What if the forests won’t grow back?

Many forests in the West are adapted to fire, but scientists are increasingly worried the hundreds of thousands of acres that burned in massive wildfires may never return.

When Jonathan Coop was 4 years old, he watched ash rain down from the sky. 

The year was 1977, and a fire was burning on the Pajarito Plateau, canyon country in the Jemez Mountains of New Mexico. 

From his backyard in Los Alamos, Coop saw a plume of smoke rise from the mesa just outside of town.

The paradigm of forest ecology had yet to shift when he explored these charred forests in his youth. Fire was destructive, but eventually the trees grew back. The ponderosa pines that dominate the dry landscape of the Southwest, trees that were adapted to flame, would drop their seeds, and ash would make way for saplings. 

But after decades of fire suppression and warming temperatures, growth after destruction is no longer a guarantee. The fire that burned through the Pajarito Plateau during Coop’s childhood wasn’t the last. The Dome Fire came in 1996, then the Oso Complex in ’98, the Cerro Grande in 2000, and the Las Conchas in 2011, which consumed over 150,000 acres, making it the largest wildfire the state had seen at the time. 

Coop is now an ecologist living in western Colorado, and researches what the impacts of repeated and intense wildfires like the ones that ignited in the Jemez Mountains could mean for the future of forests in the West. 

He’s finding the forests of his childhood won’t grow back in his lifetime, maybe not ever.

“It would take hundreds of years for old trees to grow back in those areas. But increasingly, we think there’s really not much hope those forests will ever come back,” he explained. 

The scars in the Jemez Mountains are just some of many that have burned deep and wide in the forests of the West in the last decade. From the Sierra Nevadas of California, to the boreal forest of Alaska, fires have been consuming ever larger chunks of land, and trees. While fire is an important part of life in many forests, the combination of hotter, drier temperatures and bigger, more frequent and severe blazes has scientists concerned that trees burned down may never grow back, giving way to invasive grasslands and shrubs that thrive in the new conditions. This shift in ecology could have a wide range of impacts: from the economic to the psychological.

Scientists like Coop are increasingly asking a once impossible question: What if the forests don’t grow back?

A firefighter walks through the area burned by the Las Conchas Fire near Los Alamos, N.M., on Thursday, June 30, 2011. | Jae C. Hong, Associated Press

A new kind of fire

In many forests across the West, fire plays an important role in the ecosystem. When high severity wildfires rip through patches of slender lodgepole pines, their pinecones open and release seeds when temperatures reach between 113 to 122 degrees. Ponderosa pines, giant sequoias, and even Douglas firs are also adapted to lower severity fires.

But scientists are now seeing that decades of fire suppression leaving an abundance of fuel on the forest floor have resulted in massive, high severity fires that take out tens of thousands of acres of vegetation are becoming more frequent. 

In the Southwest, ponderosa pines and dry mix conifer forests historically experienced a lot of fire, Coop explained. The blazes were mainly low in severity and effectively removed brush and dead debris that, when allowed to build up for decades, would otherwise result in the massive fires the West is now contending with. 

A warming climate is also amplifying the long-term devastation. When large, high severity fires burn in warmer and drier forests, more trees are killed and the seeds that would spawn new life wiped out. While ponderosa pines are adapted to fire, their seeds are also heavy and don’t travel great distances — maybe a 100 meter radius at most. Those conditions make regeneration improbable when tens of thousands of acres of forest are decimated.

“Even if seed sources are present, the post-fire climate conditions are becoming increasingly dry and warm, and there’s a reduced probability that seeds can turn into seedlings and young trees,” said Sean Parks, a Forest Service ecologist who has worked with Coop. 

Forest conversion

Once fire occurs, surviving seeds become saplings, but if another fire burns through the same area a year or two later, nothing but white ash streaks the forest floor. New life and future seed sources are obliterated. Parks and Coop point to the Jemez Mountains as a prime example of the shifts that occur with constant reburns. 

“We are seeing a lot of fires burning in California, and in Arizona, and New Mexico and even up here in Montana, where I am,” Parks said. “In some cases, we’re seeing recovery back to the pre-fire forest conditions. But in some cases, we’re not.”

Instead, a process known as forest conversion kicks in, where shrubs and grasslands take over land that was once dominated by trees.

On one research trip to northern New Mexico’s Jemez mountains, Parks couldn’t believe trees had once grown in the area now overrun with New Mexico locusts, a fire-loving shrub with small pink flowers and thorns that can draw blood.

“I’d be like, are you sure there was a forest here before? Because there was no evidence of it,” Parks recalled. 

Coop said there are now tens of thousands of acres in the eastern Jemez Mountain range that don’t have a single tree on them. 

In a paper published in BioScience, researchers estimated that the combination of fire and climate change could reduce forests in the Sierra Nevadas by 5.8% and between 1.6%-15.1% in the Intermountain West. The Southwest is particularly at risk — where already hotter and drier conditions are getting more extreme, and the authors estimated that up to 30% of forests could be at risk of wildfire induced conversion. 

