Posts Tagged: wildfire
Lambs grazing on pastures after wildfire show no significant adverse effects
Hopland REC turns 2018 River Fire devastation into research opportunity
The destructiveness of wildfire flames is easy to see, but dangers may lurk in the ashes they leave behind. A group of UC Davis scientists studied lambs at the UC Hopland Research and Extension Center, investigating whether pastures regrown after a wildfire cause toxic metal residues in grazing animals. The results, published in California Agriculture journal, showed that grazing on regrown pastures did not significantly alter the metal content of the lambs' meat and wool. That's good news for ranchers and consumers from a food safety perspective.
In 2018, the River Fire burned six miles north of Hopland, scorching two-thirds of the land at Hopland REC, including areas in its sheep station. Since Hopland REC conducts ecological and agricultural research, they had data and some meat samples from the sheep flock that lived on site before the River Fire occurred.
“A bunch of researchers came together to brainstorm how we could take advantage of this unfortunate event,” said Sarah Depenbrock, assistant professor and agronomist in the Medicine and Epidemiology department of UC Davis School of Veterinary Medicine.
Burning has played a role in agricultural processes for many years, but wildfires in California are creating a new fire landscape that interests researchers like Depenbrock. “The problem, now, is that these big wildfires probably interact with agricultural land differently than routine prescribed burns,” she said.
Large, older plants on lands that have not recently burned may contain high concentrations of metals, sequestered over years of growth. Mercury is an example of a potentially dangerous metal that can be sequestered in living things over time. These metals may be distributed in ash after the vegetation burns so the scientists examined lambs that had grazed on Hopland REC's recently burned pastures, during the first plant regrowth.
Uncertain results raise more questions
The researchers compared meat from lambs that grazed on regrown pastures in 2019, after the River Fire, to frozen meat samples that were collected the year before the fire. Lead, mercury, arsenic, molybdenum, cadmium, beryllium, cobalt and nickel were not detected in any animal samples. There were, however, a few (3 out of 26) samples that tested positive for the non-essential (potentially toxic heavy metals) chromium and thallium in the group grazing after the fire.
Due to the small number of samples testing positive, researchers could not determine statistically if this contamination was associated with grazing the burn regrowth. The concentrations of chromium and thallium found may or may not be potentially toxic, depending on the specific forms and how much meat a person consumes.
Another aspect of the study included testing lambs' wool to determine if it is a good method of judging the mineral content of its meat. “In general, we learned that it wasn't well-correlated with most meat metal content of interest, which is worth knowing. However, because we did not identify many of the non-essential metals of particular toxologic concern, such as lead or mercury, in any animal samples we could not determine if testing wool would be useful for those metals, as they are in other species,” said Depenbrock. She also notes that the wool from animals whose meat tested positive for chromium and thallium, did not test positive for these metals in their wool.
As the challenges in managing wildfires persist, so does the risk of contamination of food products stemming from grazing livestock.
“We didn't get striking evidence that tells us, when there's a fire, it means everything is contaminated with heavy metals,” said Depenbrock. “But it does raise the question that maybe we should be doing a little bit of surveillance to see if this is spurious or common. And we should be finding a way to screen grazing herds.”
Recommendations to manage copper concerns
“It's a very small study, but it was quite interesting to find that copper was actually lower in the postfire grazing group, which makes me wonder,” Depenbrock said.
Diseases associated with copper deficiency are a major concern in sheep. For example, congenital swayback can result in stillbirth or an animal's inability to stand on its own due to incurable changes to the spinal cord. Other adverse effects include reduced growth rate, anemia, wool defects and fiber depigmentation, and osteoporosis with higher risk of spontaneous fractures. Copper excess can also cause serious and sometimes fatal disease.
Many of the forage sources, grazing areas and rangelands in California are copper deficient, while some feed sources have excess copper. Screening and monitoring livestock herds for trace minerals including copper is crucial.
To test for copper, she advises livestock owners to obtain mineral concentrations from the organs of euthanized or dead animals. Samples from the liver and kidney are the most valuable organs to identify a potential problem in the herd. UC Davis Veterinary Medicine's California Animal Health and Food Safety (CAHFS) labs do this testing routinely.
Second, monitor and record mineral supplementation and, third, maintain updated health records to make informed decisions regarding supplementation based on a herd or flock's known problems. For example, if a producer is not accustomed to supplementing copper, Depenbrock highly recommends working with a veterinarian to start out (as there are numerous copper supplement products of varying concentration on the market), to determine a testing or screening plan, and review health records for problems potentially associated with copper.
