ANR Green Blog
“Landscape plants and the water they use are under unrelenting attack,” says Don Hodel, UC ANR Cooperative Extension advisor in Los Angeles County. “But most of these attacks are misguided when one looks at the facts.”
Hodel and Dennis Pittenger, UC ANR Cooperative Extension area environmental horticulturist in the Department of Botany and Plant Sciences at UC Riverside, wrote a six-page commentary, 9%: The California Drought and Landscape Water Use, with facts about the relatively small amount of California's water that goes into landscapes, and the tremendous benefits to residents, communities and the environment provided by these plants. The article was published in PalmArbor, an electronic journal for the green industry.
“Landscape water use in California accounts for only 9 percent of total statewide water use,” the authors wrote. “Yes, that's right, just 9 percent. If we never watered another home or public landscape, park, sports field, or golf course in California, the state would save 9 percent of its total water consumption.”
Pittenger and Hodel named 12 ways lawns and landscape plants enhance the quality of Californians' lives and make urban areas more livable. Trees, shrubs, groundcovers, lawns and flowers provide:
- Carbon sequestration to help mitigate global warming
- Rain capture, dust and erosion control
- Shade and energy savings in heating and cooling
- Wildlife habitat
- Beauty and ornament
- Enhanced property values
- Psychological well-being
- Cultural/historic value
- Jobs and economic value
Instead of shutting off the sprinklers, the authors call for “judicious irrigation,” providing just enough water to trees, plants and lawns to keep them alive. The authors believe judicious irrigation may be sufficient by itself to meet the 25 to 35 percent water reductions required by the state without changing the landscape to so-called “low-water use” or “drought-tolerant” plants.
“Most woody plants are actually drought-tolerant and low-water use once they are established and cared for properly,” the article says. “Research over the last 30 years has shown that water-reduction goals can be met while maintaining the quality-of-life benefits that landscape plants and functional lawns provide.”
Hodel and Pittenger also identified three urban water uses that should be considered priorities for outdoor irrigation, even in times of extreme water scarcity.
- Public parks, school play grounds and sports fields. “Children need to play and exercise on grass, not asphalt or dirt,” the article says. “And we all benefit from walking and exercising in a green, pastoral setting.”
- Bona fide botanical gardens and arboreta. “These research collections of plants have immense value,” the authors wrote. “For example, the plant collections at the world-famous San Diego Zoo actually have greater value than the animals.”
- Trees. “Mature trees are among the most valuable and difficult-to-replace plants in urban areas,” the UC ANR experts said. “Their loss would be devastating.
The director of UC ANR's California Institute for Water Resources, Doug Parker, is a spokesperson for the University of California on water issues of statewide importance. He agrees that, in much of the state, urban communities benefit from natural plantings and turf should be a priority for recreation areas.
“It's true that rock gardens, artificial turf and hardscape do not provide much wildlife habitat, carbon sequestration or environmental cooling,” he said. “But in places like Palm Springs, they are appropriate.”
Having worked closely with policymakers, scientists, government organizations and consumers during the past four years of drought, Parker said he has reached the conclusion that Californians cannot build or conserve their way out of periodic droughts.
“What we really need is a change in mindset to learn to live with drought and uncertainty,” Parker said.
Following are free water-conservation publications from UC ANR:
Water conservation tips for the home lawn and garden
By Pamela Geisel, UC ANR Cooperative Extension advisor emeritus
Carolyn Unruh, staff writer
Managing turfgrasses during drought
By Ali Harvandi, UC ANR Cooperative Extension advisor emeritus
Jaimes Baird, UC ANR Cooperative Extension turfgrass specialist, UC Riverside
Janet Hartin, UC ANR Cooperative Extension environmental horticulture advisor, San Bernardino County
Author: Jeannette E. Warnert
“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.
Sustainable and Fire Safe Landscapes website, Sabrina Drill, UC ANR Cooperative Extension natural resources advisor for Los Angeles and Ventura counties, gives tips for creating defensible 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.
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.
Research by UC Davis and UC Agriculture and Natural Resources scientists found that almonds have a relatively small carbon footprint, which could be further reduced with advanced management practices.