The loss of forest not only has a profound cultural impact on the people that love and call these landscapes home — but has the potential to impact watersheds, industries reliant on timber and potentially tourism reliant economies. 

Two high-severity fires reshaped this ponderosa pine forest in northern New Mexico into a landscape dominated by shrubs and nonnative grasses. | Sean Parks, Forest Service

What we lose

The impacts of forest conversion on the communities that rely on and love the disappearing trees remains an open question. 

“What does it mean in terms of loss, not to just have a small amount of area burned, but half your state?” asked Amanda Cravens, a research social scientist at the Fort Collins Science Center in Colorado. “We’re starting to ask that. We don’t have answers yet because it’s in the process of happening. 

There are four groups that will be impacted by forest conversion, Cravens said: resource users (everyone from cattle ranchers to ski touring companies), the communities surrounding a burned forest, land managers and the wider public that has an emotional attachment to the land. 

“You might see fewer tourists visiting an area, or ranchers who have grazing permits in a forest might not be able to rely on that area for feeding livestock,” Cravens explained. 

While the economic impact is the most obvious, she’s also interested in emotional and psychological impacts: What happens to our sense of place when a ponderosa pine forest turns to grassland?

“If something burns overnight, and then it’s very slowly regenerating, it’s created this new ecological reality very quickly,” Cravens said. “And that’s challenging for someone to adapt to because their expectations don’t have time to adapt.”

Bring the forest back

“If you had a favorite forest, people mourn the changes,” said Anne Bradley, forest program director for the Nature Conservancy in New Mexico. She also grew up in Los Alamos and explored the Jemez Mountains. Many of the meaningful forests she used to hike as a kid are no longer there. 

“A lot of places in the West have now had their seminal fire, the one that really opened their eyes to how bad the situation is,” Bradley said. For New Mexico, that was the Las Conchas fire in 2011. 

Before Las Conchas, Bradley’s work mainly focused on reintroducing prescribed burns to restore lower intensity fires as part of the ecosystem and reducing fuel loads built up by intentional fire suppression.  

Now she works on replanting burned areas where natural reforestation is unlikely to occur. Forest conversion can impact the watershed, resulting in destructive mudslides, and change the shape of stream channels, Bradley said. These are just a few of the reasons reforestation efforts are important. 

However, the acres burned in the Jemez Mountains were vast, and the continued threat of wildfire means years of progress could be wiped out in a matter of days. 

“We’re just behind the curve,” Bradley said. “We have to work faster to replant, and we have to reduce fire risk everywhere, as fast we can.”

The Nature Conservancy has been strategically replanting trees. Rather than planting rows that would quickly spread fire, they’ve been planting islands, or pods, of trees that would confine the destruction to one patch of trees. They’re considering what rising temperatures could mean for certain species, and choosing seeds that will thrive in a harsher environment. 

Their seedlings come from an experimental nursery in Mora, New Mexico, about a two-hour drive east of Los Alamos. 

“We know what we need to do,” Owen Burney, who runs the nursery in Mora and is a professor at New Mexico State University, said. “We just do not have the funding or resources to do what we need to do in terms of preemptively preventing or managing these fires.” 

The greenhouse at the John T. Harrington Forestry Research Center in Mora, N.M., provides seedlings for reforestation efforts across the state. | Owen Burney, New Mexico State University

Falling short

Burney is the second largest seedling producer in the Four Corners area and is currently producing about 100,000 seedlings per year, but has the capacity to produce up to 300,000. “Which is nothing,” Burney scoffed. “That’ll hardly cover 2,000 acres.”

He estimates up to a billion seedlings would be needed to reforest about four million acres in New Mexico, Utah, Arizona, and Colorado alone.

“The way I look at it is humans have already put their finger in the pond and created the ripple, the force that we see now is our fault. We suppressed fire. We mismanaged these forests. The density is our fault,” Burney said. “So as a result, it is our responsibility to put it back on the right trajectory.”

But the target is moving as more land goes up in flames each year. The seedling capacity and resources needed to reforest is nowhere near what it would need to be to truly offset the forests disappearing each year. 

Back in Colorado, Coop tries to accept the change.

“I think I’ve almost come to terms with it,” he said in a phone interview.

Some of the forests he grew up wandering through are now grassland. Different species are thriving where ponderosa pines once grew. 

He reminisces about the tassel-eared squirrel, “the most charismatic squirrel,” that thrives in old growth ponderosa pines. He talks about the amount of time it took for these forests to grow, and how a fire like the Las Conchas quickly altered the landscape seemingly overnight.

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He’s not completely jaded. The ponderosa pines are an amazing species. 

“It’s not the end of the world, but it can feel like the end of the world,” Coop said. 

 It’s just the end of the world as we knew it.

Correction:  A previous version of this article misspelled the 2011 Los Conchas that burned in New Mexico. It was the Las Conchas fire.

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