Forest Research and Outreach - Agriculture and Natural Resources Blogs

Author: Kara Manke

Published on: July 3, 2019

A photo of a spotted owl on a tree branch

Spotted owls, native to the old-growth forests of the West Coast, have already lost much of their former habitat to logging. Without active forest management, the birds now risk losing even more of their remaining habitat to wildfire, a new paper argues. (Photo by Tom Munton)

Spotted owl populations are in decline all along the West Coast, and as climate change increases the risk of large and destructive wildfires in the region, these iconic animals face the real threat of losing even more of their forest habitat.

Rather than attempting to preserve the owl's remaining habitat exactly as is, wildfire management — through prescribed burning and restoration thinning — could help save the species, argues a new paper by fire ecologists and wildlife biologists and appearing today (July 2 ) in the journal, Frontiers in Ecology and the Environment.

The paper compares the plight of the owl with that of another iconic threatened species, the red-cockaded woodpecker, which has made significant comebacks in recent years — thanks, in part, to active forest management in the southern pine forests that the woodpecker calls home. Though the habitat needs of the two birds are different, both occupy forests that once harbored frequent blazes before fire suppression became the norm.

“In the South, the Endangered Species Act has been used as a vehicle to empower forest restoration through prescribed burning and restoration thinning, and the outcome for the red-cockaded woodpecker has been positive and enduring,” said Scott Stephens, a professor of environmental science, policy and management at the University of California, Berkeley, and lead author on the study.

“In the West, it's just totally the opposite,” Stephens added. “Even though both places physically have strong connections to frequent fire, the feeling here is that the best thing to do is to try to protect what we have and not allow the return of frequent fire — but that's really difficult when you have unbridled fires just ripping through the landscape.”

The red-cockaded woodpecker, native to the Southeastern U.S., has benefited from prescribed burning and restoration thinning of the pine stands where it makes its home. (Photo by Warren Montague)

A tale of two birds

Spotted owls make their homes in the dense forests of the Western and Southwestern U.S., feeding on flying squirrels and woodrats and nesting in broken-off treetops or tree hollows. Red-cockaded woodpeckers, meanwhile, reside in pine stands in the Southeastern U.S., provisioning nests from nest boxes or hollowed-out cavities in living pine trees and eating insects pried from under tree bark.

Development and logging have robbed both species of much of their former habitat, and their populations have both taken a hit: Partners in Flight estimates the global breeding population of spotted owls to be at 15,000 individuals.

What habitat remains is now largely protected under the Endangered Species Act — but when it comes to fire and forest management, the act has been interpreted in dramatically different ways in the two regions, said paper co-author Leda Kobziar, associate clinical professor of wildland fire science at the University of Idaho.

“In the South, the act is interpreted to support active management through forest thinning and prescribed burning, and in the West, it is interpreted to exclude most fires and active management from protected areas surrounding spotted owl nests,” Kobziar said.

One critical difference is the degree to which active management in red-cockaded woodpecker habitat provides complementary benefits. “In the South, active management is known to reduce wildfire hazards, and it benefits local economies, along with a host of other fire-dependent species. In the West, those complementary benefits are less well-defined,” Kobziar said.

Another part of the reason for the discrepancy is perceived differences in the habitat preferences of the two birds, Kobziar explains. Red-cockaded woodpeckers live in more open, mature pine forests that result when low-intensity natural or prescribed burns limit the development of a forest midstory, where woodpecker predators take cover. Meanwhile, spotted owls generally prefer the dense, multi-layered forests that grow when fire is excluded.

A photo of pine trees on fire behind a lake

The 2014 King Fire ripped through regions of Eldorado National Forest that had been home to a long-term study of the California spotted owl. (U.S. Forest Service photo via Flickr)

However, suppressing all fires in order to encourage growth of these dense canopies also creates conditions that are ripe for large, severe wildfires that can take out not just the smaller trees, but entire forests, obliterating swaths of owl habitat in the process. The 2014 King Fire, for example, tore through regions of the Eldorado National Forest that were home to a long-term study of the California spotted owl and caused the bird's largest population decline in the 23-year history of the study.

“A key question to be asking is: Where would owl habitats be with more characteristic fire regimes, and could we tailor landscape conditions where these habitats are less vulnerable and more supportive of today's wildfires?” said co-author Paul Hessburg, a research landscape ecologist with the U.S. Forest Service Pacific Northwest Research Station.

The solution would mean, “essentially creating less habitat in order to have more in the long run,” he said.

