- Author: Sarah Yang | Media Relations scyang@berkeley.edu, (510) 643-7741
By the end of the century, almost all of North America and most of Europe is projected to see a jump in the frequency of wildfires, primarily because of increasing temperature trends. At the same time, fire activity could actually decrease around equatorial regions, particularly among the tropical rainforests, because of increased rainfall.
The study, to be published Tuesday, June 12, in Ecosphere, an open-access, peer-reviewed journal of the Ecological Society of America, used 16 different climate change models to generate what the researchers said is one of the most comprehensive projections to date of how climate change might affect global fire patterns.
"In the long run, we found what most fear — increasing fire activity across large parts of the planet," said study lead author Max Moritz, fire specialist in UC Cooperative Extension. "But the speed and extent to which some of these changes may happen is surprising."
"These abrupt changes in fire patterns not only affect people's livelihoods," Moritz added, "but they add stress to native plants and animals that are already struggling to adapt to habitat loss."
The projections emphasize how important it is for experts in conservation and urban development to include fire in long-term planning and risk analysis, added Moritz, who is based at UC Berkeley’s College of Natural Resources.
UC Berkeley researchers worked with an atmospheric scientist from Texas Tech University to combine over a decade of satellite-based fire records with historical climate observations and model simulations of future change. The authors documented gradients between fire-prone and fire-free areas of Earth, and quantified the environmental factors responsible for these patterns. They then used these relationships to simulate how future climate change would drive future fire activity through the coming century as projected by a range of global climate models.
"Most of the previous wildfire projection studies focused on specific regions of the world, or relied upon only a handful of climate models," said study co-author Katharine Hayhoe, associate professor and director of the Climate Science Center at Texas Tech University. "Our study is unique in that we build a forecast for fire based upon consistent projections across 16 different climate models combined with satellite data, which gives a global perspective on recent fire patterns and their relationship to climate."
The fire models in this study are based on climate averages that include mean annual precipitation and mean temperature of the warmest month. These variables tend to control long-term biomass productivity and how flammable that fuel can get during the fire season, the researchers said.
Variables that reflect more ephemeral fluctuations in climate, such as annual rainfall shifts due to El Niño cycles, were not included because they vary over shorter periods of time, and future climate projections are only considered representative for averages over time periods of 20-30 years or longer, the authors said.
The study found that the greatest disagreements among models occur for the next few decades, with uncertainty across more than half the planet about whether fire activity will increase or decrease. However, some areas of the world, such as the western United States, show a high level of agreement in climate models both near-term and long-term, resulting in a stronger conclusion that those regions should brace themselves for more fire.
"When many different models paint the same picture, that gives us confidence that the results of our study reflect a robust fire frequency projection for that region," said Hayhoe. "What is clear is that the choices we are making as a society right now and in the next few decades will determine what Earth’s climate will look like over this century and beyond."
Study co-author David Ganz, who was director of forest carbon science at The Nature Conservancy at the time of the study, noted the significance of the findings for populations that rely upon fire-sensitive ecosystems.
"In Southeast Asia alone, there are millions of people that depend on forested ecosystems for their livelihoods," he said. "Knowing how climate and fire interact are important factors that one needs to consider when managing landscapes to maintain these ecosystem goods and services."
The researchers noted that the models they developed focused on fire frequencies, and that linking these to other models of fire intensity and vegetation change are important next steps.
"Our ability to model fire activity is improving," said Moritz, "but a more basic challenge is learning to coexist with fire itself."
The Natural Sciences and Engineering Research Council of Canada, the U.S. Forest Service, the National Science Foundation and The Nature Conservancy helped support this study.
RELATED INFORMATION
- Climate change to spur rapid shifts in fire hotspots, projects new analysis (2009 UC Berkeley press release)
- Author: Sarah Yang | Media Relations scyang@berkeley.edu, (510) 643-7741
The paper, published in the June issue of the peer-reviewed journal BioScience, and led by researchers at the University of California, Berkeley, synthesizes 20 years of research throughout the country on the ecological impact of reducing forest wildfire risk through controlled burns and tree thinning. It comes as California braces for a potentially bad fire season, particularly in the southern Sierra where precipitation was half its normal level.
