Summary – Fire Ecologist Collin Haffey shares his perspective on Fire Adapted Communities:

From a fire ecology perspective I always think about “fire adapted communities” as being an assemblage of plants that have evolved to depend on fire for some part of their life history.

A ponderosa pine forest is one of the best examples of a fire adapted community in northern New Mexico. Historically it was not uncommon for fires to burn across entire mountain ranges in the Southwest US during a single fire season. These fires – the kind that ponderosa forests are adapted to – would rarely kill old trees, instead the fire would clear out the forest understory and remove young trees and shrubs and leave the forest open and grassy beneath the trees. Because the fire scars in the annual tree rings show us that trees survived and kept growing through many fires, we know that the fires that burned during the 400 years prior to the 20th century were lower severity, much more mild, than they are now. Humans have been living with wildfire in northern New Mexico for centuries. The Pueblo people likely lived with fire near their farms and smoke around their villages. From stories passed down for generations we understand that Puebloans appreciated fires as nature’s way of cleaning out the forests and creating grassy habitats for grazing animals like deer and turkey.

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Fire exclusion through grazing and very successful fire suppression, combined with almost two decades of relatively wet conditions from 1978–95, has led to the forest being overstocked with too many small trees all ready to burn and burn hot! Today we are being forced – by past mistakes, climate change (both natural cycles and man-made warming), and avoidable stubbornness not to act – to become a fire adapted community in northern New Mexico; it’s just that we are adapting to the wrong kind of fire. We have adapted to large, high severity fires, that are expensive to fight and difficult or impossible to recover from. Our fire managers have a wealth of knowledge gained through education and experience. Our federal fire management policy has been altered over the years to allow more flexibility in fire management. Mangers are no longer required to choose before they begin whether to allow a fire to burn or put it out. Now they can adapt on the fly as conditions change day to day. In fact, they have the flexibility to put out one side of the fire that might be burning too hot or too close to homes, and let another side maybe burning miles away to burn and clean up the forest. The policy change in 2011 that allows for more flexible fire management seems to have injected more common sense into federal fire management and could result in fire being reintroduced into many acres of Southwestern dry conifer forest. Nature forces us to adapt, move, or perish; we don’t have much choice in that matter. We can however choose how we adapt. We can learn from past mistakes, and past successes. We can choose learn to live with the fire the trees have evolved with.

 

Ecological Perspective

From a fire ecology perspective I always think about “fire adapted communities” as being an assemblage of plants that have evolved to depend on fire for some part of their life history. For example, in southern California chaparral plant communities burn frequently and at high severity, high enough that most of the above ground plant material is burned1. These communities are composed of plant species that vigorously resprout after a high severity fire, and a few years after the fire and the vegetation community appears to be the same as it was before the fire. In fact, if the area goes too long without a high severity fire it can be invaded by trees and taller shrubs which can out-compete the chaparral species for sunlight.

A ponderosa pine forest is one of the best examples of a fire adapted community in northern New Mexico. Prior to the 20th century, fires burned almost the opposite of how the do today, they were frequent, low severity, and often covered very large areas. Historically it was not uncommon for fires to burn across entire mountain ranges in the Southwest US during a single fire season2. These fires – the kind that ponderosa forests are adapted to – would rarely kill old trees, instead the fire would clear out the forest understory and remove young trees and shrubs and leave the forest open and grassy beneath the trees. The open forest allowed for habitat for a diverse ecological plant community by creating opportunities for other species, other than trees, to thrive. More plant species meant more habitat for animal species to thrive and survive, including humans.

Human-Nature Partnerships

Humans have been living with wildfire in northern New Mexico for centuries. According to the archeological and pyrodendrochronological (science of fire scars in annual tree rings) records we know that the ancestral Pueblos lived in the mountains and on the mesas of northern New Mexico at the same time as wildfire speed across the landscape. The Pueblo people likely lived with fire near their farms and smoke around their villages. From stories passed down for generations we understand that Puebloans appreciated fires as nature’s way of cleaning out the forests and creating grassy habitats for grazing animals like deer and turkey. Undoubtedly the Puebloans used fire to their advantage, although it’s hard to say how much impact that had on the landscape given the availability of natural ignitions. Between 1909 and 2012 in the Jemez Mountain there have been 7,134 fire starts, 90% of which have been lightning caused3.