Fighting fire with fire

Before European settlement, many small- to medium-sized wildfires burned through the forests of the Southeastern and Western U.S., sparked by lightning or intentionally lit by native peoples to produce food, clear land or drive game. These fires would gobble up the dead wood, seedlings and saplings that made up the forest understory, while leaving taller, older trees standing and marked with fire scars recorded in their growth rings that fire ecologists use to track the frequency of historical fires.

In the mountainous landscape of the West, these fires didn't strike uniformly everywhere, to the potential benefit of the owls, Hessburg said. “If I took you back in the way-back machine 200 years ago, you would have seen that fire regimes in the Cascade Mountains differed very much by topographic setting,” he said. “Ridgetops and south slopes would often get pounded with lightning and fires, and so tree cover would be sparse. But in shaded and cool valley bottoms and north slopes, you would see complex layered forests, and some of these would have been incredible owl habitats.”

Two panoramas of Bethel ridge in Washington State; the top one taken in 1936 and the bottom one taken in 2012. The bottom one shows a considerably denser forest cover compared to the top.

Bethel Ridge, located in central Washington State, photographed in 1936 (top) and again in 2012 (bottom). Decades of fire exclusion has allowed smaller, younger trees to flourish, making the forests considerably denser in contemporary times. (Top: National Archives photo; Bottom: Photo by John Marshall; both courtesy of Paul Hessburg)

Targeted restoration thinning and prescribed burning on ridgetops and dry southern slopes where fire used to be a frequent visitor, while leaving valley bottoms and northern slopes to develop into complex forest, could be a way to discourage large wildfires from ripping through vast landscapes, while maintaining owl habitat in a more fire-protected context.

New evidence also hints that owls may not be so dependent on dense understory canopies as once thought, the paper notes. Recent findings indicate that other aspects of forest structure, particularly the presence of large, old, tall trees, may be more important to the owls. These findings hint that prescribed burning and restoration thinning to reduce the size and severity of wildfires may not be damaging to owl habitat, even in the short term.

“We're treating the habitat as if we know precisely what habitat characteristics are preferred. It might be that these birds are tolerant of a broader range of characteristics that would enable things like fuels reduction to protect them from high-intensity wildfires,” Kobziar said.

“The South has melded fire and rare species management in a holistic way, but in the West, we're doing one or the other — (in) most places (where) we do forest restoration, we are trying to avoid owls,” Stephens said. “But the King Fire showed that owls and their habitats are vulnerable to large wildfires. More restoration thinning and prescribed burning could help us keep the habitat that we have now, modify it and actually make it more sustainable in the future.”

Other co-authors on the study include Brandon M. Collins of UC Berkeley; Raymond Davis, Joseph Ganey, James M. Guldin, Serra Hoagland, John J. Keane, Warren Montague, Malcolm North and Thomas A. Spies of the U.S. Forest Service; Peter Z. Fulé of Northern Arizona University; William Gaines of the Washington Conservation Science Institute; Kevin Hiers of the Tall Timbers Research Station; Ronald E. Masters of the University of Wisconsin-Stevens Point and Ann E. McKellar of Environment and Climate Change Canada.

RELATED INFORMATION

Is fire ‘for the birds'? (Frontiers in Ecology and the Environment)
Stephens Lab website

Tags: Brandon Collins (2), fire management (2), habitat (1), prescribed fire (12), Scott Stephens (15), spotted owls (1)

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Burning Question: Can California Prevent the Next Wildfire?

Author: Glen Martin

Published on: November 6, 2017

Reposted from California Magazine

Santa Rosa and Sonoma County officials are now in the post mortem phase of the North Bay fire storms, asking what could've been done to avoid the tragedy and what can be done in the future to prevent similar conflagrations. Discussions largely have focused on tighter zoning and fire ordinances. Those are appropriate areas to focus on, say many wildfire experts, but municipalities and counties inevitably face pressures that make effective wildfire risk reduction difficult.

“As things stand, cities and municipal or regional agencies — like the East Bay Regional Park District or the East Bay Municipal Utility District — are responsible for dealing with fuel buildup and other potential fire safety issues,” says Joe McBride, a UC Berkeley professor emeritus of landscape architecture and environmental planning. “Cites particularly are supposed to do annual inspections, notify people if there's a problem, and then take enforcement actions, including hiring contractors to do clean-up work and billing the homeowner. But people get resentful when local authorities try to vigorously enforce safety regulations. They bring their own pressures to bear, and then necessary things simply aren't done.”

