Posts Tagged: UC Davis
Connecting wildfires to climate change and drought
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.
Uncommon conundrum: When removing invasive species threatens endangered ones
Efforts to eradicate invasive species increasingly occur side by side with programs focused on recovery of endangered ones. But what should resource managers do when the eradication of an invasive species threatens an endangered species?
In a recent study published in the journal Science, researchers at the UC Davis examine that conundrum now taking place in the San Francisco Bay. The California clapper rail — a bird found only in the bay — has come to depend on an invasive salt marsh cordgrass, hybridSpartina, for nesting habitat. Its native habitat has slowly vanished over the decades, largely due to urban development and invasion by Spartina.
Their results, picked up by TIME magazine, showed that, rather than moving as fast as possible with eradication and restoration, the best approach is to slow down the eradication of the invasive species until restoration or natural recovery of the system provides appropriate habitat for the endangered species.
“Just thinking from a single-species standpoint doesn't work,” said co-author and UC Davis environmental science and policy professor Alan Hastings. “The whole management system needs to take longer, and you need to have much more flexibility in the timing of budgetary expenditures over a longer time frame.”
The scientists combined biological and economic data for Spartina and the clapper rail to develop a modeling framework to balance conflicting management goals, including endangered species recovery and invasive species removal, given budgetary constraints.
While more threatened and endangered species are becoming dependent on invasive species for habitat and food, examples of the study's specific conflict are rare. The only other known case where the eradication of an invasive species threatened to compromise the recovery of an endangered one is in the southwestern United States, where a program to eradicate tamarisk was canceled in areas where the invasive tree provides nesting habitat for the endangered southwestern willow fly-catcher.
“As eradication programs increase in number, we expect this will be a more common conflict in the future,” said co-author and UC Davis professor Ted Grosholz.
The scientists used data from Grosholz's lab as well as from the Invasive Spartina Project of the California Coastal Conservancy in their analysis.
Spartina alterniflora was introduced to the San Francisco Bay in the mid-1970s by the Army Corps of Engineers as a method to reclaim marshland. It hybridized with native Spartina and invaded roughly 800 acres. Eradication of hybrid Spartina began in 2005, and about 92 percent of it has been removed from the bay. The cordgrass has also invaded areas of Willapa Bay in Washington state, where efforts to eradicate it are nearly complete, and invasive Spartina has been spotted and removed from Tomales Bay, Point Reyes and Bolinas Lagoon in California.
The study, led by UC Davis postdoctoral fellow Adam Lampert, was funded by the National Science Foundation Dynamics of Coupled Natural and Human Systems Program.
Co-authors include UC Davis environmental science and policy professor James Sanchirico and Sunny Jardine, a Ph.D. student at UC Davis during the study and currently assistant professor at University of Delaware.
“This work is significant in advancing a general, analytical framework for cost-effective management solutions to the common conflict between removing invasive species and conserving biodiversity,” said Alan Tessier, program director in the National Science Foundation Division of Environmental Biology.
Nothing common about these beans
As you're ladling up country-style pinto beans for your weekend barbecue or fixing a cold three-bean salad from kidney, string and navy beans for a summer picnic, pause to remember what a long and storied history these “common bean” varieties share and the new scientific advances that promise to boost their productivity worldwide.
This week, a new genome sequencing is being reported for the common bean, which ranks as the world's 10th most widely grown food crop and includes the culinary favorites above, whose varieties together comprise a $1.2 billion crop in the United States.
“The availability of this new whole-genome sequence for beans is already paying off,” said Paul Gepts, professor in the Department of Plant Sciences at UC Davis and co-author of the new sequencing study.
Gepts, who leads the bean-breeding program at UC Davis, notes that the new sequence is being used to confirm many of the findings made earlier by his UC Davis research group, including identification of the common bean's two points of origin and domestication.
Sequencing and bean ancestry
The common bean is thought to have originated in Mexico more than 100,000 years ago, but -- as the Gepts group earlier discovered – was domesticated separately at two different geographic locations in Mesoamerica and the southern Andes.
“This finding makes the common bean an unusually interesting experimental system because the domestication process has been replicated in this crop,” Gepts said.
The sequencing team compared gene sequences from pooled populations of plants representing these two regions and found that only a small fraction of the genes are shared between common bean species from the two locations. This supports the earlier finding that the common bean was domesticated in two separate events -- one at each location -- but distinct genes were involved in each event.
The new whole-genome sequencing is also helping to identify genetic “markers” that can be used to speed up breeding of new and more productive bean varieties in the United States, East Africa and elsewhere, Gepts said.
The nitrogen connection
All of bean varieties that belong to the “common bean” group share with the closely related soybean the highly valued ability to form symbiotic relationships with “nitrogen-fixing” bacteria in the soil.
The plants and the bacteria work together to convert nitrogen in the atmosphere into ammonia – which includes nitrogen in a form that enriches the soil and feeds crops. Nitrogen-fixing crop plants can actually reduce or eliminate the need for farmers to apply expensive fertilizers.
One goal of the new sequencing project was to better understand the genetic basis for how such symbiotic relationships between nitrogen-fixing plants and bacteria are formed and sustained, with an eye toward increasing fuel- and food-crop productivity.
