A few months after the wildfire, Pepe Iniguez was standing at Sykes Knob on Mount Lemmon looking out at dead trees.
The Bighorn Fire in June 2020 burned this part of the forest so hot that every tree died — the Douglas firs, the white firs and the white pines. Today, young Aspens and oaks are taking their place.
The view from this spot near Summerhaven would never be the same.
“I was in the grieving process of lamenting that we had lost that mixed conifer forest and thinking how bad that was, right?” says Iniguez, a research ecologist with the U.S. Forest Service who lives in Flagstaff.
But nearby, a couple were taking pictures and gazing at the same sight. The trees’ colors were in full autumn splendor.
“And they come up to me and they say, ‘Isn’t it beautiful?’” Iniguez recalls. “And I thought, oh my God, these people are looking at the same thing I’m looking at, but they’re not looking at what it used to be. They’re looking at what it is right now.”
Many Summerhaven residents told him they had a better view from their houses after the fire due to trees being cleared out. Mount Lemmon is an example of a wildland-urban interface, which is a place where human development very closely borders the wilderness.
In the 90s, Iniguez studied fire ecology in the Santa Catalina mountains in Tucson.
He uses this story — in the wake of the Bighorn Fire — as an example of a lesson in perspective on the good changes that can come out of a fire in spite of its chaos, and how a forest can adapt so quickly.
Indigenous methods of forest management which include regular controlled burns, have long shown that fire is a natural and important part of many ecosystems. But decades of U.S. government policies of suppressing fires allowed forest fuel to build up on the ground.
“And then once the fuels build up, then when a fire occurs, good luck trying to stop it,” says Don Falk, a professor in the University of Arizona’s School of Natural Resources and the Environment. “It’s going to be very difficult.”
In the lightning-caused Bighorn Fire, 120,000 acres burned in two months.
A high intensity burn can convert a forest into a grassland. Iniguez believes this is already happening to some extent on Mount Lemmon.
Iniguez wants to manage forests so they are preserved for future generations.
“I would hate to be the generation that lost this forest,” he says.
Now, he’s part of a growing movement of forest managers who favor allowing fire to help the forest thin itself in a more natural way, he says, like Indigenous communities did before them.
Studying ‘good fire’
Iniguez researches how fire management practices have changed in response to a Forest Service policy change in 2009 that allowed a combination of fighting fire and letting it burn for ecological benefit. The old policy required managers to declare one strategy or another for each fire.
He has looked at every fire in the Western United States larger than 10 acres and used data from weather stations to classify them based on when and where they burned.
Next, he would like to compare data from 1996-2015 to see how fire affects things like tree density and bird populations.
Following Iniguez’s line of thinking: Fire can create different types of landscapes, which spurs shifts in habitats. Those new habitats are home to diverse bird communities, and diverse tree types which will be important if forests are to survive climate change
A recent Southern Methodist University study co-authored by a team of scientists, including members of the Navajo Nation, White Mountain Apache Tribe and the Pueblo of Jemez, “suggests bringing ‘good fire’ back to the U.S. and other wildfire-prone areas, as Native Americans once did, could potentially blunt the role of climate in triggering today’s wildfires.”
The study looked at 400 years of evidence in New Mexico and Arizona’s forests to trace how Indigenous people, the Apache, Navajo and Jemez, used and lived with fire.
“What’s remarkable is that this impact of Native American fire management was evident across hundreds of square kilometers,” SMU fire anthropologist Christopher Roos said. “That is across entire mountain ranges.”
Becoming a forester
Iniguez likes to think of his work with the Forest Service as caring for and managing land that is owned by everyone.
Iniguez is from Nogales, Sonora, and moved across the border with his family to Nogales, Arizona, at age 10. Having grown up in México, where picnics and river excursions were always on land owned by someone, the idea of public lands was something that drew him to forestry.
“In Southern Arizona, most of my memories were associated with the lower elevations in the Sky Islands,” he says. “In particular, we tended to explore the creeks and rivers or anything with water to cool off in the summer months.”
Exploring the deserts and forests of borderlands helped him see nature in new, less rigid ways.
“I do remember one day we went on a day trip with some family members from Nogales to Sierra Vista, the back way (dirt roads). We stopped at Montezuma Pass, and the vast views were really amazing.
“From that spot you can see the border between México and the U.S. and you realize that nature does not care about political borders. In fact, the actual border looks meaningless within the greater landscape.”
Iniguez’s ideas of home began changing.
“From there my uncle pointed out all these other areas that we had visited on prior trips, both in México and the U.S., and that’s when it occurred to me that the Sky Islands were my homeland,” he says. “That was the areas where we were from. We had family ties, all across that area.
Years later, the forests he saw from Montezuma Pass when he was a kid, would guide his career path.
“The grasslands were just beautiful, and we could also see the forests just above us,” he says. “Later on, when I was in college trying to figure out what to study, I remember looking back at that day and thinking that I wanted to study nature and those landscapes. I just had to figure out who would pay me to study that.”
While earning a bachelor’s degree in forestry from Northern Arizona University, he started working at the Rocky Mountain Research Station, a forest-health science center, where he helped researchers learn about the habitat of the Mexican Spotted Owl.
