- Author: Grace Nguyen-Sovan Dean
This spring, the Forest Stewardship and UC ANR Fire Network teams are holding the first California Tree School, where individuals attend multiple in-person classes on the forestry topics they are most curious about. “The existing online programs are very focused on forest management plans and post-fire activity, and [Tree School] lets us tackle other topics,” shared UC ANR Forest and Natural Resources Advisor Susie Kocher.
A one-stop shop for continuing forestry education
California Tree School was inspired when Forest Stewardship Academic Coordinator Kim Ingram, Post Fire Academic Coordinator Katie Reidy, and Kocher attended Oregon State University (OSU) Extension's Tree School event in Clackamas County, Oregon. OSU Tree School is a day-long experience comprised of classes that cover the different dimensions of forestry: constructing a house from your own timber, carbon cap and trade, and buying portable sawmills are just a small sampling of the options for attendees. OSU Tree School students ranged from forest landowners to community college students, contributing to a space which would facilitate community connections as well as learning.
Kocher described the experience as a “a great one day, one stop shop to keep up to date on what we [forest landowners and professionals] should know.” Excited by the breadth of opportunities offered at OSU's Tree School, Ingram, Kocher, and Reidy were inspired to bring the format to California.
“It's our time to discuss the whole ecosystem,” noted Reidy. “Tree School is bringing in the trustworthy, reliable group of experts who can provide more information on the questions pertaining to landowners' specific goals.”
California Tree School will be offered in two locations this spring, with CA Tree School- Hopland taking place on May 4, and CA Tree School- El Dorado held on June 1. Similar to OSU's Tree School, attendees are expected to be a mix of forest landowners, natural resource professionals, and interested community members.
Connecting statewide professionals; personalizing forestry education
Tree School offers attendees the opportunity to focus on subjects that pertain to their specific learning needs. This personalized approach is a new foray for the Forest Stewardship team but is something that Ingram says workshop participants have been wanting for some time.
“Our participants never think they learn enough. They are always asking for more information, and this [Tree School] gives us the chance to expand on things we might not have had a chance to go over [in the workshop series],” remarked Ingram. Additionally, Tree School instructors had creative freedom when it came to developing their classes, from the topic to the class format. This is evident when browsing through each session's class catalog. CA Tree School attendees choose four classes to attend, meaning they can build their first burn pile, understand the ins and outs of regional wildlife, paint outdoors, and learn how to aid statewide reforestation efforts all in one day.
“I felt that Tree School created a sense of trust around complex topics,” noted Reidy about her experience last year in Oregon. For CA Tree School, the Forest Stewardship team aims to do the same. This meant recruiting from throughout the UC ANR network and other organizations, including CALFIRE and CARCD, to bring trusted voices to the community. “What's exciting about Tree School is that we are bringing natural resource professionals from all around to engage everyone at the same time, and all in one place,” noted Ingram.
The team is excited to see all the connections that will be made between community members and professionals during this pilot year, and “if this is successful and we can bring it back next year,” commented Kocher, “we are definitely interested in partnering with more people and expanding our outreach.”
Making CA Tree School an in-person experience was important to the team, as much of the education is hands-on. Additionally, Kocher sees enhanced potential for building personal connections: “In person you have this opportunity for people to identify as part of a community,” noted Kocher, “So I'm excited for people to hang out with each other.”
Encouraging an informed community
“You can't separate the emotional from the physical, and there are a lot of topics in forestry like wildfire and economics that can be a bit of a downer,” said Ingram. “I'm excited to help create a positive learning environment, and one that encourages folks to turn to [UC Cooperative] Extension for these resources.”
“Our main goal here is to get science out there,” concurred Reidy. “The more exposure people have [to science], the more confident they feel in themselves and their wants and needs.”
- Author: Pamela Kan-Rice
The 8th California Oak Symposium is scheduled to be held March 22-25, 2021, at Embassy Suites, San Luis Obispo. The theme for the conference is “Sustaining Oak Woodlands Under Current and Future Conditions.”
Presented by UC Agriculture and Natural Resources, the 8th California Oak Symposium is intended for anyone involved in research, education, management and conservation of California's oak woodlands. Participants may include foresters, range managers, tribes, arborists, landowners, community groups, land trusts and policymakers.
UC ANR colleagues are invited to share their oak-related work. To propose an oral presentation or poster for consideration, please submit an abstract at http://ucanr.edu/8thoakabstracts by Aug. 10.
View the symposium agenda at http://ucanr.edu/files/331101.docx.