Scott Stephens, a professor of environmental science, policy, and management at Cal, also believes city officials are often unable or unwilling to enforce strict fire ordinance options. The incentive for city council members and county supervisors is to encourage development and expand tax bases, Stephens says. As a result, homes are often built in wild land “interface” areas with extreme fire risk, such as the scorched Fountaingrove complex in Santa Rosa, and fire safety measures are either minimized or ignored altogether.

As Santa Rosa newspaper columnist and Sonoma County historian Gaye LeBaron has written, the Tubbs Fire that ravaged Santa Rosa could've been predicted; in 1964, another wildfire followed almost the exact same path. But that earlier fire burned mostly forest and agricultural land. Fountaingrove's pricey developments weren't put in until the 1990s, rammed through by local officials anxious for the tax revenues, and in apparent violation of an ordinance that proscribed development on ridge tops overlooking the Santa Rosa Valley.

Along with mushrooming development, ongoing climate change is resulting in hotter, drier, and longer fire seasons, affecting wildfire behavior in unexpected and catastrophic ways. That was evident in the Santa Rosa fires with the destruction of Coffey Park, a large tract of middle-class homes in western Santa Rosa far from any forested areas.

“Coffey Park was a huge surprise for me,” says Stephens. “I've never seen anything like it, and I had never expected to see anything like it. But you had this terrible confluence of events. Incredibly powerful, dry winds swept down eastward-facing canyons, and threw burning embers west clear across the Highway 101 corridor into Coffey Park, where they ignited dry leaves and other fuels. Now that we know these kinds of scenarios can play out, we need to prepare for them.”

How? McBride believes that it would be wise to divest cities of some of their regulatory authority and place it with the state. State agencies, he observes, are largely immune to both the blandishments and intimidation of local development bigwigs and are motivated by larger issues than municipal and county tax bases. He points to the California Coastal Commission as a promising template. Prior to the Coastal Commission's formation in 1972, development pressures along the state's incomparably beautiful coastline were increasing dramatically. It seemed certain that California's future would include a solid wall of strip malls and gimcrack bungalow developments from Crescent City to San Diego.

“Before the Coastal Commission was authorized, each coastal city planned for its own best interests in terms of zoning, and those interests weren't necessarily aligned with coastal preservation or access,” says McBride. “Once the commission started overseeing things, though, we got much better zoning and oversight of the coast. Most of the coast is now preserved. We avoided the ‘Miamification' of California that otherwise would've been inevitable. A similar agency for wildfire regulations and enforcement – essentially a California Fire Commission – might make similar progress in community fire protection in terms of zoning and enforcing clean-up and defensible space requirements.”

Stephens agrees with McBride that state authority is likely to be more effective than local agencies in establishing and enforcing effective fire regulations, and suggests that the University of California could also play a role.

“We have to educate as well as enforce, and in fact, education and cooperation at the community level may be the best way to accomplish fire safety goals,” Stephens says. “One of the tragic things about the Santa Rosa fires is that most of the fatalities were older people: 60 and older. People in neighborhoods in fire-vulnerable areas should meet regularly to identify older neighbors who may need help in evacuating, identify escape routes for different scenarios, and discuss risk reduction measures they could take.”

As far as Cal goes, continues Stephens, “UC Cooperative Extension [under the university's Division of Agriculture and Natural Resources] maintains [agricultural and conservation] programs in every California county, so we already have a network of educators and communicators. We could coordinate with state agencies and the governor to create and implement wildfire safety and response programs that could be very effective. And because the basic structure is already in place, it wouldn't be very expensive.”

Both Stephens and McBride think certain types of ornamental trees should be minimized — even eliminated — from the urban landscape. Grasslands and native oak savannas burn readily, says McBride, but at a low intensity; grass fires can usually be countered relatively easily by firefighters. But some exotic trees, particularly eucalyptus and Monterey pine, are impregnated with oils and resins that burn explosively, often producing flame lengths of 200 feet or more and creating “spot” fires miles from primary blazes, making effective firefighting impossible.

“We really need to look at changing the landscape [in suburban and urban areas],” McBride says, “and that includes banning eucalyptus and other problematic trees as much as possible.”

McBride says some communities are approaching fire risk in a progressive and effective way, and they should be emulated.

“Landscaping at Sea Ranch [on the Sonoma Coast] largely consists of native grassland and prairie, and that provides a lot of security for the homes,” says McBride. “They also plow firebreaks throughout the development every year. They do have stands of native bishop pine, which burns with high intensity, but they prune and thin them to break up the fuel ladders, and that minimizes fire risk.”

The homes at Sea Ranch are modeled on the old barns of the ranchers who originally settled the Sonoma Coast, another factor that reduces fire risk, observes McBride.