To read the full text of the study, visit https://calag.ucanr.edu/Archive/?article=ca.2022a0016.
/h3>/h3>/h3>Wildfires may spur animal biodiversity
Naturally fire-prone ecosystems tend to have more species of birds and mammals, new study reveals
Wildfires. Many see them as purely destructive forces, disasters that blaze through a landscape, charring everything in their paths. But a study published in the journal Ecology Letters reminds us that wildfires are also generative forces, spurring biodiversity in their wakes.
“There's a fair amount of biodiversity research on fire and plants,” said Max Moritz, a UC Cooperative Extension wildfire specialist who is based at UC Santa Barbara's Bren School of Environmental Science & Management and the study's lead author. Research has shown that in ecosystems where fire is a natural and regular occurrence, there can be more species of plants — a greater “species richness” — due to a variety of factors, including fire-related adaptations. But, he said, there hasn't been nearly as much research in the way of animal biodiversity and fire.
If fire regularly consumes some of the base of an ecosystem's food chain, how does that ripple up to affect the biodiversity at higher levels?
That was the question Moritz investigated during a project supported by UC Santa Barbara's National Center for Ecological Analysis & Synthesis; he later recruited collaborators Enric Batllori from Universitat de Barcelona and Benjamin M. Bolker from McMaster University in Canada. For several years they combed through global datasets on various factors such as plant biomass, fire observations and species richness patterns.
While it might be natural to assume that plant biomass regularly consumed by fire would in turn lead to lower animal biodiversity, they found that for birds and mammals, fire is associated with increased diversity. In fact, they say, the effect of fire on biodiversity in the case of birds rivals that of the ecosystem's productivity. And in the case of mammals, fire's influence was even stronger than that of productivity.
“It's counterintuitive,” Moritz said. In the short term, fire's consumption of plant material (also known as “net primary productivity”) could result in less food for the animals that consume plants and make it more difficult to survive and reproduce. But in the longer term, he said, there may be evolutionary effects that unleash adaptations and formations of new species.
The researchers also looked at the effect of fire on amphibian species, however, the connection between fire and biodiversity in their case was difficult to make, possibly because amphibians live in wetter environments where fires may not be a regular occurrence.
So what accounts for the net positive effects of fire on mammal and bird diversity? The study is a correlative one, Moritz said, so more granular examinations have to be made to find out for sure. But it's likely that fire selects for species that can adapt to and quickly recover from a burn, and fire often creates environmentally complex habitats that meet different species' requirements.
“We know that fire creates a lot of heterogeneity and opens up all these niches,” Moritz said, and this resource availability might create favorable environments for some organisms to flourish alongside or over others. For example, animals that have strategies to survive fires or reproduce faster might do better in a fire-prone environment, as could those that make use of different habitats that emerge in the wake of a blaze.
Despite the connection between fire and species richness, the authors are careful to point out it does not mean fire is good for all ecosystems. In places where fire is not a natural occurrence, its presence “is more of a modern threat than an important process to maintain,” they said. And for places where fire is a natural part of the ecosystem, climate change-driven and intentional deforestation fires “may be quite different from natural fire regimes.”
Nevertheless, they say, these findings indicate that fire plays an underappreciated role in the generation of animal species richness and biodiversity conservation. Furthermore, the study adds nuance to the Latitudinal Biodiversity Gradient, a global pattern of terrestrial biodiversity in which the world's most biodiverse areas are located nearest to the equator, with levels of biodiversity generally decreasing toward the poles.
“This is a pattern that people have known for decades and have argued quite a bit about in terms of what drives it,” Moritz said. “And it turns out, it's hard to figure out. And it looks like fire plays a far more important role than we've ever really understood.”
/h2>/h2>Quinn-Davidson to lead UC ANR Fire Network
Wildfire has become more frequent and intense in California with climate change. To meet the challenge of wildfire, UC ANR has hired several new UC Cooperative Extension fire advisors and staff to study issues related to wildfire and to assist Californians with their preparations. Quinn-Davidson and the Fire Network will provide critical coordination and connection across geographies and disciplines ranging from forestry to food safety to livestock to water quality.
“Lenya has more than a decade of work in fire science and has carried out her work through partnerships and community engagement,” said Glenda Humiston, UC vice president of agriculture and natural resources. “Her experience and successful track record will enhance how we coordinate our many layers of research and education related to fire prevention, recovery, public policy and workforce development.”
