Longer summers, less moisture and warmer climates are predicted for California's Sierra Nevada mountains. These changing patterns bring frequent droughts and extended wildfire seasons — as seen from the current extreme drought. The question no longer is whether wildfires will be more common or more intense — they already are — but how forest managers want these fires to burn.
Jens Stevens, a postdoctoral researcher in disturbance ecology at the University of California, Davis, has tracked how forests thinned for wildfire react to high-intensity burns. The answers he found touch on growing concerns over how the state can protect its forests.
Under the context of climate change, Stevens studies how understory plants recover from wildfires, measuring the effects fuel treatments — such as the thinning of small trees — have on the way these forests burn.
Stevens' research showed fuel treatments encourage resilience to wildfires, giving forests a greater ability to withstand a burn. Under really hot, dry summer conditions this makes a powerful difference.
“If you get warmer temperatures you're going to dry out the fuels,” says Stevens. “If we want to retain forest-dominated landscapes, we don't have the choice of doing nothing, because eventually these stands are going to burn."
To preserve forests, Stevens looked to native plant diversity under each management strategy. After a high severity fire, the tree canopy is non-existent. This new high-light environment favors other species, such as shrubs and flowering plants, which crowd out young trees.
While the treatments do protect the forest and encourage plant diversity, they are expensive and lead to uncertainty over how sensitive wildlife species are affected. Yet these areas will burn eventually, Stevens argues. The choice is either a more open forest or no forest at all.
He points out research by UC Davis ecologist Malcolm North, which shows the current pace of treatments can't keep up with the extent of Sierra forests that have been fire suppressed. The US Forest Service can treat up to 40 percent of a forest before managers must start over for follow-up treatments. The other 60 percent doesn't get touched.
“So the only real way to address that is to let the fire do the work for you,” says Stevens.
The proposal North and his colleagues arrived at relies on “firesheds.” These fire-prone areas would have boundaries that allow officials to efficiently manage the fires. If a burn begins after a treatment, they don't put it out. Allowing the fire to burn fuels they would otherwise be removing frees up resources to treat other areas.
“So if it's going to burn,” says Stevens, “you need to figure out ways the fire's going to give you your desired outcome.”
Watch Stevens explain more in his seminar.
This post was adapted from a longer piece by the UC Davis Department of Plant Sciences.
The average American eats 21 pounds of onions per year. Indeed, our appetite for the fresh green as well as yellow, red, and white bulb onions is increasing in the United States, up 70 percent from several decades ago. A valued crop generating $1.2 billion a year, the onion currently ranks No. 2 in the vegetable industry, right behind the potato. Yellow onions account for nearly 90 percent of all onion consumption, followed by red and white varieties.
Onions, cultivated for more than 5,000 years, are one of the most versatile vegetables. They are found in every ethnic cuisine from breakfast to lunch to dinner and are rich in vitamin C and fiber. As Julia Child noted, “It's hard to imagine civilization without onions.”
With a thriving onion industry comes a “crying” need for onion seed planting stock; onions have to flower and set seed. California is a major worldwide supplier of onion seed, with growers producing about 3,000 acres of hybrid onion seed worth about $12 million, and generating an additional $40 million annually in subsequent retail sales. The major growing areas in our state are the Imperial Valley and Colusa County.
Seed companies from around the world contract with growers here in California to produce hybrid onion seed. The many different varieties include red, yellow and white bulbs, including types that are adapted to different day lengths from our northern to southern hemispheres. Growers plant onion bulbs or seedling transplants in late summer with distinct male (male fertile) and female (male sterile) onion lines in the same field. Generally, the field ratio is one row of males for every three female rows and they're tough to tell apart from a distance, but males produce pollen.
