Nuance

Ignite

It was a warm day during a dry summer. The outdoor recreation community in the buzzing town of Durango was enthusiastically embracing mountain summits as May gave way to June and the high country was unusually accessible. It was, in some ways eerie, cresting a high ridge and what had looked like a soft distant cloud came into focus as a soft gray rising from the horizon line, pushed to the north by the winds. Fire. I said it out loud. The people I was with, in almost perfect unison look at me blankly, "huh?". Fire. I say again, my brain hastily triangulating where the smoke was rising from. Animas River Canyon? No. It seems further south. Junction Creek? no, that's too far south. Maybe Rockwood. Maybe. Hard to say.

That night, camp went from pleasant to uncomfortable. Smoke filled mountain basins. The wind kept blowing. It was warm, dry and windy. The next day, driving back towards Durango along the Dolores River and it became clear. East side of the La Platas. Hermosa Creek, perhaps, or the east side of the Hermosa Cliffs. Slowly gathering more information, the main northbound highway, 550 was closed. Soon I would finally here - "the 416 Fire is making active runs on steep slopes in rough terrain beneath the Hermosa Cliffs, evacuations ordered". News stories were already talking about residents who prepare themselves with equipment to put fires started by other Durango Silverton Train out, a common occurrence in their back yards - but they claimed this one got too big too fast. Where humans spark, fires burn.

Risk

In the next day or so an incident command post became established at Purgatory. The highway opened to escorted traffic flow, and fire fighters lined the highway with their backs to the flames, looking east, making sure no embers carried by the wind would spot in the forested country interlaced with steep granite cliffs and multi-million dollar homes. The fire communications team was accepting media requests, and I raced to observe fire effects first hand. As we rode from Purgatory, the assigned public affairs officer said, "no I mean right now we are mostly watching it burn. Its making some runs, but then drops back down in the aspen. It looks good really". As the days carried on, the fire followed the winds and fuel and crept around on the east side of the Hermosa Cliffs. Eventually, the fire would top out the steep slopes and find opportunities to back downslope into the Hermosa Creek drainage.

By now, homes on the southern flank of the fire had been evacuated, homes with defensible space and fire preparedness procedures. Hot shots utilized these artificial fuel breaks to put fire on the ground, Wathcing as flames spread from drops of diesel into flame lengths that characterize erratic and high severity fire. Tankers and helicopters dropped slurry continuously on terrain features that would serve as opportune places to stop flames from creeping further south and into more densely populated areas. Meanwhile, as Rob Powell, a section chief put it, the fire advanced at its own will up Hermosa Creek and its tributaries, unmanaged or bothered by the army of fire fighters who instead focused on human values - homes, roads, infrastructure.

Circumstance

Days turned into weeks, weeks to months. A tropical depression, Bud, raced in with a torrent of rain and left. Dry winds stayed calm enough, and the fire danced through the fuels of Ponderosa pine, mixed conifer , and spruce-fir forests. The fire found mesic drainages, densely and sparsely forested slopes and it responded to each subtle microclimate. By early autumn, 54,000 acres burned. Most at low-moderate severity with some areas of high severity fire. We often determine that low severity fire has <10% tree mortality and is primarily a surface fire, whereas high severity fire has >80% tree mortality and has significant tree scorch. Of course, this terminology relates to the trees - but we also discuss fire in terms of its effects on soils where high soil burn severity has significant amounts of organics consumed and ashy residue leftover, sometimes being hydrophobic, and low soil burn severity would have low consumption of organics, meaning you will still find in tact plant roots. At the end of the day defining these terms in reality is actually fairly tough. Low severity fire and high severity fire are clear, but anything with a mix of all of the above often gets labeled as mixed severity fire.

Fire feels like one of those weird topics that has become interestingly political. In the early 1900s, American conversationalist and President Teddy Roosevelt had created the National Forest System and put French forester Gifford Pinchot in charge of conserving America's timber resources for future generations. Heavy logging was sweeping across the western United States. Wood was being used to build cities like Chicago, and rebuild those cities when they burnt down. At the same time, drought-stricken forests had been primed for large fires, and in 1910, fire starts were numerous. Many fires blew up to burn over a million acres in Montana, Idaho and Wyoming, The Big Burn as it would be called. In response an aggressive policy for surpassing all fires by 10:00 am the day after they are observed was enacted.