Quinn-Davidson has served as a UC Cooperative Extension fire advisor for the North Coast since 2016. During her three-year term as the Fire Network director, she will continue her research program and continue to build capacity among landowners, tribes and other communities to use prescribed fire throughout the state. Quinn-Davidson also leads the national/international WTREX program, focused on empowering women and other underrepresented people who work in fire.
“I'm honored to take on this new role, and I can't wait to further grow, connect and support our fire efforts within UC ANR,” Quinn-Davidson said.
UC ANR's Fire Network will also enhance communication.
“The network will increase the flow of information to improve how we conduct academic research, strengthen local efforts by sharing relevant data and ideas, create and build capacity for different management techniques and tools, and facilitate new research and programming related to diverse facets of fire in California,” said Deanne Meyer, UC ANR interim associate vice president.
Before becoming a UCCE fire advisor, Quinn-Davidson worked on fire projects for five years as a UCCE staff research associate. Since 2009, she has served as director of the Northern California Prescribed Fire Council. Prior to joining UC Cooperative Extension, she was a research assistant in the Wildland Fire Laboratory at California State Polytechnic University, Humboldt and worked on stream restoration for Bioengineering Associates, Inc.
She earned a master's degree in social science, environment & community from Cal Poly Humboldt and a bachelor's degree in conservation and resource studies from UC Berkeley.
Quinn-Davidson, who has published more than 70 peer-reviewed and popular articles, will be based in Humboldt County. Follow her on Twitter @lenyaqd.
Lessons from the 2022 wildfire season offer hope
As we prepare for wildfire in 2023, we reflect on what we learned from the 2022 fire season. From a statistical point of view, fewer acres were burned, and fortunately, fewer lives and homes were lost. Less than 400,000 acres were burned, a sevenfold reduction from 2021. On a similar note, less than 1,000 structures were destroyed by wildfire, representing a fourfold reduction from 2021. Those are significant changes, but as I reflect on my experience studying the vulnerabilities in our communities to wildfire, sadly, I need to share that “we're not out of the woods yet,” so to speak, but the formula for success is becoming clearer.
Recently, I worked with great colleagues to evaluate factors contributing to home loss in the town of Paradise during the Camp Fire. In that experience, we learned that the condition of the community of nearby homes has a significant impact on an individual building's survival. In our research, we found that the strongest predictor of loss was attributed to the distance to the nearest destroyed structure, especially if the destroyed building was within 50 feet. That means if a home succumbs to wildfire, it affects the survival of neighboring homes. That lens helped me look for patterns in 2022's wildfire season.
Fences create a wildfire path
I started 2022 in Boulder, Colorado, at the Marshall Fire. Many may remember that on Dec. 30, 2021, a wildfire challenged our views of when the fire season is deadliest. We were ready to welcome the new year and wildfire was furthest from our minds when several fires ignited during a significant wind event (the cause has still yet to be determined), and within minutes the fire spread to several communities around Boulder. Propelled by gusts of 115 mph, the fire burned 6,000 acres, and when it finally was suppressed by a snowstorm 12 hours later, it left behind 1,084 destroyed structures, including a hotel, a Target store and one shopping center. In January, two weeks after the fire started, I was privileged to accompany scientists from the Insurance Institute for Business and Home Safety (https://ibhs.org/risk-research/wildfire/ ) and UC ANR's Steve Quarles, UC Cooperative Extension advisor emeritus, to search for clues to help understand why some buildings succumbed and others did not.
The Marshall Fire burned on the east side of the Rocky Mountains, very different from the forested community of Paradise, where visual privacy between homes can be met through trees. During my visit, I saw that the Marshall Fire quickly spread through the region's grasslands and then to homes via a spaghetti of wooden fences.
These fences offer these communities privacy and backyard protections for kids and pets, but also create a pathway for wildfire to travel between homes. More specifically, the burning grass came into contact with debris and leaves caught at the base of wooden fences, igniting the fence and creating a pathway to bring fire directly to the house. The burning fence ignited surrounding dry ornamental plants and traveled down the fence line bringing flames directly to the house. Once a home ignited, the winds whipped embers from the burning homes to adjacent homes.
I believe that if the fences been upgraded with a 5-foot section of noncombustible materials or a metal gate attaching the fences to the houses, a burning fence would have been much less likely to damage the home.
