>Grassland Ecology

Fire {In the Sky}

In less than an hour, flames had reduced nearly 8,000 acres of grasslands to smoldering stubble and ash. Still, this historic blaze—centuries overdue—may have been the salvation of a unique and little-known ecosystem in the highlands of southeastern Arizona.

By Keith Kloor / Photography by Michael Lundgren

When Linda Kennedy drove through the ranch gate, she saw a wall of dust and smoke heading her way. She doesn't remember feeling scared or brave. But she did keep driving. As Kennedy neared Bald Hill, a grassy knoll in a rolling open valley that stretches up into southern Arizona's Huachuca and Mustang mountains, it became obvious that the fire, fanned by rapidly shifting, 40-mile-an-hour winds, was racing forward on both sides of the road, mowing down the ranch's expansive grasslands. Rather than reversing course, Kennedy hit the accelerator, squinted harder through the fog of soot, and roared down the rocky, dirt-crusted two-and-a-half-mile driveway toward the ranch buildings.

"I didn't want the fire to be chasing me!" she recalls. Flames danced around her Ford Explorer, and the smoke turned steering into an act of faith. "There was only one place I was afraid I might get trapped, and that was a curve with trees on both sides of the road. The undergrowth was burning, but none of the trees had fallen, so I had no problem getting through."

That was about noon, on April 30, 2002, the day a wildfire blazed over 90 percent of Audubon's Appleton-Whittell Research Ranch, an 8,000-acre grassland sanctuary in the Sonoita Valley of Arizona, where Kennedy lives full-time as the assistant director. At once rugged and slightly built, she is a plant biologist and 51-year-old grandmother who looks 10 years younger. Kennedy grew up in rural Kansas, but has acquired a special fancy for southwestern grasslands—with a particular fondness for sacaton (Spanish for "big grass"), one of the 90 or so grass species found on the ranch.

Since moving to the ranch in 1999, fire has never been far from her mind. "When you live in the grasslands, it's not if the fire is going to come—it's when," Kennedy says. One of her first tasks was to help make the ranch fire-ready. This involved creating firebreaks around the ranch's buildings—several houses and dormitories, a brand-new research facility, and a barn—by clearing and thinning shrubby plants and trees. This is a constant chore for her, for Bill Branan, the ranch's director and a wildlife biologist (who also lives on the premises), and for the ranch's workers.

As ecologists, Kennedy and Branan appreciate fire's essential role in cleansing and restoring landscapes. Recent studies by paleoecologists have revealed that, historically, major fires swept through southern Arizona every 7 to 14 years, effectively controlling the shrubby buildup. But since large-scale cattle ranching arrived more than a century ago, that cycle has been thoroughly disrupted. "The fire we had at the ranch was probably similar to what occurred a few hundred years ago," Branan says.

On the day of the fire, Branan was in Mexico, giving a talk on—what else?—the ecological importance of fire. That morning Kennedy was helping a neighbor, Susan Shields, evacuate her livestock and pets, as the fire was bearing down on them. When Kennedy headed home a short time later, she had no idea that the winds had shifted and the flames had jumped a firebreak just two and a half miles to the ranch's east.

It happened so fast that there was no time for rangers to head off Kennedy before she reached the ranch's long driveway. "When I finally pulled into the parking lot at headquarters," she says, "I could see that the center and houses had not caught fire, though there were some small fires in shrubs and in the mown grass." Nobody was there. But the tractor and the hoses were out, so she knew that Freddie Gonzales, a ranch worker, had had time to mow a bigger windbreak around the buildings. It turns out that Gonzales had gone a half-mile away, to the uninhabited Appleton residence, home to the ranch's previous owners, to see if he could save it. But by then the fire was expanding, so the U.S. Forest Service ordered him, from a helicopter, to evacuate.

Kennedy arrived minutes after the fire blew through and then spent most of the afternoon in a protective suit, circling the buildings, dousing small fires. The blaze started 12 miles southwest of the ranch and "ended up 10 miles northeast of us," she says. By nightfall, Gonzales had returned, and several neighbors and a deputy sheriff checked in on Kennedy. Everyone was fine. Kennedy stayed up most of the night surveying the property, even finding beauty in the smoky gray-black sky. "All around, you could see the pinpoints of yellow-orange lights where trees were still burning," she remembers."It looked like the stars had come down to the ground."