Two related articles published in the current issue of Journal of Industrial Ecology examine the environmental impact of this agricultural industry. Co-author Alissa Kendall, an associate professor in the UC Davis Department of Civil and Environmental Engineering, and her colleagues noted that certain practices substantially reduce greenhouse gas emissions and energy use, including the strategic use of co-products, and the choice of water source and irrigation technology.
"Our research shows that 1 kilogram of California almonds typically produces less than 1 kilogram of CO2-equivalent emissions, which is a lower carbon footprint than many other nutrient- and energy-dense foods," said Kendall.
“These results include the use of almond co-products — orchard biomass, hulls and shells — for renewable power generation and dairy feed,” said Kendall. “Under ideal circumstances, which are feasible but not in place today, California almonds could become carbon-neutral or even carbon-negative, largely through the improved utilization of orchard biomass."
David Doll, UC ANR Cooperative Extension advisor in Merced County, agrees.
“As California farmers improve their nitrogen and water use efficiencies, they will reduce the carbon footprint,” Doll said. “This will happen as we continue to transition into a nitrogen budgeting system, which will reduce over-applications of nitrogen. Furthermore, on the other end, research conducted by Cooperative Extension has shown that the entire biomass of an orchard can be incorporated back into the soil, which increases the amount of total carbon sequestered.”
“Only a full life cycle-based model like the one we developed for this research will allow us to accurately assess whether incorporating the biomass into the soil or using it for power generation instead results in a lower net carbon footprint,” said Sonja Brodt, academic coordinator in the UC ANR Sustainable Agriculture Research and Education Program, noting that there will be some trade-off.
The first article, "Life Cycle-based Assessment of Energy Use and Greenhouse Gas Emissions in Almond Production, Part I: Analytical Framework and Baseline Results," is authored by Kendall, Elias Marvinney, a graduate student in the UC Davis Department of Plant Sciences; Brodt and Weiyuan Zhu, a UC Davis graduate student in horticulture and agronomy.
Marvinney is lead author of the second article, "Life Cycle-based Assessment of Energy Use and Greenhouse Gas Emissions in Almond Production, Part II: Uncertainty Analysis through Sensitivity Analysis and Scenario Testing," in collaboration with Kendall and Brodt.
This research was supported by grants from the Almond Board of California and the CDFA Specialty Crop Block Grant Program.
Brodt and Marvinney will host a webinar to discuss their life cycle assessment analyzing the environmental impacts associated with walnuts, prunes, peaches, almonds and pistachios. The researchers are quantifying energy use and greenhouse gas emissions in orchard crop production both within and beyond the farm. To join the webinar, visit https://uc-d.adobeconnect.com/orchard-lca at noon on Wednesday, July 29.
The University of California Global Food Initiative aims to put the world on a path to sustainably and nutritiously feed itself. By building on existing efforts and creating new collaborations among UC's 10 campuses, affiliated national laboratories and the Division of Agriculture and Natural Resources, the initiative will develop and export solutions for food security, health and sustainability throughout California, the United States and the world.
University of California, Davis, which provides the first direct evidence of climate change impacts in the state's grassland communities.
The study, covered in TIME, LA Times, and elsewhere, was published in the journal Proceedings of the National Academy of Sciences. It's based on 15 years of monitoring about 80 sampling plots at McLaughlin Reserve, part of UC Davis' Natural Reserve System.
"Our study shows that 15 years of warmer and drier winters are creating a direct loss of native wildflowers in some of California's grasslands,” said lead author Susan Harrison, a professor in the Department of Environmental Science and Policy and a member of UC Agriculture and Natural Resources' Conservation Biology workgroup. “Such diversity losses may foreshadow larger-scale extinctions, especially in regions that are becoming increasingly dry.”
The researchers confirmed that drought-intolerant species suffered the worst declines.
Similar trends have been found in other Mediterranean environments, such as those of southern Europe, bolstering the case for increased climate change awareness in the world's semi-arid regions.
Taken together with climate change predictions, the future grassland communities of California are expected to be less productive, provide less nutrition to herbivores, and become more vulnerable to invasion by exotic species, the study said.