"We need to act, because climate change is making fire season longer, temperatures are going up, and that means more fire in many regions, particularly ones with a Mediterranean environment," said study lead author Scott Stephens, UC Berkeley associate professor of fire science.
The study authors, which included scientists from the U.S. Forest Service and six research universities in the United States and Australia, relied upon data from the U.S. Fire and Fire Surrogates Study, in addition to a wide range of other studies. Together, the studies represented a broad spectrum of ecological markers, detailing the effects of fuel-reduction treatments on wildlife, vegetation, bark beetles, soil properties and carbon sequestration.
"Some question if these fuel-reduction treatments are causing substantial harm, and this paper says no," said Stephens. "The few effects we did see were usually transient. Based upon what we've found, forest managers can increase the scale and pace of necessary fuels treatments without worrying about unintended ecological consequences."
A few of the researchers’ specific ecological findings include:
- For the first five years after treatment, some birds and small mammals that prefer shady, dense habitat moved out of treated areas, while others that prefer more open environments thrived. The study authors said these changes were minor and acceptable.
- When mechanical tree thinning was followed by prescribed fire, there was an increase in the overall diversity of vegetation. However, this also included non-native plant species. The researchers recommend continued monitoring of this effect.
- Only 2 percent or less of the forest floor saw an increase in mineral soil exposure, which could lead to small-scale erosion. Other soil variables, such as the level of compaction, soil nitrogen and pH levels, were temporary, returning to pre-treatment levels after a year or two.
- Increases in bark beetles, a pest that preys on fire-damaged trees, was short-lived and concentrated in the smaller diameter trees. Researchers noted that thinning out a too-dense forest stand improves tree vigor and ultimately increases its resilience to pests, in addition to fire.
The results of this paper may help inform an analysis of one of the larger prescribed fires in the history of the U.S. Forest Service. Called the Boulder Burn, the proposed treatment covers 6,000-9,000 acres in the Southern Sierra Nevada's Sequoia National Forest and is tentatively set to begin by late fall.
"This paper is more comprehensive and definitive than any other article I've seen," said Malcolm North, research scientist with the U.S. Forest Service and an associate professor in forest ecology at UC Davis. "In one place, it summarizes the state of the science in fuel-reduction treatments, and to my mind, it shuts the door on those who say that any type of fuels treatment is detrimental to the forest. If done properly where surface fuels are reduced, treatments work. It's time to get on with it."
Nearly a century of fire suppression and the preferential logging of large-diameter trees, which are better able to withstand forest fires, have left forests vulnerable to more destructive, albeit less frequent, wildfires, the researchers said. In addition, the lack of fire has hindered nutrient cycling in forests and the proliferation of certain plant species, such as the sequoia, that rely upon fire to promote seed dispersal.
This realization led to the gradual re-emergence during the past 20 years of fuel-reduction as a forest management tool. The goal is simple: Thin or remove overly dense stands of trees, ground vegetation and downed woody debris in a carefully controlled way before they become fuel for a raging wildfire. When low- or moderate-intensity controlled burns are not an option, fire-prone trees are mechanically removed or shredded on site.
Such techniques are an attempt to emulate the frequent fires common in California for thousands of years. Before 1800, Stephens said, an estimated 1.1 million acres of forest burned annually in California, including wildfires ignited by lightning and other natural sources, and blazes set intentionally by Native Americans as a way to manage or alter landscapes. Most were blazes of low-to-moderate intensity that more than 80 percent of the trees could survive, unlike the catastrophic wildfires of modern times.
"Today, the combination of wildfires and fuel-reducing treatments only touch 6-8 percent of the land that used to burn annually before 1800, and fuel-reducing treatments alone only affect 1 percent," said Stephens. "That's a pittance. At that level, treatments are just triage rather than fire prevention."
To approach levels that have a chance of reducing wildfire risk in the long term, he said, the amount of land to be treated in a year would need to increase to 2-4 percent — still low compared to historical levels.
Stephens noted that two-thirds of the fuel-reduction treatments in the western United States rely upon mechanical thinning, which would be much more costly than prescribed burns to scale up. In the southeast region, the use of prescribed fire dominates.
