Saving West's iconic landscapes from wildfires, one steppe at a time

The landscape is quintessentially western – vast expanses of sage-covered steppe punctuated by plateaus and mesas etched with canyons.

Known as the Greater Sheldon-Hart Mountain landscape, the tract is billed as one of the few remaining large parcels of sage-steppe habitat in the United States. Now, it's one of 10 pilot projects in a new US Interior Department program aimed at improving the resilience of iconic, ecologically important landscapes to wildfires.

The fire resilience concept isn't new, nor are the tools, such as removing the excess grass and shrubs that fuel fires or periodically setting fires intentionally to reduce these fuel loads. What is new is the expanded scope of that effort across millions of acres, involving federal, state, and tribal agencies, along with private landowners and conservation groups.

The $10 million pilot program comes at a time that fire ecologists see the potential for another severe year for wildfires, particularly in the drought-stricken western US, as well as an increasing wildfire threat from global warming.

"We have a lot of changes going on on the landscape, especially out here in the Great Basin and out West," adds Kim Trust, deputy chief of the Wildlife Refuge System for the US Fish and Wildlife Service's Pacific Region. "We have climate change happening and some really big issues with invasive species. The fire seasons are getting worse each year."

Against that backdrop, she explains, agencies responsible for managing federal land for natural resources, as well as for wildlife habitats, began looking more closely at using fire as a tool for improving habitat as well as reducing the risk of severe wildfires, particularly for ecosystems that have evolved in a regime of periodic, relatively low-level fires.

Other projects in the agency's new Wildland Fire Resilient Landscape program focus on forest ecosystems in California, New Mexico, and a swath of long-leaf pine ecosystems extending from northern Florida to southern Virginia. Other parcels of western rangelands are included as well.

Indeed, the Interior Department's move is part of a larger federal emphasis on fire-resilient landscapes that emerged after Congress passed the Federal Land Assistance, Management, and Enhancement Act of 2009. That led to the development of the National Cohesive Wildland Fire Management Strategy, says Chris Topik, who heads the Nature Conservancy's Restoring America's Forests program.

Within that broad strategy, the US Forest Service developed its Collaborative Forest Restoration Program. Congress included money in the fiscal 2015 budget for the Interior Department to begin a similar effort.

A major driver behind the increasing severity of wildfires is a nearly century-long, unnatural buildup in fuels on landscapes where frequent fires once kept the fuels and tree density in check. These fires tended to take out grasses, shrubs, and small trees.

With each passing decade, the size of the treetop-jumping crown fires, the most destructive to a forest, has grown from a few hundred acres in the 1950s to megafires covering hundreds of thousands of acres since 2000, says William Covington, who heads Northern Arizona University's Ecological Restoration Institute in Flagstaff, Ariz.  

Meanwhile, rising temperatures from global warming, as well as a increases in extremes between wet years and dry periods and even increases in the intensity of individual storms, also affect fire conditions, he adds.

For the Greater Shelton-Hart Mountain landscape, the goals are to remove cheat grass and keep junipers in check to ensure that the 350 species that depend on a sage ecosystem continue to have access to it. 

The landscape also represents a corridor for wildlife moving between two large wildlife refuges managed as a single complex – northern Nevada's Sheldon National Wildlife Refuge and southern Oregon's Hart Mountain National Wildlife Refuge. Ecologists hold that such migration routes are important to enable species to follow their preferred climate and habitat regimes as climate change leaves their existing ranges unsuitable for them.

"This particular landscape has not suffered some of the damaging wildfires that some of the areas around it have," says Cyndi Sidles, a fire-management specialist with the US Fish and Wildlife Service office in Portland, Ore., of a nearly 4-million-acre tract that straddles the borders where California, Nevada, and Oregon meet.

In one sense, that is a boon to for conservation. But it also is home to cheat grass. It's an invasive species whose assault has been under way for decades and which for all but a brief period during the year is inedible for most species.

"Cheat grass is a very, very fire-prone grass," Ms. Sidles says. If a fire strikes, cheat grass is faster to colonize the burn area than are native grasses because it responds more quickly to the first rains that reach the burn scar. And it's greening period is short, "curing" in about three weeks to become a heavy carpet of fuel that burns intensely.

If the relatively fire-free Greater Shelton-Hart Mountain landscape represents one end of the program's conservation spectrum, New Mexico's Valles Caldera area, near Santa Fe, represents the other end – a landscape overhauled by two large fires and one megafire since 2000. If left on its own to follow its current trajectory, fire resilience would be a pipe dream. 

 Valles Caldera is a nearly 14-mile-wide crater of an ancient volcano in New Mexico's Jemez Mountains. Its forested rim rings a expanse of trees, meadows, and summits inside the crater. The area now is highly vulnerable to wildfires, as well as insects, disease, and climate change, ecologists say.

Beyond its ecological value, Valles Caldera represents an important watershed influencing the Rio Grande River, notes Richard Middleton, a researcher at the Los Alamos National Laboratory. Dr. Middleton focuses on the impact that shifts in climate can have on hydrology and water supplies.

Although not directly involved in the project, Middleton shares areas of interest in Valles Caldera with the collaborative. One is figuring out which trees to replant in the burn scars following a fire. Those species present today may not be appropriate for the climate of 50 to 100 years from now.

The box of tools the collaborative plans to use is brimming: It can use mechanical thinning and prescribed burns to reduce fuel loads – though that is a sensitive topic given that prescribed burning accidentally led to a 40,000 acre fire in 2000 that destroyed 400 homes in Los Alamos. The collaborative also aims to restore wetlands, close and remove some roads, control invasive weeds, and stabilize the ground in burn areas.

Indeed, the combination of wildfire and drought can render the sloped landscape vulnerable to abrupt torrential downpours that pick up sediment and drive it downhill toward the Rio Grande.

Two years after the 2011 Las Conchas fire, the Los Alamos area, which includes Bandolier National Monument, was hit by an intense rainstorm, Middleton recalls. It wouldn't have been included in the top 10 storms to hit that area, he says. But before-and-after maps, using airborne lasers to render them in exquisite detail, showed that following the storm, portions of the monument's Frijole Canyon changed elevation by up to 30 feet.

"It's bad that we've had so much going on in terms of drought and flood and fire," he says. But these also make the Valles Caldera area a powerful laboratory for studying the factors affecting the landscape's resilience in the face of climate change and the moves needed to bolster that resilience, he suggests.

"The snow cover is much thinner these days in northern New Mexico. These are the kind of changes we might expect in Colorado in the next few decades," he says. Colorado hosts the headwaters for the Rio Grande and, west of the continental divide, feeds water into the Colorado River.

"In some ways, we're kind of like the canary in the coal mine," he says.