“They don't have eves or roof overhangs, which is a very wise design feature in wildfire-prone areas,” says McBride. “Overhangs trap burning cinders driven by the wind, and encourage fires either on roofs and walls or in attics.”

Indeed, says McBride, modern architects and urban planners can learn about a lot about minimizing fire risk by studying some of the historic structures from California's past.

“Windows are a big entry point for heat,” says McBride. “In fact, heat from wildfires can transfer directly through windows and ignite walls opposite the windows without the glass breaking. When you go through the old Gold Rush towns in the Sierra, you see these stone buildings with big iron shutters that could be closed over the windows. That was a fire prevention strategy, and it was very effective. We don't need to make shutters from heavy iron sheets, of course, but we could certainly design shutters from modern materials for the large plate glass windows that are so popular in modern homes. The [Forty-Niners] really understood the risks of wildfires, and they designed their buildings with fires in mind. We need to do the same thing.”

Tags: Coffey Park (1), cooperative extension (2), Joe McBride (1), land use planning (2), Scott Stephens (15), ucanr (2), wildfire (46)

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Expert: Grizzly Peak Wildfire Response Reveals a Potential Flaw

Author: Glen Martin

Published on: August 11, 2017

Reposted from California Alumni Magazine

Detail of photo by Bobby Lee / The Daily Californian

Expert: Grizzly Peak Wildfire Response Reveals a Potential Flaw

Last week's wild fire on Grizzly Peak Boulevard ended up scorching about 20 acres of brush and grass near the Lawrence Berkeley National Laboratory, with no major damage to property and no loss of life. That was due in large part to a fuel reduction program pursued by Berkeley Lab since the 1990s, says Scott Stephens, a professor with UC Berkeley's Department of Environmental Science, Policy, and Management and one of the country's foremost wildfire experts.

“The lab has done a good job of treating blue gum [eucalyptus] stands around their facilities and generally removing or reducing fuels,” says Stephens, noting the ubiquitous eucalypts that grow across the East bay hills are notorious for their flammability. Due at least partially to Berkeley Lab's efforts, says Stephens, the fire never “crowned”—that is, it didn't leap up the “fuel ladders” of brush and branches to the interconnected canopies of the trees, then rage across the landscape.

Firefighters also were able to jump on the flames in short order, due in large part to a signage system put in place by Tom Klatt, Stephens' predecessor at Berkeley.

“I try not to promote draconian scenarios, but I am concerned about them,” Stephens says. “A fire driven by a strong east wind on a hot day would've acted very differently.”

“Tom was concerned about just this kind of situation: a fire breaking out on Grizzly Peak Boulevard, with firefighters delayed because there are so many twists and turns to the road and it can be difficult to determine location,” Stephens said. “So he was able to get a series of sign posts installed up there. Last week's fire started at sign post 14, and firefighters were able to respond very rapidly because they knew exactly where they were going.”

But the East Bay Hills dodged an incendiary bullet for another reason, Stephens says: On the day the fire ignited, the weather was mild and a west wind was blowing, more or less pushing flames away from Berkeley Lab and the UC Berkeley campus. If the fire had started on a hot day with an east wind—the conditions that prevailed during the disastrous Oakland Hills fire of 1991—things might have concluded tragically.

“I try not to promote draconian scenarios, but I am concerned about them,” Stephens says. “A fire driven by a strong east wind on a hot day would've acted very differently. It not only would've burned very quickly, but where particularly volatile fuels such as eucalyptus are concerned, it would have thrown embers miles ahead, starting hundreds of spot fires that would also burn explosively and merge. That's what happened in 1991.”

Normally, wildfires burn more rapidly uphill than downhill, observes Stephens, but in extreme conditions such as those that characterized the Oakland Hills Fire, “the fire overwhelms the topography. If last week's fire had occurred under Oakland Hills fire conditions, there would've been impacts to university property. I'm particularly concerned about the Clark Kerr campus dormitories. They seem at significant risk.”

Stephens has long supported major fuel reduction programs for the East Bay Hills, and was particularly distressed when FEMA pulled funding for a plan to remove eucalyptus and restore native vegetation on land owned by the university along Claremont Canyon. But fuel reduction, he avers, is not enough. Public facilities in the East Bay Hills also need effective response programs. Berkeley Lab evacuated its employees during the Grizzly Peak fire, says Stephens, “and I watched from the campanile for about 45 minutes as cars slowly snaked down the hill. People were particularly vulnerable at that time. If the fire had burned down that road rapidly, as you could expect with a strong east wind, they would've been in trouble. The natural instinct for people surrounded by wildfire is to get out of their cars and run, which can put them at even greater risk. Fatalities occurred during the Oakland Hills Fire because of that reaction, and it happens regularly during Australian wildfires.”