A Symposium Planning Committee and the UC ANR Program Support Unit are organizing the symposium and monitoring the new coronavirus (COVID-19) conditions so conference details may change.
“We will go virtual if COVID-19 regulations are still in place in March,” said Bill Tietje, UC Cooperative Extension specialist and chair of the planning committee.
Registration will open in the fall. For more information, visit https://ucanr.edu/sites/oaksymposium or contact Tietje at tietje@berkeley.edu.
- Author: Jeannette E. Warnert
California oak woodlands are highly prized ecoregions where stately trees, many of them hundreds of years old, are cornerstones of a habitat for wildlife and native plants. Sadly, some of these ecosystems are seriously threatened by exotic pests and diseases, encroachment by less desirable vegetation, and wildfire.
Each year, UC Cooperative Extension hosts workshops to share scientific developments aimed at conserving these important habitats – and the economic value of ranching – on oak woodlands, which are found on the lower elevation slopes of the Sierra Nevada, the Coast Range and other foothill areas of California.
Typically, the workshops are held in person and draw moderate-sized audiences for presentations, questions and answers, and field trips. Because of the COVID-19 pandemic, this year's workshop was offered online in April with pre-recorded presentations available for viewing at the participants' convenience and a live question-and-answer session on Zoom.
The retooled event garnered 500 registrants, over 300 views of the YouTube videos and 140 participants in the live Q&A session. The presentations and Q&A session are still available online for future viewing as well.
“People from all walks of life participated, including those with professional and personal interest in oak woodlands,” said Yana Valachovic, UCCE forest advisor in Humboldt and Del Norte counties and a conference organizer.
Presentations at the 2020 conference included the following topics:
Encroachment by Douglas-fir
In Northern California, the biodiversity of oak woodlands is being threatened by Douglas-fir encroachment. The oaks' shade helps the young conifers get established with protection from harsh sun. In time, the fast-growing Douglas-fir trees pierce the oak canopies and begin to crowd out the areas' native understories, which are important for the diversity of birds, mammals and reptiles attracted to oaks.
As the Douglas-fir continue to grow and multiply, they threaten the very lives of the oak trees and the unique ecosystem they dominate.
To better understand the Douglas-fir encroachment, Valachovic established 10 research sites in Humboldt and Mendocino counties to gather information about the fate and the age of oaks. She and her research partners determined the ages of the oaks and firs, and counted the seedlings, saplings, snags and understory vegetation.
“With this research, we were able to demonstrate that even though the oak trees can be smaller in diameter they are much older than the Douglas-fir trees,” Valachovic said. “The encroachment process is happening quickly, and the oaks are falling out of the system.”
The shift appears to have been initiated in the mid-19th and early-20th centuries, coinciding with the Gold Rush and wildfire suppression.
With the data confirming Douglas-fir encroachment, Valachovic turned her attention to oak woodland restoration. At 14 sites in Humboldt and Trinity counties, her team studied the effects of Douglas-fir removal.
“Grasses and forbs under the oaks reestablished. Diameter growth on the oaks increased,” she said.
These research findings contributed directly to changes in policy that had previously limited land owners' ability to remove and sell conifers encroaching on oak woodland. The research also helped create new funding opportunities to support oak woodland restoration and conservation in Northern California.
Case study of oak woodland wildfire recovery
In July 2018, about two-thirds of the 5,289-acre UC Hopland Research and Extension Center was burned by the River Fire.
The transformation of the land, which had likely been without a large wildland fire for at least 100 years, was intense and stressful, said UC Cooperative Extension forest advisor Michael Jones. However, it also provided a unique opportunity for researchers to compare the impact of wildfire on the resiliency of vegetation on grazed and ungrazed oak woodland.
Jones established 35 one-fifth acre research plots at the research center and collected data two months following the fire and one year later. The research will continue in the future to better understand long-term impacts, but Jones was able to share revealing early results at the workshop.
Right after the fire, in severely burned areas areas, the future of the oaks looked ominous. Jones predicted 40% tree mortality.
“The oaks were exposed to persistent, intense heat. They were cooked,” he said. “But two months after the fire, we were already seeing basal sprouts. This was an amazing response by the trees. Oaks are pretty damn tough.”
A year after the fire, surveys showed that tree mortality in the burned areas was 25%, much less than Jones' early predictions. While some management for specific situations in severely burned areas may be necessary – such as removal of hazard trees, reducing fuels in defensible spaces or removal to control invasive species – the results of this work show the trees recover naturally.
