Living With Fire: Dr. Crystal Kolden on Fire Resilience, Biomimicry and TEK

Aug 28, 2020 · 12 min read
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Wildfires in California and across the Western US are razing through homes, cities, and ecosystems at record-breaking rates for yet another summer — and this problem is far from over. Dr. Crystal Kolden, a self-proclaimed “Pyrogeographer,” has spent years examining humanity’s relationship with fire through the lens of environmental conservation and land management. Using Biomimicry as a lens, Dr. Kolden and her colleagues have gained an intimate understanding of the solutions needed to adapt to a rapidly warming world, including empowering the leadership of First Peoples.

In this interview with Bioneers Senior Director of Programs and Research Teo Grossman, Dr. Kolden discusses her research into transforming our societal relationship with wildfire, leading towards the creation of fire-resilient communities which can sustainably co-exist with one of the world’s most powerful natural elements.

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Dr. Crystal Kolden

DR. CRYSTAL KOLDEN: I am an Assistant Professor of Fire Science based in the Management of Complex Systems Department at UC-Merced. My research is focused broadly on wildfire in a coupled natural-human system. I am a geographer by training, so I call myself a “Pyrogeographer” because I really look at how fire works in the physical Earth system and ecosystems. However, because humans are strongly coupled to that natural landscape and to those ecosystems, we can’t ignore humans. There are feedbacks in that human-natural systems relationship, so I look at understanding how fire works in that coupled system and where fire affects those feedback processes between humans and the landscapes we live on.

TEO GROSSMAN: It’s a crazy moment we’re in — and for many it feels like we keep having more and more of these summers. California fire managers are basically saying the fire season extends year-round at this point. There is obviously a climate signal in this, compounded by a century or more of fairly intense fire suppression. Where is the science currently at?

KOLDEN: That’s a big question. In a nutshell, as the globe warms, we see more local extremes. People have a hard time wrapping their head around global warming as a big, abstract concept. What does it really mean that the planet has warmed an average of two degrees in the last century?

One local manifestation of climate change is change in the frequency and the timing of when extreme events occur. As the temperature warms globally, the variance increases in local systems. Literally thousands of high temperature records have been broken around the world over the last several years. We see more of these extreme events, not just really hot days, but hot days coupled with strong winds, or hot days following a multi-month or multi-week, or even multi-year drought.

These extreme events affect the condition of the vegetation whether it’s forest, shrub lands or grasslands. One of the key drivers of big, explosive wildfires is what we call the vapor pressure deficit, which is a measure of aridity. Extreme heat wave events or drought coupled with heat waves produce really high vapor pressure deficits and all you need is a spark. Depending on location, there are different ratios of human to lightning ignitions. But generally, there is never a shortage of ignitions.

We have stretches of drought followed by a really wet winter that will produce massive growth in vegetation, and then we get a really dry summer following it. That’s always happened, but now the magnitude of the regrowth (and the resulting fire) is much more extreme.

It’s all very interconnected. There are other factors — forest management practices, land management more generally, where humans are building — which all relate to how a lot of these fire disasters play out. The key is that many of these other factors vary locally and can be quite different from from country to country. But we see these fire extremes that I’ve described globally. That’s why, as a fire scientist, I really point to global climate change as being the big driving factor related to increasing fire disasters.

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TEO: I first became aware of your work in an article that you wrote with Alistair Smith and David Bowman titled Biomimicry Can Help Humans to Coexist Sustainably with Fire. Can you describe what you and your colleagues were trying to accomplish?

KOLDEN: There are a number of different adaptations that plant species and even animal species have to fire. What we wanted to do with this paper was suggest that we really need to start looking at nature as we try and figure out, as humans, how to live in these fire-prone landscapes. One of the things that humans have realized over time is that nature can be a really powerful teacher, because evolution has basically required species to evolve to become efficient and effective so they can continue to occupy a niche.

“We really need to start looking at nature as we try and figure out, as humans, how to live in these fire-prone landscapes.” — Dr. Crystal Kolden @pyrogeog


We tried to look at a lot of different species and ask, How can we think about mimicking what these plants or animals have already evolved over time, in terms of how they exist in this environment of fire? How can we, as human society, adapt some of those traits in our own way so that we can learn to live successfully in these fire-prone systems and not constantly be having fire disasters.

