Central Sierra
University of California
Central Sierra

Posts Tagged: Scott Stephens

It's not too late to make California forests resilient to wildfire

Reposted from the UCANR News Blog

Even though there has been a deficit of fire in California forests for decades, their future is not hopeless, said UC Berkeley fire science professor and UC Agriculture and Natural Resources researcher Scott Stephens in an interview with Craig Miller on KQED Science.

"The next 25 to 30 years are paramount. If you begin to do restoration, reduce density, make forests more variable in pattern, and less fuel, when you have episodes of drought and fire, it's going to be fine. The forests have been doing this for millennia. It's going to be fine," Stephens said.

UC researcher Scott Stephens shows fire scars on pines that reveal regular exposure to burns and then healing and regrowth, a sign of a healthy forest ecosystem. (Photo: Lindsey Hoshaw, KQED Science)

However, under current conditions, in which fires have been regularly suppressed, the situation is dire.

"The forests used to burn every 12 to 15 years, but most places haven't been touched for 50 to 100 years. Today we have areas with 300 or 400 trees per acre, where you used to have 50 to 80," he said.

Even though, Stephens said he is an optimist. "There's still opportunity today to do restoration, so that when it does get warmer and warmer, as projected, the forests will be able to deal with that, deal with insects and disease and keep themselves intact."

UC researcher Scott Stephens believes that with restoration, California forests will be fine. (Photo: Wikimedia Commons)
Posted on Wednesday, August 17, 2016 at 5:21 PM
  • Author: Jeannette Warnert

Fried to a Crisp: Why Some Experts Say We Must Burn the Trees to Save the Forests

Reprinted from California Magazine

The recent rains have blunted the psychological impact of California's four-year drought, washing down the streets, perking up the landscaping, and heightening anticipation for a stormy El Nino-driven winter. We know, however, that one wet year is highly unlikely to end water shortages. What we may not fully grasp is that the damage done to the state's forests is so far reaching that it may be permanent.

How bad is it? Really, really bad. Horrendous, in fact. Sally Thompson, an assistant professor in UC Berkeley's department of civil and environmental engineering, cites the status of the state's iconic giant sequoias as an example.  Thompson notes that Cal biology professor Todd Dawson has been monitoring the biggest trees on earth, “and has found that they're extremely stressed. They're dropping leaves—some of them may die. These are trees that have lived 3,000 years, enduring a wide range of environmental conditions, including other droughts. And now they're being killed by this drought. That's suggestive of what we're facing. We're heading into uncharted territory.”

And it's not just giant sequoias. Virtually all of California's trees are drought-stressed, and many are going down for the count. Thompson observes the U.S. Forest Service conducted flights over 8.3 million acres of woodland in the southern Sierra, the Central Coast and Southern California in April and concluded that about 10 percent of the conifers and oaks—about 12.5 million trees—had died in recent months. They had either expired directly from drought or succumbed to bark beetles, which attack weakened trees.

The situation has only grown more grim. Two weeks ago, Gov. Jerry Brown declared a state of emergency, warning that the U.S. Forest Service estimates “more than 22 million trees are dead and that tens of millions more are likely to die by the end of this year.” He asked for federal assistance and called for an accelerated program to cut and clear dead trees, expand the practice of prescribed burns and temporarily allow more burning of wood waste.

Greg Asner, a biologist with the Carnegie Institute for Science, used spectrometers and lasers to evaluate forest canopies on flights out of Sacramento and Bakersfield. The procedures yielded 3-D topographic displays that show the forest in varying shades of blue (healthy) yellow (somewhat stressed) and red (deeply stressed to dying or dead). Bottom line: There's a lot of red in them thar hills. Asner concluded about 20 percent of California's forests are doomed—up to 120 million trees.

The images reveal the trees are dying in a mosaic pattern, says Thompson.

“You'll see patches of dying trees in the middle of healthier forest,” she says. “That's probably due to such things as south-facing slopes or shallow soils. You'd expect such areas to experience (drought-related) stress first. But there's a tremendous volume of dead wood building up all across the forests, and that's pointing to a future that is potentially very


Such a vast accumulation of fuels could lead to wildfires that are perhaps unprecedented in their ferocity. They could be so intense and of such a vast scale that they could lead to broad “ecotonal shift” —the evolution of entire forests from one vegetative regime to another. Ponderosa pine forests, for example, could convert to chaparral fields.  Oak woodlands could change to grassy savannas. (As California previously noted, such ecotonal changes already may be occurring on Mt. Laguna in Southern California.)