Because the fire scars in the annual tree rings show us that trees survived and kept growing through many fires, we know that the fires that burned during the 400 years prior to the 20th century were lower severity, much more mild, than they are now. Of course, many things have changed since the Puebloan people occupied the villages of the high mesas in northern New Mexico. The biggest change from a fire perspective, and the main difference between fires then and fires now is the amount of acres that burn at high severity or the amount of acres where fire kills all the trees. Fire exclusion through grazing and very successful fire suppression, combined with almost two decades of relatively wet conditions from 1978–95, has led to the forest being overstocked with too many small trees all ready to burn and burn hot! Some researchers claim to have evidence that once the trees are burned from dry conifer forests it is unlikely, given future climate projections, that the same tree species will be able to re-establish on the site4. Essentially, once a ponderosa forest is gone, there is a high likelihood it’s never coming back, at least not in our lifetimes.

After a more than a century our forests are developing into such an unhealthy state and with no end in sight to the current decade plus drought, is there anything to learn from the ancestral Pueblos? Today we are being forced – by past mistakes, climate change (both natural cycles and man made warming), and avoidable stubbornness not to act – to become a fire adapted community in northern New Mexico; it’s just that we are adapting to the wrong kind of fire. We have adapted to large, high severity fires, that are expensive to fight and difficult or impossible to recover from.

Many of us have lived through these kinds of big, expensive fires. The fires that makes the national news and create “holes” in the forest where there isn’t a live tree as far as you can see. These types of fires continue to get bigger and bigger. In 1977 the La Mesa fire burned just over 14,000 acres. Recently the Los Conchas fire in 2011 burned 153,000 acres. In 1977, fires the size and severity of La Mesa were anomalies, now fire managers consider fires with that amount of severity to be “good” fire. It remains to be seen whether fires like Las Conchas become the norm or if we have the ability to corral wildfires toward the “good” end of the spectrum.

We have a strong set of tools we can use to accomplish that goal. First of all, through scientific research we have a good understanding of how our ecological communities are adapted to fire. Second, our fire managers have a wealth of knowledge gained through education and experience. Our federal fire management policy has been altered over the years to allow more flexibility in fire management. Mangers are no longer required to choose before they begin whether to allow a fire to burn or put it out. Now they can adapt on the fly as conditions change day to day. In fact, they have the flexibility to put out one side of the fire that might be burning too hot or too close to homes, and let another side maybe burning miles away to burn and clean up the forest. The policy change in 2011 that allows for more flexible fire management seems to have injected more common sense into federal fire management and could result in fire being reintroduced into many acres of Southwestern dry conifer forest. Programs like Firewise are other steps down the pathway of living with – rather than always fighting against – fire in a common sense way. By reducing fire severity risk, these programs allow homeowners to take an active role in fire management. A Firewise home, or better yet a community, allows fire managers even more flexibility when responding to a wildfire and creates more opportunity to get “good” fire back on the landscape

Nature forces us to adapt, move, or perish. Our choices may be limited but we can however choose how we adapt. We can learn from past mistakes, and past successes. We can choose learn to live with the fire the trees have evolved with. We can choose to live like those that came before us and appreciate the fire that cleans out the forest floor, makes big trees, and creates a healthy and diverse forest.

  • 1. Bond, W. J., & Keeley, J. E. (2005). Fire as a global “herbivore”: the ecology and evolution of flammable ecosystems. Trends in Ecology & Evolution, 20(7), 387–94. doi:10.1016/j.tree.2005.04.025 http://www.werc.usgs.gov/OLDsitedata/seki/pdfs/k2005_bond_tree%20article.pdf

  • 2. Farris, C., Baisan, C. H., Falk, D. A., Yool, S. R., & Swetnam, T. W. (2010). Spatial and temporal corroboration of a fire-scar-based fire history in a frequently burned ponderosa pine forest. Ecological Applications : A Publication of the Ecological Society of America, 20(6), 1598–614. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/2094576

  • 3. Data from wild fires atlases on file at Bandelier National Monument and Santa Fe National Forest

  • 4. Author’s shameless self promotion of MS thesis defense video

 

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Colin Haffey, Ecologist, Jemez Mountains Field Office, USGS

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