What if US forests don’t come back?
What if US forests don’t come back?
13 July 2018
Published by http://www.fireandrescue.co/
USA – New Mexico’s Bandelier National Monument holds clues to what may happen to forests affected by massive fires. On a warm day in April, at the outset of the 2018 fire season, Laura Trader, a fire ecologist at Bandelier National Monument, braced herself against a 50 mile per hour wind and looked out over several hundred-thousand acres of burned land in New Mexico’s Jemez Mountains. Trader was near this same mesa on 10 May 2000, when a prescribed fire lit inside the monument escaped its lines and destroyed 235 homes in the nearby town of Los Alamos. The so-called Cerro Grande Fire caused such astronomical damage that Congress allocated a billion dollars just to clean up that one fire. Bandelier’s chief received death threats in the aftermath. Trader was also here on 26 June 2011, the day when the Las Conchas Fire erupted and incinerated 43 000 acres of Jemez Mountains pine forest in 11 hours. From this one mesa, Trader has witnessed two of the most destructive fires in American history.
Though she doubts one will start here today, she cannot recall a New Mexican winter more conducive to extreme fires than this past one. But then nobody alive can, it was the driest winter in 125 years of record keeping. “Usually we’ve got green up this time of year,” says Trader, toeing her Keen hiking shoe into a grass clump that’s as brown as everything else we can see. “This year, it’s brown up.”
If it feels like America has entered an era of never-ending fire seasons, that’s because it has. Wildfire smoke is now in the air from April to December, almost three months longer than in the 1970s. The last startling news from 2017, a year packed with fire tragedies, blew out of California in December, when the Thomas Fire hopscotched through Los Angeles and became the largest in state history. This was just three months after 43 civilians died in Napa Valley fires.
Last year, for the second time in three years and the second time in history, more than 10 million acres burned nationwide. Federal land management agencies spent nearly $3 billion fighting fire, just 15 years after that figure first crested $1 billion. The total costs of rebuilding, including some of the 12 000 homes and structures destroyed last season, will likely exceed $25 billion. Here we are, a little more than three months after last year’s embers cooled and what promises to be yet another historically expensive, destructive and very likely deadly fire season is starting anew. Over the coming months, we’ll explore in this column how fires became so intense, so expensive to fight and so deadly, as well as some of the solutions being tested by top foresters, economists and scientists to restore fire’s place in the forest. In other words, we’ll ask: What is the future of fire in America?
According to Trader and many experts in her field, that question may be best answered here amid the remnants of Bandelier’s forests. What is happening here, she says, foreshadows what may be coming to many North American forests. In 1995, when Trader first came to the monument as an intern, Bandelier was forested with great stands of ponderosa pines and other conifers that had stood for millennia. Because of recent fires, much of the area is now dominated by locust shrubs; those pines may never return.
“We’ve never seen this before!” Trader yells over a gust of wind so strong it knocks her off balance. “The vegetation, the composition and structure of the forest, it’s totally different than it was!”
Trader was in her office in the recently constructed East Jemez Interagency Fire Centre, a regional command post for wildland fire managers. Surrounding the metal-panelled barn outfitted with retired helicopter rotors as ceiling fans are thousands of acres of torched and forever-altered forest, standing sticks, as Trader calls them. Fire fighters’ Subarus and trucks were backed into spaces, a cultural norm for those whose job requires quick movement, while their owners discussed risk mitigation strategies inside. “We had a relative humidity of three percent in March,” Trader says, with a laugh. She’s a small woman of around 40 with curly hair, a nose ring and a Grateful Dead ornament swinging from her rearview mirror. Three percent was two percent lower than the relative humidity on the day Las Conchas blew up. Trader’s laughing a grim laugh because this year that measurement was taken three months earlier than when that fire burned. From this point until the monsoon arrives in July, it only gets drier.
Nationwide, forecasters predict above-normal fire potential arriving for most of the West in June and lasting through September, which means we’ll likely see somewhere between seven and 10 million acres burned this season. But in a sign of just how bad the season could be for the Southwest, fires are already burning in mountains that in most Aprils are still under four feet of snow. At the time of this writing, more than a thousand fire fighters were battling some 85 000 acres of fire in the Southwest, including one blaze on Arizona’s Coconino National Forest that burned 8 000 acres in a single afternoon and has since forced more than 500 evacuations. Expect more to come. Chuck Maxwell, the lead forecaster of the Southwest’s regional fire headquarters in Albuquerque, compares this season’s outlook to 2002 and 2011, the two most destructive fire years in Southwest history. A severe drought is centred over the Four Corners region and most trees and brush, even those above 10 000 feet, are already dry enough to burn. “This year has the potential to be epic,” Maxwell says.
How the season plays out is at the whims of weather. Take last year. It wasn’t expected to be a bad fire season, let alone among history’s worst. What took many fire experts by surprise is how quickly a few extraordinary heat waves dried out forests in places that had normal or even wet winters. Park Williams, a researcher at Lamont-Doherty Earth Observatory at Columbia University who has written extensively about the relationship between climate and fire in the Southwest, told me that every degree of warming does more to promote fire than the previous degree. With hotter summers as the new normal, that goes a long way toward explaining why the western United States has experienced a 1 000 percent increase in acreage burned just since 1984.