That all sounds pretty apocalyptic no matter how you burn it, but Thompson observes we don't have to just sit back and take it. It turns out there's quite a bit that could be done to fireproof our forests—and perhaps increase water availability in the process. All it will take is a fair amount of money and political will.

“It's clear that there is more standing biomass—trees—in our forests than existed before active fire suppression began a century or so ago,” says Thompson. “Studies show that the canopies are heavier, and the forests are more vulnerable to fire as a result.”

A little background: Prior to Euro-American settlement, California's coniferous forests were characterized by extremely large, widely-spaced trees. Annals of the day—both textual and pictorial— made it clear that you could ride a horse through the forests unimpeded. There was little or no fuel (branches and dead trees) on the ground. The character of the forests was due to the occurrence of fire, both natural and human-induced; California's natives burned the forests periodically to make hunting easier and encourage the growth of food plants, including acorn-bearing oaks, seed-producing grasses, and bulbs.

The good news: The forests of our forebears probably can be reclaimed. All we have to do is burn and cut down a lot of trees.

In the old days, fire noodled around in a low-energy fashion on the forest floors, killing insect pests, nibbling back the underbrush, and converting deadwood to ashes that ultimately nourished the great pines and firs. Today, wildfires rip through entire landscapes of closely-packed trees, immolating everything down to mineral earth.

“Ultimately, the fires can be so intense that they take out all tree seed sources,” says Thompson, “so the system shifts to chaparral.”

Today's dense forests also have less biodiversity and suck up much more water than the forests of yesteryear. Thompson says studies of today's Sierra Nevada forests indicate they transpire 35 percent more water—that is, extract it from the ground through the roots and transfer it to the air as vapor via foliage—than 19th Century forests.

The good news: The biologically rich, fire resilient and amply watered forests of our forebears probably can be reclaimed. All we have to do is burn and cut down a lot of trees.

“There are three ways to go about it,” says Thompson. “Mechanical thinning, prescribed fire, and managed fire.”

Mechanical thinning would be the removal of trees by chainsaws or heavy equipment. Prescribed fire would be controlled burning—setting blazes when fuels are relatively damp and conditions are cool and humid, allowing for fires that reduce the forest canopy without destroying every standing tree and living creature. Managed fire is basically letting nature run its course. Wildfires would be allowed to burn in unpopulated areas, ideally when weather conditions aren't excessively hot and dry. The U.S. Forest Service is increasingly convinced of the wisdom of this approach. It recently inaugurated new management plans for three of California's national forests, approving managed fire for 50 percent of their acreages.

Thompson and UC Berkeley professor of environmental science, policy and management Scott Stephens are working on a project in Illilouette Creek basin in Yosemite National Park that seems to confirm the healing properties of fire.

“The National Park Service backed off fire suppression and began using managed fire in the basin in 1973,” says Thompson. “Scott and I are seeing strong evidence for increased plant diversity in the basin. There's much more meadowland and scrubland, and the resulting patchiness across the landscape reduces the risk for catastrophic wildfire. We're also seeing greater diversity in water conditions. There are more areas with persistently wetter soils than were recorded under the old completely forested state. We're now trying to determine whether these changes are increasing run-off from Illilouette Creek into the Merced River. “

Posted on Monday, November 16, 2015 at 10:03 AM
  • Author: Glen Martin

Burning Down the House: Should Private Assets be Sacrificed to Protect Public Land?

Reposted from California Magazine

Back when mastodons and giant ground sloths still roamed the earth – the late 70s and early 80s – I worked as a wildfire fighter for the U.S. Forest Service, both on hand crews and engine crews. Our training was narrow but relatively deep. Mainly, we were taught to construct fire lines with hand tools and chain saws. Water, when it was available, generally was used to protect the line and firefighters; seldom was it employed to directly extinguish the flames.

Our basic strategy consisted of digging and cutting line around the flanks of the fire, then burning out fuels to the advancing flames with fusees (devices resembling highway flares) or drip torches. In this way, the “head” of the fire could be steered to natural barriers or areas sufficiently devoid of fuels to make a direct attack possible. We received zero training for structure firefighting. The one time I responded to a burning structure was in Trinity County: A vacation cabin was ablaze due to a faulty propane line. Several engines responded. Federal Forest Service engines are smaller and hold far less water than municipal or state engines, but collectively, we mustered a lot of water on the scene. A direct attack could have been possible, but we knew our training for battling such a fire was inadequate. Instead, we dug a line around the cabin so the flames wouldn't encroach into the surrounding woods, and watched it burn to the ground.

