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Dry conditions keep sudden oak death in check, yet significant outbreaks continue

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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.
 
 
Sudden oak death, which has killed millions of trees in California over the past 20 years, is spreading more slowly, according to California's most recent citizen-science sudden oak death survey. The 2018 SOD Blitz results indicate Phytophthora ramorum (the pathogen known to cause SOD) infection is currently less prevalent in many wildland urban interface areas, though significant outbreaks are still occurring in some locations.

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.

 
"SOD blitzes detected the highest levelsoffoliar infections by OD in 2017,” said SOD BlitzfounderMatteoGarbelotto, UC Berkeley forest pathology and mycology Cooperative Extension specialist and adjunct professor. “As predicted, those high levelsoffoliar infections were responsible for a high increase of infection of oaksandtanoaks by SOD.

"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.

"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.

“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.

SOD Blitz volunteers collect leaf samples and record the location using the SODmap mobile app.

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.

Video of Dr. Matteo Garbelloto describing the three steps to managing sudden oak death.

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 kmharrell@ucdavis.edu. 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.

 
Posted on Tuesday, October 9, 2018 at 4:30 PM
  • Author: Katie Harrell

Does Urban Agriculture Improve Food Security?

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A newly published literature review in the Journal of Sustainability conducted by a team of Berkeley Food Institute researchers has found that while many studies cite the potential food security benefits of urban agriculture (UA), there are few that robustly measure the impact of urban farms on improving food security in low-income communities. Results of this review are guiding a three-year research project, funded by the Foundation for Food and Agriculture Research and the Berkeley Food Institute to investigate and address urban food access challenges in the eastern region of the San Francisco Bay Area, where interest in UA abounds, yet levels of gentrification, food insecurity, and income inequality are growing.

Without understanding the actual links between UA and food security or which specific characteristics, models or approaches reduce insecurity, urban policymakers and advocates risk backing policies that could have unintended consequences or negative impacts on vulnerable individuals and communities. We argue that in addition to more robust analyses that measure the actual social, economic, and health impacts of urban agriculture, and how they impact food security, it is important to understand which approaches to policy, governance and civic engagement support UA models that are effective in reducing food insecurity.

In general, we see three trends in current scholarship on UA in relation to community food security: (1) a focus on the production potential of urban lands, (2) individual case studies highlighting various nutritional, health, and other community benefits or outcomes from urban gardening initiatives, and (3) more critical analyses of UA through food justice and equity lenses. To this latter point, robust theoretical analyses have emerged critiquing the risks of UA when approached without an equity lens, potentially reinforcing structural injustices and racism and negatively impacting communities that ideally should benefit the most.

Deeper historical and structural challenges including poverty, racism, and divestment in specific communities and neighborhoods are increasingly being recognized as the root causes of the problem of unequal access to sufficient supplies of safe, nutritious, affordable, and culturally acceptable food facing cities. Designating land for agricultural use in urban areas may conflict with other city planning priorities around affordable housing, community economic development, or smart growth approaches associated with reducing urban sprawl and mitigating climate change, such as transit-oriented development. Because of the persistent legacy of systemic discrimination, it is neither inevitable nor guaranteed that urban agriculture will redress food system inequities; in fact, urban farms can sometimes lead to displacement through eco-gentrification. This is a particularly acute concern in areas experiencing housing pressures and population growth, such as the San Francisco Bay area and New York City.

Analyzing the intersection of food access and food distribution literatures reveals three key factors mediating the effect of UA on food security in the urban food system:

(1) the economic viability of urban farms (to sustain the provisioning of affordable urban produced foods)

(2) the role of city planning and policies in advancing racial equity through UA such as secure land tenure and public investment, and

(3) the importance of civic engagement to advocate for and hold cities and counties accountable to the needs of low-income communities.

We highlight examples from both the scholarly and gray literatures that demonstrate how UA can improve food access, distribution, and justice, in a way that supports both consumers and producers of food in cities. The gray literature in particular reveals many emerging and informal distribution networks for urban produced foods that would benefit from further academic study, such as gleaning networks, distribution apps, and online platforms.

The review concludes with a set of recommendations for researchers, practitioners, and policymakers who seek to create spaces in cities for food justice, equity, access, and sovereignty. Most notably we acknowledge that urban farms are producing a lot more than food; and that equitable planning, public investment and civic engagement are crucial elements in securing the long-term viability of urban farms. More robust analyses documenting the multifaceted benefits and risks of UA such as public health, food security, youth development, food literacy, eco-gentrification and environmental justice can help inform more equitable public policy and planning efforts.

Dry conditions keep sudden oak death in check, yet significant outbreaks continue

>
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.
Sudden oak death, which has killed millions of trees in California over the past 20 years, is spreading more slowly, according to California's most recent citizen-science sudden oak death survey. The 2018 SOD Blitz results indicate Phytophthora ramorum (the pathogen known to cause SOD) infection is currently less prevalent in many wildland urban interface areas, though significant outbreaks are still occurring in some locations.

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.

"SOD blitzes detected the highest levels of foliar infections by SOD in 2017,” said SOD Blitz founder Matteo Garbelotto, UC Berkeley forest pathology and mycology Cooperative Extension specialist and adjunct professor. “As predicted, those high levels of foliar infections were responsible for a high increase of infection of oaks and tanoaks by SOD.

"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.

"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.

“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.

SOD Blitz volunteers collect leaf samples and record the location using the SODmap mobile app.

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 kmharrell@ucdavis.edu. 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.

