which destroy trees. Modern forestry policy encourages a natural ecosystem by allowing some fires, which is slowly improving matters. Meanwhile the series of hotter, drier summers may produce more and bigger forest fires than ever.

Jump to the column.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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CBS This Morning: Heat Wave Headaches and SMU Fire Research

The research of SMU fire anthropologist Christopher I. Roos was covered by CBS This Morning with Charlie Rose and Erica Hill.

In a June 12 show, The Nature Conservancy’s lead scientist M. Sanjayan, who is CBS News science and environmental contributor, discussed the record-breaking megafires burning now in New Mexico and referenced new ancient fire research by Roos. The study by Roos found that U.S. megafires in the U.S. Southwest region are unique and exceptional for the past 1,500 years.

Roos and co-author Thomas W. Swetnam, the University of Arizona, constructed and analyzed a statistical model that encompassed 1,500 years of climate and fire patterns to test, in part, whether today’s dry, hot climate alone is causing the megafires that routinely destroy millions of acres of forest.

The researchers found that even when ancient climates varied from each other — one hotter and drier and the other cooler and wetter — the frequencies of year-to-year weather patterns that drive fire activity were similar.

The findings suggest that today’s megafires, at least in the southwestern U.S., are atypical, say Roos and Swetnam. Furthermore, the findings implicate as the cause not only modern climate change, but also human activity over the last century, the researchers said.

Watch the video.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Climate Central: New Mexico Wildfire Now a Record-Setting ‘Megafire’

The research of SMU fire anthropologist Christopher I. Roos was covered by the popular Climate Central blog. In a June 2 entry, Climate Central science journalist Andrew Freedman wrote about the record-breaking megafires burning now in New Mexico and referenced new ancient fire research by Roos. The study by Roos found that U.S. megafires in the U.S. Southwest region are unique and exceptional for the past 1,500 years.

Roos and co-author Thomas W. Swetnam, the University of Arizona, constructed and analyzed a statistical model that encompassed 1,500 years of climate and fire patterns to test, in part, whether today’s dry, hot climate alone is causing the megafires that routinely destroy millions of acres of forest.

The researchers found that even when ancient climates varied from each other — one hotter and drier and the other cooler and wetter — the frequencies of year-to-year weather patterns that drive fire activity were similar.

The findings suggest that today’s megafires, at least in the southwestern U.S., are atypical, say Roos and Swetnam. Furthermore, the findings implicate as the cause not only modern climate change, but also human activity over the last century, the researchers said.

Read the full story.

EXCERPT:

By Andrew Freedman
Climate Central

The largest wildfire in New Mexico’s history continues to burn, having already charred an area larger than New York City. Known as the Whitewater-Baldy Fire Complex, the wildfire has become another in a series of “megafires” to torch the American West due to an unprecedented combination of drought conditions, climate change, and alterations in land-management practices. To make matters worse, according to The Guardian newspaper, congressional budget cuts may restrict the federal government’s firefighting efforts during what is widely expected to be a busy wildfire season.

The Whitewater-Baldy Complex is burning in New Mexico’s rugged and mountainous Gila Wilderness, an area with steep terrain that has rendered much of the fire off limits to firefighters. Instead of attacking it from within, firefighters are trying to dig in around it, hoping to slow its spread. […]

[…] In fact, the recent Southwestern megafires stand out as unusual in the context of the past 1,500 years in that region, according to a recent study. The study found that land-management changes, such as years of fire suppression activities that stifled small fires, thereby priming forests for larger blazes, have combined with climate change to create forests that are altogether different — and which burn differently — from what existed in this area for generations.

“The U.S. would not be experiencing massive large-canopy-killing crown fires today if human activities had not begun to suppress the low-severity surface fires that were so common more than a century ago,” said Christopher I. Roos, an assistant professor in the SMU Department of Anthropology, according to Science Daily.

Read the full story.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Culture, Society & Family Earth & Climate Fossils & Ruins Plants & Animals Researcher news SMU In The News

UPI: U.S. megafires put down to human activity

The new ancient fire research of SMU fire anthropologist Christopher I. Roos was covered by the international wire service United Press International. In a May 18 entry, UPI reported that Roos found that U.S. megafires in the U.S. Southwest region are unique and exceptional when compared to the past 1,500 years.

