Overall, 3.5 percent of the trees (based on those areas sampled during the blitzes) were found to be P. ramorum positive, a threefold drop from 2017. Yet, in San Mateo, Santa Clara and Santa Cruz counties, infection levels were estimated to be as high as 19 percent, followed by 12.7 percent in the East Bay.
"Oaks and tanoaks were infected last year and will be showing symptoms such as bleeding in the stem and canopy drying this year and in the next two years to follow. Hence, despite a reduction of SOD infection on leaves of California bay laurels and leaves of tanoaks in 2018, we can expect a sharp increase in oak and tanoak mortality in 2018, 2019 and 2020."
Notable outbreaks were detected in Alameda (El Cerrito and Oakland urban parks, San Leandro, Orinda, Moraga), Marin (Novato, Day Island, Woodacre, Sleepy Hollow, McNears Beach, China Camp State Park, north San Rafael, Tiburon Peninsula, east and west peak of Mt. Tamalpais, Marin City), Mendocino (south of Yorkville), Monterey (Carmel Valley Village, Salmon Creek Trail in southern Big Sur), Napa (east Napa city), San Mateo (Burlingame Hills, west of Emerald Hills and south of Edgewood Rd, Woodside ), Santa Clara (Los Altos Hills, Saratoga, Los Gatos, along Santa Cruz Co border), Santa Cruz (along the Santa Clara Co border, Boulder Creek), and Sonoma (near Cloverdale, east and west of Healdsburg, west of Windsor, east of Santa Rosa, west of Petaluma) counties.
Several popular destinations where P. ramorum was found positive during the 2017 Blitz were negative for the pathogen in 2018, including Golden Gate Park and the Presidio of San Francisco, the UC Berkeley campus, and Mount Diablo State Park. Samples from San Luis Obispo and Siskiyou counties were also pathogen-free as were those from the southern portion of Alameda County.
“It is encouraging that SOD has yet to be found in the forests of California's northern-most counties, San Luis Obispo County and southern Alameda County,” said Garbelotto.
“It is also encouraging to see that despite its continued presence in the state for more than 20 years, SOD infection rates drop during drier years,” he said. “However, in 2018, we identified a number of communities across several counties where significant outbreaks were detected for the first time, and the Salmon Creek find in Monterey County is the southernmost positive WUI (wildland-urban interface) tree detection ever. Until the 2018 Blitz, only stream water had been found positive in the Salmon Creek area. We encourage everyone in affected counties to look at the Blitz results online and to attend one of the fall workshops to learn how to protect their oaks from SOD.”
Citizen-science SOD Blitz workshops
SOD Blitz Workshops are being held this fall in Santa Rosa (Oct. 10), Portola Valley (Oct. 16) and Berkeley (Oct. 17). The trainings will discuss Blitz results and recommendations for protecting oaks in the WUI. Workshops are intended for the general public, tree care professionals and land managers (see www.sodblitz.org for details). Two International Society of Arboriculture continuing education units will be offered at each training. Data collected from the Blitz (both positive and negative samples) have been uploaded to the SOD Blitz map (www.sodblitz.org ) as well as to SODmap (www.SODmap.org) and to the free SODmap mobile app, which can serve as an informative management tool for people in impacted communities.
Twenty-five SOD Blitz surveys were held in 2018 in the WUI of 14 coastal California counties from the Oregon border to San Luis Obispo County and included three tribal land surveys. The 304 volunteers surveyed approximately 13,500 trees and submitted leaf samples from over 2,000 symptomatic trees to the Garbelotto lab for pathogen testing.
SOD Blitzes are a citizen science program, which train participants each spring to identify symptomatic tanoak and California bay laurel trees in the WUI and to properly collect samples in the interest of generating an informative map of P. ramorum disease symptoms over time. Samples are tested for the presence of the pathogen at UC Berkeley and results are posted electronically each fall. Now in its eleventh year, the SOD Blitz program is one of the first in the world to join researchers and volunteers in a survey for a tree disease.
SOD Blitz surveys were made possible thanks to funding from the US Forest Service State and Private Forestry, Midpeninsula Regional Open Space District, and the PG&E Foundation. The Blitzes were organized by the UC Berkeley Garbelotto lab in collaboration with the National Park Service, Presidio Trust, San Francisco Public Utilities Commission, Midpeninsula Regional Open Space District, Save Mount Diablo, Land Trust of Santa Cruz County, East Bay Regional Park District, Santa Lucia Conservancy, Sonoma State University, UC Santa Cruz Arboretum, Los Padres National Forest, City and County of San Francisco Department of Recreation and Parks, UC Berkeley Botanical Garden, and California Native Plant Society.
