Examples of very high hazard fences and mulch: A) parallel privacy fences, B) double lattice fences, C) wood-plastic composite #1 fence, D) good neighbor fence, E) rubber mulch. (From the NIST research)
Three weeks ago a television station in Dallas, FOX 4, streamed live video as a grass fire spread across a field and reached densely-packed houses, eventually destroying 9 and damaging another 17. There were several reasons why the structures were so vulnerable, including medium-heavy vegetation in the field adjacent to the property lines, very little impact from efforts of the fire department to stop the spread, no air support, and wood fences that connected all of the properties on the rear and sides of the homes.
Parallel fences burn as grass fire spreads into neighborhood in Balch Springs, Texas, July 25, 2022. Image from video by FOX 4 Dallas-Fort Worth.
On August 10 the National Institute of Standards and Technology (NIST) published results of 187 experiments that examined how fire spread toward a structure is affected by combustible fences and mulch under conditions that may be encountered in a wildland-urban interface (WUI) fire. They looked at mulch only, fence only, fence plus mulch, parallel fences, and long range firebrands. The materials studied were western red cedar, California redwood, pine, vinyl, and wood-plastic composites. Fence styles included privacy, lattice, and good neighbor (board on board).
A small structure was located between zero and up to six feet downwind of the fence or mulch bed as a target for flames and firebrands. A target mulch bed at the base of the structure tested the ability of firebrands produced by the burning fence and mulch bed to ignite spot fires that threatened the structure.
While not many homeowners place store-bought mulch below their fences, it can be common for debris to build up along the base on one or both sides. The amount and flammability can be extremely variable, but the researchers’ use of mulch gave them control over the flammable material which could be consistently duplicated in their experiments.
The study found that firebrands capable of igniting spot fires downwind were generated by nearly all combinations of fence and mulch tested in this study. All wood fences with mulch at the base caused spot fires in the target mulch bed. Spot fires were often ignited within a few minutes of mulch and fence ignition. Shredded hardwood mulch and pine bark mulch burned and emitted firebrands for longer than an hour. Ignition of spot fires was also demonstrated from firebrands transported by the wind over distances as far as 156 feet from the burning item under high wind conditions and over a paved surface.
The research generated a number of recommendations:
Avoid parallel fences, to reduce exposure to large flames. Parallel fences can result in highly hazardous fuel accumulation corridors that are difficult to access and maintain. Spacing of 3 feet between fences is not sufficient.
Avoid proximity to other combustible fuels, to reduce fire intensity and limit fire spread. This includes fuels above the fence and fuels across parcel boundaries. Avoid mulch at base of fence.
Avoid proximity of combustible fences to residence, including neighboring residence, to prevent direct ignition.
Fire spread is more likely with wood and wood-plastic composite fences than with fences made of vinyl or noncombustible materials such as stone, brick, or steel.
Keep fence and yard clear of debris, to reduce the amount of fuel and potential pathways for fire.
Harden structures against firebrands to prevent structure ignition from embers produced by fences or other combustible sources.
The video from the July 25 fire in Texas does not clearly show the fences between the residences, but it is likely that they directly connected to the structures. An example is seen in the photo below of two homes in Superior, Colorado, one of the communities devastated by the Marshall Fire that destroyed 991 structures south of Boulder December 30, 2021.
File photo of fence connecting houses in Superior, Colorado. July, 2012 Google image.
The images below are from the FOX 4 Dallas-Fort Worth video shot July 25, 2022.
Fences burn as grass fire spreads into neighborhood in Balch Springs, Texas, July 25, 2022. Image from video by FOX 4 Dallas-Fort Worth.Fences burn as grass fire spreads into neighborhood in Balch Springs, Texas, July 25, 2022. Image from video by FOX 4 Dallas-Fort Worth.Fences burn as grass fire spreads into neighborhood in Balch Springs, Texas, July 25, 2022. Image from video by FOX 4 Dallas-Fort Worth.
Most structures that burn in a wildfire are not ignited by direct flame impingement, but by burning embers that are lofted and carried downwind ahead of the fire. At Wildfire Today we first covered the role of embers in igniting structures in 2010, a concept brought into the public consciousness by Jack Cohen, a researcher at the Missoula Fire Science Lab. To reduce the chances of a home burning in a wildfire, the most bang for the buck is to concentrate on the Home Ignition Zone. The flammable material near the structure needs to be modified, reduced, or eliminated to the point where multiple burning embers landing in the zone will not propagate the fire and spread to the structure.
Person suspected of stealing solar panel and battery from Oregon DOF fire camera system August 14, 2022.
