Safe, healthy and happy Thanksgiving
"Trees are poems that the earth writes upon the sky,” wrote Kahlil Gibran. But trees falling into power lines have sparked catastrophic fires and falling trees have injured nature lovers.
To prevent power outages, PG&E looks for trees near power lines that need to be trimmed or removed. To prevent power outages and other mishaps caused by failing trees, Matteo Garbelotto, UC Cooperative Extension forest pathology specialist at UC Berkeley, has incorporated science into a mobile application that can be used to determine whether a tree presents a hazard and should be removed.
“PG&E was doing tree surveys with pencil and paper,” said Garbelotto, who saw the manual process as fraught with opportunities for error. A paper record needs to be sent to a central collection site where it is transcribed. In the transcription process, mistakes can be made. And there's no way of verifying if a person actually examined the tree to fill out the form.
“Why don't you do a digital survey?” he asked a PG&E tree surveyer. “Using a tablet or phone, the data could be shipped directly, in real time, to the San Francisco office. Using a phone or GPS device, you will know the precise location of the tree and know the worker did the job. If there's a fire, you have proof.”
PG&E Corporation Foundation, the philanthropic arm of the utility, gave Garbelotto a $70,000 grant to develop the app he envisioned for determining which trees are hazards. The tree disease expert created a list of questions that help evaluate tree health.
For example, in addition to asking if the tree leaning toward a power line, surveyers are asked, Are there obvious signs of internal decay? Is there a large wound on the tree?
“If a tree has a wound of 5 inches or more, there is a good chance there is significant decay behind the wound,” Garbelotto said. “If there is a mushroom or conk growing on the tree, that portion of the tree is dead and the branch or whole tree may fall down.”
The app, which Garbelotto has dubbed “Evalutree,” can be used for more than powerline safety.
UC Berkeley Ph.D. student Michael Johnson has been using the app to evaluate different species of trees.
“We have just started our third field season using the app on a project for the Department of Defense that quantifies the health and economic value of the oak woodlands on the 100,000-acre Vandenberg Air Force Base,” said Johnson. “We started with coast live oak the first summer, added tanoak the second summer, and have expanded to bishop pine this summer.”
The mobile app has simplified data collection for Johnson, who is in the Forest Pathology and Mycology Lab at UC Berkeley.
“I used pencil and paper studying postfire aspen regeneration on Forest Service land in Northern Arizona in 2012-2013, where I also did my master's work on ponderosa pine decay in 2013-2015,” Johnson said.
He described his undergraduate work collecting data with pencil and paper carried in a tatum, a 8.5-inch by 12-inch metal case with a clipboard, compared with working with the Evalutree phone app.
“Each day would start with making sure that we had all of our data sheets packed in our bulky field tatums,” Johnson said, “making sure our GPS points were preloaded in a separate, expensive GPS device, making sure that our camera had batteries and that we had dry erase markers for our small white board so that we could indicate which plot each photograph belonged to.
“After the fieldwork was complete, we would spend weeks doing data entry, trying to make out the scrawled numbers and notes – smeared with charcoal and raindrops – and sorting and compiling the data, photos and GPS points. It was time-consuming and painstaking, to say the least.”
For his graduate research, Johnson was able to enter data directly into a spreadsheet on a field computer. “At the end of the field work, I would just have to compile the data from the computer, photos from the camera, and GPS points from the Garmin to make a report,” he said.
“Evalutree has changed all of that. Instead of field tatums and multiple bulky devices, I walk out into the field with a lab cell phone. The app has preloaded survey questions, the ability to connect photographs to specific plots, and drops GPS points at each plot and tree that I survey.”
Working in the U.S. Defense Department's sprawling, undeveloped landscapes, Johnson said, “We are often in the field all day without internet or phone connectivity. The app is prepared to meet this challenge and relies on our phone's internal storage and pre-existing GPS functionality to order and store our data with precision accuracy. At the end of the day – when we have returned to civilization and technology – we simply upload all of our surveys for the day and I immediately have my data and reports in multiple formats, including pdf, xls and kml files, at my fingertips.
“Within minutes, I can update my maps to show the exact location of all of the day's surveys, start crunching data in Excel, or print out a report with the photographs from each plot for my boss,” Johnson said.
Garbelotto, the UC Cooperative Extension specialist, would like to make the technology available to cities and companies that manage trees.