In the West, particularly in California, the biggest challenge to expanding controlled burns is the potential reduction in air quality during treatment, said Stephens.
"We have a choice," he said, "of dealing with lower levels of smoke from prescribed fires that may only be needed every 15 years or so, and which can be timed for optimum wind conditions, or acute levels of smoke from catastrophic fires that can last for months when they hit."
The U.S. Department of Agriculture-U.S. Department of the Interior Joint Fire Science Program helped support this research.
- Author: Jeannette E. Warnert
Walter Bentley, UC Cooperative Extension advisor, transferred to Kearney in 1994 after 17 years as a UC Cooperative Extension advisor in Kern County, specializing in entomology. The integrated pest management team – with advisors representing the core pest management disciplines of entomology, nematology, weed science and plant pathology – was formed in response to concern about the effect of pesticides on food safety, the environment and farmworker safety.
Bentley collaborated with IPM and commodity-specific UC Cooperative Extension advisors and specialists and farmers to develop IPM approaches and alternative control strategies that have reduced the use of the highest risk insecticides (carbamates and organophosphates) in California by 80 percent to 90 percent in almonds, grapes and tree fruit since 1995.
Bentley’s career success is demonstrated by the numerous awards he has received in the past year. A group of world IPM leaders presented Bentley with its Lifetime Achievement Award March 27 at the 7th International IPM Symposium in Memphis, Tenn. He also received a Lifetime Achievement Award from the California Association of Applied IPM Ecologists in February. In October 2011, Bentley received the UC Agriculture and Natural Resources Distinguished Service Award for Outstanding Extension.
Bentley grew up in San Joaquin County on his family’s cherry, walnut and peach farm in Linden. He began laboring in the orchards as a young boy, but the hard work didn’t deter him from pursuing a career in agriculture.
“Growing up on a farm is probably the best life a youngster can have,” Bentley said. “But I can’t say that it was easy for my parents. It was a struggle for them to raise a family and depend solely on income from the farm.”
Bentley earned a bachelor’s degree in horticulture and biology in 1969 at Fresno State University, and then spent two years in the U.S. Army working on tracing mosquito movement in the 4th Army area of Texas and Oklahoma and later in Utah. He earned a master’s degree in entomology in 1974 at Colorado State University. Bentley worked in biological pest control for the Colorado Department of Agriculture before returning to his native California for the UC Cooperative Extension position in Bakersfield.
“I had heard many rumors about how tough Bakersfield was in terms of weather and environment. Within two weeks of starting the job, there was a huge dust and wind storm in the area and the first summer we had 30 days in a row with the temperature 100 degrees or higher,” Bentley said. “But I came to enjoy Bakersfield.”
As the UC Cooperative Extension farm advisor for Kern County, Bentley worked with his colleagues to develop an IPM program for almonds, addressing primarily problems with spider mites, navel orange worms and ants. Also working with colleagues, he developed an IPM program for potatoes, emphasizing careful monitoring for potato tuber moth and postponing pesticide treatment until the pest reached a level at which economic damage occurs.
Perhaps his greatest accomplishment, however, was the relationship he cultivated with growers and pest control advisers in Kern County. In particular, Bentley worked closely with pioneer Bakersfield apple grower Lewis Sherrill to combat the problem of codling moth in apples. Sherrill started his own farm at age 76 and continued farming until he was nearly 100 years old.
“Apple farmers in Kern County were relying on information from Washington state, where a large part of the U.S. apple industry is located,” Bentley said. “But in Washington, codling moth only produces two generations in the summer. In Kern County, we had four. Lou and I analyzed codling moth flight dynamics, integration of materials and we began experimenting with mating disruption.”
At Kearney, Bentley continued his work on apples and almonds, plus he began to work extensively in grapes. Mealybug management in grapes, he said, became the most important and impactful part of his job. Bentley also played a role in developing a management plan to control katydid damage in peaches and helped farmers use mating disruption against oriental fruit moth in peaches.
“In my generation as an entomologist, a major breakthrough was the development and use of pheromones for ag pest monitoring and management,” Bentley said. “We found ways to use pests’ own biology against them.”