Things are different now. For one thing, wildfires are bigger and more frequent. This is due to drought, climate change, and the sins of past forest managers. In the sixties, seventies and eighties, vast tracts of old growth timber were liquidated in massive clear cuts. These deforested landscapes were replanted as conifer monocrops, resulting in expansive stands of spindly, closely-spaced, second-growth trees that are as flammable as kerosene.

Meanwhile, the goal for wildfire fighters has changed drastically. The emphasis now is on “protecting interface,” which means preventing fires from immolating the homes that have sprouted across the West's woodlands like morel mushrooms after a rain (back when we had rain). This shift has made fighting wildfires far more expensive, more dangerous for firefighters, and has altered priorities from protecting public forests to protecting private assets. Wildfire fighters now receive training in structure fires, but that has diluted, perhaps even vitiated, their original mission. As Berkeley Environmental Science Professor and Wildfire Researcher Scott Stephens noted, more than half the U.S. Forest Service budget for the current fiscal year is dedicated to fire suppression; in the early 1990s, that figure was about 20 percent. Assuming the trend will continue, which seems certain, firefighting could consume 70 percent of the agency's budget by the 2020s.

That means there's less money than ever for restorative work. And this is work that must be done, and soon. Unless we alter the essential characteristics of our coniferous forests, they will quite literally vanish. It's already happening: Stephens observes that significant portions of California's forests are shifting from pine and fir to mixed hardwoods or even grasslands, the result of repeated, high-intensity fires and drought. And once our conifers are gone, we're not getting them back. The change will be permanent.

Even with drought and accelerating climate change, we can still have healthy coniferous forests in the West. But we won't get them by simply letting them grow — and burn (and burn). Stephens observes we need active management: intensive thinning by both mechanical means and prescriptive fire. This will result in forests with fewer but healthier trees, forests that are largely resistant to any but the most catastrophic fires.

A hundred years ago, disastrous wildfires were rare in California. Forests were characterized by widely spaced, extremely large trees; You could ride through them on horseback, unimpeded. Any fires that did ignite generally crept along. They didn't have the “fuel ladders” — dead limbs and needles on the ground, brush and ascending foliage higher up — needed to climb into the crowns of the trees and explode into rolling fireballs. Being large, the trees were thick-barked and resistant to fire. Indeed, periodic low-level fires disposed of deadwood, killed destructive insects, and returned nutrients to the soil as ashes. It was a virtuous cycle, assuring healthy, resilient wild lands that depended on fires, but were not destroyed by them.

That changed with the aggressive fire suppression of the Smokey the Bear era and accelerated clear-cut logging. But as Stephens notes, we can revitalize the “dog hair” (as in, thick as the hair on a dog's back) forests we now have. We can re-create the vibrant, fire-resistant forests of the early 20th century. We know how to do it. We have the tools: chain saws, heavy equipment, and prescriptive fire. It's not that complicated.

But it will take political will and money. It won't require a Manhattan Project-style response —but it'll require one similar to the Civilian Conservation Corps in scope and commitment. We need to put young men and women back into the woods in force, cutting trees and conducting controlled burns. By re-introducing fire into forest ecosystems, we can, paradoxically, protect them from fire. This will entail triage. We'll have to identify those areas that are most vulnerable to fire (e.g., interface communities). The first projects should be shaded fuel breaks, strips of thinned forests around highways and rural towns and residential developments. Following that, more ambitious projects could proceed on larger tracts.

Who pays? The state and feds must contribute, of course. But local communities, commercial timber companies, and private landowners must also cough up. In particular, the counties and interface residents must participate. So far, they've gotten a free ride. County planners have encouraged development in wild-land areas without thought to the implications of wildfire; After all, taxpayers have always picked up fire suppression costs. More suppression costs must be passed on to the counties so they are incentivized to discourage development in our wild lands, and homeowners must pay appropriately heavy premiums if they choose to build in the woods.

Stephens estimates we have about 30 years before it's too — before our coniferous forests are gone forever, replaced with oak woodlands, brush fields, or grassy savannas. And even then, of course, the wildfires will continue. As we saw with the recent Middletown conflagration, hardwood forests and scrublands can burn just as ferociously as conifers. As long as homes intrude into the wild lands, their continued destruction is assured.

We can continue down the current path of increasing fires and escalating suppression costs, or we can invest in forest restoration. The first course is a death spiral. The second will reduce wildfires, preserve the essential character of our wild lands, provide tens of thousands of jobs to young Americans, yield economic benefits ranging from timber production to recreation, stabilize watersheds, and preserve wildlife diversity. Let's just hope we do the right thing.

