California land managers and wildlife experts are increasingly tasked with managing the return of long-suppressed predators to the landscape, including wolves, mountain lions, badgers, foxes, coyotes, bobcats, and bears. As a result, California is poised to see growing numbers of complex human-wildlife interactions, said Justin Brashares, UC Berkeley professor and UC ANR researcher.
State and federal policies once incentivized the removal of large carnivores, even offering bounty payments, Brashares said. The last California grizzly became a victim of such practices in 1922. The gray wolf was exterminated shortly thereafter, only to make a historic return 90 years later in the form of a single young male called OR-7, who has been followed into California by several other wolves.
Beginning in the 1970s with the federal Endangered Species Act and the banning of bounties, things began to change. Poisons and leghold traps were prohibited in 1998. Next came an end to the sport hunting of mountain lions in 1990, bear hunting with dogs in 2012, and bobcat trapping in 2015. The cumulative result of these actions, which eased centuries of pressure on wild animals treated as pests, has been a “quiet carnivore recovery” happening across our state, Brashares said. And depending on whom you ask, that may be a great thing or a terrible thing.
An ecologist or environmentalist might emphasize the role of carnivores in maintaining healthy ecosystems.
“What we're seeing across the state, particularly over the last 10 years, is arguably an unprecedented recovery of our wildlife communities,” Brashares said.
A livestock rancher, meanwhile, might view the development with dread.
“They're the ones most likely to be negatively impacted by the return of these animals.” A similar divide, he notes, exists between urban and rural dwellers.
“Those who face the challenges of coexistence with carnivores on a day-to-day basis tend to be more negative about their return,” he says.
The rest of us tend to view the return of carnivores — particularly large, charismatic ones — much more favorably.
“In more-urban communities, we often have the luxury of interacting with carnivores on our own terms, by going out and seeking them in wild settings, away from our safe living and work environments, in places like Yosemite National Park,” Brashares said.
But anyone who has lost a dog or cat to a mountain lion, let alone commercial ranchers trying to protect their livelihood from hungry coyotes and wolves, may feel differently. Even so, he said, reliance on lethal control as the primary strategy for managing predators in the state is becoming a thing of the past.
How to behave instead is, in part, a question for science — and one that Brashares is working to answer through ongoing research at the University of California's Hopland Research and Extension Center (HREC), in southern Mendocino County. There the university owns a 5,300-acre parcel with oak woodland, grassland, chaparral, and riparian environments — and, according to recent surveys, wildlife densities on par with those in Yellowstone and Yosemite. Linked to the massive Mendocino and Shasta-Trinity National Forests, it's part of a corridor of undeveloped and protected land extending all the way to the Canadian border. As such, it commonly hosts coyotes, bobcats, mountain lions and black bears.
The facility is also home to more than 500 sheep, on-site since the 1950s for the study of sustainable agricultural practices. But sheep, open space, and carnivores spell conflict, and the flock has regularly suffered significant losses to coyote predation. The coyotes, in turn, have traditionally been shot on sight, in line with established wildlife management practices in agricultural settings.
In 2014 alone, nearly 50 lambs were killed by coyotes at HREC, and another 178 went unaccounted for. Meanwhile, 26 coyotes were killed to prevent further losses to the flock. Toward the end of the year, when Kim Rodrigues became director of HREC, she realized the current system wasn't working and set about to fix it.
Rodrigues brought on more guard dogs and a new shepherd; she improved fencing, and changed the rules about shooting coyotes and other predators. She also initiated a number of research efforts, in which Brashares now plays a lead role, to critically evaluate the effectiveness of tools like dogs, fences, and “fox lights,” which are randomly lit on the fields to scare off predators. Brashares and Rodrigues are also studying how to better use technology like GPS, drones, and tagging to understand the often-mysterious behavior and movement of carnivores and their prey, in hopes of gaining new insights for human-wildlife coexistence.
After Rodrigues instituted some of these changes, the numbers of lamb and coyote deaths at HREC began to decrease dramatically. In 2016, fewer than five lambs were believed to have been killed by coyotes, with another eight unaccounted for, and just seven coyotes were shot.
In a bid to make HREC a statewide hub for cutting-edge research and discussion around human-wildlife interactions, Rodrigues enlisted Brashares's help in December 2015 in hosting a community conversation with stakeholders about the management of wildlife and livestock using nonlethal methods. A second discussion is planned for this June.