During his 36-year career, Bentley authored 65 chapters or sections in pest management manuals and 75 peer-reviewed articles. In addition, he wrote more than 250 articles for trade journals and newspapers.
"Mr. Bentley's career represents the best UCCE's faculty has to offer, “ said his IPM colleague, Pete Goodell, UC Cooperative Extension advisor based at Kearney. “Unselfish service, loyalty to his peers and clientele, intellectual honesty, dedication to the mission of UCCE and a genuine love for his work.”
Bentley credits the success of his program to the UC Cooperative Extension research and education continuum, which is designed to foster communication and collaboration from campus laboratories to farm fields and back again.
“I think this is one of the best educational programs in the world,” Bentley said. “We take information from UC campuses to the farms. And those of us who work with farmers bring first-hand experiences back to the campus and work with scientists to develop solutions.”
Bentley’s personal interest in insects, which got him into his line of work, will carry through into his retirement. One of his goals, he said, is building a teaching collection of insects, spiders, mites and other arthropods at Kearney. He has already acquired some of the equipment needed to house the collection, and plans to maintain some samples on pinned displays and others in live colonies. The collection will be a learning tool for farmers, pest control advisers, students and interns.
“Knowing what’s out there is an important part of understanding entomological science,” Bentley said.
Insects are also a part of his favorite pastime, fly fishing. Bentley said retirement will give him more time to spend on local rivers catching (and releasing) trout with his hand-tied flies. Bentley speaks passionately about the joy of fly fishing.
“There’s a pulse that runs through you,” Bentley said. “It feels like you’re a child on Christmas every time the fish hits the fly. It’s such a thrill.”
- Author: Jeannette E. Warnert
Since 1977, Lazaneo has been the UC Cooperative Extension advisor for San Diego County urban horticulture, a job aimed at educating the county’s residents about plant selection, pest control and other cultural practices that protect the environment and ensure safe and successful gardens and landscapes.
During childhood, Lazaneo tinkered in his family’s backyard gardens, first planting bean and popcorn seeds from the kitchen pantry.
“Amazingly, they grew and produced an edible crop,” Lazaneo said. “I was hooked.”
Lazaneo has faced physical challenges in his life and career. As a 17-year-old high school student experimenting with fireworks, he shook a jar of chemicals to tragic effect. An explosion took off his right hand at the wrist and most of his left hand. Lazaneo also was born with a degenerative eye disorder that resulted in lifelong deteriorating vision and blindness in 2002. However these disabilities did not bring him down.
After earning a bachelor’s degree in horticulture at California Polytechnic State University, San Luis Obispo, Lazaneo took a retail nursery sales position in San Jose.
“I discovered that the thing I enjoyed the most was educating customers about plants.” Lazaneo said.
He returned to college, earning a master’s degree in horticulture and a teaching credential in vocational agriculture at UC Davis. While looking for a permanent teaching job, a serendipitous contact led him to a temporary position with UC Cooperative Extension in Sacramento County, where administrators encouraged him to pursue a career with the organization. In 1977, he successfully applied for the urban horticulture position in San Diego County.
Around this time, an idea that took shape in the state of Washington was beginning to garner interest in California: Provide gardening enthusiasts with first-class training in horticultural methods in exchange for their commitment as a Master Gardener to share that information with others in the community. Lazaneo decided to offer the volunteer program in San Diego County, the second-most populous county in the state and a location which boasts a mild climate ideal for gardening year-round.
About 120 gardeners applied for Lazaneo’s first Master Gardener class in 1983, from which he selected 32 well-qualified individuals. The volunteers underwent 16 weeks of rigorous training with Lazaneo and other UC academics, including experts in integrated pest management, soil and water management, fruit tree, and vegetable culture. All members of the first class passed the final exam. San Diego’s newly certified Master Gardeners helped staff the UC Cooperative Extension booth at the county fair and answered phone inquiries from the public about plants and pests.
The application process has been competitive each time a new class of volunteer Master Gardeners was trained. Today, more than 220 active Master Gardeners staff well over 40 educational exhibits each year, and answer 5,000 phone and email inquiries annually. Another 55 Master Gardeners will complete the training program before Lazaneo retires.