He later studied what types of plants are important to Mexican tropical birds that moved to mountains in Southern Arizona. After graduating, he started gathering forest data in Southern Arizona, including tree density, types and sizes.
That led Iniguez to studying forest fire at the world-famous Laboratory of Tree-Ring Research at the University of Arizona, where he earned a Ph.D.
Iniguez focuses on understanding the different impacts of high-severity and low-severity fires on Southern Arizona’s mountain ranges.
Today, he describes himself as someone who breathes and thinks fire.
Healthy forest, healthy fire
Iniguez thinks the healthiest and most beautiful forests of the American Southwest are the Gila Wilderness in New Mexico and Saguaro National Park in Tucson.
That’s because they’re wilderness areas restored by frequent fires rather than mechanical thinning.
Part of Saguaro National Park stretches into the Rincon Mountains east of Tucson. Their remote nature and lack of development means there is what Falk calls “a continuous fire regime.”
Fires burn more frequently but at a lower intensity in the Rincons, and they typically do not experience a stand-replacing fire, which is a burn that drastically changes which tree species compose the forest.
The Rincons see fires every 3-10 years. The Santa Catalinas, including Mount Lemmon, have fires every 10, 15 or 20 years, says Molly Hunter, an associate professor in the University of Arizona’s School of Natural Resources and the Environment.
In 2003, the Aspen Fire on Mount Lemmon destroyed hundreds of homes and businesses, burning more than 84,000 acres over a month.
Mica Mountain, the high point in the Rincons, is an example of a healthier fire regime, Iniguez says.
Its ponderosa pine forest is met with more frequent fires. As a result, the forest is clean and open, with fewer trees. This is largely due to the mountain range’s lack of roads, which encourages a more hands-off approach and less fire fighting.
Fire suppression is often to blame for many forest ecosystems that don’t have an ideal, healthy fire regime like this one, Iniguez says.
Due to Mount Lemmon’s highway, residential development and high visitation rates, the Forest Service adopted a strategy of aggressively fighting every single fire that ignited.
The issue is that, after 100 years of fire suppression, there is now a massive amount of fuel lying around. Iniguez says his generation inherited this issue from previous generations, and he laments that the trend is still continuing to some extent.
“Anytime there’s a fire out there and we go and suppress it, we’re just passing the buck to the next generation,” he says.
Managed fires, managed intensity
In the 1970s, land managers began reversing course by allowing fire back into the equation.
Fires that are allowed to burn for the health of the ecosystem are called number of names, Iniguez says, including “prescribed natural fire” and “wildland fire use.” Currently, they are called “managed fires,” meaning they are managed for resource benefit.
One of the other options for forest health, mechanical thinning, is pricey and involves cutting a certain number of trees to open up the ecosystem and reduce the risk of a high-severity fire, he says. Managers can have more control — right down to the number of trees they want per acre. It can cost $500 to $1,000 an acre.
Iniguez says there is simply too much land for managers to handle overgrowth this way.
And in the case of Mount Lemmon, mechanical thinning is blocked by both steep topography and legality, because machines are not allowed in designated wilderness areas, which make up most of Mount Lemmon.
Managed fires are a more cost-efficient method at $100 to $200 an acre, he says.
There’s less control, and the possibility of a fire escaping managers’ control, damaging public perception of fire.
Rather than mechanical thinning, Iniguez is a firm believer in burning on what he calls the “shoulder” season, when fire conditions are less intense.
In the American Southwest, fire season peaks in May and June of each year. A midsummer fire will burn at a high intensity.
Fires during the shoulder season, before and after peak season, have lower intensity because plants are more likely to be wet.
Forests will change, and so will we
Forest managers are concerned about how Arizona’s forests will adapt and cope to climate change and drought.
Iniguez believes that plant species diversity presents a way for ecosystems to protect themselves from the effects of climate change. He compares it to diversifying one’s portfolio in the stock market.
The Sky Islands surrounding Tucson boast impressive biodiversity.
If you drive the highway up Mount Lemmon, you’ll start out seeing a desert ecosystem at the bottom that brings to mind those of México. By the time you reach the summit, the ecosystem will have transitioned to a forest that more closely resembles Canada.
Iniguez discusses how this biodiversity can provide strength. He brings up the contrasting example of Northern Arizona’s forests, which is heavily populated by ponderosa pine.
“So if that one species gets an insect outbreak then, or goes down because of drought, then we are screwed,” he says.
But if the ponderosa pine were to meet one of these dreadful fates in the Sky Islands, which Iniguez says are home to six or seven different species of pine trees, there would be more options. The ponderosa could be replaced by another type of pine, such as pinyon or white pine.
With prolonged drought and fuel build-up on forest floors, “fires are gonna happen,” he says.
“We are the richest country in the world and we have proven that we cannot stop fires,” he says.
The choice, he says, is: Do we want it to be high- or low-severity fires?
He imagines a near future where Arizonans “learn to live with fire.”
We’ll have smoky fire seasons and we’ll have to find ways to help people for whom this presents a health concern.
We’ll visit a Mount Lemmon that has more oaks and fewer pines. But we’ll visit just the same.
And we’ll have a better understanding of fire’s important role in the forests.
Visuals: Michael McKisson Editor: Becky Pallack Copy Editors: Irene McKisson. Dianna M. Náñez