“My research and extension focus is now on how we can start to explore standard operating procedures that actually have a stated goal to protect both the livestock and the wildlife, and not one or the other,” Rodrigues says. “It's changing the either/or conundrum to thinking about how we really value both on the landscapes that we're managing.”
Excerpted from the Spring 2017 issue of Breakthroughs, the magazine of the College of Natural Resources at the University of California, Berkeley. Read the full article.
Two more trees infected with huanglongbing (HLB) disease were identified and destroyed in the days before UC Cooperative Extension and the Citrus Research Board kicked off their spring Citrus Growers Education Seminar in Exeter June 27. The new infections raise the total number of HLB-infected trees in Los Angeles and Orange counties to 73.
The latest statistic set the stage for spirited discussions about a looming threat that cut Florida citrus production by 60 percent in 15 years. The devastating citrus losses in Florida were recounted by Ed Stover, a plant breeder with USDA Agricultural Research Service in Fort Pierce.
"One of the benefits of coming here is I am reminded how beautiful citrus is," Stover said. "In Florida, there are more than 130,000 acres of abandoned groves." He showed slides of trees with thin canopies, pale leaves and green fruit; in one image the trees were skeletons among tall weeds.
Huanglongbing disease is an incurable condition spread by Asian citrus psyllid (ACP). The psyllid, native of Pakistan, Afghanistan and other Asian regions, was first detected in California in 2008. Everywhere ACP is found, the pests find and spread HLB.
Stover and his colleagues are searching for citrus cultivars that have natural tolerance for the bacteria that causes HLB, but progress is slow. Transgenic citrus, he said, is the best bet for developing citrus with HLB immunity.
"In my opinion, commercial genetically engineered citrus is inevitable, and GE crop concerns will likely decline with time," he said.
In California, the aggressive push to keep psyllid populations low, regulations to limit the spread of psyllids when trucking the fruit, and active scouting for and removal of HLB infected trees in residential areas could buy time for researchers to find a solution before California suffers the fate of Florida citrus growers.
"Be vigilant," Stover said. "As long as you are still making a good return, there is almost no investment too great if it keeps HLB out of California."
Beth Grafton-Cardwell, UCCE citrus entomology specialist and director of the UC Lindcove Research and Extension Center near Exeter, said the prime research in the San Joaquin Valley is aimed at early detection techniques.
Once a tree is infected, it takes nine months to two years for the bacteria to spread throughout the tree, so that when leaves are selected for testing, they detect the bacteria. Capturing and testing psyllids is one way to to find the disease early. Other early detection techniques focus on the microbes, proteins and aromas produced by sick trees.
"These can be measured with leaf test, a VOC (volatile organic compound) sniffer, swab or even dogs," Grafton-Cardwell said. "Scientists are studying every conceivable way to stop the disease."
In the meantime, growers were encouraged to carefully monitor for and treat psyllid populations in their orchards with pesticides. Pesticide treatment recommendations are available on Grafton-Cardwell's Asian Citrus Psyllid Distribution and Management website, http://ucanr.edu/acp.
"We have lots of challenges," Grafton-Cardwell conceded. "We hate disrupting our beautiful integrated pest management program. But monitor your own groves, apply the most effective treatments and remove suspected (infected) trees. Going through the pain up front will save us in the long run."
University of California students are taking a long journey through California to trace the state's complicated and critical water supply. The recent graduates and upper-division co-eds from UC Merced, UC Santa Cruz, UC Berkeley and UC Davis are part of the UC Water Academy, a course that combines online training with a two-week field trip for first-hand knowledge about California water.
The tour began June 18 at Lake Shasta, the state's largest reservoir, and followed the water's course to the Sacramento Valley, through the Sacramento-San Joaquin Delta and south along the Delta-Mendota Canal. Since a key water destination is agriculture, the UC Water Academy toured the UC Kearney Agricultural Research and Extension June 23, where research is underway to determine how the state's water supply can be most efficiently transformed into a food supply for Americans.
“You're visiting a place ideal for growing high-quality fruits and vegetables, because of the Mediterranean climate and low insect and disease pressure,” said Jeff Dahlberg, director of the UC KREC.
UC Cooperative Extension water management specialist Khaled Bali joined the students next to his alfalfa research plot, where different irrigation regimens are compared to determine the maximum yield that can be harvested with the minimum amount of water.