Fuel reduction works
Fast forwarding to May, another fire challenged California's view of the fire season. The Coastal Fire burned on May 11, 2022, in Laguna Niguel near the California coast in Orange County. It was a small fire (200 acres) that burned through dense brush known as chaparral and raced up steep slopes to a network of homes that had been managed to withstand wildfire. In the end, 20 homes were lost. During my visit with my colleague Luca Carmignani, UC Cooperative Extension area fire advisor, we observed that the situation could have been much worse.
The community had completed a significant amount of fuel reduction and prevented flames from directly contacting the homes. This is a huge success that should be celebrated. Their weakness, however, was not preparing for the ember cast that came from the burning chaparral. These homes exhibited the classic effect of having the fire burn to the edge of the community and stop. Then 30 minutes later, fire personnel and the media observed puffs of smoke emanating from the roofs of the homes. So, what was the cause?
Embers found ways inside homes
Embers had penetrated the attic vents, found combustible materials, and fire ignited inside these houses. Fortunately, fire personnel were able to contain the damage to the homes at the exposed edge of the canyon rim and prevent a widespread home-to-home tragedy. Had these communities upgraded their vents to resist embers, the odds that these homes would have survived would have greatly increased.
Defensible space adds protection
The Oak Fire in Mariposa County in July provided another interesting lesson. The fire burned 20,000 acres and took 182 structures. A colleague from CAL FIRE shared that homes that had failed their defensible space inspection before the fire were six times more likely to be lost in the Oak Fire.
Defensible space is the modification and reduction of combustible materials and vegetation around a home. This required fuel modification provides a safe place for fire personnel to safely stage to address the approaching wildfire, and it also protects the house from catching fire. We all know this is a good practice; perhaps this data can help underscore its importance in building protection.
Wildfire preparation makes a difference
So, what did 2022 tell us? Simply, the details of wildfire preparation matter. Homes are destroyed by one or a combination of exposures: direct flame touching the building, embers penetrating a building through open windows or porous vents, or the radiant heat from the combustion of nearby fuels or homes leading to window breakage.
As Californians, we must prepare for all three types of exposures. We need to break the pathways of continuity from fences and vegetation to our structures. We need to harden our structures to resist heat and embers. We need to reduce fuels around our homes through the creation of defensible space.
To me, home loss to wildfire is predictable; however, the solutions to reducing home loss are within our sights and, with some tenacity and attention to the details, are within our capacities.
UCCE seeks statewide input to develop future wildfire programs
University of California Cooperative Extension has recently expanded their team of fire advisors and staff. This new group of UCCE fire professionals is interested in learning about the concerns of the communities that UCCE serves, as well as the natural resource professionals already working to address these issues.
Results from this survey will enhance the team's ability to partner with residents, landowners, agencies, academics, and other organizations to reduce California's vulnerability to wildfires. These new advisors will also share survey results with UCCE colleagues throughout the state, who already provide important fire-related programming across diverse landscapes and audiences.
"Wildfires will continue to affect all Californians, either directly or indirectly," said Katie Low, UCCE statewide fire coordinator. "It's invaluable to have the input of as many people as possible to guide the development of our wildfire-related extension programs, so that they can provide the most useful resources and information to communities across California."
The survey asks questions about topics such as:
- Gaps within existing educational programming and resources
- Challenges community members are facing in addressing wildfire risk
- Empowerment of communities to make property management decisions and prepare for wildfire
- Acceptability of prescribed fire and other fuels treatments
By participating in this study, you can choose to enter a drawing to win one of fifty $20 VISA gift cards.
To take the online survey, please visit https://bit.ly/UCCE_Fire_Survey.
This research is being led by a team of new UCCE fire advisors and staff. If you have any questions about this survey, please contact the fire/forestry professionals involved in this survey effort:
- Luca Carmignani, UCCE fire advisor for Los Angeles, Orange, Riverside, and San Diego counties, carmignani@ucanr.edu
- Alison Deak, UCCE fire advisor for Fresno, Madera, and Mariposa counties, aldeak@ucanr.edu
- Katie Low, UCCE fire academic coordinator for Nevada and Placer counties, katlow@ucanr.edu
- Barb Satink Wolfson, UCCE fire advisor for Monterey, San Benito, Santa Clara, and Santa Cruz counties, bsatinkwolfson@ucanr.edu
- Ryan Tompkins, UCCE forestry advisor for Plumas, Sierra, and Lassen counties, retompkins@ucanr.edu
For more information about wildfire-related programming from University of California Cooperative Extension, please visit https://ucanr.edu/sites/fire/ or the Facebook page https://bit.ly/fireSolutions.
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