“Esthetically, I know these systems aren't as pleasing as they were before, but ecologically, they are healthy and recovering,” he said. “In 100 years, it will look just as good as before the fire.”
Fire impacts in woodland areas previously grazed and not grazed
The fire on the research station also permitted Jones to compare the fire's differing impact on non-grazed and grazed oak woodland. At first, the grazed areas looked almost unscathed with minimal flame scorching on the bark, while an area where the pasture hadn't been grazed for 25 years had evidence of much higher severity fire.
“Grazing is a phenomenal way to help manage fuels,” Jones said. However, the grazed areas displayed ecological shortcomings a year later.
“In grazed pastures, the large mature trees were still alive, but there was no oak regeneration (basal sprouting or seedlings),” Jones said. “In the ungrazed area, a lot of biomass had been killed, but there's nearly 100% resprout of oak trees and we have an impressive amount of oak seedling recruitment.”
Jones said he isn't discouraging grazing.
“But it is important to protect sites from grazing, and especially wildlife browse, when a landowner or land managers' objectives are to regenerate or conserve oak woodlands,” Jones said.
New ambrosia beetle another threat to California oaks
Akif Eskalen, UC Cooperative Extension specialist in the Department of Plant Pathology at UC Davis, has identified a new insect-fungus team that causes oak borer wilt in Northern California Valley and Blue Oaks. It is an ambrosia beetle, commonly known as Mediterranean Oak Borer, which carries several fungi in its mouth. The beetle bores into the tree and introduces fungi to grow for food. The fungi spreads and disturbs the transportation of water and nutrients, causing wilt in the tree.
The oozing and staining lesions on the bark are similar to other oak fungal diseases, such as Sudden Oak Death. The beetle – native of Mediterranean basin countries in Africa, Asia and Europe – cannot fly far, so most likely is transported for long distances on infested firewood.
During the workshop, Eskalen suggested not moving firewood, removing heavily infested trees and chipping infested wood into 1-inch particles to reduce the spread of the ambrosia beetle and its fungal partner. He asked viewers to report any suspected oak tree infestations to the local agricultural commissioner, CDFA Diagnostic Laboratories, UC Cooperative Extension advisors or CALFIRE. Chemical options for sparing oaks from the ambrosia beetles' devastation are under investigation.
Threats to oaks and other native plants from root rotting Phytophthora
Restoration plantings have inadvertently introduced plant pathogens to native oak woodland ecosystems in California, said Ted Swiecki of Phytosphere Research, an organization that provides consulting services related to natural resource management, horticulture, urban forestry, and agriculture. The group of pathogens causing the damage are largely from the Phytophthora genus, first described in the 1860s. The name translates from Greek to “plant destroyer.”
Swiecki has observed when Phytophthora infested plants and soils are introduced to native habitats, the pathogens can attack various native plants, including toyon, madrone, manzanita and full-grown oaks. Once established, the pathogen can spread along drainages, by moving soil from one area to another and by hitchhiking on equipment, tires and hiking boots.
The pathogen can easily be overlooked at nurseries, which, by their nature, have conditions that favor Phytophthora development. Plants at nurseries are well watered, have high root density and are often placed on the ground where they can pick up pathogens.
He said the best approach to tackling Phytophthora is not using nursery stock for restoration or beautification of natural oak woodland. Direct seeding, using natural regeneration, or onsite propagation are safer ways to enhance vegetation in oak woodland.
“It's easier to prevent Phytophthora from being introduced in the first place and much cheaper and more effective than trying to eradicate it later,” Siewcki said.
One of the things I love about the Napa Valley is its sense of community. For most of us, community means shared experience, common needs and values, and a sense of mutual support.
Plant communities aren't much different. Plants form a community when they are adapted to similar soils, sun exposure, drainage, slope, wind and access to water. When creating a native or mostly native garden, thinking in terms of plant communities can make planning easier and success more likely.
Because of the incredible diversity of California's terrain and its Mediterranean climate, our state has contributed more than 6,000 native cultivars to the horticultural world, more than any other state. So we have much to choose from as we plan our native or nearly native gardens, keeping in mind what thrives naturally in our area.
Imagine taking a hike in the hills on the west side of Napa Valley. Your hike would start in the deep cool of a redwood grove where you might see Western sword fern, coastal wood fern, mosses, trillium, redwood sorrel and wild ginger growing in the moist humus-rich soil among the broad roots of the giants.