The researchers expect these negative to cascade up through the food web—affecting insects, seed-eating rodents, birds, deer and domesticated species like cattle, all of which rely on grasslands for food.
Rescue effect may be too late
Grasses and wildflowers may be able to withstand the current drying period through their extensive seed banks, which can lie dormant for decades waiting for the right conditions to germinate.
However, California's drought is expected to intensify in the coming decades, so this rescue effect may end up being too late for some species.
Author: Kat Kerlin
UC Agriculture and Natural Resources turf expert Jim Baird.
“People have gone from one extreme to another,” said Baird, UC ANR Cooperative Extension turf specialist based at UC Riverside. “When we weren't in a water crisis, people were watering seven days a week, 365 days a year. Now, people feel like they're doing the right thing by putting no water on their lawn at all.”
Baird developed a keen appreciation for turf as a teenager playing golf and later working at a municipal golf course in Pueblo, Colo. “I found my passion,” he said. “The rest is history.” He earned a bachelor's degree in horticulture, a master's degree in agronomy, and a doctorate in botany, all the while focused on turf.
Baird's research and the lawn in front of his own Riverside home show that turf can be kept alive, and even attractive, with a minimal amount of water. And maintaining lawns rather than letting them die or replacing the grass with synthetic turf, concrete or so-called drought-tolerant plants offers important ecological services.
As anyone who has enjoyed a picnic in the park can attest, grass is cool. In contrast, the surface of artificial turf has been found to reach 180 degrees on a hot day. It often must be cooled with water before it can be used for sports. Bare soil, concrete and asphalt get significantly warmer and hold heat longer than a grassy lawn, which functions like a natural evaporative cooler.
“The more we let our grass lawns die or go away, the hotter it's going to get,” Baird said.
Grass, like all plants, absorbs carbon from the atmosphere and sequesters it in the soil, a vitally important quality as the country searches for ways to slow global warming. The production of plastics to make artificial turf has the opposite impact. And after a decade or so, artificial turf will wind up in the landfill, where it could take hundreds of years to decompose.
With all these benefits, Baird is dismayed to see the abundance of unnecessarily dead and dying lawns in California. The loss of green growing grass is an ecological loss in the short term, and difficult and expensive to revive once the drought ends.
“A dead lawn could come back as nothing but weeds,” Baird said.
He and his UC ANR colleagues wrote an eight-page publication on managing turfgrass under drought conditions that will help homeowners and lawn managers keep their lawns alive with minimal water.
The publication outlines the concept of deficit irrigation, a system in which the grass has just enough water to maintain an adequate appearance, but with less growth. Irrigation can be cut back to two times per week. If the blades spring back after being walked on, the lawn doesn't need more water.
“The grass may not be as lush and green as usual, but you can still have a lawn where kids and pets can play and families can enjoy outdoor barbecues,” Baird said.
Additional water savings can be achieved by carefully managing the sprinkler system. Areas shaded by trees or a house need less water than grass with day-long sun exposure. Irrigating before dawn reduces evaporation, leaving more water for the plant roots to absorb. Using sprinklers when there is less wind will help prevent overspray onto sidewalks and the street.
Mowing practices also impact the lawn's water use. The grass should be maintained at the tallest height recommended for the species being grown to encourage development of deep roots. Leaving the grass clippings on the lawn with a mulching mower will reduce evaporation from the soil surface.
If new lawns are being considered, water use can be cut by selecting a turfgrass species that uses less water. For example, Baird is studying kikuyugrass in plots at UC Riverside Turfgrass Research Facility. A native of East Africa, kikuyugrass is well adapted to warm, temperate climates in coastal areas and inland valleys of Southern and Central California. Other drought-tolerant grasses being studied at the facility are Bermudagrass and seashore paspalum.
For professional landscapers and home gardeners interested in detailed turfgrass research information, UC ANR is hosting a Turfgrass and Landscape Research Field Day Sept. 17. Registration is $90 before Aug. 28, $100 on or after Aug. 28 and $120 onsite. The complete agenda, registration form and previous research reports can be found on the field day website.
An initiative to improve California water quality, quantity and security is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.
Author: Jeannette Warnert