Posts Tagged: Oak
My name is Valentina Evans, and I am a new volunteer at the UC Hopland Research and Extension Center. My partners Benjamin Evans, and Zane Petersen have chosen to volunteer with me at the HREC for our senior project at Ukiah High School. A few weeks ago on the twenty-first of December we volunteered to help two researchers, Paulo who studied at UC Santa Cruz, and Wyath, who is still studying at Humboldt State University, to plant acorns from different ecosystems, and analyze how they will adapt to conditions with more water, less water, more sunlight or a lack of sunlight. This study is part of Dr. Blair McLaughin's study from the Zavaleta Lab at UC Santa Cruz.
We started off by digging holes about 1 foot deep and laying a thin square piece of chicken wire at the bottom of the holes to prevent gophers from entering and eating the acorns. We then took a circular strip of chicken wire and placed it on top of the flattened piece at the bottom. With the second strip of chicken wire standing horizontal, we continued by covering the holes with the same dirt we originally dug out. Now with the metal secured in place, Paulo came around and gently placed the acorns inside of the holes. The hands-on experience was extremely fascinating, not to mention peaceful. The view at the top of the hill was breathtaking, and the weather was just perfect. The entire process was tiring, but having had the opportunity to participate in a lab/research project made the whole experience worth it.
Although the project will not produce any data until the acorns sprout, the idea behind the project is captivating. Paulo and Wyath are studying the growth of oak trees from all sorts of climates, locations, and ecosystems. Some of the acorns are from northern California and others from way down in southern California. They will be monitoring the water levels, and amount of sunlight the oak trees will receive, all in hopes to see how the oak trees will adapt to different changes in their environments. Seeing as how I want to major in Biological Sciences in college, this experience was exceptionally informative for me and has taught me how critical patience, effort and time are in order to successfully accomplish a lab and receive the most accurate facts. I am very grateful to have been able to participate in this ongoing project and am looking forward to continuing to be a part of the younger generation who can benefit from having the Hopland Research and Extension Center available to us, to further our knowledge about the environment.
Acorns are dropping from the mighty oaks at the UC Hopland Research and Extension Center (HREC) – marking a time to celebrate the 5,358 acres of oak woodland and rangeland at the facility.
On Oct. 15 the doors to the center will open, inviting the public to join scientists and staff as they enjoy the fruits of the season with a farm-to-table luncheon, live bluegrass music and an oak-inspired silent auction. Funds from this event will support educational programming at the site.
The event offers the community the chance to learn about the research being conducted and enjoy the best in local produce.
“From 10 a.m. to 12 noon there will be optional field tours of some of our key research projects, where visitors can meet the scientists, see what tools they use and what they are learning about our environment,” said Hannah Bird, community educator at HREC.
Participants can choose from four field experiences, including large mammal wildlife research using the latest in drone technology with UC Berkeley researcher Justin Brashares to a relaxed visit in the vineyard tasting Mediterranean wine varietals with UC Cooperative Extension viticulture advisor Glenn McGourty. A stroll with the HREC director will offer a visit to the Shippey Hall, woodworking and mechanic shops, lambing barn and greenhouse to experience a slice of the diversity of research, outreach and teaching offered on the site.
A three-course luncheon runs from 12 to 3 p.m. and includes presentations from HREC director Kim Rodrigues, live bluegrass music from local band “Gibson Creek” and the silent auction.
“We've been so grateful to all those who have offered artwork, jewelry, food and oak woodland experiences for this silent auction,” Bird said. “I'm going to struggle not to bid for them all myself.”
Auction items include gorgeous oak paintings, a stunning oak table made by Ben Frey, a dinner and farm tour with Magruder Ranch and a family science adventure kit focused on our woodlands, alongside books, posters and photographs.
Funds raised at the event will support the creation of a new nature trail to Parson's Creek, which cannot currently be safely accessed during school field trips.
“We are now offering many more opportunities for the public to visit our site. More than 500 K-12 students and 2,000 community members visit annually, yet we cannot currently access the creek safely,” Rodrigues said. “This trail will open up great opportunities for riparian educational activities with our local students.”
Tickets cost $65 for adults and $15 for children.
or by calling Hannah Bird at (707) 744-1424, Ext. 105. The registration deadline is by October 11. The event will be at the Rod Shippey Hall, 4070 University Road, Hopland.
Due to the nature of the research with sheep and a commitment to using guard dogs as part of a predator control program, no dogs are allowed on UC ANR HREC for public events.