Where the nearby stream passes through, the brighter green leaves of alder and red-twigged dogwood (creek dogwood), the orange of Western columbine and the bright yellow face of Seep monkey flower catch the light. You notice the scent of spicebush and California bay.
Following the trail along the stream, you begin to climb through the oak-dominated canyon. On the shadowy west side (east-facing), you may see big leaf maple, madrone, California bay, vine maple, tanbark oak, toyon, snowberry and the occasional fir mixed with ferns.
On the relatively sunnier east side, you may see coffeeberry, grasses, coyote mint, sticky monkey flower, bulbs like Mariposa lily and, yes, poison oak taking advantage of light breaks in the canopy.
As you move up the side of the canyon, you emerge onto meadow-like grassland dotted with oaks and, depending on the season, flashes of color from sun-loving shrubs and wildflowers. Looking down on the valley floor, you can still find majestic valley oaks and grapevines tapping into the rich alluvial soil and relatively high water table.
Along the river and tributary creeks are oaks, cottonwoods, alders and buckeye. In the hills on the east side of the valley where the western sun shines hot much of the day, you'll find manzanita, scrub oaks, coyote brush, ceanothus, sages, penstemon and both digger and Coulter pines reaching into the dry and gravelly or serpentine soil.
Wander your own garden. Notice the light at different times of the day and year. Where do you find near-constant shade? Where is it warm and sunny all day? Where do you find morning light and afternoon shade, or hot sun in the late afternoon? What is the soil like and how well does it drain? What is the access to water? Light, moisture, soil and temperature determine what grows well.
In areas of moist shade, the citrus-scented blossoms of Western mock orange or the deep red blooms of a spicebush would lend fragrance and color. Flowering currant, creek dogwood (red-twig dogwood), western sword fern or giant chain fern would add mid-height interest, and wild ginger or yerba buena could serve as ground cover. The wild ginger root can be used in cooking, and yerba buena makes a delicious fragrant tea.
In dry shade—under native oaks, for example--cream bush (also called ocean spray), coffeeberry, snowberry, twinberry, sticky monkey flower and hummingbird sage find enough light and are content with the dry summer soil that the oaks want. Succulents like liveforever appreciate the shelter and light at the edge of the tree canopy, as long as there is good drainage.
Where the sun is bright and the soil dry in summer, manzanita, toyon, ceanothus, mountain mahogany and sugar bush would do well if drainage is good. Borrowing from the coastal scrub zone, you might add coyote bush, sages, sagebrush, buckwheat and California fuchsia, mixing species for foliar and floral color and a longer blooming season. A garden containing coyote bush, ceanothus and buckwheat provides nectar and pollen for our native pollinators all year.
Consider a few well-placed grasses that have graceful form all year, like deer grass or the smaller muhlenbergia dubia. They are stunning when backlit by morning or late afternoon sun. Add blue-eyed grass, sedges, lupines, poppies and bulbs such as harvest brodiaea, single-leaf onion and Ithuriel's spear that prefer to be dry during summer dormancy, and you will create a meadow-like feel that will delight you in spring and carry you through the year depending on bulb and perennial choices.
Mendocino feather reed grass is charming when mixed with perennials like spring blooming Penstemon heterophyllus ‘Margarita BOP' and fall-blooming California fuchsia. Arrange them next to a boulder or cluster of good-sized rocks to suggest the rocky slopes they come from. Your garden is your home and can be as welcoming to your plants as it is to you and your guests.
Workshop: U. C. Master Gardeners of Napa County will host the workshop “Winterize Your Garden Tools” on Saturday, October 8, from 9:30 a.m. to 11:30 a.m., at University of California Cooperative Extension (address below).Properly winterizing the garden helps your plants survive the winter and produce in the spring. Learn the importance of proper garden winterization via discussion and demonstrations. Also learn the proper care and upkeep of garden tools and get some ideas for new and/or improved ones. Feel free to bring one hand tool to refurbish. On-line registration (credit card only)
Mail-in/Walk-in registration (cash or check only).
Native Plant Sale: U.C. Master Gardeners of Napa will have an information table at the California Native Plant Society Napa Chapter's plant sale on Saturday, October 15, and Sunday, October 16, from 10 a.m. to 4 p.m., at the Martha Walker Native Garden in Skyline Park in Napa. Volunteers from both organizations will help you choose the right native plants for any spot in your garden. The preview party for CNPS members and guests is Friday, October 14, from 6 p.m. to 8 p.m., at Skyline Park.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
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.