Many of Berkeley Lab's buildings are heavy concrete structures that could be largely impervious to wildfire, particularly given the aggressive fuel reduction policies the lab has pursued for the past 20 years, Stephens observes.

“I think it might be time for them to consider a shelter-in-place policy for their wildfire response strategy,” he says. “It would warrant an evaluation, at least. And they might also consider additional entrances and exits, a major reason the cars were so slow in getting out is because access is so limited. I also think UC needs to revisit and update its evacuation policies for its buildings, including the Clark Kerr dorms.”

Tags: eucalyptus (1), Scott Stephens (15), UC Berkeley (12), wildfire risk (6)

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Study refutes findings behind challenge to Sierra Nevada forest restoration

Author: Brett Israel

Published on: May 9, 2017

Reposted from the UC Berkeley News

A study led by ecologists at UC Berkeley has found significant flaws in the research used to challenge the U.S. Forest Service plan to restore Sierra Nevada forests to less dense, and less fire-prone, environments.

An example of a mixed-conifer forest in the Sierra de San Pedro Martir National Forest, Baja California Norte, Mexico. This forest experienced active, natural fires until the 1970s. (Photo by Carrie Levine).

Until recently, the consensus among forest ecologists was that before European settlers arrived in the Sierra, the forests were mostly open conifer forests dominated by big trees and low-to-moderately severe fires every eight to 12 years. The Forest Service recently released a plan to restore the range's forests back to this state following decades of fire suppression and timber harvesting regulations, which have created dense, fire-prone forests.

But recent studies, using a newly developed methodology, have argued that the Sierra Nevada was actually a more dense forest than the consensus view. These new studies were used to back a lawsuit to stop the agency's plan to restore Sierra forests following the 2013 Rim Fire. The Berkeley study refutes the conclusions of these studies and identifies flaws in their methods.

“We went through the data and showed that, in every case, this method estimated that the density of trees was two to three times higher than was the reality,” said Carrie Levine, a Ph.D. student of forest ecology at Berkeley and lead author of the study.

The study was recently published online in the journal Ecological Applications. Berkeley professors John Battles and Scott Stephens and research scientist Brandon Collins were co-authors on the publication. Also involved in the study were researchers from Harvard Forest, the USDA Forest Service Pacific Southwest Research Station, the University of Montana, Utah State University, University of California, Davis, and the USDA Forest Service Pacific Southwest Region.

An example of a densified mixed-conifer forest in the Plumas National Forest, California, USA.

An example of a densified mixed-conifer forest in the Plumas National Forest in Northern California. Fires have been suppressed in this forest for more than 100 years. (Photo by Carrie Levine).

When the U.S. was divvying up land in the West in the late 19th and early 20th centuries, the General Land Office performed surveys so that the land could be parceled and sold. Land was divided into square-mile blocks, with markers used to indicate every corner point. In case a marker was moved, so-called “witness trees” near the stake were identified as reference points. The result of this data is a grid survey of the entire American West.

Using this historic field data, two ecologists at the University of Wyoming, Mark Williams and William Baker, developed a method that claims to calculate the area that a tree occupies, which is then used to calculate a forest's density. This approach is based on the observation that trees create space to keep other trees from cramming next to them, and that this space correlates to a tree's species and size.

To assess the validity of this area-based method of density estimation in the Sierra Nevada, Levine and her co-authors assembled data from plots of mapped trees across the Sierra and Baja California, Mexico. They tested the performance of the area-based method in these mapped stands where the true density was known.

Levine and colleagues found that the area-based method has two basic flaws when applied to the Sierra, the most notable being an inability to actually predict the area that a tree occupies based on its species and size due to a weak relationship between these variables. The other flaw was a failure to account for differences in the number of trees sampled at each corner. The methodological flaws led to an inflated number of trees estimated in a pre-European Sierra Nevada forest, Levine and colleagues argue.

“We have a mapped plot where every tree is measured, so we know the true density,” Levine said.

The study is important not only for the current state of the Sierra Nevada, but for its future.

“As climate changes, we want to have an accurate understanding of the past. This allows us to manage for forests that are resilient to the changes we're expecting in the future,” Levine said.

Tags: forest density (1), John Battles (5), Scott Stephens (15), Sierra Nevada (8)

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