UCCE Humboldt - Del Norte Counties
University of California
UCCE Humboldt - Del Norte Counties


Sudden oak death still a threat and still spreading

Humboldt County tanoak trees that have succumbed to sudden oak death.
Thirteen years after sudden oak death was first detected in California, the disease's range in northern coastal areas of California and southwest Oregon continues to grow, according to a report by Michael Joyce on Jefferson Public Radio.

Joyce interviewed Yana Valachovic, a forest advisor for UC Agriculture and Natural Resources in Humboldt and Del Norte counties. Valachovic is also director of the UC ANR Cooperative Extension offices in Humboldt and Del Norte.

"For me, the challenge is communicating to the public the disease has not gone away; in fact, it's actually getting substantially worse," Valachovic said.

Sudden oak death is caused by the pathogen Phytophthora ramorum. Currently less than 2 percent of Humboldt County's 2.25 million acres of forest are impacted by sudden oak death. But the average annual rate of expansion per year is 3,500 acres, Valachovic said. One challenge related to containing the disease is the structure of California forest agencies.

"The wildlands of California don't have a single agency that's responsible for controlling invasive introductions," she said. "Secondarily, there is no funding source that is set aside to manage these kind of epidemics. And so everything is piecemealed together: piecemealed responsibility, piecemealed in funding to address these issues."

Furthermore, Forest Service funds can only be used for monitoring, containment and education. 

Joyce concluded the story with a question: "How will we learn more about this disease that is spreading through our forests at a clip of about 5 miles per year?"

Read more about sudden oak death on the California Oak Mortality Task Force website.

Posted on Friday, June 19, 2015 at 10:35 AM
Tags: SOD (5), Sudden Oak Death (23), Yana Valachovic (4)

Norwegian newspaper covers California's drought

An almond orchard in Winton, Calif.
The California drought is so severe, it is drawing worldwide attention, including recent news coverage in Norway. Reporter Kristoffer Rønneberg visited a farm and reservoir in the Central Valley and spoke to a UC Agriculture and Natural Resources expert for an article in Aftenposten (Evening Post), Norway's largest newspaper.

"Look at this," said west side farmer John Diener. "In this field, I tried to cultivate a type of wheat that doesn't need as much water. But it did not (thrive). We did not get enough rain. Now the entire crop has withered." (Translation by Google Translate.)

Rønneberg walked on the bank of Millerton Lake, north of Fresno, where he would have been wading through water in a normal year. He reported that the reservoir is at 30 percent of its capacity.

The reporter also touched on a common theme during the 2010-14 drought: the water needs of California's almond crop, which has more than doubled in size over the last 20 years. Each almond, the story said, requires 4.2 liters of water.

"There are many who believe that almonds require much more water than other plants. That's just nonsense," Diener said. "But there are some who have an interest in blaming farmers for water shortages, and they have chosen to use the almond as a kind of symbol."

The Norwegian newspaper reported that urban Californians were irritated when Gov. Brown's April 1 water conservation restrictions didn't include agriculture.

“Why should they give up their lawns when farmers are growing vegetables, grains and nuts?” the story asks, noting that a significant portion of alfalfa and almonds grown in California are exported to other countries.

Doug Parker, director of the UC ANR California Institute for Water Resources, said that's the wrong way to look at the issue. “So what if it is exported?” Parker said. “We also import plenty of food to California. That's how the global market works.”

Posted on Wednesday, June 17, 2015 at 8:14 AM
Tags: almonds (24), Doug Parker (12), drought (103)

Clever infographic outlines wildfire history in the American West

UC Riverside's Richard Minnich is featured in a KQED infographic on wildfires created by artist Andy Warner.
Wildfire frequency is increasing, and the fires are getting bigger, hotter and more destructive, explained artist Andy Warner in an infographic posted on KQED's The Lowdown, a website that connects the newsroom to the classroom. The source of information for the 10-panel comic was research by Max Moritz, UC Agriculture and Natural Resources Cooperative Extension specialist, and his colleagues.