Roos and co-author Thomas W. Swetnam, the University of Arizona, constructed and analyzed a statistical model that encompassed 1,500 years of climate and fire patterns to test, in part, whether today’s dry, hot climate alone is causing the megafires that routinely destroy millions of acres of forest.

The researchers found that even when ancient climates varied from each other — one hotter and drier and the other cooler and wetter — the frequencies of year-to-year weather patterns that drive fire activity were similar.

The findings suggest that today’s megafires, at least in the southwestern U.S., are atypical, say Roos and Swetnam. Furthermore, the findings implicate as the cause not only modern climate change, but also human activity over the last century, the researchers said.

Read the full story.

EXCERPT:

By UPI
DALLAS, May 16 (UPI) — Today’s mega forest fires in the U.S. Southwest are truly unusual compared to the long-term record and may be the result of human activity, researchers say.

A study that examined hundreds of years of ancient tree ring and fire data from two distinct climate periods suggests today’s dry, hot climate is not the lone cause of the megafires that routinely destroy millions of acres of forest, researchers from Southern Methodist University reported Tuesday.

Human activity over the last century in terms of dealing with fires is at least partly to blame for today’s megafires, they said.

“The United States would not be experiencing massive large-canopy-killing crown fires today if human activities had not begun to suppress the low-severity surface fires that were so common more than a century ago,” said Christopher I. Roos, a professor in the SMU Department of Anthropology.

Read the full story.

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Ancient tree-ring records from southwest U.S. suggest today’s megafires are truly unusual

Unprecedented study relies on more than 1,500 years of tree-ring data and hundreds of years of fire-scar records gathered from Ponderosa Pine forests

Today’s mega forest fires of the southwestern U.S. are truly unusual and exceptional in the long-term record, suggests a new study that examined hundreds of years of ancient tree ring and fire data from two distinct climate periods.

Researchers constructed and analyzed a statistical model that encompassed 1,500 years of climate and fire patterns to test, in part, whether today’s dry, hot climate alone is causing the megafires that routinely destroy millions of acres of forest, according to study co-author and fire anthropologist Christopher I. Roos, Southern Methodist University, Dallas.

The researchers found that even when ancient climates varied from each other — one hotter and drier and the other cooler and wetter — the frequencies of year-to-year weather patterns that drive fire activity were similar.

The findings suggest that today’s megafires, at least in the southwestern U.S., are atypical, according to Roos and co-author Thomas W. Swetnam, the University of Arizona. Furthermore, the findings implicate as the cause not only modern climate change, but also human activity over the last century, the researchers said.

“The U.S. would not be experiencing massive large-canopy-killing crown fires today if human activities had not begun to suppress the low-severity surface fires that were so common more than a century ago,” said Roos, an assistant professor in the SMU Department of Anthropology.

Today’s extreme droughts caused by climate change probably would not cause megafires if not for a century of livestock grazing and firefighting, which have combined to create more dense forests with accumulated logs and other fuels that now make them more vulnerable than ever to extreme droughts. One answer to today’s megafires might be changes in fire management.

“If anything, what climate change reminds us is that it’s pretty urgent that we deal with the structural problems in the forests. The forests may be equipped to handle the climate change, but not in the condition that they’re currently in. They haven’t been in that condition before,” Roos said.

Roos and Swetnam, director of the University of Arizona Laboratory of Tree-Ring Research, published their findings in the scientific journal The Holocene.

Study combines fire-scar records and tree-ring data of U.S. southwest
This new study is based on a first-of-its-kind analysis that combined fire-scar records and tree-ring data for Ponderosa Pine forests in the southwest United States.

Earlier research by other scientists has looked at forest fire records spanning the years from 1600 to the mid-1800s — a climate period known as the Little Ice Age — to understand current forest fire behavior. Those studies have found that fires during the Little Ice Age occurred frequently in the grasses and downed needles on the surface of the forest floor, but stayed on the floor and didn’t burn into the canopies.

Critics dispute the relevance of the Little Ice Age, however, saying the climate then was cooler and wetter than the climate now. They say a better comparison is A.D. 800 to 1300, known as the Medieval Warm Period, when the climate was hotter and drier, like today’s.

Scientists who favor that comparison hypothesize that forest fires during the Medieval Warm Period probably were similar to today’s megafires and probably more destructive than during the Little Ice Age.

