- Author: Jeannette E. Warnert
A tell-tale sign of spring in California is a flush of new leaf growth on citrus trees. Because the feathery light green leaves are particularly attractive to Asian citrus psyllids (ACP), the leaves' emergence marks a critical time to determine whether the pest has infested trees.
“We encourage home citrus growers and farmers to go out with a magnifying glass or hand lens and look closely at the new growth,” said Beth Grafton-Cardwell, UC Agriculture and Natural Resources (UC ANR) citrus entomologist. “Look for the various stages of the psyllid – small yellow eggs, sesame-seed sized yellow ACP young with curly white tubules, or aphid-like adults that perch with their hind quarters angled up.”
Pictures of the Asian citrus psyllids and its life stages are on the UC ANR website at http://ucanr.edu/acp. If you find signs of the insect, call the California Food and Agriculture (CDFA) Exotic Pest Hotline at (800) 491-1899.
Asian citrus psyllids are feared because they can spread huanglongbing (HLB) disease, an incurable condition that first causes yellow mottling on the leaves and later sour, misshapen fruit before killing the tree. ACP, native of Pakistan, Afghanistan and other tropical and subtropics regions of Asian, was first detected in California in 2008. Everywhere Asian citrus psyllids have appeared – including Florida and Texas – the pests have found and spread the disease. A few HLB-infected trees have been located in urban Los Angeles County. They were quickly removed by CDFA officials.
“In California, we are working hard to keep the population of ACP as low as possible until researchers can find a cure for the disease,” Grafton-Cardwell said. “We need the help of citrus farmers and home gardeners.”
Grafton-Cardwell has spearheaded the development of the UC ANR ACP website for citrus growers and citrus homeowners that provides help in finding the pest and what to do next. The site has an interactive map tool to locate residences and farms that are in areas where the psyllid has already become established, and areas where they are posing a risk to the citrus industry and must be aggressively treated by county officials.
The website outlines biological control efforts that are underway, and directions for insecticidal control, if it is needed. An online calculator on the website allows farmers and homeowners to determine their potential costs for using insecticides.
There are additional measures that can be taken to support the fight against ACP and HLB in California.
- When planting new citrus trees, only purchase the trees from reputable nurseries. Do not accept tree cuttings or budwood from friends or relatives.
- After pruning or cutting down a citrus tree, dry out the green waste or double bag it to make sure that live psyllids won't ride into another region on the foliage.
- Control ants in and near citrus trees with bait stations. Scientists have released natural enemies of ACP in Southern California to help keep the pest in check. However, ants will protect ACP from the natural enemies. Ants favor the presence of ACP because the psyllid produces honeydew, a food source for ants.
- Learn more about the Asian citrus psyllid and huanglongbing disease by reading the detailed pest note on UC ANR's Statewide Integrated Pest Management website.
- Assist in the control of ACP by supporting CDFA insecticide treatments of your citrus or treating the citrus yourself when psyllids are present.
- Support the removal of HLB-infected trees.
The loss of oak woodlands in California's North Coast is a critical conservation concern because it is associated with losses of biodiversity and wildlife habitat, range values, cultural resources, and other oak-dependent ecosystem services. In the absence of natural disturbances like fire, conifers can outcompete deciduous oaks and eventually the oaks die. In recent years, the effects of conifer encroachment on oaks have become a focal point for UC Agriculture and Natural Resources, which has conducted important research on oak woodland conservation in Humboldt and Mendocino counties.
“UC ANR research has shown that conifer encroachment is threatening oak woodlands throughout the North Coast. This project is really exciting because it will give landowners the resources they need to restore their oak stands — resources that haven't been there in the past,” said Lenya Quinn-Davidson, UC ANR Cooperative Extension staff research associate, who led development of the project proposal.
Oak woodland restoration requires removing conifers from oak stands with prescribed fire or by cutting down the conifer trees.
“The North Coast Oak Woodland Conservation Project will provide technical guidance and resources for landowners who wish to restore or conserve their oak woodlands, and foster a strong alliance of organizations and agencies who can continue oak woodland conservation efforts into the future,” said Quinn-Davidson, who is based in Eureka.
For more information about the project or funds for oak conservation activities on private lands, contact Quinn-Davidson at lquinndavidson@ucanr.edu and (707) 445-7351.
The North Coast Oak Woodland Conservation Project was one of six projects in California selected for Regional Conservation Partnership Program funding. The funded projects focus on a range of issues, including bird habitat, climate change and forest health. The program, which is funding 84 projects totaling $220 million nationwide, is highly competitive, requiring strong partnerships that address critical conservation issues.
