Cooperative Extension San Joaquin County
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Cooperative Extension San Joaquin County

Posts Tagged: forest

Community effort beats back sudden oak death in Humboldt County

From left: Mark Rodgers, Julie Lydick, Pete Angwin, Rizzo, Valachovic, Phil Cannon, Ed Burton, Stephen Smith, Jack Marshall, Chris Nota and Russ Henly
Sudden oak death is a misnomer because it doesn't fell a tree like a lightning strike nor does the disease limit itself to oaks. Nonetheless, the moniker has stuck and UC scientists remain committed to containing the culprit. 

UC, federal and state agencies and landowners in Humboldt County recently received national recognition for their collaborative efforts to halt the spread of sudden oak death. Kathleen Merrigan, U.S. Department of Agriculture deputy secretary, praised the partnership during her visit to Davis on May 16.

Yana Valachovic, UC Cooperative Extension advisor in Humboldt County, and Dave Rizzo, professor in the Department of Plant Pathology at UC Davis, were joined at the USDA offices in Davis by their partners from USDA Forest Service, CAL FIRE and the Natural Resources Conservation Service to accept the Two Chiefs’ Partnership Award. Merrigan presented the award on behalf of the “two chiefs” – the head of NRCS and the head of the Forest Service.

For me, it was a pleasure not just to see Yana’s efforts rewarded, but also to see Dave Rizzo. About a decade has passed since the days I was on the phone and email almost daily forwarding reporter requests for interviews to the UC Davis plant pathologist. Rizzo was first to identify Phytophthera ramorum as the pathogen that causes sudden oak death in 2000.

Matteo Garbelotto of UC Berkeley demonstrates sudden oak death diagnosis and treatment for members of the media at the Berkeley campus.
As tens of thousands of California's beloved oaks fell to the disease, Rizzo and his colleague Matteo Garbelotto, UC Cooperative Extension specialist at UC Berkeley, an expert in forest pathology, were thrust into the limelight.

Although SOD doesn't make the news as frequently as it did in the early 2000s, it continues to spread. Garbelotto’s "SOD Blitz," his annual survey, found in 2011 that the rate of infection in trees between Napa and Carmel had grown as much as three times the rate of the previous year.

Since the disease was first reported in Marin County in 1995, it has been found in 14 coastal California counties and killed over 5 million tanoak, coast live oak, California black oak, Shreve oak and canyon live oak trees, according to the Forest Service.

UC Cooperative Extension employees were surprised in the spring of 2010 when routine  monitoring near the mouth of Redwood Creek in Humboldt County detected P. ramorum in leaf samples. It meant that trees were infected somewhere in the 200,000-acre watershed – more than 50 miles from the nearest known infestation and farther north than the pathogen had ever been detected in California.

UCCE staff coordinated a swift management response, embarking on the largest SOD management project ever to occur in California. They collaborated with the Forest Service, NRCS, CAL FIRE, tribes, local timber companies and private landowners to remove infected plant material. Rizzo pitched in with diagnostics for the project and matching funds to qualify for a federal grant.

From left, UCCE staff research associate Chris Lee, NRCS forester David Casey and Yana Valachovic inspect the treated area for signs of sudden oak death.
“We’ve been closely monitoring the disease for years and anticipating a scenario like Redwood Valley, so we were ready to take action and respond quickly,” said Valachovic, a forestry expert.

It’s still not clear how the pathogen got to Redwood Valley, said Valachovic, but it could threaten the dense tanoak forests of the surrounding area, killing trees and leaving behind dry brush, which could fuel wildfire. 

Landowner support has been critical to the success of the project, according to Valachovic. More than 20 landowners in the valley have allowed monitoring and treatment activities on their properties, recognizing that their cooperation may keep the disease from spreading to other areas.

The first phase of treatment is currently wrapping up, and UCCE is beginning to monitor project efficacy and watch for spread of the pathogen beyond project boundaries. The Yurok and Hoopa tribes will be paying close attention to this effort, as they are only a ridge away from the infestation. 

“Oaks are an important part of our culture and history, and we will do what we can to keep sudden oak death out of our forests,” says Ron Reed, a Yurok tribal forester.

The OakMapper app and website enable hikers and others to report SOD.
The Redwood Valley project highlights the benefits of people working together. If you would like to report sudden oak death, you can download the OakMapper smartphone app or submit reports at the OakMapper website. The website also features a map showing suspected and confirmed cases of sudden oak death.

Scientists, managers, regulators and policymakers will gather June 19-22, 2012, to discuss the latest news about the disease at the Fifth Sudden Oak Death Science Symposium in Petaluma.