When fire scientists look at how natural systems function with and without fire, one of the things we see over and over again is that a great many species on Earth are adapted to fire in some way, shape or form. They have evolved with fire. That evolution and those characteristics take many different forms. Some species have evolved to actually be fire dependent. The charismatic mega flora that everyone loves to point to is the Giant Sequoia, a revered tree in California and in Western North America. Giant Sequoias are these amazing trees. It turns out that they actually depend on fire to regenerate. Their cones have a bit of a resin on them and they only open up, allowing the seeds to actually get into the soil to regenerate, if there has been relatively frequent or recent low-severity fire.

Other species are fire adapted in that they will tolerate fire. These might be trees that have developed really thick bark, or armor essentially, so that when fire comes through, they can survive. The Ponderosa Pine tree is one of the most widespread trees in Western North America. Ponderosa Pine can grow very large and has these big, thick plates of bark. When a fire comes through, the first branches on a mature Ponderosa pine are so high up in the air that the flames on the fire actually can’t even reach the lowest branches. The bark is so thick that the heat never penetrates into the core, the living piece of the tree where the water and the food are moving. Ponderosa is a species that is adapted to fire. It doesn’t depend on it, but it also is used to frequent fire and easily repels the effects of fire.

Then there are species that don’t do very well with fire. We think of them as fire intolerant and they are the species that grow in spaces where there is not very much fire or it is highly infrequent. When these species they experience any kind of fire, even just a little bit, they will die and they won’t come back again, often for hundreds of years.

TEO: How similar were your biomimetic findings compared to current approaches for creating fire-resilient or fire-permeable communities. Did they match up? Did you find new strategies that you hadn’t expected?

KOLDEN: Yes. One of the things that we really try and push in our paper is that we as humans have an opportunity to use biomimicry to think more outside the box in terms of how to create fire-resilient communities. A good example of this is that for many decades now, our approach has been to view communities as places where fire should not be. We’ve tried to prevent fire from coming into communities. This approach may work in a city or in a suburban or ex-urban area with relatively dense housing, but as we look at some of these more rural areas, there are subdivisions that are half-acre, one-acre, two-acre lots with houses relatively spread out and with a fair amount of vegetation between homes. Trying to keep fire from moving into those communities is an exercise in futility in many ways.

Instead, one of the things we see when we look to nature is that fire is not kept out of some forests. It is allowed to move through. The evolution of certain forests has facilitated fire actually moving through quickly and at relatively low severity so that it doesn’t kill the big trees. I’ll go back to my example of the Giant Sequoias and to some extent the Ponderosa pines. There are a lot of pictures from early explorers and some of the early settlers in the Western US that show these big park-like areas where the trees are incredibly widely spaced, and the understory is relatively short. It’s grass. It’s mostly short. When a fire moves into those areas, the only thing in the understory is either short or tall grass. Fire burns grass pretty quickly, so it moves fast, and then it also burns at low intensity. There’s not a lot of heat coming off of a grass fire, so there’s not a lot of what we call residence time around the bowl of a tree.

If you light a match, take your finger and you can actually touch the head of a match for a nano second and you won’t really burn yourself. You can put out a candle by just quickly pinching your fingers together on the flame. But if you take the match and you have it right next to your finger, and you hold it there you’re going to give yourself a pretty bad burn. It’s the same thing with trees.

These forests have evolved so that fire moves through quickly and burns off the understory grass and doesn’t have a high residence time around the bowls of the trees. We asked whether we can do the same thing with a lot of these rural communities. Can we actually set them up so that we facilitate fire moving through a community, through some of these land parcels, moving through quickly and at low severity, so that there aren’t a lot of embers generated that can land on houses and ignite housing materials, and so there’s not a high residence time.