"We are excited and energized by these new projects that bring together a diverse mix of partners to improve California's ecosystems and landscape," said Carlos Suarez, Natural Resources Conservation Service state conservationist. "It is very powerful to be able to engage in partnerships that embrace both agricultural and environmental interests and perspectives—and find collaborative ways of making progress on critical issues."
Partners in the North Coast Oak Woodland Conservation Project include University of California Cooperative Extension, CAL FIRE, the Watershed Research and Training Center, the North Coast Regional Land Trust, the U.S. Fish and Wildlife Service, the Mattole Restoration Council, Yager/Van Duzen Environmental Stewards, and the Mendocino County Resource Conservation District.
Frerichs, who has served as a Davis city councilman since 2012, started his position with UC ANR on Jan. 4. In his new position, Frerichs will work with UC ANR scientists to make research-based facts more accessible to help Californians make informed policy decisions.
“I am excited to use my experiences working in state and local government to assist UC ANR in building more effective relationships with local and state elected officials and community leaders throughout the state of California,” said Frerichs.
Frerichs brings to UC ANR a decade of experience working in the California State Assembly in Sacramento. Most recently, from 2010 to 2015, he served as legislative director for Assemblyman Rich Gordon, chairman of the Assembly Rules Committee, advising him on agriculture, housing, natural resources, energy and the budget process.
“I'm amazed by the diversity of UC Agriculture and Natural Resources,” said Frerichs. “Seeing the full scope of UC ANR's footprint throughout California — whether through Cooperative Extension working as the bridge between local issues and the power of UC research, the statewide 4-H Youth Development Program, UC Master Gardener Program, UC Master Food Preserver Program, or the Statewide UC Integrated Pest Management Program — if it has to do with agriculture in California, UC ANR is there!"
Frerichs spent his childhood in upstate New York and Alaska, but has been active in the Davis community since graduating from Davis High School. He has served on the planning commission (2008–2012), innovation park task force (2010–2012), housing element steering committee (2007–2008) and social services commission (2004–2008).
In addition to the city council, Frerichs serves as vice chair for the Capitol Corridor Joint Powers Authority (Amtrak California), and as board member for the Sacramento Area Council of Governments, Yolo County Transportation District (Yolobus) and the Yolo Habitat Conservancy. He is also an appointed member of the California Tax Credit Allocation Committee.
The Sacramento State alumnus also spent nearly a decade advocating for affordable housing throughout Davis and Yolo County as president of Yolo Mutual Housing Association. During his tenure, the nonprofit association created affordable rental housing for 450 residents.
On environmental matters, Frerichs is a board member for the Yolo Basin Foundation, which oversees the management of 16,000 acres of wetland habitat in the Yolo Bypass Wildlife Area.
Frerichs received a B.A. in government from California State University, Sacramento, and earned a certificate in land use and environmental planning from UC Davis. He and his wife Stacie live in Davis with their German shorthaired pointer, Poppy, and a flock of backyard chickens.
Sample costs to produce and harvest romaine hearts and organic spinach in the Central Coast Region – Monterey, Santa Cruz and San Benito counties – are presented in these studies.
The analysis is based upon a hypothetical farm operation of a well-managed farm, using practices common to the region. Input and reviews were provided by growers, UC ANR Cooperative Extension farm advisors and other agricultural associates. Assumptions used to identify current costs for these crops, material inputs, cash and non-cash overhead are described. A ranging analysis table shows profits over a range of prices and yields. Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment and business overhead costs.
These two studies can be downloaded for free from the UC Davis Department of Agriculture and Resource Economics website at http://coststudies.ucdavis.edu. Cost-of-production studies for many commodities are also available.
For additional information or an explanation of the calculations used in the studies, contact Don Stewart at the UC ANR Agricultural Issues Center at (530) 752-4651 or destewart@ucdavis.edu.
- Author: Jeannette E. Warnert
“There is currently a great need for forest restoration and fire hazard reduction treatments to be implemented at large spatial scales in the Sierra Nevada,” the scientists wrote. “The next one to three decades are a critical period: after this time it may be very difficult to influence the character of Sierra Nevada forests, especially old forest characteristics.”
The scientists' recommendation is in the final report of a unique, 10-year experiment in collaboration: the Sierra Nevada Adaptive Management Project (SNAMP). A 1,000-page final report on the project was submitted to the U.S. Forest Service at the end of 2015. In it, scientists reached 31 points of consensus about managing California forests to reduce wildfire hazards and protect wildlife and human communities.