Thankfully, there are few pests of onion seed, although the recent introduction of the iris yellow spot virus vectored by the onion thrips has resulted in increased insecticide use to control this potentially devastating pest and disease. Recent research by UC Cooperative Extension specialists in Yolo County and UC Davis, however, documented that more than three insecticide sprays applied pre-bloom per year can reduce honey bee visitation to flowers. Insecticides may also interfere with the ability of female flowers to receive pollen; that is, sprays applied near to bloom time can lead to overall lower pollen germination. As a result, growers are now careful to minimize insecticide use in onion seed production fields to ensure good pollination and yields.
After cross-pollination occurs and seeds are set, growers knock down the male rows to remove them to facilitate harvesting of female lines and ensure purity of the seed. Once the female umbels dry down, they are harvested primarily by hand, placed on tarps to fully dry, and then the tiny black seeds from the florets are mechanically threshed with a combine, and cleaned and packaged for retail sales.
Although a small acreage crop in California, onion seed is an important specialty crop that significantly boosts our agricultural economy, as well as providing needed seed for farmers throughout the world.
But, before you can slice them, chop them or dice them, you have to grow them and our California growers do it best.
Additional information on onion seed production can be found at:
Onion umbel with seeds
Timm's career has focused on managing wildlife damage and providing science-based advice for people to solve conflicts between humans and wildlife, which increasingly arise as both human and wildlife populations expand. One of his research subjects was finding better ways to prevent coyotes from preying on sheep.
He compiled, edited and published the reference book “Prevention and Control of Wildlife Damage” in 1983 and co-edited the 2004 revision. Since 1989, he has served in many leadership roles on the Vertebrate Pest Council, including managing editor of the Vertebrate Pest Conference Proceedings since 2002.
In 2007, Timm planned the first Urban Coyote Symposium and published papers from the symposium as a management guide. He also created the website CoyoteBytes.org to provide current, science-based management recommendations to wildlife managers and decisionmakers at the city, county and state levels who were dealing with urban coyote conflicts.
As director of the Hopland Research & Extension Center, he was instrumental in the design and construction of Rod Shippey Hall, an outreach and research facility that was completed in 2012. The late Rod Shippey was a UCCE advisor in Mendocino County.
Timm earned a B.S. in biology at the University of Redlands and master's and Ph.D. in ecology at UC Davis. He began his career at the University of Nebraska at Lincoln, where he served for nine years as Cooperative Extension vertebrate pest specialist and assistant professor. In 1987, he returned to California to become the second administrator in the history of the “Hopland Field Station,” as it was then known. The late Al Murphy served as the center's first administrator from 1951 to 1986.
In retirement, Timm and his wife Janice plan to stay in Ukiah and spend more time gardening, fishing, traveling and attending Giants games. Timm, who has been granted emeritus status, also plans to finish several publications and continue participating in the Vertebrate Pest Council.
Inspired by an uptick of diet-related diseases and emerging antibiotic-resistant microbes, doctors are overdue when they insist that hospitals practice their prescriptions for healthy diets and healthier agricultural practices. Anything less would be a violation of their ethic to “first, do no harm.
However, transitioning hospital food service to what they would like their patients to eat has been a two-year struggle. Many institutions do not systematically provide higher budgets for food procurement just because their doctors insist. Organic or antibiotic-free foods are consistently more costly and seldom available in the form that foodservice facilities have grown dependent on: prewashed, precut and preportioned.
Nonetheless, lessons have been learned and six hospitals in the San Francisco Bay Area are sharing those in a How-To Guide based on two years of collaboration through the Farm Fresh Healthcare Project (FFHP). The guide describes how the hospitals were able to purchase almost 67,000 pounds of local produce from 10 family farmers who practice sustainable agriculture.
The guide features a photo of Capay Organic mandarins arriving at UCSF. The other hospitals in the project are John Muir Health, San Francisco VA Medical Center and Washington. (Stanford recently joined.)
Participating farms also include Coke, Durst Organic Growers, Las Hermanas, GreenSolar, Greene & Hemly, Dwelley, Zuckerman's, Casteneda Brothers, and Gowan Orchards.
