Wildfires, Climate Change, and Irvine Ranch Open Space

It’s about 10 a.m. on Thursday, Oct. 24, and it’s hot, bone-dry and windy outside the operations center. The day before this was just another conference room on the Irvine Ranch Conservancy campus, but today it’s a nerve center for the non-profit’s Fire Watch program. The half-dozen or so volunteers in the room are relaxed, but there’s concern just beneath the surface. 

The operations center is up and running because it’s a Red Flag Day–a National Weather Service designation for a day of maximum wildfire potential. This is bad enough, given how much flammable landscape there is in Southern California. But everyone in the room also knows that six hours earlier, a car hit a utility pole on Santiago Canyon Road near the 241 and burst into flames. The resulting five-acre brush fire would have been far worse had an off-duty Orange County Sheriff’s sergeant not been driving by at the time, saw the fireball from the impact in his rearview mirror and called it in, according to this Orange County Register story. It’s also around the 12th anniversary of the Santiago Fire. Considered one of Orange County’s most destructive wildfires, it burned for 19 days, scorching more than 28,000 acres throughout the Irvine Ranch Open Space, which includes Gypsum, Fremont, Weir and Limestone Canyons. 

The purpose of the operations center, as program manager Tony Pointer said, is “to keep situational awareness of what’s happening, and the locations of our volunteers.”

The Irvine Ranch Conservancy’s Fire Watch program, which started in 2006, had about a dozen volunteers back then. This year, that number has swelled to 375. While impressive, the volunteers have to monitor the 20,000 acres of Irvine Ranch Open Space that the Conservancy manages, plus the open space owned by the cities of Irvine and Newport Beach as well as land run by the OC Parks Department (which contracts the Conservancy for a variety of land management tasks).

What’s more, today is a weekday, which means there are only about 40 volunteers spread throughout the old Irvine Ranch. Posted in singles and pairs at 36 locations, they put on Conservancy vests and stand in the blazing sun watching for possible arsonists (human-caused ignition is how most wildfires start), talk to hikers about the dangers of going out on Red Flag days as well as reporting occasionally on local weather conditions. Their job is tough, and every volunteer is asked to do at least two hours, though many stay longer.

At 11:15 a.m., Pointer received a notification on his phone of a possible vegetation fire. “Who do we have at Irvine Ranch Open Space One?” Pointer asked a volunteer at one of the phones. They scanned through a log, and started making calls, advising those in the field that there’s a possible fire near Gypsum Canyon and the 91 freeway. 

Painter then turned to another volunteer in front of a laptop and two large flatscreens, which are displaying Southern California Edison’s many camera feeds posted around the region. “Bring up the Sierra camera,” Pointer said (there are dozens of feeds providing images all over the region, and Pointer seemed to have each one memorized). A few mouse clicks later, the camera came up, but showed no smoke.

Five minutes later it was all over. Pointer got word that there was no fire. “Someone’s motorhome overheated, so they called the fire department,” Pointer said. “It’s what we want to happen.” This kind of thing happens two or three times each Red Flag day, he added.

Though it’s unclear whether the Fire Watch program has actually prevented any wildfires, the Irvine Ranch Conservancy considers it a great success. “It is difficult to prove a negative, so we don’t measure the success of the program on how many wildfires we help prevent,” said Scott Graves, the Conservancy’s Communications Manager. “Instead, we look at the growth of the program (number of volunteers), the coverage we are able to provide during deployment (locations and number of volunteers deployed), and the education opportunities we provide to the public. The Fire Watch program allows the community to get involved with Wildfire Prevention, and the more we work together as a community on this issue, the better results we will see.”

Fire Watch is the most dramatic way the Conservancy is trying to protect the open space it manages, but it’s not the only–or possibly even the most important–action it’s taking. We live in a world where climate change has vastly accelerated natural fire cycles. Simply deploying more volunteers or recruiting more prison inmate firefighters isn’t enough. The land itself has become a threat in ways researchers are still trying to figure out.

A group of reporters and I got a look at this earlier this month, during a media tour of Limestone Canyon. As we bounced along dirt roads through the old Irvine Ranch land in the back of a Ford Super Duty pickup, Graves talked about how the Santiago Fire had devastated it all back in 2007.

“If you have fires every 50 to 100 years, like the area did historically, then the ecosystem can survive, even thrive,” Graves said. “But the problem is we now have fires every five to 10 years. It doesn’t give time for the land to recover. A lot of the land out here is in great condition But some of the land is degraded. This was the Irvine Ranch, and it needs help to get back to its natural condition.”

