Wildfires in the West, especially what are being termed “mega-fires” can be terrifying and destructive events. Terms such as “environmental disaster” and “moonscape” are often heard in media reports discussing the effects of such conflagrations, further feeding such fears of fire in the West. These terms are symptomatic of a collective emotional response to wildfires. An emotional response we are encouraged to feel as small children. Perhaps the most memorable example of this indoctrination is the lovable Smoky the Bear who has been scaring children straight about wildfires since the 1940s. These stories along with dramatic images of charred trees and blackened soil reinforce the notion that burned forests are completely destroyed, essentially converted to desolate wastelands for decades to come. But what do these landscapes actually look like if we continue watching long after the smoke clears? The Rim Fire, a mega-fire started by a hunter in August of 2013, dramatically burned through the Toulumne River watershed into Yosemite National Park. The Rim Fire burned through an area approximately twice that of Lake Tahoe and is, to date, the largest wildfire in Sierra Nevada history and the third largest ever recorded in California. The fire encompasses huge swathes of land with near-total mortality of pre-fire vegetation and has undoubtedly left a huge mark on the landscape. Certainly these fires can be tragic to the people who depend on these forests for their livelihoods, but is this truly an environmental disaster?
Following an intense wildfire, a ponderosa pine must start from scratch, from a cone dropped by a scorched adult or gathered from a nearby surviving stand and cached by a forgetful Clark’s Nutcracker. The process can be slow and, in places far from surviving trees, it may not begin for decades. But not all species suffer the same setback and some begin bouncing back shortly after the flames are quenched. For example, fire-killed hardwood species like black oak, white-leafed Manzanita, and (lamentably) poison-oak, are able to utilize unburned resources stored in their roots and re-sprout within a year. Wood boring beetles arrive almost immediately following the fire to begin feeding on the dead standing wood. Snag forest specialists such as the Black-backed Woodpecker follow close behind feeding on these xylophages and excavate nest cavities in the remaining arboreal skeletons. New tree and shrub recruitment may be measured on the scale of years, but a recently opened canopy is an ideal setting for the spring burst of blues, oranges, and greens of wildflowers that have been patiently awaiting this new infusion of light and resources. Hardly the purported moonscape from months before.
As the years since fire accumulate, annual plants give way to the slow-starting shrubs and soon the field biologist or mushroom hunter finds himself fighting through waste-high deer brush and scratchy wine-thorn. At this stage shrub-loving wildlife move in, drawn to these ephemeral shrublands, now rare in a fire-suppressed landscape. To observe these changes one is not obliged to wait the interceding years, but only trade space for time and move on to one of the numerous older fires in the Sierra Nevada. The Power Fire, 35 miles north of Rim as the raven flies and a decade later on the successional timeline is one such example. Standing in the midst of Deer Brush it’s easy to glimpse blue flashes of the Lazuli Bunting flitting through the foliage and hear the scolding of a House Wren near its nest cavity (acquired secondhand, courtesy of a more industrious woodpecker from years past). The decade-old fire is still strikingly apparent, with the charred matchsticks of dead but standing conifers looming over the dense re-growth below. As these old snags begin to fall under years of decay, they supply crucial structure to the understory for chipmunks and amphibians but also dry fuel for the next inevitable fire.
Far from a wasteland, this mid-successional state contains too much life in the eyes of some. To expedite a return to its pre-fire condition, this is when the forester may turn to herbicide or mechanical mastication to knock back shrubs that steal water and nutrients from more economically important species. Eventually converted to timber (as cows are converted to beef), these species will someday be used to build our children’s homes. Or perhaps they will be maintained as mature plantations to hold back just a bit of the climate-warming carbon we’re steadily adding to the atmosphere. Or maybe due to a lack of funding or change in policy, the land is ignored and left to a more natural, more chaotic – also potentially more flammable – but more diverse successional trajectory.
In some areas hardest hit by these mega-fires, it will take decades or even a century to return to a forested state. Without human intervention, some areas may never again be a conifer forest as species struggle to keep pace with a warming climate. Instead hardwood trees may become dominant or montane chaparral may find a more permanent place. Due to fire suppression, densely planted forests, and a warming climate, we are seeing larger and more intense fires in dry western forests than was the norm a century ago. These events can be devastating for those who live nearby and are often symptoms of unhealthy forests and a disrupted climate. We can certainly manage our forests better to encourage fire patterns that result in improved ecological and economic outcomes, but in the meantime let’s not resort to hyperbole or fatalism, and consider a more nuanced and far-sited perspective.
There are, however, difficult choices ahead. Do we stay the course and try to suppress fires at increasing costs to taxpayers, at increasing risk to lives, and with decreased success? Do we instead return to fuels management through mechanical means and reduce stand density, hoping to reduce these large high intensity events? Do we provide the incentives necessary to allow fire managers to adopt the ’let burn' policies that exist within our public agencies? None of these are foolproof actions with universal popular support. Thus we need greater education and citizen action to help our decision makers choose the path forward for our western forests.
For more on this topic and some real nice photos of the Rim Fire see this recent Audubon Magazine article. Also see Malcolm North and others’ original Science article about improving forest and fire management in these forest types.
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