Tree rings and fire scars provide the evidence for moisture, drought and burn activity
Scientists 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. Similarly, scientists’ best evidence for fire activity is the scarring on tree rings that dates the occurrence of fires. While tree-ring data for climate are available for long time periods, annual forest fire records don’t yet exist for the Medieval Warm Period.

In response to the need for data, Roos and Swetnam tested the Medieval Warm Period hypothesis by calibrating a statistical model that combined 200 years of Little Ice Age fire-scar data and nearly 1,500 years of climate data derived from existing tree rings. With that they were able to predict what the annual fire activity would have been almost 1,500 years ago.

They discovered that the Medieval Warm Period was no different from the Little Ice Age in terms of what drives frequent low-severity surface fires: year-to-year moisture patterns.

“It’s true that global warming is increasing the magnitude of the droughts we’re facing, but droughts were even more severe during the Medieval Warm Period,” Roos said. “It turns out that what’s driving the frequency of surface fires is having a couple wet years that allow grasses to grow continuously across the forest floor and then a dry year in which they can burn. We found a really strong statistical relationship between two or more wet years followed by a dry year, which produced lots of fires.”

Modeling of tree-ring and fire-scar data can be applied to any locale
The research, “A 1416-year reconstruction of annual, multidecadal, and centennial variability in area burned for ponderosa pine forests of the southern Colorado Plateau region, Southwest USA,” was funded by the International Arid Lands Consortium.

“The best way to look at how fires may have varied — if climate were the only driver — is to do this type of modeling,” Roos said. “Our study is the first in the world to go this far back using this methodology. But this method can be used anyplace for which there is a fire-scar record.”

The study’s tree-ring-derived climate data are from the southern Colorado Plateau, a region that includes the world’s largest continuous stand of Ponderosa Pine stretching from Flagstaff, Ariz., into New Mexico. Large Ponderosa Pine forests have existed in the area for more than 10,000 years.

Fire-scar data for the region go back as far as the 1500s, but are most prevalent during the Little Ice Age period. Fire scientists have analyzed fire-scars from hundreds of trees from more than 100 locations across the Southwest. All fire-scar data are publically available through the International Multiproxy Paleofire Database, maintained by the federal National Oceanic and Atmospheric Administration’s paleoclimatology program.

Ancient fires were frequent, but didn’t burn the forest canopy
Fire scientists know that in ancient forests, frequent fires swept the forest floor, often sparked by lightning. Many of the fires were small, less than a few dozen acres. Other fires may have been quite large, covering tens of thousands of acres before being extinguished naturally. Fuel for the fires included grass, small trees, brush, bark, pine needles and fallen limbs on the ground.

“The fires cleaned up the understory, kept it very open, and made it resilient to climate changes because even if there was a really severe drought, there weren’t the big explosive fires that burn through the canopy because there were no fuels to take it up there,” Roos said. “The trees had adapted to frequent surface fires, and adult trees didn’t die from massive fire events because the fires burned on the surface and not in the canopy.”

Today’s huge canopy fires are the cumulative result of human activity
The ancient pattern of generally small, frequent fires changed by the late 1800s. The transcontinental railroad had pushed West, bringing farmers, ranchers, cattle and sheep. Those animals grazed the forest floor, consuming the grasses that fueled small fires but leaving small saplings and brush, which then grew up into dense, mature bushes and trees. In addition, the U.S. began to restrict the traditional land use of the region’s Native American communities, including confining them to reservations. This removed another source for frequent surface fires in the forests — burning by Native Americans for horticulture and hunting.

By the early 20th century, the U.S. Forest Service had been established, and fighting fires was a key part of the agency’s mission. Without continuous fuel, fires on the forest floor ceased.

“Many of our modern forests in central Arizona and New Mexico haven’t had a fire of any kind on them in 130 or 140 years,” Roos said. “That’s very different from the records of the ancient forests. The longest they would have gone without fires was 40 or 50 years, and even that length of time would have been exceptional.”

The research reported in The Holocene is the basis for a new four-year, $1.5 million grant from the National Science Foundation in which Roos and Swetnam are co-principal investigators. That project will examine how human activities have changed forests and forest fires over the past 1,000 years of Native American occupation, as well as the influence of droughts during the Medieval Warm Period and Little Ice Age in New Mexico’s Jemez Mountains. — Margaret Allen

SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smuresearch.com.

SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.

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Researchers collaborate to study human-fire-climate interactions in New Mexico’s Jemez Mountains

An interdisciplinary team of researchers will examine how humans in the Southwest have responded to changes in the surrounding forests over multiple centuries. The research is funded by a four-year, $1.5 million grant from the National Science Foundation.