Posted on Tuesday, October 9, 2018 at 12:27 PM
  • Author: Katie Harrell
Focus Area Tags: Environment Natural Resources

Clean Water Act dramatically cut pollution in U.S. waterways

Reposted from the UC Berkeley News

The 1972 Clean Water Act has driven significant improvements in U.S. water quality, according to the first comprehensive study of water pollution over the past several decades, by researchers at UC Berkeley and Iowa State University.

The team analyzed data from 50 million water quality measurements collected at 240,000 monitoring sites throughout the U.S. between 1962 and 2001. Most of 25 water pollution measures showed improvement, including an increase in dissolved oxygen concentrations and a decrease in fecal coliform bacteria. The share of rivers safe for fishing increased by 12 percent between 1972 and 2001.

A forest stream

The Clean Water Act has decreased measures of water pollution in U.S. lakes, streams and rivers.

Despite clear improvements in water quality, almost all of 20 recent economic analyses estimate that the costs of the Clean Water Act consistently outweigh the benefits, the team found in work also coauthored with researchers from Cornell University. These numbers are at odds with other environmental regulations like the Clean Air Act, which show much higher benefits compared to costs.

“Water pollution has declined dramatically, and the Clean Water Act contributed substantially to these declines,” said Joseph Shapiro, an associate professor of agricultural and resource economics in the College of Natural Resources at UC Berkeley. “So we were shocked to find that the measured benefit numbers were so low compared to the costs.”

The researchers propose that these studies may be discounting certain benefits, including improvements to public health or a reduction in industrial chemicals not included in current water quality testing.

The analyses appear in a pair of studies published in the Quarterly Journal of Economics and the Proceedings of the National Academy of Sciences.

Cleaning up our streams and rivers

Americans are worried about clean water. In Gallup polls, water pollution is consistently ranked as Americans' top environmental concern – higher than air pollution and climate change.

Since its inception, the Clean Water Act has imposed environmental regulations on individuals and industries that dump waste into waterways, and has led to $650 billion in expenditure due to grants the federal government provided municipalities to build sewage treatment plants or improve upon existing facilities.

However, comprehensive analyses of water quality have been hindered by the sheer diversity of data sources, with many measurements coming from local agencies rather than national organizations.

To perform their analysis, Shapiro and David Keiser, an assistant professor of economics at Iowa State University, had to compile data from three national water quality data repositories. They also tracked down the date and location of each municipal grant, an undertaking that required three Freedom of Information Act requests.

“Air pollution and greenhouse gas measurements are typically automated and standard, while water pollution is more often a person going out in a boat and dipping something in the water.” Shapiro said. “It was an incredibly data and time-intensive project to get all of these water pollution measures together and then analyze them in a way that was comparable over time and space.”

In addition to the overall decrease in water pollution, the team found that water quality downstream of sewage treatment plants improved significantly after municipalities received grants to improve wastewater treatment. They also calculated that it costs approximately $1.5 million to make one mile of river fishable for one year.

Comparing costs and benefits

Adding up all the costs and benefits — both monetary and non-monetary — of a policy is one way to value its effectiveness. The costs of an environmental policy like the Clean Water Act can include direct expenditures, such as the $650 billion in spending due to grants to municipalities, and indirect investments, such as the costs to companies to improve wastewater treatment. Benefits can include increases in waterfront housing prices or decreases in the travel to find a good fishing or swimming spot.

The researchers conducted their own cost-benefit analysis of the Clean Water Act municipal grants, and combined it with 19 other recent analyses carried out by hydrologists and the EPA. They found that, on average, the measured economic benefits of the legislation were less than half of the total costs. However, these numbers might not paint the whole picture, Shapiro said.

“Many of these studies count little or no benefit of cleaning up rivers, lakes, and streams for human health because they assume that if we drink the water, it goes through a separate purification process, and no matter how dirty the water in the river is, it's not going to affect people's health,” Shapiro said.  “The recent controversy in Flint, MI, recently seems contrary to that view.”

“Similarly, drinking water treatment plants test for a few hundred different chemicals and U.S. industry produces closer to 70,000, and so it is possible there are chemicals that existing studies don't measure that have important consequences for well-being,” Shapiro said.

Even if the costs outweigh the benefits, Shapiro stresses that Americans should not have to compromise their passion for clean water — or give up on the Clean Water Act.

“There are many ways to improve water quality, and it is quite plausible that some of them are excellent investments, and some of them are not great investments,” Shapiro said. “So it is plausible both that it is important and valuable to improve water quality, and that some investments that the U.S. has made in recent years don't pass a benefit-cost test.”

Catherine L. Kling, professor of agricultural and life sciences and environmental economics and Cornell University, is a co-author on the Proceedings of the National Academy of Sciences paper.

Research funding was provided by the U.S. Department of Agriculture through the National Institute of Food and Agriculture Hatch Project IOW03909 and Award 2014-51130- 22494 and a National Science Foundation Award SES-1530494. Much of the research was completed while Shapiro was at Yale University.

Posted on Tuesday, October 9, 2018 at 12:03 PM
  • Author: Kara Manke

Targeting the Tsetse Fly

Medical entomologist Geoffrey Attardo in his office. (Photo by Kathy Keatley Garvey)

He targets the tsetse fly. Tsetse flies, large biting flies that inhabit much of Africa, feed on the blood of humans and other vertebrates and transmit such parasitic diseases as African trypanosomiasis. In humans, this disease is better known as...

Medical entomologist Geoffrey Attardo in his office. (Photo by Kathy Keatley Garvey)
Medical entomologist Geoffrey Attardo in his office. (Photo by Kathy Keatley Garvey)

Medical entomologist Geoffrey Attardo in his office. (Photo by Kathy Keatley Garvey)

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