The Irvine Ranch Open Space that encompasses places like Black Star Canyon, Limestone Canyon and Weir Canyon is considered Mediterranean climate zone–which is actually quite rare around the world, according to Dave Raetz, the Conservancy’s VP and COO. “We actually rival tropical rainforests in terms of biodiversity,” he said. “This zone comprises one percent of the land mass around the world, but contains 20 percent of the known plant species in the world.”

Even today, there are still burned out oak trees throughout the Conservancy’s open space–killed in the 2007 fire. Considered a “keystone plant” in the local ecosystem, the oaks play a vital role for a wide variety of organisms. Though we also saw many that seemed destroyed, we also occasionally drove through dark and cool oak woodlands that were still intact–welcome diversions from the otherwise arid and brown land.

Dr. Sarah Kimball, a researcher with the UC Irvine Center for Environmental Biology, has studied the Irvine Ranch Open Space ecosystem for over a decade, and has co-written a few papers on how climate change is altering it. Oaks are currently a focus of her research, which should be ready for submittal sometime in the spring of 2020.

“Oak woodlands are a really important habitat type in Southern California,” Kimball told me. “They are host to so many organisms–acorn woodpeckers, but also fungi and insects. Their bark is somewhat resistant to fire–healthy oak woodlands are more resistant to fire. Non-native trees spread fires more generally–palm trees are really bad. Oak trees don’t have those negative aspects. It’s so hot this time of the year here, but oak woodlands are like being in another world.”

For the most part, as Graves and Raetz explained during our media tour, grasses and vegetation that are brown this time of year are nonnative, while anything that’s green (oaks, sagebrush, cactus, etc.) are native. The problem with an accelerated fire cycle is that it also speeds up the replacement of native species with more flammable nonnative plants, which in turn contributes to further wildfires.

Kimball’s research into how fire is altering the habitats of the Irvine Ranch Conservancy open space confirms this, and has vast implications for much of California. Here are a few of the findings from papers she’s co-written during the last few years:

* “Locations with a history of repeated fire at short intervals tend to have increased cover of nonnative grasses relative to locations that experienced less frequent fire… In other ecosystems invaded by nonnative grasses, the resulting grasslands burn more frequently than native systems due to high flammability of standing dead grass, leading to a positive feedback mechanism that forces the system to a new stable state.” (“Altered water and nitrogen input shifts succession in a southern California coastal sage community,” Ecological Applications, 2014)

* “High cover of nonnative grasses following fire may increase fire frequency, which can lead to permanent vegetation-type conversion of shrublands to grasslands… Recovery of native shrubs from fire was generally delayed and diminished with reduced water input [drought].” (also from the 2014 paper)

* “Native shrubs were generally able to recover from wildfire within several years and maintained high cover in years of extreme drought, although areas with highest shrub cover demonstrated lower resilience and were more likely to experience drought-based mortality. Non-native grasses were a persistent problem, especially after fire in grasslands, and native diversity increased in years with heavy rainfall without heavy invasive grass seed banks.” (“Resistance and resilience: ten years of monitoring shrub and prairie communities in Orange County, CA, USA,” Ecosphere, May 2018)

Of course, it is possible to fight this. Near the Augustine Staging Area in the Irvine Ranch Open Space is a small nursery run by Matilde De Santiago that aims to do exactly that. “It’s for restoration projects in this land management area,” she said during the media tour.

There, on tables with legs stuck in PVC pipes to protect against ants, De Santiago and other Conservancy volunteers grow four varieties of native plants. One of them, sage brush, was known as “cowboy cologne,” De Santiago said. It provides considerable habitat for birds, was possibly also used by the native Tongva people when they went hunting, and is native to the area.

But even with an army of volunteers, it’s not possible to eradicate every mustard plant or other nonnative species in the old ranch–there’s just too much of it. The best they can do, as Graves said, is “tip the scales in favor of native plants.”

But to do so also means stopping the shrinkage of the oak woodlands. “They’re feeling the pressure of urbanization,” said Raetz. And that’s where the long-term solution to the climate change-fueled wildfire cycle comes in: quit ripping out sagebrush to build homes on ridgelines. Building in wild areas is unsustainable, and these days, dangerous. And that means higher density living in cities. These are the kinds of choices climate change is demanding that we make.

“I think it’s possible to take a degraded landscape and return it to native-dominated plants,” Kimball said. “Though it will never be as good as it was originally.”