Douglas DeWitt McCreary, UC Cooperative Extension natural resources specialist, died on Feb. 15 in Grass Valley. He was 72.
“Doug was the epitome of what a CE specialist should be - a world-renowned researcher, a first-rate teacher, and an attitude that could bring people from diverse backgrounds and philosophies together,” said Richard B. Standiford, UC Cooperative Extension forest management specialist emeritus and long-time colleague of McCreary.
Born in San Mateo and raised in Berkeley, McCreary earned a bachelor's degree in economics at UC Riverside. After graduating from UCR, he studied at the London School of Economics for one year, then traveled throughout Europe. He earned his master's degree and Ph.D. in forestry at Oregon State University.
In 1986, McCreary joined UC ANR as part of its statewide Integrated Hardwood Range Management Program, newly created in response to public concern that oaks, the most common tree species in California hardwood rangelands, and their habitats were declining through neglect.
McCreary's research and extension work revolutionized oak regeneration in the state.
“Prior to Doug's work, oak planting on rangelands was a costly and low-success enterprise,” Standiford said. “Natural oak regeneration of white oaks was lacking in many areas, raising concerns about the long-term sustainability of oak woodlands. Doug developed low-cost, practical techniques for planting oaks, predominantly blue and valley oaks, on rangeland sites. This work was widely adopted throughout the state.”
McCreary introduced the use of tree shelters from Europe, and found that they increased survival of oak seedlings in California's Mediterranean climate. He also developed the timing for successfully gathering acorns for regeneration. After the 49er Fire, which started near Highway 49 in Nevada County in 1988, he organized Project Acorn, a county-wide effort with dozens of volunteers who collected and planted acorns in areas devastated by the fire. In 1990, McCreary was honored for Project Acorn with the Take Pride in America Award from the U.S. Department of the Interior in Washington, D.C.
McCreary, who was based at the Sierra Foothill Research and Extension Center, worked with state, federal and private nurseries to produce high-vigor bare root and containerized seedlings. He also developed silvicultural techniques to encourage natural seedlings to recruit into larger size trees.
“Doug was not content to just produce voluminous scientific journal articles on oak regeneration, but organized countless oak regeneration field days, workshops and symposia throughout the entire state,” Standiford said. “His biannual oak regeneration field days at the Sierra Foothill Research and Extension Center were must-attend events for the restoration and conservation community.”
The ANR publication, “Regenerating Rangeland Oaks” written and updated by McCreary in 2009, Standiford said, “is the bible for oak restoration, and provides a practical guide for all parts of the regeneration cycle for landowners and professionals.”
“We will all miss Doug very much. He was a wonderful colleague and friend,” Standiford said.
“I concur with Rick,” said Mel George, UC Cooperative Extension rangeland management specialist emeritus.
McCreary is survived by his partner, Therese Hukill-DeRock, his children Tyson McCreary and Megan Cielatka, and his grandchildren Hazel, Sybil, Ian and Isaac.
A celebration of McCreary's life is planned for June 10 in Grass Valley.
Only about half of conifer trees regenerated five to seven years after wildfire in sites studied.
Study spanned 10 national forests and 4 burned areas in California.
Study presents tool to help foresters prioritize which lands to plant after a wildfire.
A study spanning 10 national forests and 14 burned areas in California found that conifer seedlings were found in less than 60 percent of the study areas five to seven years after fire. Of the nearly 1,500 plots surveyed, 43 percent showed no natural conifer regeneration at all.
The study was co-led by UC Davis and the USDA Forest Service and published December 21 in the journal Ecosphere. It presents a tool to help foresters prioritize which lands to replant immediately after a fire, and which lands they can expect to regrow naturally.
“High-severity fires are knocking out seed sources and leading to a natural regeneration bottleneck, which poses a predicament for the sustainability of our forests,” said lead author Kevin Welch, a research associate with the UC Davis Department of Plant Sciences.
For example, 10 of the 14 burned areas in the study, which include well-known wildfires like the Moonlight (2007) and Power (2009) fires, did not meet Forest Service stocking density thresholds for mixed conifer forests, making them good candidates for replanting and restoration efforts.
“Knowing that the Forest Service doesn't have the time, budget and staffing levels to restore everything, we basically want to help foresters predict what will be there five to seven years later so they can better focus restoration efforts,” Welch said.