In addition to working with homeowners, the San Diego Master Gardeners have maintained an active outreach program with schools interested in providing garden-based learning to their students. A group of Master Gardeners, with Lazaneo’s oversight and editing, created an elementary school curriculum, “Plant a Seed - Watch it Grow,” and offered to serve as consultants to schools that wished to develop gardens. On May 23 the School Gardens program was awarded a Certificate of Excellence by the San Diego Science Alliance.
“Our volunteers currently consult with more than 200 schools in the county each year,” Lazaneo said.
In the last few years, the Master Gardeners have also turned attention to community gardening. They have conducted workshops on how to start community gardens and worked with other gardening groups to change zoning regulations that will give county residents more community gardens.
Lazaneo also collaborated with the horticulture department at Cuyamaca Community College in El Cajon to study vegetable varieties that are best adapted to local growing conditions, including tomatoes and asparagus. He conducted a study in cooperation with Sunset Magazine evaluating floating row cover cloth for maximizing plant growth and deterring pest damage on vegetables.
“We used the quarter-acre community college plot for 12 years,” Lazaneo said. “When we harvested surplus tomatoes, we donated them to the food bank.”
Throughout his career, Lazaneo has written a gardening column for the San Diego Union-Tribune. He said he will continue writing during his retirement. He also plans to write answers to local residents’ most frequently asked questions to post for the San Diego Master Gardener website.
In addition to these activities, Lazaneo said he looks forward to having time for growing specialty plants in his home garden and for more reading, hiking and fishing.
- Author: Jeannette E. Warnert
The Selma native was raised on a farm, where his family produced fruits and vegetables for sale at Highway 99 fruit stands. McKenry earned his degree in soil science with a biochemistry minor at California Polytechnic State University, San Luis Obispo, in 1966, where his senior project targeted the microscopic soil-borne true round worms that would shape his career.
“Very few farmers knew much about nematodes at the time,” McKenry said. However, the pest was causing serious damage and yield loss, especially when crops were replanted into previously farmed land.
After serving as a vocational agriculture teacher in Yucaipa, a town east of San Bernardino, and conducting field trials with his students, McKenry was offered the opportunity to study nematodes at UC Riverside. He obtained his Ph.D. in 1972 and was soon appointed by UC Riverside to his nematology research position at Kearney.
McKenry said his research focus changed with the times. The first two decades, he studied the movement of fumigants and other pesticides in soil, and the timing and placement for nematode congregation under trees and vines. Equally important were his activities to develop newer methods to assure that California’s nursery stocks would remain nematode-free.
“As drip systems evolved, we encouraged farmers to pay more attention to the root flush in order to be more efficient with whatever treatments they used,” McKenry said.
Increasingly stringent regulations and bans on the use of certain fumigants began to turn nematologists’ attention to reduced rates using timing and placement as well as botanically derived alternatives to synthetic products. McKenry noted an unreported biological control process under way at Kearney where certain naturally occurring fungi and bacteria were lethal to nematodes.
“We’ve been working on that for 40 years,” McKenry said. “We’re still missing pieces, but the potential and limitations are better understood.”
During this period, McKenry also developed a portable drenching system that reduced off-gassing of soil fumigants and led the way for pre-plant delivery of degradable nematicides deep into soil.
The next 20 years was the period of rootstock exploration. Grape rootstocks that had been released in the 1960s were losing their resistance to nematodes in the 1980s. McKenry and his staff evaluated as many as 1,000 potential grape rootstocks from around the world. This was followed by evaluation of 100 peach and almond rootstocks and then thousands of potential walnut rootstocks.
More recently, McKenry identified the first effective nematode treatment that in very low doses could be sprayed onto leaves of trees and vines. This new chemistry was hidden away as an insecticide. Thousands of soil samples evaluated by McKenry and his research team at UC reported that if farmers followed a few guidelines, their yields could be boosted 10 percent to 20 percent.
In all, McKenry has written more than 250 research papers, half of them in pest management manuals, the other half peer-reviewed conference proceedings, book chapters and research journals.
Even though he will retire this summer, McKenry said he plans to continue with a few special projects.
“There is so much yet to be done,” he said.
He said he also looks forward to having more time to spend at his coastal home in Cayucos while continuing his worldwide travels.