Category: Eugene
Our Eugene Team Talks EAB
When it comes to Emerald Ash Borer, we’re finding hope in the gloom
The discovery of the emerald ash borer in Oregon has many people rightfully worried about the fate of ash trees in our region. The emerald ash borer, or EAB, is an invasive wood boring beetle that feeds on ash trees. There are thousands of wood boring beetles in the world, and most cause no problems at all, but EAB isn’t native to North America, where it has fewer natural predators and the ash trees have no natural defenses.
EAB was first detected in our area near Forest Grove in 2022 and has been found as far south as Silverton. The amount of time that it takes for a healthy ash tree to die from EAB is 3-5 years, which is why we are seeing some of the first trees in active decline right now.
“There’s an overwhelming sense of doom and gloom around this subject,” says Eugene Director Erik Burke. “But I believe we’ll be planting EAB-resistant Oregon ash within 20 years.”
Erik understands why people are worried that some ash species might go extinct if they are completely wiped out. In addition to the loss of mature trees in our cities, another key issue is the danger to arborists who will be doing removals, as trees become brittle after infestation. In natural areas, primary concerns are losing critical shading for streams and likely pulses of invasive species with a sudden loss of shade.
But Erik points out that EAB often doesn’t kill ash completely, it kills the tree to the ground, and then rootsprouts grow, forming a multi-stemmed shrub. In the eastern US, some stands have been killed to the ground, and begun to grow back multiple times. So while the species may not be able to grow to full size trees, there will still be existing plants, giving more opportunities for a resistant strain to be found.
Oregon Department of Forestry and U.S. Forest Service have been very proactive in collecting seeds across the genetic range to save and use to help find resistance. “In general, the response in Oregon has been really strong,” Erik says. “Proactive management decisions might mean that Oregon suffers less than other states have.”
Even with hope for the future, there are still huge consequences of EAB’s arrival. One of the biggest concerns is that many ashes grow along streams, and help keep the water cool and healthy. Planting replacement trees along streams is one of the most important steps toward maintaining water quality and wildlife habitat.
Some things concerned citizens can do is to make a plan for their site or property if it has ash.
- Report potential sightings of EAB.
- Consider getting trained to identify EAB and helping find it when it arrives so it can be addressed quickly.
- Remember, the cause of EAB and most invasive species is buying nonlocal goods, so consider buying local wherever possible. If you burn firewood, be sure not to transport it or purchase it from other areas.
- Support reintroduction and restoration of native prairies and their associated prescribed and cultural fire, which focuses on controlling ash in natural areas.
- Consider replanting trees now if you have ash, and prune or remove trees to be sure the replacement trees have enough light. Here’s a key article on what to replant with on private land.
- Support Friends of Trees and your local city urban forestry program.
- Help scout for EAB when it starts to arrive and help scout for resistance once it arrives.
The question in urban areas many homeowners will face is: to inject or not to inject? Ash trees can be injected with an insecticide, Emamectin benzoate, that will circulate throughout the tree and prevent infection for 1.5-3 years. The downside is that it doesn’t only kill EAB; It will also kill many of the other insects that live in or on the tree, like aphids, lacewings, and moth larvae. So many people will face the choice of losing an old friend tree that is providing shade and other benefits, or injecting and losing much of the life within the tree.
“The urban and rural responses will need to be different,” Erik says. “Injection makes a lot more sense in cities, protecting the most valuable trees to buy time for replacement planting, and eventually removal.” Once a tree becomes infected with EAB, it becomes very brittle and dangerous to climb, making removal extremely difficult and costly.
“There are a lot of tradeoffs with managing this crisis. And there are a lot of unknowns. But we’ve developed disease resistance for other species like sugar pine and Port Orford cedar, and we will for ash as well. Local arborists have found resistance to bronze birch borer. Oregon ash will not go extinct.”
On June 26th, Erik participated in a talk on how to be prepared for emerald ash borer hosted by the Eugene City Club, alongside Jeff Chandler, owner of Chandler’s Tree Service, and Alby Thoumsin of Sperry Tree Care. You can watch it in full here!
Friends of Trees will be hosting a series of tree walks meeting in ash groves around Eugene and Springfield. These walks will feature guest speakers from City of Eugene, ODF and others, and hopefully will generate attention and interest in positive responses to EAB. You can find information on upcoming EAB tree walks on the Eugene calendar page here.
Spring Splendor
How can you not be romantic about fresh leaves and flowers?
We’ve got a hot-button question for you: Does the spring leaf-out compete with fall color when it comes to visual splendor? Eugene Director Erik Burke thinks so.
“When trees are one-third leafed out and have that fresh yellow-green, they’re so full of life and vibrancy,” Erik says. “And trees leaf out at different times, so you have trees and all these different stages. For me, it’s equivalent to fall color.”
The days are getting longer and warmer, the trees and plants are waking up—these are the signs of spring that make it such an exciting time.
“This time of year people seem to really remember their trees and we get a lot of calls,” says Eugene-Springfield Program Manager Taylor Glass. “We get people wanting to plant trees but also worried that their tree might be dead. We tell them to wait a little bit longer because some trees are late bloomers (or late leafers!).”
Some trees like Oregon white oaks, Kentucky coffeetrees, and crepe myrtles don’t leaf out until later in the spring, which can be a bit worrying when their neighbors are fully leafed out already. Each species responds to its own set of parameters as to when to leave dormancy based on daylight, temperature and angle of the Sun.
“I really love the leaves that ginkgos put out,” Taylor says. “They’re tiny versions of the full grown leaf. They’re so cute!”