“It used to be that the No. 1 objective was to maximize yield,” Bali said. “But with the limited supplies and the cost of water, now the No. 1 objective is to get the maximum economic return. Growers might be better off selling some of their water to other jurisdictions.”
A water tour wouldn't be complete without an introduction to drought research. A recently planted sorghum trial provided the backdrop.
“California is a great place to study drought tolerance,” Dahlberg said, “because you can induce a drought by withholding irrigation.”
The sizable field contains 1,800 plots with 600 sorghum cultivars under three irrigation schemes: one irrigated as usual, one in which water is cut off before the plants flower, and the final one where water is cut off after the plants flower.
“Every week, a drone flies over to collect data on the leaf area, plant height and biomass,” Dalberg said. “Hopefully we will get associations with gene expression and this phenotype data."
Dahlberg and his collaborating researchers believe identifying the genes responsible for drought tolerance in sorghum will help scientists find drought-tolerant genes in other cereal crops – such as wheat, corn, rice and millet. “This will go a long way to feeding the people of the world,” he said.
There is still much to learn about sorghum drought tolerance – is it conferred by the plant's waxy leaves, the way stomata are controlled, accumulation of sugar in the leaves, or a mechanism in the roots?
“These are all questions you will have to answer to feed the world,” Dahlberg said. “That's why I would encourage you to continue studying water. There's a lot for you to get into.”
A third-year earth science student at UC Santa Cruz and a member of the academy, Denise Payan, said the sense of responsibility for the future is not daunting, but encouraging.
“It makes me feel like I can make a difference,” she said. The tour through California is shaping her plans for the future, which may include a career at the intersection of geology and biology.
“This has opened my eyes to a lot of issues,” she said.
The next stop for the UC Water Academy is the vast Tulare Lake basin to learn about groundwater recharge before heading east to the Owens Valley and the shores of Mono Lake. From there the academy turns to the Sierra Nevada to visit San Francisco's water supply, which is collected by Hetch Hetchy Dam. The field trip ends with a two-day rafting trip on the American River.
The UC Water Academy is offered through UC Water and led by UC Merced professor Joshua Viers and UC Cooperative Extension water management specialist Ted Grantham. In addition to the two-week tour, students participated in weekly online meetings and complete a project on communicating California water issues to public stakeholders. Students receive 1 unit of academic credit.
Bees are the most important pollinators of California agriculture — helping farmers grow field crops, fruits, nuts, and vegetables. Honey bees receive most of the credit for crop pollination, but many other kinds of bees play an important role as well. There are 1600 species of bees in California! Take time during Pollinator Week to learn about the different kinds of bees and what you can do to help them flourish.
Why should I care about other kinds of bees?
Bees other than honey bees contribute significantly to crop pollination. For example, alfalfa pollination by alfalfa leafcutter bees is worth $7 billion per year in the United States. Other bees can also boost the result of honey bee pollination — in almond orchards, honey bees are more effective when orchard mason bees are present. The more bee species, the merrier the harvest.
While growers often rent honey bee colonies to pollinate their crops, some wild bees pollinate certain crops even better than honey bees do. For instance, bumble bees are more effective pollinators of tomato because they do something honey bees do not: they shake pollen out of flowers with a technique known as buzz pollination. Likewise, native squash bees are better pollinators of cucurbits — unlike honey bees, they start work earlier in the day, and males even sleep in flowers overnight.
How can I help honey bees and other bees?
When it comes to land management and pest management practices, some bees need more accommodations than others. That's why it is important to know what bees are present in your area and important to your crop, and plan for their needs. Use this bee monitoring guide to identify bees present on your farm.
You can help all kinds of bees by using integrated pest management (IPM). This means using nonchemical pest management methods (cultural, mechanical and biological control), monitoring for pests to determine whether a pesticide is needed, and choosing pesticides that are less toxic to bees whenever possible. Check out the UC IPM Bee Precaution Pesticide Ratings to learn about the risks different pesticides pose to honey bees and other bees, and follow the Best Management Practices To Protect Bees From Pesticides.
Bees also need plenty of food to stay healthy and abundant. Plant flowers that provide nectar and pollen throughout the year. See the planting resources below to find out which plants provide year-round food for specific types of bees.
Like honey bees, native bees need nesting areas to thrive. Bumble bees, squash bees, and other bees nest underground. Ground-nesting bees may require modified tilling practices (such as tilling fields no more than 6 inches deep for squash bees) or no-till management to survive. For above-ground nesters, like carpenter bees and mason bees, consider planting hedgerows or placing tunnel-filled wooden blocks around the field. See the habitat resources below for more information about native bee nesting in agricultural areas.