More on our speakers
Justin Brashares, Ph.D., is an associate professor at UC Berkeley in the Department of Environmental Science, Policy and Management. His focus areas include
the catastrophic global decline of biodiversity widely recognized as among the most pressing problems we face as a society. His research attempts to understand how consumption of wild animals and conversion of natural habitats affects the dynamics of animal communities and the persistence of populations. Work in his group extends beyond traditional animal conservation to consider the economic, political and cultural factors that drive and, in turn, are driven by, changes in wildlife abundance and diversity. Through these efforts, his group strives to propose empirically based, interdisciplinary strategies for biodiversity conservation.
Glenn McGourty is the UC Cooperative Extension viticulture and plant science advisor for Lake and Mendocino counties. He received a bachelor's degree in botany from Humboldt State University in 1974 and an master's degree in plant soil and water science from the University of Nevada, Reno, in 1979. McGourty joined UC Cooperative Extension in 1987, and works with winegrape growers, wineries, nurseries, landscapers and vegetable growers. Present research activities include evaluating 14 Mediterranean winegrape varieties; clonal trials of Sauvignon blanc, comparison of organic, biodynamic and conventional farming for their effects on winegrape and soil quality; and evaluation of cover crop species.
Prahlada Papper is an educator and naturalist as well as a graduate researcher at UC Berkeley in David Ackerly's ecology lab. His research at the Hopland Research and Extension Center involves the genetic and ecological diversity of California oaks. Papper doesn't really expect to find answers to the age old mysteries of oaks, but does think that by using modern tools like genome sequencing and ecological models, we can look at some of the old questions in new ways.
Kim Rodrigues, Ph.D. is the director of the Hopland Research and Extension Center. She began her UC career with Cooperative Extension in 1991 as a forestry and natural resources advisor for Humboldt and Del Norte counties. She became the county director two years later. Her research and extension activities have focused on environmental policy and engagement of the public in resolving environmental conflicts. Her experience, coupled with a great passion for HREC's 5,300 acres of oak woodland and a keen desire to reach out to the community to encourage collaboration and partnerships, offers new opportunities and exciting times at HREC./span>
“Concern has grown since severely stressed and even dead oak trees are becoming common observances,” said William Tietje, UCANR Cooperative Extension area natural resources specialist based inSan Luis Obispo County. “People are asking, ‘What can I do to help?'”
“Three options come to mind: deep water, mulch or do nothing,” said Tietje. Below, he and Steven Swain, UCANR Cooperative Extension environmental horticulture advisor for Marin and Sonoma counties, discuss the advantages and disadvantages of each option.
Q: Should oak trees be watered?
If the soil under your oak 12 to 18 inches down is dry and crumbly, the oak is out of water. A deep watering will invigorate the drought-stressed tree. Perhaps it seems ill-advised to water an oak tree during a drought. But think about it a minute. If you lose the oak, you lose substantial aesthetic and property values. Also lost are the many ecosystem services provided by this “keystone” structure, such as shade, soil nutrients, wildlife habitat and biodiversity. These take a very long time to replace.
Q: How do I deep water?
Deep watering of the drought-stressed tree is accomplished by moving a hose under the canopy of the tree during the day for one or two days at a low flow or trickle, such that the water percolates into the soil. Do this once or twice during the summer to early fall with at least a month between watering to allow the soil to dry, reducing the likelihood that fungi will attack the tree roots.
Q: Why mulch?
A prudent approach to the current drought and the maintenance of tree health is to conserve existing soil moisture as much as possible. Mulching under the tree helps to control moisture by keeping the soil cool and suppressing weed growth. Mulching also adds valuable soil microorganisms.
Q: Does mulch need to be composed exclusively of oak leaves and twigs?
A: No—Although the best mulch is the oak's natural leaf litter, other plant-based mulches can provide a similar benefit. In fact, there may be some advantages to having other plant components in the mulch.
Q: Can commercially available mulch provide the benefits of natural oak mulch?
A: Yes—Most any plant-based, commercially available mulch should be fine, especially mulches that are derived from multiple sources, such as municipal green-waste that has been composted. Composting allows some of the more reactive compounds that may be present in the mulch to be broken down by heat, chemical and biological means. There isn't necessarily a problem with using a single-source mulch (e.g., grape pressings, nitrolized sawdust [nitrolization allows nitrogen to remain available to the plant]), but because single-source mulches lack the variety of densities, chip sizes and nutrient compositions typically found in multiple-sourced mulches, there is a somewhat greater risk of problems using single-source mulches. Commercial compost may be listed as green-waste compost. The best recipe is 1 to 2 inches of compost overlain with 2 inches of coarsely chopped fir, redwood bark or wood, totaling 3 to 4 inches of mulch. Cover the area under the tree canopy at least up to the drip line. Don't mound the mulch against the tree trunk.
Q: Should mulch be mixed into the soil?