For more information about sudden oak death disease, visit the California Oak Mortality Task Force website at  


Posted on Wednesday, May 30, 2012 at 12:01 PM

Using Lidar to map forest structure and characterize wildlife habitat

UC scientists with the Sierra Nevada Adaptive Management Project (SNAMP) are investigating the uses of Lidar (light detection and ranging) in providing detailed information on how forest habitat is affected by fuels management treatments across a large landscape. Mapping forest structure can illustrate how a forest influences surface hydrology, provides for wildlife and how a forest might burn given certain weather and wind patterns. This research is proving useful in wildlife studies, water quantity and fire modeling and forest planning.

Airborne lidar works by emitting a light pulse from an emitter onboard a plane towards a ground target. A portion of the light is reflected back to the airborne sensor and recorded. The time between sending out the light pulse and receiving it back is converted into distance.

This data, along with GPS information on the aircraft’s exact position and orientation, allows scientists to calculate the height of a target and create 3D maps of the forest vegetation and the bare ground. Raw lidar data is first received as a ‘point cloud’ which consists of millions of points from which meaningful and detailed measurements can be extracted.

Lidar generated maps.

Some of the current SNAMP research focuses on developing new methods to detect and delineate individual trees from the point cloud even in complex mixed conifer forests and rugged terrain. The SNAMP spatial team recently published a method that maps all the trees in the forest with 90 percent accuracy. The individual tree identification method identifies trees from the tallest to the shortest and is especially useful in mapping wildlife habitat. For example, the SNAMP spatial and California spotted owl teams collaborated using lidar to map large trees and canopy cover in spotted owl territories. These areas are often hard to identify and map over large areas. Lidar data was used to measure the number, density and pattern of large trees in areas used by the spotted owl. These kinds of data can be used to understand the forest habitat of other bird species and in Pacific fisher research. Below is a short video on the exploration of a lidar point cloud down to an individual tree:

Our goal is to provide methods to map the forest in detail, and thus to help forest managers anticipate the impacts of management decisions. 

Images by SNAMP Spatial team/Kelly Labs, UC Berkeley  


Posted on Wednesday, February 29, 2012 at 8:28 AM

Pollute, poach, dewater: Legacies of illicit cannabis grows

While the legality of California’s medical marijuana dispensaries is being debated in courtrooms, a UC Cooperative Extension forestry and wildlands ecology advisor says there are a number of issues related to the unregulated land-use practices of illicit cannabis growing that have not been addressed.

Greg Giusti
“As a forest ecologist, I spend a lot of time outdoors, and I talk to thousands of people every year about forest-related subject matter,” says Greg Giusti. “And you can’t talk to anybody today on the North Coast without the topic of cannabis growing and cannabis impacts on land coming up.”

In Lake and Mendocino counties, Giusti performs research and shares information with public agencies and private landowners in relation to forest management and freshwater ecology on behalf of UC Cooperative Extension. Marijuana farming is not a topic that Giusti ever intended to address.

Illegal water diversion is common among many illicit cannabis plots in wildlands. (Photo from Giusti's presentation, courtesy of Lake County Sheriff's Office)

Effects on natural resources
Most of the data available about illicit cannabis grows is based on drug enforcement actions, specifically how many sites were busted and how many plants or pounds of plant material were seized. Giusti has gathered photographs and anecdotal evidence of the effects on natural resources of commercial-scale marijuana grows operated illicitly on public and private lands.

Some of the effects he has documented:

  • illegal water controls (including dams, stream diversion and water storage)
  • water pollution from petroleum, pesticide and fertilizer products
  • pesticides applied without permits
  • pesticides, fertilizers and other chemicals left behind
  • indiscriminate fish and wildlife killing (including poisoning, trapping and poaching for food)
  • human trash and waste left after camping

“It’s not this green industry that people talk about,” Giusti says. “They’re diverting water, they’re polluting streams, and there’s a portion who are poaching. We’re also seeing all of the negative effects of unregulated road building, unregulated construction and unregulated human inhabitation for months and months out in the woods.”

Giusti explained that some cannabis growers divert water from streams to store in large water bladders, prematurely lowering stream levels during critical times in the year.

“It's illegal to do, but at the same time you can drive up and down Highway 101 and easily buy these huge bladders,” he said.

He notes that local businesses are selling compost by the ton, rodenticide by the pallet, thousands of pairs of clippers and turkey bags in lots of 100.

“Mainstream businesses are supporting this underground industry,” Giusti said. “You don’t have to be growing cannabis to be making money off of it.”

Raising awareness
In 2010, Giusti organized two community workshops in Lake County to address the impacts of illicit cannabis land-use on forest resources, for a combined attendance of nearly 400 community members. Giusti has shared his results with the board of supervisors for Lake and Mendocino counties, local news media, local foresters and the staff of the North Coast Regional Water Quality Control Board.

“My intention was to initiate a communitywide discussion to ask, ‘Is this what you want to happen to your forests?’” Giusti said. “Up until now it's been talked about in hushed tones, and I wanted to initiate a dialogue out loud. Everybody has been whispering about it.”