“SNAMP was founded on a desire to work collaboratively to protect the forests of the Sierra Nevada,” said John Battles, professor of forest ecology in the Department of Environmental Science, Policy and Management at UC Berkeley and SNAMP principal investigator. “The challenges are multifaceted with a huge diversity of perspective among the public, among managers, and among scientists. SNAMP tried to bring all these interests and talents together to safeguard a vital resource and a natural wonder."
SNAMP was created to help develop a collaborative management and monitoring plan consistent with the Sierra Nevada Forest Plan Amendment, signed by regional forester Jack Blackwell on Jan. 21, 2004. The amendment called for the use of fuel reduction treatments – such as prescribed burning, mechanical chopping of underbrush, and harvesting certain trees – in strategically placed areas to slow down potential wildfires and improve forest health.
Because of disagreements over forest treatments in the past, which often led to lawsuits that languished in court for years, the U.S. Forest Service, U.S. Fish and Wildlife Service and the California Natural Resources Agency decided to take a new approach in 2005. They asked the University of California to provide unbiased scientific assessments of the impacts of the proposed treatments. UC was also charged with engaging the public concerned about repercussions of the forest treatments on wildlife habitat and water quality.
The scientific efforts and the forest treatments were all conducted in an open and transparent process. To ensure the greatest number of stakeholders were taking part, SNAMP included a public participation team of social scientists and UC Cooperative Extension outreach professionals to conduct and study the collaboration process.
Susan Kocher, UC Agriculture and Natural Resources Cooperative Extension forestry advisor in the Central Sierra, was a member the project since 2008 and served as the leader of the public participation team during the final two years, succeeding Kimberly Rodrigues, a UC forestry scientist who is now the director of the UC Hopland Research and Extension Center in Mendocino County. Kocher said having outreach and public participation included as a funded part of a science project is unusual.
“We were able to make great strides in getting everybody on the same page,” Kocher said. “That's what our data shows, too.”
A large volume of new scientific information was generated by the science team, and was published in 46 journal articles. The science spread fast and far, according to citation analysis conducted by the public participation team.
“We found that the average time it took for a SNAMP publication to be cited in another journal was about seven months,” Kocher said. “Citations to our articles came from all over the United States and around the globe.”
In addition, SNAMP science-based information was immediately useful to forest managers, according to a 14-page response to the SNAMP final report by the Forest Service, Fish and Wildlife and the California Natural Resources Agency. For example, an excerpt of the response submitted by California Fish and Wildlife noted that “SNAMP proved successful at modifying treatment methodology to meet the ever-changing reality of forest management.”
“The results were able to prove useful for managers past and future regarding how management can be implemented, in the face of wildfires while still retaining important owl nesting/roosting and foraging habitat features in and near owl activity features,” the document said.
SNAMP – funded with $15 million in grants mainly from the U.S. Forest Service, with support from U.S. Fish and Wildlife, California Natural Resources Agency and University of California – ran from 2007 to 2015. The project ended with the submission of the final report that contains details about the study areas, the treatment processes and reports from each of the six science teams. The science teams and their final reports are:
- Fire and forest ecosystem health
- Spatial - The study of forest canopy and understory with remote sensing technology called lidar, which uses reflected light for analysis.
- Wildlife: California spotted owl – A bird that is dependent on high-canopy forests.
- Wildlife: Pacific fisher – A weasel-like nocturnal animal that roams a wide area and nests in the hollows of old-growth trees.
- Water quality and quality
- Public participation
A key chapter in the publication is titled Integrated Management Recommendations. In it, the 31 points of consensus are outlined.
“The integration in this project is also unique,” Kocher said. “Scientists tend to work in their own focus areas, but we can learn a lot from each other's research projects.”
Working together, the scientists looked at all the research outcomes. The first 18 recommendations in the chapter are the direct result of scientific research conducted in SNAMP projects; the remainder of the recommendations are based on other scientific work and research.
Each of the recommendations is linked to a management goal. Some goals may conflict with achieving one or more of the other management goals. This approach to organizing the recommendations was taken to demonstrate that, while many of the management recommendations do not clash, a few may. For example, suggesting treatments across a landscape in a way that minimizes the negative effects on wildlife might reduce the efficiency of treatments aimed at reducing wildfire behavior and impacts.
The next steps are for the U.S. Forest Service to consider and adapt the SNAMP results and recommendations to continue to restore and protect the natural resources at risk in the Sierra.
“My hope is the SNAMP will be seen as a promising first try to apply adaptive management in the Sierra Nevada,” Battles said. “We gained important new insights about the ecology of these forests and we learned how to conduct applied research in an inclusive manner that engages not only scientists from multiple disciplines but also managers and the public."