For information on the status of P. ramorum/SOD tree mortality in California wildlands, see the US Forest Service 2018 Aerial Detection Survey results at https://www.fs.usda.gov/detail/r5/forest-grasslandhealth/?cid=fseprd592767.
For more information on the SOD Blitzes, visit www.sodblitz.org or contact Katie Harrell at (510) 847-5482 or email@example.com. For more information on Sudden Oak Death and P. ramorum, visit the California Oak Mortality Task Force website at www.suddenoakdeath.org or contact Harrell.
"We encourage everyone in affected counties to look at the Blitz results online and to attend one of the fall workshops to learn how to protect their oaks from SOD,” Matteo Garbelotto.
SOD symptoms guide
Google map shows results of the SOD blitzes available online at sodblitz.organd SODMAP.org. Green icons identify trees sampled that tested negative for SOD. Red icons were SOD-infected trees.
SOD Blitz volunteers collect leaf samples and record the location using the SODmap mobile app.
A torrent of technology is flowing into the agricultural sector. To make sense of it, UC Agriculture and Natural Resources, Fresno State and West Hills Community College came together with technology vendors and growers at Open Farm 2018, held in October at UC ANR's Kearney Agricultural Research and Extension Center in Parlier.
“A lot of technology is coming out,” said Kearney director and UC Cooperative Extension agronomy specialist Jeff Dahlberg. “I need to caution you, it's not all is based on science. We are helping with testing.”
Dalhberg has been working with Blue River Technologies to monitor the growth of dozens of sorghum cultivars. Throughout the growing season, Blue River flew drones over the sorghum nursery with cameras to capture their growth and development.
“We have a huge phenotypic dataset,” Dalhberg said. “It will be compared at the genetic level with plant samples and help us identify genes associated with drought tolerance.”
At Open Farm, Dahlberg's field presentation was paired with Smartfield, a company that uses fixed cameras and field sensors to gather information for “big data crunching.”
PowWow Energy, based in San Francisco with a field office at the Water, Energy and Technology (WET) Center at Fresno State, met near a well at Kearney to explain how the company can help growers with decision support tools. The company believes their technology will be useful for farmers tracking groundwater usage, data that will be key to complying with new rules associated with the Sustainable Groundwater Management Act (SGMA). SGMA, signed by Gov. Brown in 2014, gives local agencies the authority to manage groundwater in a way that achieves sustainability by 2042.
UCCE agriculture mechanization specialist Ali Pourezza introduced a prototype he developed with junior specialist German Zuniga-Ramirez that he believes will make early detection of the devastating citrus disease huanglongbing as easy as taking a photo with a smartphone camera.
The idea is based on the optical characteristics of the disease in leaves. By using a polarizing light, leaves on diseased trees are immediately identified. Infected trees can then be torn out before insects have the chance to spread the disease to other trees.
Pourezza and Zuniga-Ramirez are seeking funding to take the prototype to the next level, and eventually commercialize the product.
This sampling of innovations being showcased at Kearney is part of a continuing effort by UC to connect the ag community with technology developers and resources that is shepherded by a new UC ANR program called The VINE, Verde Innovation Network For Entrepreneurship. The VINE was created by UC ANR in 2017 to link entrepreneurs with mentors, advisors, collaborators, events, competitions and education.
At Open Farm 2018, UC ANR vice president Glenda Humiston was the keynote speaker. She outlined three areas where farmers, the technology sector and academia can work together to accelerate technology application in rural parts of California: improve broadband access, identify high-value uses for biomass and establish water infrastructure in rural communities.
To address the broadband issue, Humiston is leading an initiative to document mobile internet speed across California – including rural areas. In April 2019, Humiston plans to enlist 4-H members across the state to test internet speed using the free smartphone app CalSpeed several times over a period of a week.
“This will give us a snapshot of mobile broadband service availability,” Humiston said.
The crisis in the Sierra Nevada – where millions of trees died from the drought of 2010-16 – could prompt the development of high-value uses of biomass and establish a market for biomass derived in the agricultural sector, she said.
Humiston also took the opportunity to ask participants to help make sure the critical services UC ANR provides – including county-based UC Cooperative Extension, nine research and extension centers, the UC integrated pest management program, 4-H youth development, UC Master Gardeners and others – continue to fuel the California economy. Diminished funding from the State of California is taking a toll on the UC ANR budget.
“We need people like you to work with the VINE to set up improved support,” Humiston said.
Kearney REC director Jeff Dahlberg speaks to participants at Open Farm.
