- Author: Jeannette Warnert
Responding to the giant fire that burned 39 homes and 70,000 acres in the Clear Lake area, Warren Olney of KCRW's Which Way LA asked a UC Agriculture and Natural Resources (UC ANR) fire expert in Southern California, "Could it happen here?"
"It happens here all the time," said Tom Scott, wildlife and urban interface UC ANR Cooperative Extension specialist in the Department of Environmental Science, Policy and Management at UC Berkeley. (Scott is based at UC Riverside.)
He said of the 50 major fires recorded on the CalFire website, 30 were in Southern California. "It will probably happen again."
Media outlets are reporting that the Rocky Fire in Northern California is burning so hot, it is creating its own weather. Scott said the phenomenon is less likely to occur in Southern California fires.
"A lot of times our fires are coupled with Santa Ana winds," he said. "You don't necessarily see the fire creating its own wind because winds are already blowing 50 or 60 miles per hour."
One thing that can lead to particularly hot fires in the LA area is the lack of summer rain.
"This creates a very dry environment in the summertime," Scott said. "Plants can dry down to a point where they ... are very low moisture, which makes them very flammable. The other thing is, our plants don't decompose. We have a lot of biomass hanging around for a long time, sometimes centuries. When that burns, there's a tremendous amount of fuel and it causes hot and quick-moving fires."
Clearing a defensible zone around homes in fire-prone areas is one way to reduce the risk that a house will burn down. But it takes a long-term concerted effort to manage the landscape to prevent fires from becoming major conflagrations that roar from the mountains to the sea, Scott said.
"One of the things that a lot of people imagine," he said, "is where we can get back to a point where the landscape has fires that are smaller, at a time (of year) when it's not as hot and we don't have Santa Ana winds."
In the meantime, people in fire-prone areas may consider putting their irreplaceable valuables in storage from April to November, he said.
- Author: Jeannette Warnert
Northern California's Rocky Fire is roaring through shrublands that have no previous recorded history of wildfires, reported Kirk Siegler on All Things Considered. It has already burned 65,000 acres and is 12 percent contained, according to CalFire's Incident Report.
The area has been protected from fire for decades, primed for the type of catastrophic blaze California officials have been predicting.
"We've got miles and miles of contiguous chaparral vegetation and literally there are no breaks in the vegetation," Giusti said. "It's extremely steep and, in many cases, it's a roadless area."
Four years of drought has left the vegetation bone dry.
'When these fires get to an intensity we've seen, because of the fuel loading, because of fire suppression for the last 50 or 60 years, it allows the plant communities to get so dense, so thick and so expansive that, once a fire starts, it's beyond the capabilities of human control," Guisti said.
Reposted from the UCANR Green blog:
“There are two factors that help fires spread - winds and topography,” explained Scott L. Stephens, a professor of fire science in the Department of Environmental Science, Policy and Management at UC Berkeley, in Scientific American. “The thing about wind is, it can change so quickly and the fire will change with it — it can happen in 15 seconds,” said Stephens, who is also co-director of the Center for Fire Research and Outreach at UC Berkeley.
Wildfires are unpredictable, but there is much that residents of fire-prone areas can do to keep their families, homes and pets safe. UC Agriculture and Natural Resources has many online resources for homeowners and landowners in English and in Spanish for dealing with fire.
Protecting homes from fire
To protect houses in the wildland-urban interface from fire, homeowners should start with fire-resistant building materials and architectural features. The Center for Fire Research and Outreach at UC Berkeley has a toolkit for homeowners to assess their vulnerability to fire and offers advice for mitigating fire risk.
On the Sustainable and Fire Safe Landscapes website, Sabrina Drill, UC ANR Cooperative Extension natural resources advisor for Los Angeles and Ventura counties, gives tips for creatingdefensible space around the house. She also provides suggestions for designing a landscape around the home that reduce risk of fire spreading from plants to the structure.
Protecting animals from fire
The School of Veterinary Medicine at UC Davis offers resources for preparing a plan for horses, livestock and pets in case of wildfire or other disaster. A disaster preparedness plan would include things like transportation for evacuating the animals and emergency shelter.
What to do after a fire
If your home is burned, the Center for Fire Research and Outreach has a list of resources and things to do after a fire, including contacting a local relief organization to help with housing, food and other essentials. Before re-entering the home or site, the center recommends checking with the fire department to ensure it is safe to do so.
Revegetating the site
In oak woodlands, wildfires are an ecologically important process. Fire may actually help sprouting oaks survive by eliminating competing plants and creating a more favorable seedbed for acorns to germinate, and reducing the habitat of wildlife species that eat acorns or seedlings, according to Doug McCreary, UC ANR Cooperative Extension advisor emeritus.
Wildfire in an oak woodland can kill some trees outright and leave others with burn damage that may or may not eventually kill them. UC Cooperative Extension has developed a quick method for assessing the extent of burn damage and the likelihood that an affected tree will survive. Instructions can be downloaded for free at http://anrcatalog.ucdavis.edu/Items/8445.aspx
For forest landowners, UC ANR has “Recovering from Wildfire,” a guide that covers how to protect land from erosion damage, where to get help and financial assistance, how to manage salvage harvesting, and how to help the forest recover from wildfire.