 

The Audubon research ranch, 60 miles southeast of Tucson, is nestled in a lonely, rugged valley 4,800 feet up in Sky Islands country—so named because the surrounding mountain ranges rise high above an ocean of desert, providing largely isolated and undeveloped habitat for wildlife. The ranch no longer runs cattle but instead has become a combination of environmental refuge and ecological laboratory where the goal is to preserve a unique swath of a historic ecosystem.

Still, this pocket of Arizona is as Old West as it gets, and Sonoita—despite the recent influx of 40-acre ranchettes—looks pretty much today as it did in the late 1800s, when the first Anglo settler rode through and saw grass up to his horse's belly. The Spaniards had brought cattle to the area in the 1700s, but by the mid-1800s, decimated by malaria and the Apaches, they abandoned most of their land. By the mid-1880s cowboys ruled the range, and tens of thousands of cattle grazed in the Sonoita Valley.

Ranchers then thought the bountiful grasses were inexhaustible, and didn't yet understand the semi-arid region's weather patterns, characterized by extreme dry and wet seasons. Nor did they recognize the area's pattern of frequent, naturally occurring wildfires, which had helped maintain the grasslands over millennia. In 1891 and 1892, during an extended drought, the cattle began to starve. By 1893 more than three-quarters of them had perished, but before they did, they ate everything in sight and "pounded the range into oblivion," write Carl and Jane Bock, biology professors at the University of Colorado at Boulder, in The View From Bald Hill, a recent history of southern Arizona's grasslands that is based on three decades of fieldwork at the research ranch.

The grasslands eventually recovered and the cattle returned, but the ecosystem was irrevocably altered. Since then livestock grazing itself has served as a form of fire suppression (by keeping grass low), a condition federal land authorities have supported by extinguishing the fires that do break out—though obviously not always successfully. The result, however, is a steady creeping of woody plants and trees onto the grassy plains, rendering the area a mixed grass-shrubland.

In 1968 the ranch's owners, Ariel and Frank Appleton, removed all livestock from the property, turned it into a nature preserve, and invited scientists to make use of it for all manner of biological study. Today the richness of this legacy is borne out by the several hundred university students and researchers who flock to the ranch yearly to study everything from wintering grassland birds (such as vesper and Brewer's sparrows) to the wildlife corridors used by local mountain lions, bobcats, and other mammals. Since 1980 Audubon has partially owned the ranch, courtesy of an endowment provided by the Whittell Foundation. About three-quarters of the ranch's 8,000 acres belong to the US Forest Service and the Bureau of Land Management (BLM); the two agencies allow Audubon to manage the entire property.

 

Within 10 days of the fire, green shoots began poking out of the gray ash. Although the summer monsoons proved drier than average, dropping only seven inches of rain, by July the sacaton—Kennedy favors it because of its particular resilience—turned emerald green and reached three feet. "If we had gotten 10 to 12 inches [of rain]," she says, "the grass would have been over our heads."

The nights are already shockingly cold when I visit the ranch in November, six months after the fire, and the grass is strawlike. No matter. Kennedy and Branan are still chirping about the ranch's good fortune. "It was a great fire," Kennedy says over coffee and oatmeal my first morning at the ranch.

"We had hoped to burn 750 acres this year," says Branan, 56, a voluble, high-decibel wildlife biologist who spent much of the 1980s working in Florida to protect a watery grasslands—the Everglades. (Unfavorable weather conditions prevented the prescribed burns from going forward.) "Well, the reality is that we got 7,500 acres burned," he says. Clearly, for Kennedy and Branan, the fire was a once-in-a-lifetime experience, the ecological equivalent of winning the lottery.

"Nobody got hurt, property damage was minimal [though the Appleton house was lost], and this whole area was really fire-starved," Kennedy says. A few days later she and Branan did find several dead rattlesnakes and lizards. But animals generally survive wildfires. Rodents scamper underground to safety, and birds and large mammals fly or run away. On the plus side, migratory mourning doves, vesper sparrows, and horned larks began feasting on the fire-germinated seeds produced in abundance by the ranch's wildflowers and grasses.