Posted on Monday, September 21, 2015 at 10:20 AM
  • Author: Glen Martin

Manic suppression: Now is our chance to reform wildfire management

Reposted from UC Davis News

With nearly 9 million acres burned this year across the nation, 2015 is shaping up to be one of the most destructive wildfire seasons yet in a decade strung with devastating fire seasons. And with drought and climate change, wildfires are only predicted to get worse.

Photo: Wildfire at night

At a time when forest fires are predicted to grow throughout the West, national forest managers, policymakers and the public currently have unique opportunities to reform wildfire management. (U.S. Army/photo)

In a commentary published Sept. 17 in the journal Science, a team of scientists led by a UC Davis affiliate describe unique opportunities and suggestions to reform forest fire management to lessen the impacts of inevitable wildfires in future years.

In the U.S., 98 percent of wildfires are suppressed before reaching 300 acres. Yet the 2 percent that escape containment account for 97 percent of fire-fighting costs and total burned area, the paper said.

The current funding structure for fire management encourages that imbalance. The authors write that, for individual national forests, “fire suppression is steadfastly financed through dedicated congressional appropriations,” which are supplemented with emergency funding. However, funding for fuels reduction and prescribed burns comes out of a limited budget allotted to each national forest and is often borrowed to cover suppression costs. 

‘Management reform has failed'

The recently released National Cohesive Wildland Fire Management Strategy and the U.S. Forest Service's current efforts to revise national forest plans provide incentives — and distinct opportunities — for change. Most of the 155 national forests will begin writing new plans and holding public forums within the next 10 years.

Further, public resistance to controlled fire management, such as objections to smoke and negative perceptions of forest fires, is starting to change.

This growing public and congressional awareness of the problem is placing additional pressure on state and federal agencies to better manage forests and fire. The authors said this kind of support is needed to enact true change — not just at the policy level but also with actual wildfire response.

“Management reform in the United States has failed, not because of policy, but owing to lack of coordinated pressure sufficient to overcome entrenched agency disincentives to working with fire,” the authors write.

The paper suggests that change come in the form of more prescribed and managed burns, increased thinning, and less suppression. The authors point to Parks Canada, which divides the landscape into different zones for fire management.

For example, U.S. forest plans could:

  • Use mechanical thinning and suppression near homes;
  • Use prescribed fire and mechanical treatments just outside of the wildland-urban interface;
  • Allow more remote lands to burn as managed wildfires when naturally ignited and use prescribed fires.

Additional authoring institutions include UC Berkeley, University of Washington, The Wilderness Society, Northern Arizona University, and the U.S. Forest Service.

Read the full study.

Media contact(s):

Posted on Friday, September 18, 2015 at 10:04 AM
  • Author: Kat Kerlin

King fire provides learning opportunities

Reprinted from the UCANR Green Blog 

Rubicon River, El Dorado National Forest

Over a dozen UC Agriculture and Natural Resources (UC ANR) California Naturalists, fire ecology experts, wildlife biologists, resource managers, educators, and artists met at UC Berkeley's Blodgett Forest Research Station and the adjacent El Dorado National Forest April 23 and 24, and not one of them complained about the much-needed deluge of rain and intermittent hail that soaked the group. The weekend's ambitious goal? To dive deeply into a UC California Naturalist Program and California Fire Science Consortium advanced training workshop on the subject of wildfire effects on Sierran mixed conifer forests.

With the 2014 El Dorado National Forest's King Fire as a case study, a mix of lectures, field studies, art, field journaling techniques, and Native American story telling were used to examine land management practices that influence fire behavior and explore how the landscape recovers from fire. UC ANR Cooperative Extension Central Sierra's forestry advisor Susie Kocher and community education specialist Kim Ingram organized and facilitated the workshop. 

King Fire soil burn severity map

Blodgett Forest, situated on the Georgetown Divide in El Dorado County, was donated to the University of California in 1933 to provide a research site and practical demonstrations of forestry for students, forest industry, and the public. The adjacent El Dorado National Forest is home to the notorious September-October 2014 King Fire that burned 97,000 acres of forest, including 63,000 acres of public land. Aided by low relative humidity and wind, the fire spread quickly up the steep Rubicon River and surrounding subwatersheds. According to the incident report, approximately 46 percent of the burn area burned at a high and moderate soil burn severity, consuming all organic duff on the soil surface along with leaves and needles on standing live vegetation.