UC ANR fire experts work with the California Fire Science Consortium to integrate science into sound fire prevention programs.
In the Lake Tahoe region, UC ANR Cooperative Extension advisor Susie Kocher collaborates with University of Nevada Cooperative Extension and Tahoe Basin fire agencies on a community education project called Living with Fire. Together they provide information for Lake Tahoe communities to prepare for wildfire. Many of the recommendations could apply to any community.
- Author: Susie Kocher
The fourth winter in a row of disappointing precipitation has triggered a die off of trees in the Sierra Nevada, most of which is now in ‘exceptional drought' status. The US Forest Service conducted aerial monitoring surveys by airplane in April 2015 and observed a large increase in tree mortality in the Southern Sierra (from Sonora south). Surveyors flew over 4.1 million acres of public and private forest land and found that about 20 percent had tree mortality on it, totaling over 10 million dead trees.
The Forest Service found severe mortality in many pine species especially ponderosa pine. On private lands along the foothills of the Sierras, surveyors found extensive areas of dead pines. Large areas of blue and live oak mortality were also suspected though it was too early in the season to be sure.
On the Stanislaus National Forest, areas with dead trees doubled since last year. Pine mortality, mostly caused by western pine beetle, was common at lower elevations. Over 5 million trees were killed on the Sierra and Sequoia National Forests up from the 300,000 trees killed last year in the same area. Conifer mortality was scattered at higher elevation, though surveyors note that the survey was conducted too early in the year to detect the full extent of mortality levels.
The insects killing trees in the Sierra are all native insects that are multiplying because of drought conditions. Native insects are a necessary part of the forest ecosystem that speed decay of wood back into nutrients, prey on other insects, and provide food for wildlife. They are normally present at low levels and cause tree mortality only in localized areas.
However, drought weakens trees and reduces their ability to withstand insect attacks. Normally trees use pitch to expel beetles that attempt to burrow into the tree through the bark. Weakened trees cannot produce the pitch needed to repel these beetles which are able to enter under the bark and lay eggs. Larvae feed on a tree's inner bark cutting off the tree's ability to transport nutrients and eventually kill it. Attacking beetles release chemicals called pheromones that attract other beetles until a mass attack overcomes the tree. Many beetles also carry fungi that weaken the tree's defenses.
Western pine beetle is one of the main culprits killing pines in the Sierra during this drought. It is a bark beetle, one of a genus of beetles named Dendroctonus which literally means ‘tree-killer'. Adult beetles are dark brown and about a quarter-inch long. Adults bore into ponderosa pines, lay eggs which develop into larvae in the inner bark then complete development in the outer bark. When beetle populations are high, such as during drought periods, even healthy trees may not be able to produce enough pitch to ward off hundreds of beetle attacks.
Western pine beetle often attacks in conjunction with other insects. Other beetles causing tree mortality in Sierra forests include mountain pine beetle, red turpentine beetle, Jeffrey pine beetle, engraver beetles (Ips) and fir engravers. Forests with a higher diversity of tree species are typically less affected because beetles often have a preference for specific tree species. Some species may attack only one tree type. For example Jeffrey pine beetles attack only Jeffrey pine.
Signs that bark beetles are affecting a tree include pitch tubes (streams or tubes of pitch visible on the trunk), small holes through the bark, or boring dust. If the tree is extremely water-stressed and cannot produce pitch, boring dust may be the only visible sign. Trees with needles that have turned from green to red are dead. Most beetles have emerged by the time trees turn red.
The best defense against bark beetles is to keep trees healthy so they are able fight off insects themselves. Widely spaced trees are typically less susceptible to successful attack by bark beetles since they face less competition for moisture, light, and nutrients compared to densely growing and overcrowded trees. Forest health can be promoted by thinning to reduce overcrowding (so each tree has access to more resources) and removing high risk trees during thinning (such as those that are suppressed or unhealthy).
For landscape trees of high value close to a home, watering may be one option to increase tree vigor against bark beetle attacks. Apply about 10 gallons of water for each inch of tree diameter (measured at chest height) around the dripline of the tree once or several times a month during dry weather.
There are some insecticides registered for bark beetle control, but all are preventative only. Carbaryl may prevent attack for up to two years, while pyrethroids can deter attack for up to a year. Spraying can be tricky because the chemical must be applied up to 50 feet up the trunk of the tree usually while standing on the ground. Since misapplication may have toxic consequences, any insecticide must be administered by a licensed pesticide applicator. All applications must follow the label. Though some systemic treatments applied to the soil or inserted into the tree may work in some cases, there is not a lot of documented evidence that they are effective against western pine beetle. No insecticide can prevent tree death once a tree has been successfully attacked.
- Author: Sarah Yang
Efforts to predict the emergence and spread of sudden oak death, an infectious tree-killing disease, have gotten a big boost from the work of grassroots volunteers.