How Does The Tool Work?
The researchers surveyed a range of elevations, forest types and fire severities –including in the Sierra Nevada, Klamath Mountains, and North Coast regions –to determine which factors promote and limit natural conifer regeneration and how different conifer species respond after a fire.
Using a simple tool developed by the research team, a manager can enter the forest the year following a fire and take a few field measurements –including distance to seed source, slope, and the cross-sectional area of living trees in the nearby forest. They can then predict whether a severely burned site is likely to meet a desired level of tree density five to seven years later.
Tested against four wildfires that were not in the study, the researchers found the tool was able to predict with more than 70 percent accuracy whether an area would likely need to be replanted or not.
The study plots were in California, but the authors suggest study results could apply to mixed conifer forests across the North American Mediterranean Climate Zone, which stretches from southwestern Oregon through California to northern Baja California and includes parts of western Nevada.
A Race For The Sun
As the research team saw while hiking through miles of dense brush, high-severity fires also stimulate shrub growth to the detriment of fire-resistant tree species that foresters try to encourage. The conifer regeneration that is occurring is heavily dominated by species that tolerate shade but not fire, such as Douglas fir, white fir and incense cedar.
Fire-resistant and drought-tolerant trees, such as ponderosa, sugar and Jeffrey pine, do not tolerate shade well. Such species are likely to better withstand the warmer, drier climates projected for California in the future.
Currently however, forest and fire conditions are not favorable for the survival of these more desirable trees. According to the study, strategies for increasing pines in California forests include reducing forest densities and fire severities while increasing overall fire occurrence (both prescribed fires and managed wildfires). They also suggest planting pines before shrubs and shade-tolerant trees crowd them out and remove their light source.
“As western forests increasingly experience warmer weather and more frequent and more severe fires, a better understanding of what conifers need to regenerate naturally after fire can help us create and manage more sustainable, resilient forests,” said co-author Hugh Safford, regional ecologist for the USDA-Forest Service's Pacific Southwest Region and a member of the adjunct faculty in the UC Davis Department of Environmental Science and Policy.
The study was funded by the USDA Forest Service and UC Davis.
The vast majority of trees have roots that interact with below-ground fungi, together forming a 2-species complex known as mycorrhizae. In our study, which was recently published in the journal, Mycologia, we looked at the way roots of giant sequoia seedlings formed mychorrhizae relationships and how that influenced the growth of giant sequoia seedlings. Learning about how giant sequoia seedlings grow is particularly important since seedling establishment in giant sequoia has been below what is needed for long-term sustainability. We found that when we planted giant sequoia seedlings, beneficial fungi would attach on to the seedling’s roots mainly when the seedlings were planted in open sunny conditions. While it was hypothesized that the fungi would not be as common on roots in areas that had been burned, there was no difference between burned and unburned locations. Also interestingly, the beneficial fungi actually seemed to outcompete harmful fungi, thus possibly helping seedlings to avoid other diseases. This mycorrizal interaction between tree and fungus is a potentially important requirement for giant sequoia to grow fast as a seedling, and may be a key ingredient in how it eventually becomes the world’s largest organism.
The triple crown of resources: Light, water, and nutrients
Nature is dominated by individualistic, chaotic, and brutal selfishness. Organisms are hard wired to have a primary goal- to reproduce. Often, plants achieve this goal at the expense of other organisms via a fierce competition for the triple-crown of resources: light, water, and nutrients (it’s a baseball theme today). But sometimes it is in an organism’s best interest to be of assistance to another. Such is the case with mycorrhizae, which is a combination of plant roots and fungi attached to each other (“myco” = fungi; “rhizae” = roots).
Giant sequoia is an interesting species because it is so different than any other in so many ways. The most obvious difference that people know about is its tremendous size- larger than any other tree on earth. But the way that it reaches this size, and in fact its entire “life history strategy” is somewhat of an outlier when you compare it to other tree species. All trees form mychorrhizae, but the way in giant sequoia forms this relationship with fungi also appears to be an outlier. It forms what are known as “arbuscular mycorrizae,” which is uncommon in conifer trees. Beyond that, not much is known about this plant-fungus interaction in giant sequoia, but this study offers some insight.