Historically, American wildfires were as varied as the forests they burned. Depending on how often lightning struck or native peoples lit fires, sequoias in California, ponderosas in the Southwest and longleaf pines in Florida and Georgia all burned at campfire intensities every year or every ten or 20. Aspen stands in Utah’s mountains, on the other hand, need extreme fires every few centuries to regenerate. So too, at varying frequencies, do lodgepole pines in Montana and Idaho, black spruce in Minnesota and pitch pines in New Jersey. The towering flames and visceral fear those burns generated prompted the US Forest Service to treat all fires as a scourge. The irony is that 100 years of fire suppression later, the policy not only homogenised American forests, making them dense with trees of mostly the same height and age but it also homogenised America’s fires, turning more of them into the very monsters the Forest Service feared.
Unruly vegetation caused this change. Think of a campfire as fire in the Jemez a hundred years ago. Now add wood to it like you’re trying to get a steam-powered train to break the sound barrier. That’s today’s fires. Trader pulls up a chart on her computer that plots fire frequency in the Jemez. Sheep, she says, knocked the fire regimen out of rhythm when ranchers introduced tens of thousands of them to the Jemez in the 1890s. The animals grazed on the grasses that historically carried fires. Then suppression took root. Before these changes, forests here burned every five to 20 years at such low intensities that a ranger on horseback could control flames over hundreds of square miles with little more than a shovel; after, fire all but vanished. Now it has returned as Las Conchas or any number of other blazes that have yet to burn this summer.
“It’s a statement on what the structure of the forest was,” Trader says, clicking through pictures of burning forests that could be mistaken for weapons tests on Bikini Atoll. Before fire suppression, there were around 100 trees per acre. Today, in places that haven’t burned in a century, there are often 3 000.
“This view still breaks my heart,” Trader says. Over her 23-year career, she’s seen ponderosa pines disappear from this part of the Jemez. We’ve left the mesas we toured earlier and are now at 9 000 feet overlooking Bandelier’s recent major fires. Across the Rio Grande Valley, we can see Santa Fe, with the pine-covered Rockies behind it. Below us are canyons that would look at home in the Mojave. The view is a study in contrasts. Through darker lenses, it’s a look into the future of many western landscapes.
The reasons the pines aren’t coming back here are myriad. Some seem obvious: Ponderosa pines sprout from seeds held in cones and there are essentially no cone-producing trees for tens of thousands of acres. Others are less so. For example, the fires actually changed the soil’s composition. A recent study on how fire affects artefacts found that the only way to replicate Las Conchas’ heat was in a pottery kiln set to 900 degrees for 15 minutes. When Trader first came back to the park after that fire, the ash was as fine as baby powder and knee-deep. Then the rains came and swept the ash and soil into the Rio Grande in biblical floods.
“Bandelier is a canary in the coalmine for North American forests when it comes to climate change,” says Craig Allen, a researcher at US Geologic Survey who has studied these woods for most of 40 years. Under optimal conditions, the Southwest lies on the dry margin of where ponderosa pine forest can exist. Allen says the warming climate is pushing parts of the Southwest, particularly the lower elevations where ponderosa pine historically dominated, outside those margins. “As a general principle, extremes will get more extreme everywhere,” Allen says.
Most concerning for Allen is the warming temperature. According to one recent paper, the Southwest is three degrees warmer than it was in 1950. That change has already extended fire season by two additional months across much of the West, making it essentially year-round in places like California and New Mexico. In the Southwest in particular, that’s delivered nine extra critical fire danger days a year and has increased the acreage burned by a factor of ten. By century’s end, climatologists expect the average to climb another three to six degrees and the pace of acreage burned to keep pace.
Allen says the change is already visible in the Jemez. Before suppression, the largest fire he’s aware of in this landscape that killed most of the trees was on the order of 1,000 acres. Since 2000, forests in New Mexico and Arizona were torched by the Cerro Grande (48 000 acres), Rodeo-Chediski (467 000 acres), Wallow (538 000 acres ), Las Conchas (156 000 acres) and Whitewater Baldy (289 000 acres) fires, all of which burned in drought years like this one. At some point, Allen says, the megafires will become self-limiting. The holes that the previous burn tore into the ponderosa forests are slow to (or may never) regrow as forest and with less fuel to burn, the fires wither. It’s a grim thought that the most likely way out of this new paradigm is for our forests to burn themselves out.
“There are plants out there,” Trader says, nodding toward the canyons radiating out below us. “Vegetation is coming back slowly. It can’t not. It just won’t look anything like it did before.”
Another strong gust strafes the rock outcrop we’re sitting on. A tornado of dust spins toward Santa Fe. A burned tree falls somewhere below and my wife texts me an emergency warning. A fire has just started in a patch of unburned forest between our home and the monument. The road I drove to Bandelier has been shut down. We’re in for another long fire season.
Source: Outside Online