I envision being able to live in a community someday in a house that is fully hardened against fire. You see the fire coming, you close all your doors and your windows, and you turn off your air circulation system so it’s not sucking anything in, and you watch the fire go racing by, and you wait a half an hour for the last bits of it to burn out, and then you open your door again, and, yes, you’ve got a blackened property around you, but at low severity, within a week or two, it will actually begin to green up. That type of approach is much more aligned with what happens in a functioning ecosystem than what we see today with communities trying to keep fire out. That’s a really simple example.

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When I say that Biomimicry generates outside-the-box ideas, some of the things that we speculate on in the paper are questions and ideas such as whether we could have of elevated communities where the wildlands grow from the soil, from the surface, and the housing is built up on stilts or up in the trees. There are boreal communities of different kinds of species whose approach when a fire comes is to climb the tree, get out of the way, that’s where their nests are, and fire does not affect them at all. Could we say, okay, let’s go ahead and put our houses up on stilts. We do it in some places in flood plains. We do it in some places for hurricanes. It’s an interesting question and one that I’m not qualified to answer from an engineering perspective, but we wanted to put that out there as an idea that it’s in the natural world and it works for species in the natural world. It is something that we can think about that’s an outside-the-box solution for wildfire-prone areas.

TEO: One of the themes in your work (and hopefully increasingly in fire science in general) is the realization that fire is both an essential regenerative process of the landscape as well as a reality that humans, as a species, have always been living with. Modern society seems to have lost touch with the reality of living with fire. You note that Indigenous fire management practices were historically widespread and sophisticated. I’ll add that these practices were frequently stamped by colonizers. Some of the first laws on the books in colonial California and Australia were bans on traditional burning practices. In some places traditional ecological fire management is still taking place. The science appears to be catching up in some ways. What’s the next step? Where do we go from here?

KOLDEN: It’s interesting that you note that the science may have caught up. I would say science still actually has a lot of catching up to do, particularly with regard to Indigenous knowledge and how Indigenous people were part of that evolutionary process in terms of fire-prone landscapes globally. This has been an interesting debate among fire scientists for a long time. There are fire ecologists and fire scientists who don’t think that there was actually that much Indigenous burning across the landscape. Then there’s a substantial amount of anthropological research and traditional ecological knowledge that supports that there actually was an enormous amount of Indigenous burning, to the point that in places where there was not very much lightning, these landscapes are still very, very much shaped by fire.The only place that that fire could have come from was from widespread Indigenous burning with high frequency. We’re still sort of catching up in that regard.

There are Indigenous communities and tribes throughout the world, who still have that knowledge and have maintained it through oral history and by continuing to use cultural fire. As we start to look at next steps going forward, I think those are the people who should be leading. We should be empowering them as leaders to think through and prescribe how we can take some next steps towards increasing fire on these landscapes.

It’s always really counterintuitive for people to think that the best way to increase our ability to live on these fire-prone landscapes is to fight fire with fire. But it really is. The place that we should be starting from is applying fire in a smart and intentional way, consistent with how fire was applied on these landscapes for millennia by lightning as well as Indigenous people.

TEO: It is really about living with fire, isn’t it? If there’s one takeaway here, it might be getting everyone to really wrap their heads around that phrase, because it’s not going away. We live with wind and rain. Fire is always going to be there.

KOLDEN: I do a lot of press interviews and community outreach work, and one of the things I always ask is: How do you want your smoke? Because that’s really the thing that ends up impacting the most people. The dream of living in a smoke-free world for most of us in the Western US is gone. Those decades are gone. It’s hard for people to let go of that. It’s like addiction. In stage one, admit you have a problem. Once we get to the point of saying, okay, we’re going to have fire and we’re going to have it every year, then we have to ask: how do you want it? Do you want it predictable and spread out over the course of the year via prescribed burning so if you’re highly sensitive to smoke you can plan around it? Or do you want it for two or three weeks in late summer when you simply can’t control it, and you’re stuck, and it’s hot, and you want to be out recreating but you can’t because there’s so much smoke it’s unhealthy?

It’s hard for people to wrap their head around that because they want the good, ole days without fire. But thanks to global climate change, those days are gone. Now we have to figure out how to mitigate the discomfort of having a little bit of smoke instead of being trapped by a lot.

We’re a long way from living sustainably with fire, and we need to get there faster rather than slower.


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