From the Jackson County, Oregon, Sheriff’s Office, August 16, 2022:
Jackson County Sheriff’s Office (JCSO) is investigating the theft of Oregon Department of Forestry (ODF) equipment stolen from a lookout tower in the Prospect area (map). Two men broke into the tower on Sunday afternoon August 14, 2022 around 12:45. The thieves stole batteries and solar panels used to power the lookout tower’s fire detection camera. With these items stolen, the camera is no longer operational, leaving a hole in the camera network and taking away the opportunity for early fire detection.
The ODF Southwest Oregon Detection Center is a system of cameras across Jackson and Josephine counties used to monitor rural areas in an effort to catch fires at a small size, provide critical fire information to firefighters responding to active incidents, and allow the department to use resources more strategically. This particular tower enables early fire detection for the northeastern portion of Jackson County near Prospect. ODF is currently working as quickly as possible to get the camera system back up and running. The list of items stolen includes batteries and solar panels to power the cameras.
If you can identify the subjects in the video and photos or have any information about the theft please call the JCSO Tip Line at (541) 774-8333 and reference case # 22-4725.
Solar panel that was stolen from Oregon DOF fire camera system August 14, 2022.Person suspected of stealing solar panel and battery from Oregon DOF fire camera system August 14, 2022.
There is also a video on Facebook showing two people climbing the stairs to the lookout.
“As soon as we found out, we started re-ordering all of the batteries, solar panels and specialty pieces that make this system run, but the bad news is a lot of these things are hard to come by and shipping can take some time,” said the Oregon DOF. “Getting the site back up and running is one of our top priorities, but in the meantime, we have firefighters out patrolling the area to make sure we’re still finding fires quickly and keeping them small.”
From the National Park Service, Yosemite National Park, August 12, 2022:
“We are sad to report that pioneering Yosemite scientist Jan van Wagtendonk died on July 15, 2022.
“Jan was a Yosemite and National Park Service legend: an accomplished scientist, a preeminent fire ecologist, a wilderness advocate, and a beloved colleague. He was an innovative wilderness manager, coming up with the trailhead quota system that we still use today to protect wilderness while ensuring that hikers are free to enjoy that wilderness on their own terms. His impact affects fire policy to this day as one of the authors of the first federal fire policy in 1995. Jan possessed an amazing intellect, deep humility, a sharp wit, and a profound love of Yosemite and the Sierra Nevada.
“Jan was a strong advocate for returning fire to the Sierra landscape. His pioneering use of prescribed fire in the early 1970s in and around the Mariposa Grove started us on the path to reestablishing an ecological balance lost in over 100 years of fire suppression. There is poetry, in the words of Jan’s son Kent, that in Jan’s final days the fruits of those efforts had a direct and dramatic effect in saving the Mariposa Grove from the Washburn Fire, which started just outside of the grove.
“Our heartfelt condolences go to Jan’s family and wide circle of friends and colleagues. He was one of a kind, and will be deeply missed.”
The article below from the US Geological Survey was originally written in 2020, based on an interview with Jan van Wagtendonk in 2019:
The first thing to know about emeritus scientist Jan van Wagtendonk is that he loves trees—always has and always will. As a kid, he looked at trees, inventoried trees, wrote a report on trees. One of his neighbors as a kid described young Jan by saying “I never saw him inside.”
He was a forest scientist before he even knew that was a thing you could be.
At age 13, van Wagtendonk was on two-months long family camping trip when he met a forest ranger. Upon realizing that he, too, could work with trees for a living, van Wagtendonk decided to become a forester. Several years later, he entered the forestry school at Purdue University in Indiana.
Wildfire 101
One day in college, van Wagtendonk found a listing on a campus bulletin board for a summer job on a wildland firefighting crew in Oregon. He applied, got the job, and headed West. It was his first experience with wildfire, the subject that would become his life’s work. Unsurprisingly, he loved Oregon—it had great trees—and ended up transferring to Oregon State University. He would spend several summers on fire crews in Oregon and then Alaska, first mopping up the final embers of wildfires and later working as a smoke jumper. The job was to put the fires out. Years later, his job became more about the opposite—reintroducing fire to Western forests.
Van Wagtendonk claims he “had no inkling about fire ecology at all” at the time, but he thinks that several experiences he had during his smoke jumping days may have shaped his thinking as a forest scientist and led him to fire ecology. In one instance, he was assigned to a put out a fire in a remote part of Alaskan tundra. The landscape was dotted with bird nests. The flames were about two inches high, and the fire crept along at about a foot per minute. Van Wagtendonk was struck by the birds’ seemingly nonchalant reaction to the fire: “the fire would be coming, they’d go up like this”—he mimes a bird flapping its wings and rising into the air a few inches as he tells this story— “fire’d go by, and they’d go right back on the nest.”
Many wildfires, he found, were not destructive. They burned slowly, part of the landscape.