Workshop participants were treated a lecture and field studies of basic fire ecology concepts by Scott Stephens, professor of fire science at UC Berkeley. Stevens lectured in class, and later demonstrated on a number of wet, lush forested treatment plots in the field, topics ranging from fire policy, fuels management options and objectives, and carbon sequestration to fire suppression consequences, fire behavior and severity, soil stability, and post-fire forest structure.  Stephens is a researcher with the Sierra Nevada Adaptive Management Project (SNAMP), a long-term collaborative research project investigating how forest fuels thinning impacts fire behavior, fire risk, wildlife, forest health, and water. Fire is a vital to maintaining healthy California forests and ecosystems and Stephens's work demonstrates that both prescribed fire and its mechanical thinning replacements can successfully change forest structure and fuel loads, resulting in potential overall improvement of forest health. He finds that treated forest stands are more resistant and resilient to high-intensity wildfire and that these treatments have minor to negligible negative impacts on birds and small mammals, understory plant diversity, exotic plant invasions, and insect attack. Current and future research is in part focused on the impact and feasibility of treatments across the landscape.

Also joining participants was Sheila Whitmore from the University of Wisconsin-Madison. Whitmore is the assistant project leader on SNAMP's owl team, which studies how fuel reduction treatments affect California spotted owl survival, forest occupancy, and reproductive success. The California spotted owl is one of three sub-species of spotted owls and the only spotted owl that has not yet been placed on the endangered species list, although its population is widely thought to be declining. Late in the evening, accompanied by Whimore, three nocturnal field technicians, and armed with tools of the trade like bird call whistles and flashlights, participants quietly slogged deep into the forest along the 22-mile system of El Dorado Irrigation District canals, listening for the territorial four-note hoot of the California spotted owl. While the crew eventually found one female owl on the night hike, the owl team has just started surveying breeding territories this spring and are uncertain how and if the owls will be impacted by the King Fire. Modeling efforts and a radio telemetry study seek answers to questions about demography, habitat, individual range size, and foraging preferences, given different levels of severity in burned forests.

Day two of the workshop, under warm sunshine, began with a discussion of Native American fire ecology and traditional stories shared by Kimberly Shiningstar Petree. Petree is a Tumelay Nissenan Miwok, the cultural preservation officer for her tribe, and the founder of the Cosumnes Culture and Waterways, a non-profit dedicated to promoting, preserving, and stewarding Indigenous Culture and waterways of their land. As told by a descendant of the first stewards of the area's forests and a carrier of an ancient oral tradition, the fire stories that Petree shared with the group were both relevant to today's fire management practices, and moving, setting a positive tone for the rest of the day.

Patricia Trimble, El Dorado National Forest's Georgetown district ranger, and Laurie Wigham, illustrator, painter and art teacher, accompanied participants on field activities. Trimble took participants on a road-based tour of the King Fire, demonstrating the effects of low, moderate and severe fire on the landscape. She shared information on consequences of long-term fire suppression, fire impacts, Forest Service strategies for protecting cultural resources, forest replanting and erosion abatement efforts, National Environmental Policy Act regulations, and public perception of fire. More than seven months after the fire, the Forest Service has just opened the burn back up to the public, and the public was out in force mushroom hunting, fishing, and cutting firewood within the high severity areas of the King Fire.

Wigham thoughtfully braided art and field journaling techniques seamlessly into the stops along the way. She shared inexpensive and novel ways to document the landscape in a group or individual setting at difference scales. She offered low-tech tricks to help participants deepen their ability to absorb dense and technical information, observe nature closely and scientifically, and to connect with feelings about a place and time in nature.

Lectures, field study, art, field journaling techniques, knowledge sharing, and Native American story telling: supported by a solid framework of current science topics and research results, they all had their place in this advanced training workshop. Each individual piece of the fire ecology workshop was enriching and informative, and forced participants to move deeper and more thoughtfully into their understanding of the dense topic than they might on their own. The regeneration of the El Dorado National Forest after the King Fire will undoubtedly provide inspiration, research, and education opportunities far into the future.

The UC California Naturalist Program uses a science curriculum, hands-on learning and service to inspire stewardship of the state's natural resources. The public and UC-certified Naturalists alike may sign up for future California Naturalist Advanced Trainings here.

Posted on Wednesday, April 29, 2015 at 10:25 AM
  • Author: Brook Gamble

First storyPrevious 5 stories  |  Next 5 stories | Last story

Webmaster Email: cecentralsierra@ucdavis.edu