The primary relevance to landowners and stakeholders might be that this research reminds us that planting a tree and getting it to survive and grow is a complex, ecological process. It is important to understand how planted seedlings survive and grow because planting is something we might be doing a lot more of in forests, as climate change and wildfires become forces that hinder natural regeneration across larger and larger areas. Successfully planting a tree, where the measure of success is getting the tree to complete its life cycle (i.e. to reproduce), involves much more than planting a tree and walking away. It involves understanding the resource requirements for that species, and how that particular tree will be able to make its way up into the canopy to become mature. For giant sequoia, and most other trees, the mutualistic interaction that seedlings will have with root colonizing fungi is key information. This study suggests that planted giant sequoia seedlings have the best chance of success when they are placed in distinct canopy openings in sunny conditions, in part because this is where the mutualistic relationship with fungi can benefit giant sequoia most by helping it to grow quickly into the tall canopy above.
By the way, I think most green campaigns that ask you to pay a little extra so that you can sponsor the planting of tree seedings are scams. I would not advise believing or certainly not paying for such “plant-a-tree campaigns” unless you know the species that is being planted, the location, and the method to be used for tracking survival.
Imagine that giant sequoia is a base runner, where rounding third means going home, which in terms of a tree is equivalent to reaching the canopy and reproducing (and for a person on a date, this is of course equivalent to something similar).
The fungus that forms the mycorrhizae is the third-base coach, hoping to be of some assistance to the base runner but hoping to get something in return (a job).
A base runner doesn’t really need the third base coach, but the third base coach definitely needs the base runner to have a job and make a living. Often the third base coach can be helpful to the runner, but only when things are already going pretty well for the runner. When they are rounding third base, the runner is in pretty good position to score, and the third base coach can help them score. Sometimes, however, the third base can be a hindrance if they get in the way or if they give the runner some bad advice. But usually they are a help. And of course no championship team (such as the Giants) would be without a third base coach.
Get it? Giant sequoia seedlings are happy to have this relationship with fungi, but only when things are already going well. Mycorrhizae were more common on seedlings when they were planted in the open, so there was plenty of carbon for the seedling to spare. It is carbon that is the currency paid by the tree, in return for nutrients like Phosphorous from the fungus. And fungus can also keep the plant out of trouble by fighting off pathogenic fungi, kind of how a third base coach can tell the runner to get back when the pitcher tries to pick them off.
Implications? If you plant giant sequoia, do so in distinct canopy openings and pay attention to how the nursery either sterilized or inoculated the soil. In this case, the nursery had sterilized the soil so the mycorrhizae developed on roots after the seedlings were planted in the field. When you plant far away from a mature forest edge, don’t worry about it taking a long time for fungus to colonize the area- they are probably already there because of lateral roots from surrounding trees.
When: Thursday, June 30, 2011 9:00am-2:30pm. Please register by Friday, June 24th.
Where: Avenales Ranch Road, Pozo, CA 93453, San Luis Obispo County. We will meet at the American Canyon Forest Service Campground
Who: Anyone interested in research, education, management and conservation of oak woodland ecosystems. This includes landowners and managers, consulting range managers and registered professional foresters, community and conservation groups, land trusts and policy makers.
What: Agenda for the day
9:00 am - Arrive for coffee and registration
10:00 am - Brief Introduction to Avenales Ranch
10:15 am - Oak woodland management concerns
10:30 am - Oak regeneration, seeding, stump-sprouting
11:15 am - Oak thinning, measuring, management
12:00 pm - Lunch*
12:45 pm - Forest production and management
1:15 pm - Wildlife in Oak woodlands
1:45 pm -Sycamore regeneration study
2:15 pm - Alternative Review Program
2:30 pm - Adjourn
*Please remember to bring your own bag lunch. In addition, appropriate clothing and footwear are recommended. There will be some off-trail hiking.
For more detailed information, including directions, please Click Here! Please note: you do not need to be an Oak Webinar participant to attend this field trip.
Questions? Email Rick Standiford: standifo@berkeley.edu
Pictures from one of our field trips to the Sierra Foothills Research and Extension Center:
Overlook of the Yuba River from Sierra Research and Extension Center.
Greg Giusti, UCCE forester and wildlife biologist, speaking with landowners and managers on the field trip.
12 year old planted blue oak established with in a tree shelter.
Doug McCreary speaking to field trip participants on the one mile nature hike around the center about Native American uses of oak woodlands at a grinding rock location.