A joint study reveals the power of citizen science in SOD Blitz, a survey project in which volunteers are trained to identify symptoms of sudden oak death. Led by Matteo Garbelotto at UC Berkeley and Ross Meentemeyer at North Carolina State University, the study was published today (Friday, May 1) in the journal Frontiers in Ecology and the Environment.
Sudden oak death is a fungus-like disease that has felled hundreds of thousands of trees in California. Crowdsourcing the survey and sampling work allowed researchers to gather information that would otherwise be too impractical and cost-prohibitive to obtain. Researchers then used the data to create a model that predicts the presence of the sudden oak death pathogen, Phytophthora ramorum, based upon such variables as rainfall and density of host trees.
Study authors compared the model based upon crowdsourced data gathered from the 2008-2013 blitzes with models using “pre-Blitz” research observations collected from 2000 to 2007. They found the SOD Blitz model to be more powerful, correctly predicting the presence of the pathogen 74 percent of the time, compared with models based on other sources of data.
“This paper shows that volunteers are as proficient as professionals in collecting data after they get some initial training,” said study principal investigator Garbelotto, an adjunct professor and cooperative extension specialist at UC Berkeley's Department of Environmental Science, Policy and Management. “The data we got from SOD Blitz resulted in the formulation of the best predictive model yet about the spread of sudden oak death in California. Additionally, we were able to identify new infestations and identify trees that needed to be removed. In one case, in Atherton, tree removal resulted in the only successful eradication of the pathogen in North America.”
The SOD Blitz model also revealed novel findings about the spread of the disease, finding that average population density and average maximum temperature were negatively correlated with the presence of the sudden oak death pathogen.
“The population density finding is important because of the debate about the role of humans in spreading sudden oak death disease,” said Garbelotto. “From this work we can say that humans are not currently spreading the disease, and that the pathogen is doing well spreading on its own.”
Beginning the Blitz
Jean Morrell, a retired biologist living on the Santa Lucia Preserve in Monterey County, learned about sudden oak death in 2007 through an on-site presentation and subsequent hike with Garbelotto that was organized for the homeowners on the preserve. The event provided the seeds for the idea of the SOD Blitz as a way to get more people – particularly other homeowners on the preserve – engaged. For Morrell, the idea kicked off a round of phone calls and personal outreach to her neighbors.
Garbelotto launched SOD Blitz the next year, in 2008, and it has since grown into one of the largest citizen science projects in the country, incorporating 21 coastal communities in California. Each spring researchers reach out to participants through news stories, radio announcements, community groups and other recruitment methods.
Participants go through mandatory, on-the-ground training by professionals to learn how to detect and sample infected trees. Training workshops last about an hour, and then volunteers are provided with symptom detection guides, a mobile mapping tool and packets for storing leaf samples.
“When it comes to predictive models, the more data the better,” said study lead author Meentemeyer, a professor of forestry and environmental resources and director of the Center for Geospatial Analytics at North Carolina State University. “This is especially true in less-studied urban ecosystems and people's backyards, where research scientists typically have little to no data. But the data need to be good, otherwise researchers are left dealing with a lot of noise. Motivated people, given a minimal amount of training, are clearly able to provide information that researchers need.”
‘People want to protect their trees'
In any one year, the return rate of participants ranges from 15 percent to as high as 40 percent, Garbelotto noted.
“From that first Blitz, we developed a core group of workers that have continued their interest and have followed up year to year,” said Morrell. “Sudden oak death is in all of our backyards, and it will have an effect on our neighborhoods. This is why we can engage people in the program. It not only allows participants to monitor their own space, but also, if they so desire, they can tromp out into the woods and do work in more remote areas. One only has to give up some ‘sweat equity' to participate, and the results are available to everyone at no cost. It's a win- win.”
Many participants are attracted to SOD Blitz by a shared love of the environment.
“I am an environmentalist, and my passion is trees. I believe they are the lungs of the Earth,” said Debbie Mendelson, who recruits SOD Blitz volunteers as a member of the Woodside Sustainability and Conservation Committee. “I think first and foremost, people want to protect their trees. Then there are folks who want to do something for the good of their community.”
Mendelson noted that SOD Blitz has also provided an opportunity to engage students in science. She has given presentations at local high schools about sudden oak death and citizen science. “I think it is a fantastic opportunity for students who have an interest in science to hear a scientist speak in an understandable and warm manner,” she said.
This year's SOD Blitz recruitment has already begun. Community meetings will be held at various locations through early June for those interested in learning more.
Once verified, data from SOD Blitz is uploaded and freely available online.
The National Science Foundation, U.S. Forest Service, Gordon and Betty Moore Foundation and PG&E Foundation helped support this work.
- Citizen Science Helps Predict Risk of Emerging Infectious Disease (Link to Frontiers in Ecology and the Environment study)
- SOD Blitz Project
- Citizen Scientists Key to Halting Sudden Oak Death (LiveScience op-ed)
- UC Berkeley a pioneer in citizen science