After graduating from Oregon State University, van Wagtendonk served in the army as an officer in the 101st Airborne Division and as an advisor to the Vietnamese army. But after four and a half years, he was ready to move on and applied for graduate school, eventually ending up studying fire ecology under Dr. Harold Biswell at UC Berkeley.
Bringing Fire Back to the Forest
Van Wagtendonk began his study of fire ecology just as it was coming into its own as a field and taking forestry by storm. When van Wagtendonk was an undergraduate forestry major, fire ecology was only obliquely mentioned.
Dr. Harold Biswell (L) and Jan van Wagtendonk NPS sit against a ponderosa pine near a prescribed fire in 1970 in Yosemite National Park. Van Wagtendonk’s dissertation work on prescribed fire in Yosemite around this time led to prescribed burning guidelines still in use in Yosemite today, and a long career in forest and fire science with the federal government.
At the time, he says, “fire had not been truly accepted as an academic discipline, certainly not something you tell people you’ll set.”
Biswell, van Wagtendonk’s graduate school mentor, was something of an outlier. Biswell would conduct prescribed burns and then take students, scientists, ranchers, land managers, and interested citizens out into the field and show them what he was doing.
Those efforts paid off. By 1968, the year that van Wagtendonk began his doctoral dissertation, lessons from fire ecology were starting to reshape federal fire management policy. The National Park Service, in particular, began incorporating prescribed fire programs in recognition of the ecological role of wildfire; other agencies followed suit in the decade that followed.
Van Wagtendonk’s dissertation research played a major role in this transition. Biswell’s guidance for prescribed burning was based on experience.
“He could go out in the woods and snap a twig and say, okay it’s ready to burn,” as van Wagtendonk tells it. That method wouldn’t do if prescribed burning was to be adopted more broadly. For his dissertation, van Wagtendonk set out to quantify Biswell’s prescriptions. Van Wagtendonk conducted his work at Yosemite National Park after being turned down by the Forest Service. The result? A set of guidelines for prescribed burning that are still in use in Yosemite today.
From Wilderness Management to Megafires: A Career at Yosemite
Soon afterwards, van Wagtendonk was offered a job at Yosemite—and 48 years later, he’s still there, first as an employee and now as an emeritus. The decades have brought changes—to fire ecology, to the park, and to federal government science–and lots of fascinating research about fires, forests, and the way people engage with wild places.
In the 90s, van Wagtendonk moved from the National Park Service to the USGS along with many other federal scientists, keeping his home base at Yosemite. He was among the original scientists of the USGS Western Ecological Research Center that served on the founding Science Council under its first Director, Anne Kinsinger, who is currently the USGS Associate Director for Ecosystems. That Council helped form the Center into the outstanding scientific institution that it is today.
Van Wagtendonk’s research over the years has touched on many aspects of fire science. He has developed methods for mapping fuel types, assessed the effects of fire suppression and fuel treatments like prescribed fire, analyzed patterns of lightning strikes, and studied the influence of fire on owls and small mammals. Over the years, van Wagtendonk has incorporated new technology and methods to the study of fire and wilderness, including GIS, remote sensing, and computer modeling, not only using these tools but also publishing highly-cited guidance on using these tools for fire science.
Van Wagtendonk’s work hasn’t been limited to fire research. Early on in his time at Yosemite, he began to study recreation in the park, especially in its backcountry wilderness areas. Backcountry had increased drastically in the 1960s and ‘70s. Van Wagtendonk described the changes in a 1981 paper, writing that in 1972, managers found trampled vegetation, eroded trails, and up to 200 people camped at popular sites. In the 1970s, the park implemented mandatory permit and quota systems for backcountry use that were informed by van Wagtendonk’s research.
Van Wagtendonk has witnessed Yosemite and fire science shift over the decades. In several publications, he’s traced the history of fire policy and management in Yosemite and beyond. Visitor numbers have skyrocketed at Yosemite, and larger wildfires burn in California as the climate warms. In the past two decades, his research has given more attention to today’s megafires and climate change. There’s still a lot to learn about the future of fire.
It can take a long time for new science to really shape management on the ground, but van Wagtendonk marvels at how far we have come, and how much the still-young field of fire ecology has influenced policy already.
“It has been very gratifying to see my work actually be used in park management and beyond,” he says.
Van Wagtendonk has been in Yosemite for 48 years, and still can’t get enough of it. When he’s not working on his writing and research, he loves to hike and backpack the trails.
“I’ve hiked every trail in the park,” he says. “I’ve been backpacking every summer. . . I’m at the point where I’m going back to places I’ve liked the most . . .but I want to be able to keep doing that as long as I can, do it now before my legs give out.”
Jan van Wagtendonk in the Mariposa Grove, Yosemite National Park, approximately 2019. USGS photo.