Bee habitat resources
- Habitat for Bees and Beneficials
- Managing Wild Bees for Crop Pollination
- Native Bee Nest Locations in Agricultural Landscapes
- Farming for Bees: Guidelines for Providing Native Bee Habitat on Farms
- Hedgerow Planting for Pollinators: Central Valley, Central Coast, Southern California
- Conservation Cover for Pollinators: Central Valley, Central Coast, Southern California
- The Integrated Crop Pollination Project: Tools for Growers
- Insect Pollinated Crops, Insect Pollinators and U.S. Agriculture: Trend Analysis of Aggregate Data for the Period 1992–2009.
- Native bees are a rich natural resource in urban California gardens. (PDF)
- Honey bees are more effective at pollinating almonds when other species of bees are present.
Healthy soil does much more than hold plants upright on the surface of the earth. It is a mix of mineral bits and old plant particles teeming with microbes to form a mysterious and complex web of life scientists are just beginning to understand.
While scientists use high technology to study heathy soil – painstakingly counting soil worms and bugs, sequencing the DNA of soil bacteria, for example – some farmers know intuitively whether the soil is healthy just by walking on it.
Scott Park is a first-generation Meridian, Calif., farmer. “When I step on a field and it feels like a road, something is wrong,” he said. “If it feels like a marshmallow or sponge, that's good.”
Park shared his farming experiences with 200 farmers, industry representatives, University of California Cooperative Extension scientists, Fresno State students, news media and others during a half-day UC workshop at the UC West Side Research and Extension Center in Five Points.
“The last 31 years I've been on a mission of building soil,” Park said. “I discovered it by accident and I've made lots of mistakes. But yields trend upwards every year on every crop. Being sensitive to building soil, I'm making a lot of money. And if I'm doing something for the earth, all the better.”
Park said he adds 10 to 15 tons per acre of biomass to his farm every year. He's using less fertilizer, up to 20 percent less water, and even experimenting on the farm by growing a commercial crop with just four inputs: cover crops, water, seed and sun.
“We got high-yielding, good-quality crops,” Park said. “Nobody was more shocked than I am that I got a good crop.”
Researchers are now using the scientific method to figure out the root causes of these empirical observations.
“There's a lot going on in soil,” said Radomir Schmidt, a UC Davis soil microbiologist who spoke at the soil health field day.
A teaspoon of soil has a billion bacteria and six miles of fungal hyphae, the filaments that branch out through the soil from fungi, Schmidt said. The microbes' interaction with living plant roots, the larger pores left by decomposing vegetation and tunneling worms and insects create a system that confers resilience to unforeseen challenges – such as pest pressure, torrential rainfall and plant diseases.
The field day was held under a tent pitched adjacent to an 18-year research trial at the 320-acre facility. The trial compares four farming systems side by side:
- Conventional system, with annual soil tillage and no cover crops.
- Conservation agriculture, with no tilling whatsoever and annual winter cover crops.
- No-till without the cover crop.
- Conventional tilling with a cover crop.
“Take a look over my shoulder to see the difference,” said Jeff Mitchell, UC Cooperative Extension specialist and the study leader. “We've found the cover crops and no-till reduce water needs, cut dust, and lower costs. And there may be more benefits than we realized.”
For example, a graduate student counted the worms, bugs, beetles and other microfauna in soil samples from each of the treatments. There were double the amount in the no-till, cover crop plots compared to the conventional farming system.
UC Cooperative Extension specialist Sloan Rice found that cover crops promote water retention in the soil after rainfall. There is very little water evaporation from the soil surface and water transportation from the cover crop plants in the winter, so little water is lost. Cover crops also promote more water infiltration below three feet.
Healthy soil management also shows promise in confronting global climate change by sequestering carbon in the soil, rather than depleting it.
Manager of Sano Farms in Firebaugh, Jesse Sanchez, was a speaker at the field day. He wasn't surprised by the overflow crowd.
“Farmers are more and more curious. They see some of us using cover crops, and they want to learn more,” Sanchez said. “There has been a swell of interest. I have a tremendous number of visitors every year.”
For more information about soil building, see the UC Conservation Agriculture Systems Innovation website at http://casi.ucanr.edu.