Two hours later Kennedy takes me on a drive through the ranch; within 10 minutes, I feel lost in a labyrinth of grass. As we explore a field of regrowth, I let slip that all the grass looks, well, indistinguishable. Kennedy's Kansas drawl suddenly deepens as she offers up a kind of mini Grasslands for Dummies tutorial. It's not just that the grama grasses can grow to between 12 and 16 inches, she says, and that the side-oats grama can reach 2 feet. It's that many of the ranch's dozens of native grasses "perform different duties at different times of the year," and "germinate, flower, and pollinate at different times of the year, providing a continual flow of food sources for all sorts of wildlife, from the Montezuma quail to the black-tailed jackrabbit." Within minutes the scales fall from my eyes, and I start to notice all types of grasses poking out of the ground, some in even-size bunches, others more solitary and haphazardly scattered. As if on cue, a pronghorn antelope saunters into view below a distant mesa, as if to say, "See, this is what I get by on."

Our next stop is a wind-whipped basin that grades out into a brownish, oak-grassland savanna (speckled with the ever-opportunistic mesquite). I'm drawn toward a few charred trees that are spookily iridescent under the rising sun. "The night after the fire, I kept hearing what I thought were gunshots," Kennedy recalls, sticking her head inside the hollow of a blackened trunk. "I learned later that the trees were actually exploding." This dead oak, she says, is now prime habitat "for a whole range of critters. Lizards and rodents will use it as protection from predators."

Right after the fire hit, the local media descended upon the ranch. Typical questions were "How are you coping with the devastation?" and "How long will it take before the ranch recovers?" Kennedy bit her tongue. "It was hard for me to get across that we don't have to recover, because we're not injured, and that this was a very natural thing to have happened," she says, plainly still annoyed. "In fact, the only thing unnatural is that it was decades since it happened."

Fire & Rain With flames that soared 30 to 40 feet in the air, the wildfire burned a stand of sacaton grass to the ground, leaving behind bare soil and piles of ash. But sacaton will resprout quickly after a fire, especially following the summer rains.

Besides the suppression of fire and the dominance of livestock over the past 100 years, something else unnatural has since occurred at the ranch. In the 1920s and 1930s land managers searched for exotic grass species that would stand up better to grazing. "Range scientists finally hit pay dirt with the discovery, import, and seeding trials of a variety of African lovegrasses," write Carl and Jane Bock in The View From Bald Hill. The imports were planted widely in the Sonoita Valley all through the 1940s, and by 2000 had spread to 2,000 acres on the ranch. "My threshold for invasive species is not whether it’s an exotic invasive," says Kennedy, as we pull up next to a dense monoculture of Lehman's lovegrass that has crowded out all the native grasses. "It's whether it plays well with others."

Combating the exotics has so far proven an exercise in futility for Branan and Kennedy. In the past five years Branan has alternately tried mowing, burning, and pulling—mostly to no avail. Reluctantly, the two ranch managers have resorted to the ultra-careful application of herbicides. "It's the one aspect of my job at the research ranch that I dislike the most," says Kennedy. "We'll never get the exotics totally off the ranch. What we want is to loosen [their] grip on the land and prevent any further expansion."

 

After lunch it's Branan's turn to be driver and tour guide. In addition to overseeing the ranch's operations, Branan is a member of a BLM advisory group (appointed by the governor to examine Arizona land-use issues) and chairman of Santa Cruz County's planning and zoning commission.

He clearly likes to think big. "When Linda came here three years ago, she and I discussed what we wanted this ranch to look like in 100 years." It boiled down to this: If people come to southeastern Arizona in 2103 and want to see a grassland, they should be able to visit the research ranch and see one. "But it has to be robust, not just land with grass on it," Branan says. "It has to have all the wildlife and plant interaction that is historically native." The pint-size vesper sparrows darting in front of the truck seem to punctuate his point. The big wild card in Branan and Kennedy's 100-year plan, of course, is fire, or the absence of it.

We've stopped momentarily to take in the panorama beyond Bald Hill, where the Mustangs' limestone cliffs loom to the north and the Huachucas rise to the south. "This was where the fire jumped over to the ranch and ripped through," Branan says. It's also where Kennedy realized she was about to drive through an oncoming firestorm.

Earlier in the day, when she was showing me one of her beloved sacaton thickets in a wildflower-dotted gully fed by a year-round spring, I had pressed her on why she hadn't turned around at the first sign of smoke, why she had kept going. "At that point, there was no guarantee that any other place would be safer," she said. "Besides, this is my home, my responsibility." Then she pointed to a cardinal flower and started telling me how "the hummingbirds just go nuts down here" when it shoots off stocks of bright red flowers. "It's an absolute magical place at the end of August and beginning of September, when these flowers bloom and the hummers are just whizzing in and out of their grapevines." Kennedy's eyes were sparkling and reverential. The grasslands had spoken.