UCCE specialist Ali Pourreza compares a citrus leaf infected with HLB with one that is not infected.
Representatives of PowWow Energy meet with Open Farm participants near a well at the UC Kearney Agricultural Research and Extension Center.
On Oct. 2, the prescribed-fire workshop will be held at Colfax Veterans Memorial Hall, 22 Sunset Circle, Colfax.
On Oct. 4, the workshop will be held at Ebbett's Pass Fire District, 1037 Blagen Road, Arnold.
The one-day workshop is designed for landowners and land managers who want to learn skills in prescribed-fire planning and implementation. In addition to reducing wildfire fuels, prescribed fire is used to control invasive plant species and for ecological restoration.
Each workshop will feature similar content including presentations on prescribed fire, including local fire history and current fire research, prescribed fire permitting and legal considerations, fire weather forecasting and online tools, air quality and smoke management, fire terms and fire behavior, burn plan development, burn unit preparation and fire tools and equipment. Instructors will also discuss models for accomplishing prescribed fire on private lands, including prescribed burn associations and CAL FIRE's Vegetation Management Program.
During the last week of October, participants in each workshop will be invited by UC Cooperative Extension to a field trip to look at lands actively managed with prescribed fire and to participate in a live training burn (weather permitting) at UC Berkeley's Blodgett Research Forest in Georgetown in El Dorado County.
For more information, contact Susie Kocher, UC Cooperative Extension advisor, at (530) 542-2571 or firstname.lastname@example.org.
Californians received bleak news last month when the state released its fourth assessment of climate change in California. The report predicts severe wildfires, more frequent and longer droughts, rising sea levels, increased flooding, coastal erosion and extreme heat.
“It's great to be living in a state where science and facts around climate change are valued,” said UC Cooperative Extension specialist Adina Merenlender, “but the recent forecasts may make you want to devour a quart of ice cream in a pool of salty tears.”
Modern civilization has changed the world climate, and even dramatic reductions in global greenhouse gas emissions at this point won't turn back the clock. The warming now predicted by Cal-Adapt is likely already “baked in,” even with our best mitigation efforts, said Igor Lacan, UC Cooperative Extension advisor in the Bay Area of California.
California has been a leader in facing the future climate head on. The state's first comprehensive assessment on climate change was produced in 2006 under then-Gov. Arnold Schwarzenegger. The second assessment, released in 2009, concluded that adaptation could reduce economic impacts of loss and damage from a changing climate. The third assessment was shaped by a request for more information on the adaptation options in the 2009 report. The fourth assessment was the first effort to break down global climate predictions and their impacts onto specific regions of California.
Author of the North Coast Region Report of the Fourth Assessment, Ted Grantham, praised state leaders for pushing forward efforts to slow climate change and adapt to the new weather conditions expected in California.
“California is playing a unique role in filling the void of leadership on this issue that the federal government was beginning to address under the Obama administration,” Grantham, a UC Cooperative Extension specialist based at UC Berkeley, said.
Across California, UC Cooperative Extension specialists and advisors are working in their local communities to prepare for warming temperatures and adapt to the changing climate. Following are examples of the efforts now underway.
Managing forests to survive the future
Among the suggested adaptation strategies in the 81-page North Coast Region Report, written by Grantham and his colleagues, the authors encourage government agencies and private forest owners to use prescribed fires and active forest management to reduce an overgrowth of trees and shrubs that fuel the more frequent and intense fires expected in the future.
Although climate change will create conditions conducive to catastrophic wildfire, the reason for dangerous forest overgrowth is related to decades of fire suppression on the landscape.
“Our forests are much denser and have more fuel buildup than they would have under a natural fire regime,” Grantham said. “Mechanical thinning, removing wood from the landscape and prescribed fires can help limit the impacts of wildfire.”
Native American tribes are being tapped to share their traditional ecological knowledge to inform this practice.
“Native Americans have used fire since time immemorial to manage their landscapes,” Grantham said.
Connecting habitats to allow species movement
When climate changes, plant and animal species may find their current habitats no longer fit the environment where they evolved. The fourth assessment technical report, Climate-wise Landscape Connectivity: Why, How and What Next, written by UCCE specialist Adina Merenlender, documented potential techniques to erase barriers to plant and animal movement.
“When we talk about wildlife corridors today, we might view a road as a barrier,” Merenlender said. “With climate change, the movement is over a much longer range for species to find suitable habitat at the end of the century.”
The report says research is needed to compare different approaches to designing climate-wise connectivity, determining how wide corridors need to be, and quantifying the impact of natural and anthropogenic barriers on possible range shifts.