The research team successfully identified a handful of genes involved with moving nitrogen around, which could be helpful to farmers who intercrop beans with other crops that don't fix nitrogen.
Findings from this study are reported this week online in the journal Nature Genetics. The sequencing project was led by researchers at the University of Georgia, U.S. Department of Energy Joint Genome Institute, Hudson Alpha Institute for Biotechnology and North Dakota State University.
Biodigester turns campus waste into campus energy
Last week, on Earth Day, the university and Sacramento-based technology partner CleanWorld unveiled the UC Davis Renewable Energy Anaerobic Digester (READ) at the campus' former landfill. Here, the anaerobic digestion technology Zhang invented is being used inside large, white, oxygen-deprived tanks. Bacterial microbes in the tanks feast on campus and community food and yard waste, converting it into clean energy that feeds the campus electrical grid.
“This technology can change the way we manage our solid waste,” Zhang said. “It will allow us to be more economically and environmentally sustainable."
It is the third commercial biodigester CleanWorld has opened using Zhang's technology within the past two years and is the nation's largest anaerobic biodigester on a college campus.
The system is designed to convert 50 tons of organic waste to 12,000 kWh of renewable electricity each day using state-of-the-art generators, diverting 20,000 tons of waste from local landfills each year. It is expected to reduce greenhouse gas emissions by 13,500 tons per year.
The READ BioDigester encompasses several of the university's goals: reducing campus waste in a way that makes both economic and environmental sense, generating renewable energy, and transferring technology developed at UC Davis to the commercial marketplace.
The biodigester will enable the more than 100 million tons of organic waste each year that is currently being landfilled in the U.S. to be converted to clean energy and soil products. The READ BioDigester is a closed loop system, moving from farm to fork to fuel and back to farm. Whatever is not turned into biogas to generate renewable electricity can be used as fertilizer and soil amendments — 4 million gallons of it per year, which could provide natural fertilizers for an estimated 145 acres of farmlands each day.
Nearly half of the organic waste, or feedstock, needed to operate the biodigester to full benefit will come from UC Davis dining halls, animal facilities and grounds. CleanWorld is working with area food processing and distribution centers to supply the remaining amount. Meanwhile, UC Davis will earn 100 percent of the project's green energy and carbon credits and receive all of the electricity generated.
Anaerobic digestion is an age-old process. However, Zhang's patented technology made it more efficient — capable of eating a broader variety and bigger quantity of waste, turning it into clean energy faster and more consistently than other commercial anaerobic biodigesters.
View a video about the UC David biodigester here:
(This blog post is condensed from a UC Davis news release about the biodigester.)
Additional information:
- Read the full press release
- Download biodigester photos
- Vine video: From lunch to lights
- Visit http://www.cleanworld.com/
Choosing healthy foods might be easier than you think
Doctors say we'll live longer if we exercise and eat right. Okay, but what does that mean, exactly? You hear so much about super foods and super diets that knowing how to “eat right” can be super confusing.
“This isn't about starving yourself or biting off more than you can chew at the gym,” Applegate says. “It's about making good-for-your-body decisions, rather than punishing you with cutting calories and tough-to-do workouts.”
Applegate teaches nutrition at UC Davis, including a wildly popular online and in-person nutrition course that attracts several thousand students each year. She's a triathlete, a sports nutrition columnist for Runner's World, an author of several sports nutrition books, director of sports nutrition for Intercollegiate Athletics at UC Davis, and a consultant for Olympic athletes.
In short, she knows her stuff. And when it comes to healthy eating, she says, don't over-think it.
“Eating well isn't about being perfect, but about finding out what food has to offer, and striking a balance between your needs, personal preferences, culture and family experience,” she says.
That philosophy is central to her healthy eating and exercise challenge, which you can pick up at any Nugget Market or download from its website here. Applegate's shopping list includes a wide variety of tasty foods — a bounty of fresh vegetables, various meats and poultry, fish, eggs, grains, dairy, chocolate and much more. What's not to like?
- Eat breakfast. A solid morning meal sets the stage for a good day of healthy eating.
- Eat some protein at every meal to manage weight and support your exercise.
- Whole grains like brown rice, quinoa and whole wheat are your friends (unless you cannot tolerate gluten. If so, stick with brown rice and other non-wheat products).
- Aim for at least 2½ cups of veggies and 2 to 3 pieces of fruit each day.
- Include healthy fats from fish, nuts and seeds. Use olive, canola or avocado oils.
- Aim for 2 to 3 servings of calcium-rich foods like dairy or soymilk. Each day, eat a probiotic such as yogurt or kefir for digestive and immune support.
As for fitness, the plan provides a do-at-home circuit of strength training exercises, such as planks, push-ups, squats and leg lifts. Her general rules are:
- Switch things up. You'll build stronger muscles when you try different types of exercises.
- Aim for 30 to 60 minutes of moderate to vigorous activity five to seven days a week. Anything that boosts your heart rate counts — fast walking, jogging, bike riding, swimming, dancing, basketball, you name it. If you can't find time for 30 minutes straight, 10 minutes here and there will do the trick.
- Include three to five do-at-home strength-building sessions that help shape and tone major muscle groups while building core strength.
Adjusting to healthy eating and routine exercise takes time, Applegate says, so don't be too hard on yourself.
The joy is in the journey.