“The app can be used by any agency or government that owns or manages a significant number of trees and needs to run surveys on a regular basis to ensure these trees are not at risk of failing, causing property damage or, worse, casualties or injuries to people,” Garbelotto said.
“The surveys can be easily customized for different projects,” he said. “It can be used for campgrounds or parks to calculate the likelihood of a tree failing and likelihood of causing damage. You could have an answer within minutes of submitting the survey.”
Healthy California wildlands were managed with periodic wild and cultural fires for millennia. As the state's population and development grew, officials suppressed most fires out of concern for people, homes and businesses.
Though well-meaning, the strategy left land overgrown with vegetation capable of fueling even more dangerous high-intensity wildfires. The past few years have seen an exponential increase in catastrophic wildfires in California.
As a result, there is growing interest in using prescribed fire to bring nature back into balance. Despite the current interest, communities have limited capacity, shared knowledge and experience to bring it back. To close those information gaps, UC Cooperative Extension in Mariposa County hosted a five-session webinar series because the in-person workshop was cancelled due to the coronavirus pandemic. The switch to a virtual series enticed more than 500 people from across the U.S. and more than 12 countries register for the series, and 200 people regularly attended each session. In comparison, 34 people were registered for the in-person workshop.
The webinar series provided guidance on fire ecology, prescribed burn permitting and planning, plus cost-share and the concept of launching a prescribed burn association with neighbors, local agencies and the community in five 90-minute sessions. Recordings are now available free on the UCCE Mariposa County YouTube channel.
The training is designed for California landowners and land managers, but contains information that can be applied broadly in areas where landowners and managers are faced with unmanaged vegetation growth that poses a fire risk.
“Whether you live in a mixed conifer forest, oak woodland, chaparral or grassland habitat, returning prescribed fire to California is part of well-managed landscapes,” said Fadzayi Mashiri, UC Cooperative Extension livestock and natural resources advisor and the webinar series coordinator.
The webinar series struck another first for the small foothill county. The recorded series was approved for continuing education units by the national Society for Range Management. Following are links to individual sessions:
Session 1 – Fire ecology
Fire ecology and behavior and benefits of prescribed fire, Susie Kocher, UCCE forestry advisor in Lake Tahoe
Prescribed fire for invasive plants and weed control, Fadzayi Mashiri, UCCE natural resources advisor in Mariposa and Merced counties
Session 2 – Permitting
CAL FIRE permitting and prescribed burning, Brian Mattos, CAL FIRE unit forester for resource management
Air quality permitting and the health impacts of fire – David Conway, environmental health director, Mariposa County Health Department
Session 3 – Prescribed fire planning
Wildland-urban interface dynamics and community planning – Steve Engfer, senior planner, Mariposa County Planning Department
Developing a burn plan – Rob York, UCCE forestry specialist
Session 4 – Resources for burning
Prescribed burn associations – Lenya Quinn-Davidson, UCCE fire ecology advisor
EQUIP funds for prescribed fire through the National Resources Conservation Service – Robyn Smith, Natural Resources Conservation Service district conservationist
Session 5 – Cultural burning
Benefits of cultural burn, Honorable Ron Goode, North Fork Mono Tribe
Social History of Fire in Southern Sierra – Jared Dahl Aldern, Sierra-Sequoia Burn Association.
The workshops were funded in part by California Climate Investments, a statewide initiative that puts cap-and-trade dollars to work reducing greenhouse gas emissions, strengthening the economy and improving public health and the environment. Sponsors include the North Fork Mono Tribe, CAL FIRE and the Southern Sierra Prescribed Fire Council.
UCCE leads development of prescribed burn association in San Benito, Monterey and Santa Cruz counties
With a $379,785 grant from CAL FIRE, UC Cooperative Extension and the Resource Conservation District of Monterey County are spearheading a community effort to create a prescribed burn association along California's Central Coast region.
The grant is one of 55 awarded by CAL FIRE to reduce the risk of devastating wildfires that take lives and destroy homes and valued wildland environments across California.
“These 55 local projects will play a critical role in augmenting our fire prevention efforts,” said CAL FIRE director Chief Thom Porter.
Prescribed burn associations (PBAs) are made up of ranchers, volunteer firefighters, non-profit organization and other community members. They pool their resources and energy to plan and conduct prescribed burns on private land. The first California PBA was established in 2018.