The project and the guide is the result of a collaboration between Community Alliance with Family Farmers, Health Care Without Harm, and San Francisco Bay Area Physicians for Social Responsibility.
To get a more complete picture of public perceptions of cattle grazing, Sheila Barry, University of California Cooperative Extension advisor in the San Francisco Bay Area, analyzed photos and comments in the photo-sharing website Flickr.
Her study, published in the February 2014 issue of Environmental Management, showed that Flickr can provide insight both through photos and comments into public perspectives on grazing in parks and open space lands.
“These are just a first step toward broadening this understanding,” Barry wrote. “Further analysis of social media may provide managers with broader insights into public opinion compared to those afforded by traditional methods on a wide range of issues important to park and open space management.” Livestock grazing reduces the volume of plants that can fuel fire and improves wildlife habitat. But some public land managers, concerned about potential conflicts with park users, limit or ban grazing. In 2009, the city of Walnut Creek decided to end grazing in two city parks. A year later, neighbors who were concerned about weeds contributing to wildfire petitioned the city to resume cattle grazing.
Assessments of public perceptions are often based on public hearings, which tend to attract special interests and favor negative input, or on surveys, which focus on a topic.
“Despite numerous studies that have shown benefits of grazing for endangered species in California, some environmental groups and park users have filed lawsuits to curtail grazing on public rangelands,” Barry said. “I think there's an opportunity to educate people that if grazing is well managed, it won't interfere with their recreational use and there are benefits to society.”
The San Francisco Bay Area has over 133,000 acres of public land that is grazed by cattle and used by people to hike, ride bikes, walk dogs, ride horses and hang glide.
Barry set out to explore how people voluntarily described their feelings about cattle grazing in the San Francisco Bay Area on social media. She examined photos and comments on Flickr. Using the search terms “cow,” “cows” and “grazing,” she found 1,087 photos of grazed regional parks in Alameda, Contra Costa or Santa Clara counties by 328 people with 956 comments.
Of the 733 photos that were accompanied by comments, 71 percent showed a cow and 71 percent of the comments were descriptive without expressing opinion about cows or grazing. Comments included “Lots of wildflowers and cows. Hello tiny cows on the hillside.” “Taken at Lake Del Valle.” “I don't know why, but I thought cows in California were kept indoors.” About 23 percent were positive toward cows and grazing, such as “Wonderful to see cows being just cows and happy ones” and “As much as I struggled over the steep hills on this hike, all the grazing cattle and howling coyotes made it worth the sweat.”
Fear of cows was expressed by 5 percent of commenters and included comments such as “I try to conquer my fear of cows by photographing them,” “The cows scared us to death. I told them that I'm a vegetarian and they let me go” and “We turned around when we were faced with the option of having to walk right through a herd of cows.”
Less than 1 percent described cows behaving aggressively, such as “At least these cows didn't chase us like last week's did.”
Although more research is needed to learn how to collect, analyze and interpret data from social media, Barry believes it could be a valuable source for informing decisions about public policy.
Insight into public perceptions of cattle grazing will enable park managers to craft more effective education and interpretation messages about park use and management.
“We are currently using insight from this project to develop education and interpretative information and panels for parks in the East Bay,” Barry said.
Barry is publishing fact sheets for park managers and interpreters to share with park visitors. The fact sheets will address concerns she saw raised in the Flickr study such as how to safely and comfortably recreate in a park near grazing cattle and the benefits of cattle grazing in parks. She will also address public interest and questions revealed in the Flickr study with facts sheets titled “A Year in the Life” and “Bovines, Ovines, Caprines and Equines: What's the difference?” The fact sheets will also be available online and similar information will be posted in parks on interpretative panels.
The article “Using Social Media to Discover Public Values, Interests, and Perceptions about Cattle Grazing on Park Lands” can be downloaded at http://link.springer.com/article/10.1007%2Fs00267-013-0216-4.