California's wine industry is based on international varieties that come from Northern France, where the climate is cool, mild and consistent.
“They really require a cool to warm climate, not a hot climate,” said Glenn McGourty, UCCE viticulture advisor in Mendocino County.
There are many wine grape cultivars from Southern Europe – areas in Italy, Portugal and Spain – that are adapted to heat and make quality wines, but aren't well known. The varieties include Monepulciano, Sagrantino, Periquita and Graciano.
McGourty is studying how these cultivars perform in the warm interior of Mendocino County at the UC Hopland Research and Extension Center.
“We have many options as climates warm in the interior part of California to make wine that needs less amelioration in the winery compared to cultivars from Northern France,” McGourty said.
Recruiting and training climate stewards
California Naturalist, with trained volunteers across the state working with myriad conservation organizations, will be using its educational network to improve the public's understanding of climate change and engage the public in community action and local conservation.
“Climate stewards will offer in-person communication with your neighbors, tapping into science,” Merenlender said. “Improving climate literacy is an important outcome, but that won't happen through a website.”
Helping growers modify farming practices due to changing climate
USDA Climate Hub has awarded a grant to UC Cooperative Extension to support tools to assist growers in making strategic decisions in season and long term.
“We have many credible sources of weather and climate data, but often times we are challenged with translating it into decision support tools tailored to growers' needs,” said Tapan Pathak, UCCE specialist in climate change adaptation in agriculture. “It's too early to say which specific tools we will develop, but we are aiming to help farmers use weather and climate information in decision making processes.”
Pathak is also working with colleagues to analyze how generations of navel orangeworm, a significant almond pest, might shift for the entire Central Valley under climate change and how growers can adapt their practices to manage the higher pest pressure.
Using epigenetics to impart drought tolerance
At the UC Kearney Agricultural Research and Extension Center in Parlier and the UC West Side Research and Extension Center in Five Points, sorghum nurseries are being grown under drought and well-watered conditions to compare the environmental impacts on the plants' gene expression.
“We hope to tease out the genetics of drought tolerance in sorghum,” said Jeff Dahlberg, UCCE specialist, who is managing the trials at Kearney. “Using sorghum as a model, we expect this research to help us understand drought tolerance in other crops as well.”
Historically, the genetic manipulation of crops, which has been critical to increasing agricultural productivity, has concentrated on altering the plant's genetic sequence, encoded in its DNA.
Recent studies have shown that environmental stresses – such as drought – can lead to epigenetic changes in a plant's genetic information. Because epigenetic changes occur without altering the underlying DNA sequence, they allow plants to respond to a changing environment more quickly.
Cities can plant street tree species suited to future climate
Many common street trees now growing in the interior of California are unlikely to persist in the warmer climate expected in 2099, according to research published in the July 2018 issue of the journal Urban Forestry & Urban Greening. (Read the research report here until Sept. 27, 2018)
“Urban foresters in inland cities of California should begin reconsidering their palettes of common street trees to prepare for warmer conditions expected in 2099 due to climate change,” said the study's co-author, Igor Lacan, UC Cooperative Extension environmental horticulture advisor in the Bay Area.
Common trees in Coastal California cities appear to be better suited to withstand the 2099 climate.
“Our research shows that some trees now lining the streets of cities like Fresno, Stockton and Ukiah are likely to perform poorly in 2099,” Lacan said. “Those cities need to look at the conditions – and trees – now found in El Centro, Barstow and Fresno respectively.”
Trees to shade California in a warmer future
The changing climate predicted for California – including less rain and higher day and nighttime temperatures – is expected to cause chronic stress on many street tree species that have shaded and beautified urban areas for decades.
Realizing that popular trees may not thrive under the changing conditions, UC Cooperative Extension scientists are partnering with the U.S. Forest Service in a 20-year research study to expand the palette of drought-adapted, climate-ready trees for several of the state's climate zones.
“The idea is to look at available but under-planted, drought-tolerant, structurally sound, pest resistant trees for Southern California that do well in even warmer climates,” said Janet Hartin, UCCE horticulture advisor in San Bernardino County.
Twelve tree species were selected for each climate zone in the comparative study, with several area parks used as control sites.
Managing the forest for survival in warmer conditions
UC Cooperative Extension scientists are part of a collaborative research project with the University of Nevada, Reno, CAL FIRE and the U.S. Forest Service aimed at developing new strategies to adapt future forests to a range of possible climate change scenarios in the Sierra Nevada.
“It includes the idea that we may be struggling just to keep forests as forests, let alone having the species we value,” said Rob York, manager of UC Berkeley's Blodgett Forest Research Station near Georgetown.