The project is about forest fire history, fuels and forests, how human activities have changed them, and the influence of drought and dry conditions, said Thomas W. Swetnam, co-principal investigator on the grant and director of the University of Arizona Laboratory of Tree-Ring Research.

The scientists are focusing on New Mexico’s Jemez Mountains, where native peoples lived within the ponderosa pine forest in significant numbers for centuries before Europeans came to North America.

Swetnam and Southern Methodist University fire anthropologist Christopher I. Roos will use tree-ring and archaeological methods to reveal the fire history of the forest and of the forest close to the human settlement sites. Roos, co-principal investigator, is an assistant professor in the SMU Department of Anthropology.

While fire is a natural part of the Southwest’s forests and grasslands, the region’s massive forest fires this year were exacerbated by decade-long drought. In addition, more people are living in or near fire-adapted ecosystems, increasing the likelihood that human activities will affect and be affected by forest fires.

“Humans and fire are interconnected all the way back to our beginnings,” said Swetnam.

The team will study the interplay among human activities at the wildland-urban interface, climate change and fire-adapted pine forests.

“Drought and dry conditions are going to keep going on, so there’s an urgency in understanding what’s happening,” Swetnam said. “We’re seeking to know how we can live in these forests and these landscapes so they are more resilient in the face of climate change.”

Unprecedented approach to studying interaction of people, climate and fires
The team includes experts in tree-ring science, fire ecology and forest fire behavior, archaeology and anthropology, and education and outreach.

In addition to Roos, Swetnam’s co-principal investigators are T.J. Ferguson, a professor of practice in UA’s School of Anthropology; Sara Chavarria, director of outreach for UA’s College of Education; Robert Keane and Rachel Loehman of the USDA Forest Service’s Missoula Fire Sciences Laboratory; and Matthew J. Liebmann of Harvard University’s department of anthropology.

The team’s research approach is unprecedented, Swetnam said. By studying how people and climate and fires have interacted in one place over long time scales, the researchers will learn something fundamental about how the people-fire-climate system works.

“What are the tipping points?” he said. “What amount of change with regard to fuel, forest densities, how often you burn it or don’t burn it, leads to forests that are sustained through time?”

Native American life in Jemez Mountains will provide clues to living in sustainable forests
In the Jemez, Native Americans moved from their forest homes during the Spanish period, returned after the Pueblo Revolt of 1680, and left again in the 1690s. Liebmann has conducted extensive archaeological studies of the sites where the Jemez people lived.

Comparing the forest-fire-climate-human interactions during times of high and low human habitation will provide clues for living within forests sustainably, Swetnam said.

Ferguson said, “We’re interested in how the ancient populations in the Jemez responded to fire. We’re melding together settlement patterns and fire patterns, mapping one against the other.”

Ferguson is partnering with John Welch, Simon Fraser University, and with four tribes in the region to gather traditional knowledge of how ancient peoples responded to forest fire and their uses of fire. The tribes are the Pueblo of Jemez, the Pueblo of Zuni, the Hopi Tribe and the White Mountain Apache Tribe. All the tribes have lived in ponderosa pine forests at some time in their history.

“Who better to tell us about the human response to fire than the people who have lived in the Southwest for thousands of years?” Ferguson said. “They have a lot to teach us.”

Keane and Loehman will incorporate the information gathered into dynamic computer models of fire behavior and landscape-fire interactions.

Chavarria will lead the project’s outreach effort. She will conduct workshops for local-area teachers and help them develop teaching materials about the nature of fire and forests in the local landscapes.

Community outreach will bring students and teachers to join scientists in the field
In the summer, local high school students and teachers will join the scientists in the field to help with the archaeological and tree-ring research. “Connecting with the high school students this way will expose them to research and to the idea of a career path that involves college,” Chavarria said.

The research project is a homecoming of sorts for Swetnam, who grew up in Jemez Springs, N.M. and spent much of his youth roaming the Jemez Mountains. His father was the U.S. Forest Service district ranger in Jemez Springs. Swetnam has conducted many research projects in the Jemez over the years.

“I grew up around archaeology and went to school with pueblo kids,” he said. “It’s a dream project for me. I hope this project will help me learn some social sciences and learn something from my former classmates and childhood friends.” — University of Arizona

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