“Improving forage and reducing fire risk are key goals of our prescribed burns,” said Devii Rao, UC Cooperative Extension natural resources advisor and project manager. “We will also plan fires to control non-native invasive weeds and restore and enhance wildlife habitat.”
Funds for the CAL FIRE grant program are part of the California Climate Investment, a statewide program that uses cap-and-trade dollars to reduce greenhouse gas emissions, strengthen the economy, improve public health and conserve the environment. While prescribed burns emit smoke and carbon dioxide, the amount is much lower than high-intensity wildfires.
Rao said UCCE will be holding workshops and meetings to teach potential association members and the general public about fire ecology, fire permitting, prescribed burn planning and liability associated with burning.
“People are really seeing the value of prescribed fire and they are seeing that it's better to have several smaller burns throughout the year as opposed to these giant, catastrophic wildfires that cause so much damage,” Rao said. “If we can have many smaller burns, we can achieve resource conservation goals, we can achieve forage improvement goals and we can improve fire safety all at the same time.”
Grazing cattle for fire safety
Rao is also leading a study, funded by the California Cattle Council, to better understand the influence of livestock grazing on fire safety of California wildlands. This project is in collaboration with UCCE rangeland specialist Luke Macaulay, UCCE livestock and natural resources advisor Sheila Barry, rangeland consultant Felix Ratcliff and recent UC Berkeley graduate Rowan Peterson.
The researchers used brand inspection data, USDA Ag Census data and county crop reports to estimate the number of rangeland cattle in each county across the state. They estimated how much forage – or from the fire safety perspective, how much fuel – the cattle are consuming.
“Thanks to Felix's great work analyzing these multiple complex datasets, our preliminary results show that cattle consumed approximately 12.4 billion pounds of forage across California in 2017,” Rao said.
Tulare County had the greatest amount of wildfire fuel consumed (1.3 billion pounds), and Orange County had the least (896,000 pounds). Forage removed per grazed rangeland acre ranged from a low of 13 pounds per acre in Alpine County to 2,157 pounds per acre in Tulare County.
Counties in the San Francisco Bay Area, the Sacramento and San Joaquin Valleys, the Sierra Nevada Foothills, and the northernmost counties in the state had somewhat higher removal of wildfire fuel per grazed acre compared with other counties in the state.cedx
“Our analysis is currently ongoing. However, this preliminary analysis shows that many counties have adequate rangeland grazing to significantly reduce wildfire risk, at least in certain strategic areas,” Rao said.
In many counties, grazed rangelands are only a fraction of total grazeable rangeland.
“These counties highlight opportunities for grazing to help fight wildfire risk,” Rao said.
Preventing embers from getting inside may save homes
Photos and video of the Northern California communities that have been hit by wildfires show buildings reduced to ash. How could so many homes and businesses burn so quickly in the 2017 Wine Country fires? Many houses that burned to the ground in the Northern California fires likely burned from the inside out, says Yana Valachovic, UC Cooperative Extension forest advisor for Humboldt and Del Norte counties.
Red hot embers carried on the wind can enter the attic via the venting. “In the case of the wind-driven fires on October 8, these fires created ember storms that blasted little coals into everything in their pathway,” Valachovic said. These embers also create small spot fires near the home that fuel new sources of embers.
Weather played a large role in these fires and generated a fire storm of embers that ignited grass, shrubs, trees and anything in its path. “While the landscape can be the fuse, the homes really can be the most burnable part of the landscape,” Valachovic said. “These embers likely lodged in the small spaces and openings of homes and buildings. A common location is for the embers to enter via attic venting or HVAC systems distributing little fires into the buildings.
“Embers also landed on receptive leaves, outside furniture, and other flammable materials outside the buildings that created fires adjacent to the buildings. Once enough buildings were engulfed in fire, the radiant heat of each building fire led to exposures on the neighboring buildings, creating a house-to-house burn environment.”
Residents can reduce the risk of embers setting their house on fire by removing dry plants around the structure.
“These fires remind us that everyone in California could help the fire situation by managing the vegetation, leaves in the gutters and decks, newspaper piles, brooms and other flammable sources near to their houses now before they get the evacuation call,” Valachovic said. “If you are likely to have to evacuate soon, temporarily covering or sealing up the vents with metal tape or plywood can help harden your home to an ember storm.”