The era of fire suppression began. Slowly at first, in part because the 19-teens and 20s had some favorable wet years that contributed to halting fire spread. After WWII fire suppression became armed with aircraft and victories were more numerous. Simultaneously logging continued or even accelerated in some parts of the country. The wet 1980s gave way to the warmer 90s which dissolved into what some called a drought of the century and fires became numerous and large. These fires include the Hayman fire in Colorado, which included massive patches of high severity fire. The trend continued. By the 2020s, drought has not ended and some might say we are now experiencing aridification, not drought, and bigger fires that spread fast in extreme wind events seem common place. Now, with a century of systematic experience in fire suppression, better aircraft and improved coordination we cannot keep pace with fires which are burning more acres every year .

Perspective

A fierce dialogue has unfolded on this topic. Some say these big fires are driven by climate change, others suggest these fires are driven by a century of fire suppression. Some seem able to walk the line and accept both perspectives as contributing factors, but even this centrist view seems focused on a narrow lens of forest ecology and some dogma around processes that shape forests.

The fire suppression view holds the idea that a century of fire suppression has resulted in significant fuel accumulation of both living trees and dead wood, particularly in dry forests, and thus fire intensity is greater. Lots of evidence demonstrates historically lower tree densities in many southwestern ponderosa pine forests (Moore and Convington 1999). Thus, this logic makes a lot of sense. However, the fallacy comes with assuming this to be true for all ponderosa pine forests. In other regions, like Southwest Colorado, tree density was much more variable, some areas were lower, others area higher (Baker 2018). This logic of fire suppression yielding higher tree densities also leaves out important other contributing variables. Some studies have shown that historic logging made the opportunity for the thicket of small diameter trees to grow, thus logging and fire suppression may be the interaction term that results in today's conditions, especially once we consider grazing and other land use changes (Nacify et al. 2010, Romme et al. 2009). Not in contrast or exclusion to this view is the climate lens.

The climate view holds the idea that warm dry conditions are more common and thus fire intensity is greater. Drought contributes to tree mortality, dries out fuels, and primes the pump for ideal fire conditions. This is what drove the big fires of 1910, and has periodically always played a big role in contributing to large wildfires in forests. Its pretty easy to see how both of these factors are true. Further this lens points out that bark beetle related tree is mortality is higher because of warmer temperatures and drought. While this may be true, it still feels difficult to parse out whether that is just part of a forests' disturbance cycle, and whether beetle kill actually contributes to more rapid fire spread is very complex (Andrus et al. 2019) . Further, often these forests end up with substantial tree regeneration and remain mesic from decaying wood that absorbs water like a sponge.

No sense in arguing either of them, except when it comes to 'what to do about it'. The fire suppression narrative argues that because fuel accumulation happened from fire suppression, we can then manipulate fuels to restore forests to a historic structure. Once this is done fire can be returned to the forests . This also seems logical enough, without much need for arguing. The climate argument proposes that slowing carbon dioxide emissions and sequestering carbon can slow climate change and minimize the likelihood of extreme weather events that drive such fires. Both options can co-exist, they are not mutually exclusive. But there is nuance, and sometimes it feels like letting forests respond to change is off the table.

Value

Fire history and specific changes in stand structure in forests is often a site specific exercise. So specific that we often discuss it in terms of a given forest type, within a specific area. For example, we might discuss the history of fire in Ponderosa pine forests in Northern Arizona on the Mogollon Rim. But of course forests exists in their current form, and thus in their historical form, in a continuum of conditions and types that do not necessarily fit into a clean box of 'forest types' but rather make a gradient of conditions that is sometimes easier to refer to as unique forests types or successional stages. So what happens when a fire occurs? The place often becomes the area within the perimeter of the fire, commonly referred to as a burn scar.

In the modern era, we talk about the deficit of fire on the landscape, articulating the need for more fire. Often values are placed on fire - good fire is cultural fire or fire that is low severity - bad fire is something that gouges a wound into the forest. We suppress fires that are perceived to be bad. And let other fires burn, sometimes we even carefully purposely put fire on the landscape. But what happens when a place you love dearly burns in an unplanned ignition, during a drought, likely started by a train? It seems most mourn it as bad fire. Love is complex.

Place

Hermosa Creek. A deep valley that rapidly descends from steep limestone ridgelines on the east side of the La Plata Mountains. A lush and wet landscape decorated with rapidly changing forests from Ponderosa pine to spruce fir. Productive soils. With rich soils and water, trees reach for light from the shaded valley bottoms. Steep slopes kept saws out - the place has never been logged and has had some use of prescribed fire. The result is relatively low density forests despite a century of fire suppression. Put an untamed fire on the ground in the landscape and the results feel easy to call a catastrophe, but the context seems more variable.

