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.
Fahey, C, RA York, and TE Pawlowska. 2012. Arbuscular mycorrhizal colonization of giant sequoia (Sequoiadendron giganteum) in response to restoration practices. Mycologia 104(4):988-997.
- Author: Richard B Standiford
Volume Harvest Trends
California’s North Coast, covering the four counties of Sonoma, Mendocino, Humboldt and Del Norte, is an important forested region of the state, with redwood and Douglas-fir forests occupying a dominant place in these forests. Since 1948, harvest levels have ranged from a high of 2.8 billion board feet in 1955, to a low of 169 million board feet in 2009 (Figure 1). There have been significant fluctuations from year to year as a result of market variability, policy constraints, and changing landowner demographics.
Figure 2 compares the total state harvest in California to harvest in the North Coast from 1978 to 2011. The North Coast represents 21 to 40 percent of the total statewide harvest over this time period. The species harvested changed from an predominance of old growth timber in the early part of this period, to an exclusively young growth timber harvest today. In California, the amount of timber harvest on federal lands has declined dramatically with changing federal policies, and currently represents slightly less than 12 percent of the total volume harvested statewide, despite the fact that around 50 percent of the total commercial forest acreage is in federal ownership. On the North Coast, virtually all volume harvested takes place on private land, with no year having over 2 percent public harvest since 1998.
Stumpage Price Trends
Stumpage prices are reported annually by the State Board of Equalization as part of the basis for payment of yield taxes. Figure 3 shows the fluctuation of prices for young growth redwood and Douglas-fir, expressed in real 2011 dollars, after deflating with the Producer Price Index. These are the two major species harvested on the North Coast. The trend line is also shown for these price series.
From 1978 to 2011, there was a general upward trend for both redwood and Douglas-fir. On average, real redwood prices increased by 2.4 percent annually, and real Douglas-fir prices increased by 0.9 percent over this time period. There was a rapid increase in prices for redwood from 1984 to 2000, with real price increases over this time period of 10.2 percent. Douglas-fir also had rapid real price increases from 1984 to 1994 of 17 percent. However, prices been flat to declining since 2000 for redwood (9 percent real price decreases), and since 1994 for Douglas-fir (6 percent real price decreases).
Stumpage price trends have had a general upward trend over the past 30 plus years, although there has been tremendous price volatility over this period, amounting to year to year variability of minus 30% to positive 70 percent annually for these two species. This shows that landowners need to have flexibility in the timing of log sales from their properties in order to be responsive to market conditions.
Redwood represents the most valuable tree species in California, and has a unique niche for fencing, decking, and paneling, and is tied in with homeowner remodeling, and is less tied in with the housing market. Douglas-fir is more of a commodity species, and is closely linked with pine and Douglas-fir from other regions of North America, and is highly correlated with the strength of the housing market.
The North Coast is a major forest products region in California, but has seen a very significant downturn in the amount of timber harvest over the past decade. Harvest constraints, brought about by endangered species and watershed protection standards have been partly the cause, as well as the economic recession in the country. These trends will have a major effect on the financial returns for private forest owners in the North Coast.
- Author: Susie Kocher
In the many forested areas where wildfires are currently burning, the question will soon arise: What should be done after the fire goes out? That depends on the severity of the burn and land owner goals.
For high severity burns where very few or no live trees remain to provide seed for the next generation, forest recovery can take a very long time. Typically forest landowners want to restore their lands to a forested condition as quickly as possible. In that case, an active approach can help them reach their goal sooner.
The California Tahoe Conservancy has just released a report on the outcomes of active restoration of 40 acres of Conservancy lands where all trees were killed by the 2007 Angora fire in South Lake Tahoe. That fire burned 3,100 forested acres as well as 250 homes.
Post-fire Conservancy goals were to re-establish a native forest, reduce hazards posed by dead trees, and avoid water quality impacts. Contractors cut large dead trees, skidded them to a landing, loaded them on a log truck and sent to a nearby mill. Some large dead trees were left on site to provide wildlife habitat. Small trees were ground up (masticated) and left on site to control erosion and suppress competing vegetation. Then one- to two-year-old native conifer seedlings were planted.
The report's authors estimate this active approach has hastened the return to a forested condition in the area by about 60 years. This is because planted seedlings are growing quickly while there are few naturally sprouting tree seedlings in adjacent untreated areas and these face competition from vigorously growing native brush that was stimulated by the wildfire. Soil monitoring showed no compaction by heavy equipment during tree removal and minimal soil erosion. Woody mulch left on site was also effective at suppressing brush to give newly planted tree seedlings a competitive edge.
Landowners looking for guidance on post-fire forest management are encouraged to download the free UC Cooperative Extension publication “Recovering from Wildfire: A Guide for California Landowners” and consult the UC Center for Forest Research and Outreach website at http://ucanr.edu/forestry.
Will tanoak die out – is it worth saving? Tanoak (Lithocarpus densiflorus) is a California native hardwood tree common in the forest of Northern California and susceptible to Sudden Oak Death (SOD). Since tanoak is not a commercial tree should we just let it die? Tanoak has stumped manufacturers and researches alike trying to find a place for it in the market. It has many first-rate material properties but it has a reputation of being very difficult to dry without creating serious drying defects. The Fifth Sudden Oak Death Science Symposium was held in Petaluma, CA from June 19-22 to address the current knowledge of SOD and devoted a day to shed light on tanoak’s worth. The conference brought together scientists, researchers, and other experts to share information and solutions. More information on the conference presentations can be found at the conference website.
Friday’s session focused on tanoak’s importance and value. Its history and background were discussed first, summarizing its uses, advantages vs. disadvantages and economic viability. This was followed by a discussion of the efforts and studies being done to prevent tanoak trees from succumbing to SOD. The conference did an excellent job of connecting people, bringing people from different fields together to share knowledge and expertise on how to use and protect tanoak.