Thanks and a tip of the hat go out to Jim, Gerald, and Kelly.
Precipitation, during the seven days ending at 11 a.m. MDT August 13, 2022.
It seemed to me that over the last few weeks the wildfire activity has been slower than typical for this time of the year, so I did a little digging. Using historical data from the National Interagency Fire Center and acres burned to date from the August 13 national Situation Report, it turns out that Alaska has burned nearly three times their 10-year to-date average while the other 49 states combined are running 12 percent below the to-date average.
Over the last 10 years Alaska’s average acres burned in a full year is 1.1 million. This year they are at 3.1 million, more than the other 49 states combined. There has been a major increase in Alaska acres burned after mid-August in only 2 of the last 18 years. And it has been fairly quiet there, fire wise, for the last four weeks.
So far this year, fires in the other 49 states have blackened about 2.8 million acres, 12 percent below the to-date 10-year average of 3.2 million. The 49 states typically burn 6.2 million in a full year, so if this year turns out like the average of the last 10, we’re about half done.
The Situation Report does not break out data for Alaska and the other 49 states, so just looking at their 50-state numbers a person would see that the 5.9 million acres burned to date is 27 percent higher than the average of 4.3 million, when actually the +27 percent figure is very wrong for both Alaska and the lower 49 states.
We usually separate Alaska stats because fires in that huge state are managed far differently from the other 49. Most of them are not fully suppressed since they are less likely to endanger people or private property than in the lower 49 states. The second reason is that the fire occurrence is extremely variable, with the acres burned since 1990 ranging, for example, from 43,965 acres in 1995 to 6,645,978 in 2004. Including the Alaska numbers in the total would skew the data for the other 49 states making it more difficult to spot trends.
Wildland fire potential for September, 2022. NIFC.Wildland fire potential for August, 2022. NIFC.
Forest thinning project in the Umpqua National Forest. Credit, Oregon State University.
NBC News conducted an investigation into some of the claims and statistics about vegetation management projects that are designed to improve forest health and/or and reduce the threat of wildfires. The emphasis of the very lengthy article about their findings was not so much to question the need or effectiveness of the hazardous fuel reduction projects, but to examine their claims of accomplishments, which are sometimes misleading.
Many fuel management projects on National Forests include multiple treatments of a single area. There can be some combination of thinning, pruning, piling, chipping, or prescribed burning, all considered independently and occurring at different times. In an extreme scenario, if the project was 100 acres and five different treatments occurred, each might be reported as accomplishing 100 acres of fuel treatment. They then tell Congress they treated 500 acres.
The NBC article gave an actual example of a project on the San Bernardino National Forest in Southern California near Big Bear Lake. The 173-acre project had multiple treatments. From the article:
They first [step] appeared in 2016, when the Forest Service assigned workers to cut trees to reduce the area’s density. The agency came back two years later, pruning the remaining trees and piling the cut wood across the full 173 acres, then chipping 52 acres of it. A few months later, workers burned 18 acres of the piles.
The pruning, piling, chipping and burning were entered as separate items in the database and the agency reported them as 416 acres of treated land in its 2019 fiscal year totals to Congress. In summer 2021, it burned the remaining 155 acres of piles, reporting them in that year’s totals.
The Forest Service’s efforts ultimately reduced fire risk on 173 acres of land, but they were reported to Congress as 744 acres over four fiscal years.
“These acres are reported six times because we must request funding to accomplish the full suite of activities on the same 173 acres,” said [Wade] Muehlhof, the service’s spokesperson. “Each of these activities needs to be planned and budgeted for annually.”
The Forest Service tells Congress that it reduces wildfire risk on more than 2.5 million acres of its land every year. But this process of recounting the same acres any time more than one type of work is completed means that far less land is protected from damaging fire than is being reported.
NBC estimates that nationwide the FS has overstated accomplishments by 2.5 million acres, or 17 percent. In California the numbers are higher, 27 percent in the past five years, and by roughly 35 percent in the places near the most people, the state’s wildland urban interface areas.
The NBC article was written by Adiel Kaplan, with assistance from Monica Hersher and Joe Murphy.
June 13, 2022 flood in Yellowstone National Park. YNP image.
Yellowstone National Park released a video yesterday describing the massive damage to the park’s infrastructure that occurred June 13 when unseasonably warm weather, melting snow, and very heavy rain produced widespread flooding across the north end of the park. Yellowstone Digital Communications Specialist, Jake Frank, gives his first-hand account of the 500-year flood event.
These photos are still images from the video below.
June 13, 2022 flood in Yellowstone National Park. YNP image.June 13, 2022 flood in Yellowstone National Park. YNP image.June 13, 2022 flood in Yellowstone National Park. YNP image.