Steve Quarles, UC Cooperative Extension advisor emeritus, who spent his career studying fire behavior on building materials and around homes, created an online Homeowner's Wildfire Mitigation Guide at http://ucanr.edu/sites/Wildfire. Quarles, who now does research for the Insurance Institute for Business and Home Safety, demonstrates how embers can ignite and quickly engulf a house in flames in a video https://www.youtube.com/watch?v=IvbNOPSYyss. After the 3-minute mark, video shows embers drifting up and flying through a screened vent into the house, where they could ignite combustible materials in the attic resulting in fire starting on the inside of the home.
“If you have time to prepare your home, use the wildfire last-minute check list at https://ucanr.edu/sites/fire/Safety/Evacuation/,” Valachovic said.
Valachovic has co-authored publications in home survival in wildfire prone areas http://anrcatalog.ucanr.edu/pdf/8393.pdf and how landscape plants near homes can create more vulnerability to wildfire http://anrcatalog.ucanr.edu/pdf/8228.pdf.
Once these fires are extinguished, a more detailed analysis will be possible.
“Past wildfire events have shown that this is the common way homes in the wildland urban interface (WUI) burn, and this scenario was likely translated to the urban environment,” she said.
The Camp Fire that destroyed the town of Paradise and other wildfires that have devastated communities in recent years have convinced wildfire experts that Californians need to take more than one approach to coexist with fire.
To better protect new houses against wildfire, California has building codes, but where residential communities are built on the landscape and how they are designed are also very important to limit wildfire-related losses, according to University of California Cooperative Extension specialists Max Moritz and Van Butsic.
“Defensible space and vegetation management is important, but in the long term, where and how we build new developments will be equally important for keeping Californians safe,” said Butsic, who studies land use.
To develop their recommendations for reducing wildfire risk for future community development, Moritz, who specializes in wildfire, and Butsic reviewed fire studies and consulted firefighters and community planners.
Their new publication, “Building to Coexist with Fire: Risk Reduction Measures for New Development,” is designed for city planners, fire districts and communities to incorporate community-scale risk reduction measures when building or rebuilding in fire-prone areas.
“There is currently little codified guidance for where and how to build our communities in California, aside from building codes for individual structures and a few requirements for road access and water supplies,” said Moritz, who is based at UC Santa Barbara.
Wildfire consultant and architect David Shew, who retired as a CAL FIRE chief after 31 years, said, “I can state without hesitation that the land use planning principles and design recommendations identified in this study are necessary steps to help increase wildfire resiliency to existing and future communities. Being a first-hand witness to the increasingly destructive nature of wildfires, I can attest to the value and necessity for these improvements to be integrated into our built environment. This should become a much-used reference for every planning and fire official who face wildfire impacts.”
To reduce fire vulnerability of communities, Moritz and coauthor Butsic, who is based at UC Berkeley, recommend including fire professionals and biological resource experts early in the community planning process. They also recommend considering the placement of communities on the landscape, such as near bodies of water and agricultural land, and how they are laid out to minimize exposure to wildfire. Key considerations include defensibility, risk of ignition and ease of evacuating residents.
“This report provides both a robust justification for integrating resilience practices into land use planning and community design, and a toolbox for doing so,” Sarah G.Newkirk, director of disaster resilience with The Nature Conservancy in California. “The risk reduction measures described can be put to use immediately – ideally in combination with each other – both in ongoing wildfire recovery planning, and in local hazard mitigation planning. Furthermore, the report should be a wake-up call to FEMA to think broadly about how best to support wildfire mitigation in California.”
To more efficiently reduce fuel in new communities, Moritz and Butsic write, “The design, maintenance and use of defensible space for fire protection is easier when neighborhoods are developed more densely and are built to stringent fire-resistant building codes.”
In the 31-page publication, they present risk reduction measures for four design contexts:
- landscape setting – engage in strategic planning much earlier, use hazard maps and use major landscape features
- separation from wildfire source—use nonflammable amenities in design, employ safe setbacks on slopes and concentrate on inner side of roadways
- density management – cluster with other homes
- protective infrastructure – harden public facilities and refuges, locate power lines underground and augment water requirements.
They provide examples for each risk reduction measure, along with some discussion of challenges associated with each measure.
“Our hope is that this guidance will be helpful for agency personnel involved in evaluating and approving future development in California,” Moritz said. “Because there is a pressing need for additional housing in California, communities must be built with design principles that make them safer to inhabit and less vulnerable to inevitable wildfires.”
The publication “Building to Coexist with Fire: Risk Reduction Measures for New Development” can be downloaded for free at https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8680.