The presentation he developed for those meetings continues to generate discussion. Most recently, he has presented to the North Coast Water Quality Control Board staff and other agencies. He has shared photos collected for his presentation with Congressman Mike Thompson’s office as well.

“With the water quality control board, I had the opportunity to engage people whose job it is to protect the beneficial uses of water — and hopefully stimulate an internal dialogue so that they can continue the discussion after I leave their office,” he said. “There are other resource agencies that need to be involved, and county planning departments too. This is an unregulated land-use practice.”

This month, the Lake County Record-Bee ran an article by reporter Linda Williams with the headline “Thirsty marijuana grows suck Eel River dry,” which included some information presented at Giusti’s meetings.

“My efforts seem to be improving people's awareness,” he says. “The very thing I wanted to accomplish — creating broader dialogues — is happening.”

Posted on Wednesday, November 16, 2011 at 12:37 PM
Tags: forest (12), Greg Giusti (6), land use (4), marijuana (5), natural resources (3), pollution (1), water (19)

Forest Biology Research Center opens at UC Davis

A Forest Biology Research Center has been created at UC Davis, bringing good news for students, researchers, and all of us who like to breathe clean air.

“Trees are as important as agriculture to the landscape of California and the world,” says UC Davis Department of Plant Sciences Professor David Neale, a forest geneticist and the driving force behind the new center. “Creation of the center culminates the work of many people over many years to bring a visible presence to forest biology research and education on the UC Davis campus.”

UC Davis is a prime location for forest biology research and education because of its proximity to the Sierra Nevada and coastal mountain forest ecosystems and its extensive faculty expertise in all aspects of forest biology, says UC Davis Plant Ecology Professor Mark Schwartz, director of the John Muir Institute for the Environment (JMIE) where the new center is located.

“The creation of this forest-focused center is both an affirmation of what UC Davis has been doing really well for a long time, and a big step forward in JMIE’s efforts to rally faculty expertise around the central environmental issues facing California and the world”, Schwartz says. “As California joins Europe in adopting carbon standards, developing a better understanding of the role of forests in carbon sequestration has become a priority for environmental organizations.”

The new center will also provide a framework for the cross-disciplinary work so central to forest biology.

“Forest biology draws from many of the core biological sciences such as genetics, ecology, plant pathology, entomology, plant biology, and geography,” Neale explains. “Before this framework was in place, graduate students could study genetics with me, for example, but they couldn’t really go broader into other areas of forest biology. Now when they come to UC Davis to do graduate work in, say, ecology, they will also have access to interdisciplinary work in forest biology.”

The Forest Biology Research Center is working to develop a certificate program in forest biology that can be awarded along with a degree from an existing graduate program.

At the Forest Biology Research Center website, you can learn more about the 24 UC Davis faculty and affiliated members of the US Forest Service who founded the center. They look forward to working with others to help develop forest biology research and education at UC Davis.

In addition to Neale and Schwartz, the executive committee includes UC Davis Plant Pathology Professor Dave Rizzo, UC Davis Plant Biology Professor Alison Berry, and Research Ecologist Malcolm North with the UC Davis Department of Plant Sciences.

Posted on Wednesday, June 1, 2011 at 10:46 AM
  • Posted By: John Stumbos
  • Written by: Diane Nelson,, (530) 752-1969

UC offers webinar series on community forests

If you are passionate about a forest near you then you may want to tune into the UC Cooperative Extension webinar series on Community Forests.  The webinars will begin at 6:30 p.m. Pacific Standard Time on April 7 with additional programs on April 13, 20 and 27. Participants may also want to take part in related field trips to Arcata Community Forest, Usal Redwood Forest, Tahoe-Donner and Weaverville Community Forest.

Community forests are forested lands that are managed to produce what people value. Forests may be valued as a source of timber for lumber, clean water, wildlife habitat, recreational purposes or for all of these benefits in combination.

The webinar series aims to present an overview of community forestry as it is currently being practiced in California. The intended audience is natural resource managers, environmental and forest activist groups, residents of forested regions who might benefit from a community forest approach in their areas and the general public concerned with forest management.

This program is a collaborative effort of the University of California Cooperative Extension and the Northern California Society of American Foresters, with funding support from the USDA Forest Service and the University of California.

Additional information and a link to registration are available at

UC collaborators on the project are natural resources advisors Mike De Lasaux, Susie Kocher, Gary Nakamura and contractor Richard Harris.

A webinar series and field trips will educate the public on community forests.
A webinar series and field trips will educate the public on community forests.

Posted on Thursday, March 24, 2011 at 8:26 AM
Tags: forest (12), Gary Nakamura (1), Mike De Lasaux (4), Susie Kocher (14)

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