A presentation, titled “Tanoak as a Forest Product Recourse: Past, Present, and Future”, by John Shelly and Steve Quarles, two University of California forest products experts was presented by Steve, currently employed at the Insurance Institute for Business & Home. This presentation looked at tanoak as a potential lumber resource and compared it to more traditional hardwood species. Tanoak has a rich history as an acorn food source for Native Americans, a source of tannin—a natural chemical used to produce leather from animal hides, firewood, lumber, and pulp for paper. Compared to Northern red oak (a benchmark species), tanoak is stronger and harder, however it is more difficult to dry and exhibits greater tangential and radial shrinkage. More information is available at the UC Woody Biomass Hardwood Utilization webpage. An accumulation of experience from various researches and practitioners has led to core knowledge of best practices. These include avoiding the dark-colored core zone as it cannot be dried without defects, quarter-sawing lumber to improve dimensional stability, and using a drying schedule of air drying to 30% MC followed by a mild kiln-drying schedule. Additionally restraining the movement of wood as it dries by placing a uniform weight of about 150 lbs/ft2 on top of the lumber stack as it dries is known to be beneficial in reducing warp.
Some people are concerned that removing trees that are inflicted with the SOD tree disease pathogen will increase the risk of spreading the disease. Research reported by Shelly however, indicated that the very low risk of spreading the disease when fresh cut wood is transported to different locations disappears entirely once the wood is processed and dried. In fact, using diseased wood my even have some positive benefits. Further information is presented at: http://ucanr.org/sites/WoodyBiomass/HardwoodUtilization/SOD/ .
One such potential benefit is the presence of spalted wood –an early stage of decay—often found in SOD diseased trees. This, combined with the insect tunnels often associated with SOD infected trees creates an appealing aesthetic appearance, often called character wood. This character has the potential to set it apart from other woods. However, it was noted that spalted wood should not be used for flooring because the hardness of the wood with incipient decay is greatly reduced making it too soft for flooring. The interesting appearance of spalted wood can be very attractive in furniture, art, and craft uses. This could create a niche market for SOD-diseased tanoak that is unique, appealing to select buyers.
The participants in the tanoak session also had the opportunity to view an exhibit of a display of pictures, a slide show, and examples of tanoak lumber and finished products (e.g. flooring and furniture). The pictures and slide show depicted tanoak lumber being cut and quartered, then dried. Here the audience could see the preparation process—from forest to flooring—as well as examples of drying effects. Many people’s questions revolved around the option of using tanoak for flooring and its expected durability. Another common topic was the amount of unutilized tanoak in California forests. It is clear that there is continuing interest in finding uses for this tree. The UC experts concluded that with expansion of the market and improvements in the processing we could see a dramatic increase in the use of tanoak across California.
For almost 20 years now, UC Forest Advisors and Specialists, along with a dedicated group of volunteers, have been leading summer training opportunities to inspire K-12 teachers to teach about environmental issues.
Living in an urbanized state, few Californians recognize how much they depend on the forest for water, wood products and wildlife habitat, as well as their responsibility for its proper management. Through environmental learning integrated into the educational system, students can discover how to make critical choices about issues such as forest health, ecosystem management, consumerism and local economies.
The goal of the Forestry Institute for Teachers (FIT) is to provide California's K-12 teachers with knowledge, skills and tools to more effectively teach forest ecology and forest resource management practices. The program is co-sponsored by UCCE, the Northern California Society of American Foresters, US Forest Service and many other organizations. FIT brings natural resource specialists together with teachers from both rural and urban schools for one week, working side by side to explore the intricate interrelationship of forest ecosystems and human use of natural resources. The science-based curricula explore many subject areas, including environmental science, physical science, social science, biology, forestry and history. At each session, more than 40 local resource professionals representing many disciplines are invited to teach components of the course. UCCE advisors and specialists serve as co-directors and teachers. FIT offers annual institutes in three Northern California locations: Humboldt, Shasta and Plumas Counties. Back at their schools, FIT participants conduct in-service training for colleagues, and develop forestry education projects with their students.
Since 1993, over 1,300 K-12th grade teachers, evenly spread among grades, have participated in FIT. About one-third of the teachers come from Southern California, one-third from central and rural California and one-third from the Bay Area and Sacramento. Their responses to the course emphasize (1) new insight into the complexity of forest management and (2) activities and lessons that prove valuable in the classroom. Because teachers have utilized the activities and information gained from FIT in the classroom, students are improving their knowledge and decision-making skills. FIT has received a number of environmental education awards.
A graduate from the 2011 program shared, “I came up here expecting more of a science based workshop but left with so much more. Yes, science based but more of an understanding of our forest, the timber industry and ways to implement this information into the classroom- even when we don’t live near a “forest” environment. The web of involvement (people, agencies, policies, environmental groups, landowners) to most people is not known. I have gained a greater appreciation for those who are involved. Taking this back to the classroom will be much different than just teaching “the surface” (leaves, water, habitats). Now I will have the “meat” to all these lessons I have been teaching for years. Thank you for a wonderfully organized and extensive week! I will be taking what I have learned not only to my students but to the staff of my school, my friends and my family.”
While another stated; “Awesome! I really appreciate this opportunity. The FIT program is one of the BEST training courses I’ve ever participated in- great mix of perspectives & activities. It’s obvious that you’ve been offering the program for many years- it’s fine-tuned & perfect. Thank you!”
Four week-long sessions are offered in California. To learn more about FIT visit: www.forestryinstitute.org.
Learning how to read a tree core.
FIT teachers busy learning to identify amphibians.
Learning to measure the diameter of a redwood tree.
Sampling gravel to learn if conditions can support fish spawning.