2015 was a bad year for forest fires. Here, the Wolverine Creek Fire, northwest of Lucerne, Washington. Photo courtesy of the U.S. Forest Service.
Parts of the arid West are so biologically different than the temperate East that they seem like they’re on a different planet. Even places that sound like they should be familiar – a forest, for example – are not. I grew up in Vermont and still remember my first trip to Inyo National “Forest,” which stretches from California to Nevada, and which, to my eye, appeared to have more sagebrush, cows, craters, and lava flows than trees.
I now live in Jackson, Wyoming, which would be more recognizable to an easterner. This intermountain region includes parts of Idaho and Montana and boasts an impressive trees-to-people ratio. The forest is a part of our everyday lives: there are public radio announcements about timber products; you can find hikers, hunters, mountain bikers, and horseback riders recreating in the forest on any day of the week; there are signs everywhere emblazoned with slogans like “Keep Your Forests Green.”
Spend any amount of time here, and you’ll come to see that such public service announcements are not throwaway warnings. The forests burn here. Often.
Last summer was an especially bad year for fires. Though no fires burned in this part of Wyoming, smoke from the fires in California, Oregon, Washington, Idaho, and Montana all blew here. At Teton Science Schools, where I manage field education programs, the smoke forced fire ecology, western fire history, and future fire predictions and management implications to the forefront of our field science curriculum. During one of our programs in August, for example, there were 1.3 million acres on fire at one time across the west, from as many as 76 big, active fires. There was also a large red-flag warning zone surrounding Jackson, meaning that if a fire started, it would spread rapidly because of high temperatures, low humidity, and high winds. The summer would prove to be a record-setter: 10.1 million acres of forest burned, an area one-and-a-half times the size of Vermont; 4,500 homes were destroyed; and 13 wildland firefighters lost their lives.
It can be hard – as western forests burn and you can taste the smoke in the air – to remember the many ecological benefits of wildfire. Fires are a critical part of wildlife habitat, nutrient cycling, plant diversity, and ecosystem health in western forests. Here, in the Greater Yellowstone ecosystem, we have several fire-dependent tree species, including lodgepole pine and Douglas fir. Other species, such as aspens and willows, along with cavity-nesting birds, are not necessarily fire-dependent but do benefit from the heterogeneity that fire creates.
Wildfires are also an important part of western forest history, a history that, to me, feels much closer – more apparent in today’s trees – than forest history feels on the East Coast. Even as late as the 1890s, United States Geological Survey workers in Jackson wrote of “fires which have swept over the country so completely and persistently that scarcely any part has been entirely exempt from them, while nearly all portions have been burned again and again within a generation.”
Ask anyone in New England what they think about wildfire, and the answer will largely be theoretical, and maybe not even linked to forests. Ask anyone in the West, and the answer is going to be based on lived experience and closely linked to forests, whether from hiking through a stand of snags, clearing “defensible space” around a home, or watching a local mountainside go up in smoke.
Out here, land management has evolved alongside the understanding of fire. We’ve come a long way from thinking of wildfire as “a great obstacle in the way of the practice of forestry,” to quote Henry Graves, an early U.S. Forest Service chief. Some of the smoke we experienced this past summer in Jackson, for example, was from prescribed burns in Grand Teton National Park, where fire is used to encourage native plants to return to what used to be ranchland. In a nutshell, fire management in western forests has gone from a doctrine of complete suppression everywhere to “let burn” policies in wilderness areas, coupled with gigantic firefighting efforts around population centers. (Fighting the fires of 2015 cost the government $2.6 billion.) The goal – at least since the 1990s, when ecosystem management became the official policy of the U.S. Forest Service – has been to manage wildfires in ways that maintain or mimic a forest’s natural fire cycle. I think of this as adhering to Aldo Leopold’s warning that “to keep every cog and wheel is the first precaution of intelligent tinkering.” Usually, we imagine those cogs and wheels as species to be kept from going extinct, but we can also think of them as the abiotic forces, like fire, that keep our forests ticking even while we tinker.
Applied to the Yellowstone area, though, this policy starts to get tricky, and the difficulties of western forest management become clear. There’s a general sense here that all fuel reduction is good and all fuel buildup is bad, and a lot of resources are spent thinning the forest to prevent fires. But there is huge variation in forest type here, meaning that a blanket fire-management system is no better than blanket fire suppression. In dry, low, arid pine forests, fire is driven by fuel build-up, with climatic conditions such as temperature and humidity playing relatively small roles. In these forests, reducing the fuel load is essential to reducing forest fires. However, in the high altitude, fir-dominated, wetter parts of the western landscape – the subalpine canyons of the Tetons, for example – fire is driven not by fuel load but by climate. Reducing the fuel load in these forests does nothing to mitigate forest fires, and yet, at least here in Jackson, forest management for fire has come to mean fuel reduction, everywhere, and nothing else.
Complicating matters is that it’s getting harder to determine what baseline fire cycle is “natural” in a place where climate, water supply, economy, and human population have been changing for decades. Data from 1974 to 2004 show that as spring and summer temperatures increase above average, so does the number of large (greater than 500-acre) forest fires. Since the 1970s, more acreage has burned each decade – to the extent that in the 2000s large fires were over 480 percent more frequent and burned 930 percent more area than in the 1970s. While changes in fire-management policy have contributed to this trend, these numbers also correlate to increases in average temperature. Some scientists predict that fires the size of the 1988 Yellowstone fire – which, at the time, was an anomaly in terms of size – will become the norm for forests of the Intermountain West by 2050. The Greater Yellowstone ecosystem could shift from a fire cycle of 120 years to one of less than 10 years by the end of this century. Can the cottonwood trees along the Snake River withstand a 10-year fire cycle? What about the stands of lodge-pole pines covering the glacial moraines in the valley? Or the massive Douglas firs on the Tetons’ lower ridges? Should fire management work to protect and maintain those trees? Or should it shift as the baseline fire cycle shifts to recognize a new reality? Western forests may face massive changes in composition over the next few decades, and western communities and economies that depend on those forests will have to respond.
I love living in these forests. Elk walk through my backyard. Moose come during the night to eat the willows outside my bedroom window. I can hear owls hoot, and I observe the daily flight patterns of hawks without leaving my deck. These western forests hold an expansiveness and wildness that is unique to the region. Wildfire, though, is our reality check. Today’s forest fires are not the fires of the past, and they are taking us, and our forests, into a different future.