54,000 acres sounds big, and it is. But studies show fires up to 125,000 acres in the San Juan Mountain region are not uncommon (Bigio et al. 2017). High severity fire sounds bad, but in itself is not. Some forests, like wet mixed conifer and spruce-fir characteristically had stand replacing fire during dry periods. Fire that burns down homes is certainly a catastrophe, but 416 left all structures standing. After the fire there was some sediment movement, debris flows, flooding that impacted peoples homes and ditches for agriculture and this certainly deserves mention. But all in all, the consequences that may imply catastrophe feel perhaps limited to the forests. Was this fire a loss for the trees?

Seeing the Forest

I certainly have no grounds to offer a singular answer. Immediately following the fire was one of the most brilliant displays of Golden Smoke, or Cordylis aurea, a beautiful flower that thrives with disturbance and otherwise lays dormant in the seed bank. The prevalence and abundance of such a plant gives the glowing idea that a disturbance like this is not novel to this drainage. Some trees died. Some big trees died. But all in all legacy tall and old trees are still towering over the patchwork of dead. There is variability in forest types and variability in burn severity. Dry forests with lower stand densities burned at lower severity than wetter forests with higher stand densities. And even where things got hot, the landscape is mostly a mosaic. Pockets of green are never that far from burnt trees. So was it a catastrophe?

It feels rather difficult, in my heart, to apply such a label to this fire. As I sweat, grinding up a familiar trail for the 4th spring in a row after the fire I continue to see changes on the landscape. Once wet streams now remain elusive as a dusty drainage. Springs have emerged in places that they were not years ago. Aspen sprouts in a celebratory youth and shrubs flower among buzzing pollinators. Bobcat tracks eloquently prance through dust. Woodpeckers and nuthatches dance up and down dead trees. Green needles brown in the warm spring sun. I imagine next year will be different yet - and perhaps that is just it. I got to watch a forest evolve. Its prompted me to pay closer attention, to the shrubs and trees. To the seedlings and plants that thrive after the fire and slowly wean out with time since fire. Its not my prerogative to tell the forest that it is suffering, rather I am just an active listener to its journey. Some trees will regenerate when the conditions are right, and on the scale of a tree decades are insignificant, so patience must be practiced. If so much complexity exists with this fire, then surely all fires must have a complex and nuanced story and must be unique relative to one another? Its not simply climate or fire impression or both.... its myriad of story.

But perhaps the biggest tragedy is the label that gets applied. The negative terminology of burn scar. Devastation. Catastrophe. Fire bad. Fire started by humans, worse. Awful. These judgemental terms neglect the reality that fire has always danced through the forests, and it always will. Should we wish to tango with the trees, then we too must accept fire as a partner.

Works Cited

Andrus, R.A., Veblen, T.T., Harvey, B.J., Hart, S.J., 2019. Fire severity unaffected by spruce beetle outbreak in spruce-fir forests in southwestern Colorado. Ecological Applications. 26, 700-711. https://www.jstor.org/stable/24701979

Bigio, E.R., Swetnam, T.W., Pearthree, P.A., 2017. Late Holocene fire-climate relationships of the western San Juan Mountains, Colorado. Int. J. Wildl. Fire 26, 944–962. https://doi.org/10.1071/WF16204

Baker, W.L., 2020. Variable forest structure and fire reconstructed across historical ponderosa pine and mixed conifer landscapes of the San Juan Mountains, Colorado. Land 9, 1–35. https://doi.org/10.3390/land9010003

Harvey, B.J., Andrus, R.A., Battaglia, M.A., Negrón, J.F., Orrego, A., Veblen, T.T., 2021. Droughty times in mesic places: factors associated with forest mortality vary by scale in a temperate subalpine region. Ecosphere 3318. https://doi.org/10.1002/ecs2.3318

Moore, M.M., Covington, W.W., Fulé, P.Z., 1999. Reference conditions and ecological restoration: A Southwestern ponderosa pine perspective. Ecol. Appl. 9, 1266–1277. https://doi.org/10.1890/1051-0761(1999)009[1266:RCAERA]2.0.CO;2

Naficy, C., Sala, A., Keeling, E.G., Graham, J., DeLuca, T.H., 2010. Interactive effects of historical logging and fire exclusion on ponderosa pine forest structure in the northern Rockies. Ecol. Appl. 20, 1851–1864. https://doi.org/10.1890/09-0217.1

Negrón, J.F., Huckaby, L., 2020. Reconstructing historical outbreaks of mountain pine beetle in lodgepole pine forests in the Colorado Front Range. For. Ecol. Manage. 473. https://doi.org/10.1016/j.foreco.2020.118270

Romme, W.H., Floyd, M.L., Hanna, D., Crist, M., Green, D., Lindsey, J.P., Mcgarigal, K., Redders, J.S., 2009. Historical Range of Variability and Current Landscape Condition Analysis : South Central Highlands Section , Southwestern Colorado & Northwestern New Mexico Table of Contents. Phys. Geogr.