Forests sequester a tremendous amount of carbon. As the climate changes, foresters will need to be proactive to reduce the risk of these massive carbon sinks becoming carbon sources.
“We're working to mitigate predicted impacts to forests, including regeneration failures, drought mortality and catastrophic wildfire,” Ricky Satomi, UCCE natural resources advisor in Shasta County.
At three separate study sites across the Sierra Nevada, novel approaches to forest management are being implemented to develop treatments that scientists believe will increase resilience, resistance and adaptability of Sierra Nevada mixed conifer forests.
The 2018-21 project is led by Sarah Bisbing, forest ecology professor at the University of Nevada, Reno, and funded with $2.7 million from CAL FIRE.
Climate change impacts on vulnerable communities
The latest climate assessment also reports on the serious nature of climate threats to vulnerable communities and tribal communities in California, with a focus on working collaboratively with these communities on research and solutions for resilience.
“The impacts of climate change will not be experienced equally among the population,” Grantham said. “The most significant public health and economic impacts – from flooding, extreme heat, air quality degradation, etc. – will be disproportionately experienced by vulnerable populations, including people of color, the poor and the elderly.”
The assessment includes a Climate Justice Report, which shares the idea that no group of people should disproportionately bear the burden of climate impacts or the costs of mitigation and adaptation. The report suggests collaborating with these communities on research and solutions for resilience.
Plants and wildlife, like this mountain lion, will need to find natural corridors to migrate into areas with suitable climates. (Photo: National Park Service)
Following years of drought, millions of trees succumbed to bark beetles in the Sierra Nevada.
The Italian grape variety falanghina could be a sought-after white wine varietal in the future. (Photo: Wikimedia Commons)
Volunteer UC California Naturalists will be recruited to engage the public in climate change resilience.
UCCE specialist Ted Grantham is the lead author of the Fourth Climate Assessment's North Coast Region Report.
Identifying drought tolerance in sorghum may help scientists impart drought tolerance in other crops. (Photo: Peggy Lemaux)
Cities in inland areas can begin planting street trees that are suited to their future climates.
The California Natural Resources Agency released California's Fourth Climate Change Assessment today (Monday, Aug. 27), at http://www.ClimateAssessment.ca.gov. UC Agriculture and Natural Resources scientists contributed substantially to the report.
The Fourth Assessment is broken down into nine technical reports on the following topics:
- Biodiversity and habitat
- Forests and wildlife
- Ocean and coast
- Projects, datasets and tools
- Public health
The technical reports were distilled into nine regional reports and three community reports that support climate action by providing an overview of climate-related risks and adaptation strategies tailored to specific regions and themes.
The regional reports cover:
- North Coast Region
- Sacramento Valley Region
- San Francisco Bay Area Region
- Sierra Nevada Region
- San Joaquin Valley Region
- Central Coast Region
- Los Angeles Region
- Inland South Region
- San Diego Region
The community reports focus on:
- The ocean and coast
- Tribal communities
- Climate justice
All research contributing to the Fourth Assessment was peer-reviewed.
UC Cooperative Extension ecosystem sciences specialist Ted Grantham – who works in the Department of Environmental Science, Policy and Management at UC Berkeley – is the lead author of the 80-page North Coast Region Report. Among the public events surrounding the release of the Fourth Assessment is the California Adaptation Forum, Aug. 27-29 in Sacramento. For more information, see http://www.californiaadaptationforum.org/. Grantham is a speaker at the forum.
Other UC ANR authors of the North Coast Region Report are:
- Lenya Quinn-Davidson, UC Cooperative Extension area fire advisor for Humboldt, Siskiyou, Trinity and Mendocino counties
- Glenn McGourty, UC Cooperative Extension viticulture and plant science advisor in Mendocino and Lake counties
- Jeff Stackhouse, UC Cooperative Extension livestock and natural resources advisor for Humboldt and Del Norte counties
- Yana Valachovic, UC Cooperative Extension forest advisor for Humboldt and Del Norte counties
UC Cooperative Extension fire specialist Max Moritz contributed to sections of the main report on Forest Health and Wildfire and to the San Francisco Bay Area Report.
UC ANR lead authors of technical reports were:
- Economic and Environmental Implications of California Crop and Livestock Adaptations to Climate Change, Daniel Sumner, director of UC ANR's Agricultural Issues Center
- Climate-wise Landscape Connectivity: Why, How and What Next, Adina Merenlander, UC Cooperative Extension specialist
- Visualizing Climate-Related Risks to the Natural Gas System Using Cal-Adapt, Maggi Kelly, UC Cooperative Extension specialist