Moritz' 2014 research is titled Large wildfire trends in the western United States, 1984-2011. Warner also referenced an article by Moritz and colleagues published in Ecosphere called Climate change and disruptions to global fire activity.

Warner's infographic features images of and quotes by Richard Minnich, a UC Riverside earth sciences professor. 

"They're getting bigger and bigger," Minnich is quoted in large, bold print in front of a blazing fire. "It has to do with the effort to try to eliminate natural processes in a climate where burning is normal."

Americans' resolve to quickly extinguish wildfires began after a devastating fire season in 1910, which burned millions of acres of forest and killed scores of firefighters. Aggressive firefighting efforts since then have changed U.S. forest ecology, providing excess fuel in forests that lead to larger, hotter blazes. 

In order to protect people and property while maintaining forest health, American firefighting agencies and UC ANR researchers are seeking to adapt management strategies.

"There's been fire ever since there's been oxygen in the atmosphere," Minnich is quoted in a speech bubble. "It's been going on for a third of a billion years, and it's not as though we're ever going to stop it."

Posted on Tuesday, June 16, 2015 at 10:34 AM
Tags: Max Moritz (10), Richard Minnich (1)

Warmer winter is hurting California cherry crop

The drought isn't helping matters, but the primary concern for cherry farmers in California is the lack of winter chill, reported Lisa Morehouse on KQED's The California Report.

Morehouse spoke to Bill Coates, a UC Agriculture and Natural Resources expert based at the UC Cooperative Extension office in San Benito County. He said cherries are more sensitive than other crops to a lack of chill hours. Because of a warming weather trend during the winter, bing cherry trees look confused about what season it is.

“You have some ripe cherries, you have some blossoms, some branches that are almost devoid of leaves, and you have some buds that are still dormant,” he explains. “And this is all a result of lack of chilling.”

Bing cherries need about 1,000 hours under 45 degrees for healthy dormancy. Last year San Benito County got just over 500 hours.

"People may disagree on the cause of the change," Coates says, "but there definitely has been a change in the climate, and it's going to impact tree crops greatly."

The warming climate is threatening California's cherry crop.
Posted on Friday, June 12, 2015 at 10:35 AM

Bats save walnut growers money on pest control

Rachael Long stands under the Yolo Causeway with bats hanging overhead.
Bats prey on insects and can consume as much as their body weight in insects per night. Rachael Long, UC ANR Cooperative Extension farm advisor, discussed how bats protect walnut orchards with Capital Public Radio show Insight  host Beth Ruyak. Long's research has found that each bat provides about $10 worth of pest control savings for walnut growers.

California farmers produce most of the nation's walnuts, about 500,000 tons of walnuts on 290,000 acres, with an annual crop value of $1.8 billion.

Long, who works on field crops and pest control in Yolo, Sacramento and Solano counties, noted there are 250,000 bats living under the Yolo Causeway alone that could be employed for pest control.

When asked how she knows that the nocturnal animals are eating the damaging pests, Long explained that she examines the guano to identify the insects they've eaten. "Bats have very shiny poop," she said, because their fecal matter is full of insect exoskeletons.

Long, who has studied the design elements of bat houses, brought a sample of a bat house to the studio. She said the box should be placed in an area that gets afternoon shade and at least 10 feet off the ground to protect the bats from cats and dogs.

Long also talked about the Black Rock Desert trilogy, a series of educational children's books about the adventures of a boy and a pallid bat that she has authored.  

For more information about Long's bat project, see her blog post Bats in the belfry? No, bats in walnut orchards.

Long will be discussing her bat research with the Capital Science Communicators group tonight at G Street Wunderbar in Davis. She will bring specimens of common bat species for people to see and touch. The talk is part of UC Davis' Science Café series and is a free event that's open to the public.


Rachael Long shows a bat and bat box.
Rachael Long shows a bat and bat box.

Posted on Wednesday, June 10, 2015 at 12:06 PM

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