A: No—Although the oftentimes repeated advice that mixing mulch into the soil can cause a nitrogen shortage is mostly a myth, there are other reasons for not incorporating the mulch into the soil:
- The process can cause root damage to existing plants
- The process can degrade existing soil structure
- Organic matter breaks down over time, and in the process causes the soils in which it has been mixed to eventually shrink in volume. This is fine in some instances, but it can spell disaster if one has incorporated mulch into soils that were placed beneath sapling trees, for instance. In this case, the soil under the tree will shrink in volume, and the tree will sink into the soil. Water then pools around the base of the tree, and the tree eventually develops root rot.
Because mulches are incorporated naturally into soils by earthworms, springtails, and microorganisms, the benefits of digging mulches into the soil are pretty much balanced by the liabilities. In short, save yourself the work. Put the mulches on the ground and let the earthworms do the work for you.
Q: Is there any mulch that is categorically unacceptable?
A: Common sense should prevail—Coarsely chopped bark, wood and leaves is probably the best composition for a mulch, and that same material composted is about as ideal as one can get. The very best are oak leaf mulches, which exist, but are quite pricey and are typically derived by stripping wild oaks of their natural mulch base. Even less-than-ideal source material, such as eucalyptus leaves or black walnut roots, can be safely used if properly composted.
Q: If oak trimmings and dead leaf fall from native oak trees are used for mulch, is the presence of termites or the spreading of oak bark beetles a concern?
A: No—Termites do not live (for long) in wood chips. They require contiguous, solid wood to form colonies. The spread of termites in wood chips, or even in small branches, is therefore a non-issue. Every spring, summer and fall, oak bark beetles actively hunt stressed oak trees in central coast woodlands, and will find them from miles away. Worrying about spreading any of the various bark beetles that can attack oaks is a little like worrying about getting salt spray at the beach. They've been here for millions of years before us, and they'll likely be here millions of years after we're gone. That said, you may not want to encourage large colonies in your back yard by, for example, stockpiling large amounts of beetle infested firewood right beneath an oak tree.
If your tree appears healthy, with dense and green leaves over at least most of the canopy, it could be best to do nothing. In other words, “If it isn't broken, don't fix it.” Give proper considerations for the use of water during the current severe drought, and mandatory water-use restrictions, and deep water only if the tree shows symptoms of severe stress.
On the Central Coast, the predominant native oak trees are valley oak and blue oak, which drop their leaves in the winter, and the evergreen coastal live oak. Keep in mind that the two deciduous oaks, blue oak and valley oak, can respond to drought by undergoing leaf browning and leaf fall as early as July. This is a natural mechanism that the tree has evolved for water conservation. The tree is not dead and should be fine. All else considered, mulching that includes a green waste compost as described above could well be the most appropriate solution. Mulch conserves water as opposed to using water for deep watering, and mulching can improve important soil properties.
For more information, visit the UC Cooperative Extension San Luis Obispo County website http://cesanluisobispo.ucanr.edu and the UCANR oak woodland management website http://ucanr.edu/sites/oak_range.
7th California Oak Symposium Nov. 3-6. This is the symposium's first appearance in the San Joaquin Valley since its inception 35 years ago.
"The drought will be a major focus of the symposium," said Rick Standiford, UC Cooperative Extension forest management specialist based at UC Berkeley, and symposium coordinator. "We will also have cutting edge research and policy presentations on sudden oak death, gold-spotted oak borer and conifer encroachment in black and Garry oak woodlands, among much more."
California's oak woodlands cover 10 percent of the state, and oaks are a key ecological component of conifer forests. There are more than 20 species of native California oaks; several are found nowhere except within the state's borders and some others range only as far as Canada and Mexico. Oak woodlands are the most biologically diverse habitat in the state, making conservation a policy and management priority.
The symposium begins with tours of regional oaks on Nov. 3. One group will tour the Visalia urban oak forest; a second group visits the Kaweah Oaks Preserve and Dry Creek Preserve. Over three days, scientists will present 58 research papers on oak management, wildlife, ecosystem services, ranching and utilization, gold-spotted oak borer, oak restoration, and sudden oak death. Ten of the projects focus on oak conservation, touching on such topics as economic incentives for oak conservation, the oak conservation program at Tejon Ranch, and establishment of Oregon white oak and California black oak in northwestern California.
The wildlife series of presentations provides new information about native and introduced species that make their homes among the oaks, including European starlings, Pacific fishers, bats and wild pigs. Some of the ranching topics to be discussed include the public and private incomes from forests in Andalusia, Spain, economic incentives related to recreational use of private oak woodland, and acorn production and utilization in South Korea.
Since 1979, the California Oak Symposium has been held every 5 to 7 years; the last one was in Rohnert Park in 2006. Visalia was selected for the symposium because of its geographic convenience for both northern and southern California oak scientists, and the city's commitment to the preservation and protection of native oak trees.