Trees take the energy that’s been stored in their trunk and roots and send it out to make leaves and grow buds. Some trees like magnolias and some maples will even put out their flowers before their leaves.
“We have a long spring ecologically,” Erik says. “It begins with the first osoberry bloom in early to mid-February.”
Just like with our own sleep cycles, there are benefits to rising early or sleeping in. Some native trees like California buckeye, Western redbud and Oregon Ash leaf out early, taking advantage of water in the soil for their growth pulse. These trees often will enter dormancy early, too, in the middle of summer drought, and will throw off their leaves as early as August.
Having trees flower in different stages is great for pollinators so that they have steady food sources throughout spring and summer. The Chinese scholar tree will be in full bloom in August or September when pollinators don’t have much else.
Friends of Trees stops planting trees during the summer months so that we can plant trees while they’re dormant, giving time for their roots to establish before they need to put their energy toward growing leaves. But spring and summer is the best time to think about what tree you want to plant, both for the conditions at the planting site and for the spring splendor you want to enjoy.
A River Runs Through Campus
Our Eugene Team partnered with University of Oregon for a natural area planting project
As University of Oregon students cross the Willamette River to get to the football stadium on game day, they’ll pass through the Willamette River Natural Area where they’ll see trees that Friends of Trees volunteers planted this year.
In 2022, the university designated 20+ acres of property as the Willamette River Natural Area which presents a great opportunity to restore and expand the riparian forest there. The planting area included a few different sections, including an oak savannah and a grove with 19 different tree species native to the Willamette Valley. Both of these areas were designed not just for restoration but with educational purposes in mind, too. The project planners wanted the event to empower students by involving them in every step from the design, event preparation and teaching tree planting skills.
“We focused our outreach on getting students to volunteer so that they could feel ownership over the positive change these trees will have on the campus where they spend their time, ” says Emily Hamblen, Campus Natural Areas Steward at UO.
“That’s the special nature of tree planting,” says Carson Houchen, the student tree steward who works with Emily. “You make such an impact. I know exactly which black hawthorne I planted and I will definitely be going back to check on it!”
Student volunteers were joined by other community members on a beautiful sunny day at the end of January. Together, the 84 volunteers planted 174 trees in a single morning, well on the way to the 455 total for this project. These trees will add to the riparian buffer along the river and shade the multi-use bike path for walkers and bikers. Funding for the project comes from an Oregon Department of Forestry Urban and Community Forestry grant and includes three years of watering and student tree stewards to help the trees establish.
“Events like this create a sense of hope for the future,” Emily says. “As the volunteers progressed through the natural area, it was completely transformed. They were planting so fast we had to get more trees!”
Emily explains that they take a three-pronged approach to projects like this: restoration, engagement, and research. While the restored natural area will engage people in recreation and education, this planting project will also allow for some experimentation. The white oak planting area had the addition of duff from an established grove to see if the mycorrhizae can help these new trees get established. Emily’s team will also be measuring the growth of each tree to determine which species are most successful.
“We’re feeling really good about the survivorship of these plantings,” Carson says. “Friends of Trees volunteers do such a great job planting, even if they show up with zero experience.”
“We couldn’t have done this without Friends of Trees, the volunteers, and the student employees,” Emily says.
Creating Long-Term Impact in Eugene
Northwest Youth Corps crews have worked to protect our natural area plantings for the future.
This fall, the Eugene Branch hosted three crews from Northwest Youth Corps, which provides hands-on education and job training in conservation fields to youth and young adults. The crews spent much of their time at our Green Space planting sites making sure the work done to enhance these natural areas continues to have an impact well into the future.
“They’ve done such great work for us and for the City of Eugene,” Eugene Director Erik Burke says. “We really want to show native plant restoration work that looks healthy and cared for so that we can inspire people to plant that way at their homes.”
The work involved weeding and mulching at the planting sites along Northwest Expressway in Eugene, Bob Straub Parkway in Springfield, and in the Bethel neighborhood near Danebo Pond in West Eugene. This work protects the trees, shrubs, and herbaceous plants from grass competition and mowers. It also protects pollinator habitat and bridges gaps for wildlife alongside major arterials.
“The members had the opportunity to work alongside great staff who took the time to educate our folks and explain the why behind the work,” says Will Wildebrandt, Urban Community Forestry Program Coordinator for Northwest Youth Corps. “They enjoyed being able to see a visible difference. It feels good to walk away from newly created tree mulch rings knowing they will be crucial in helping those trees grow and reach their full potential.”
The NYC members also had a chance to do neighborhood outreach, connecting with community members about the benefits of trees and green spaces in their neighborhoods.
“In our Urban Community Forestry program, we really care about making people feel more connected to the city they live in,” Will says, “and this project is a great way to build connections with neighbors while sharing the work we are doing with the community.”
“All the youth corps members were excited about the work,” says Taylor Glass, Eugene-Springfield Program Manager. “They were really into trees and could tell that the work was part of something bigger.”
The Eugene team has loved working with the Northwest Youth Corps crews, who have accomplished work that otherwise didn’t have funding. For everyone involved, it shows the power of partnerships to create a lasting impact.
“The work gives the city a better chance to expand its green space while giving our members the opportunity to know that the work they are doing is benefiting an entire community and truly matters,” Will says. “This can be very empowering.”
Community Pruning in Eugene
Community Pruning—An Art and a Science
The Eugene Branch just wrapped up its pruning season before kicking off the planting season. They keep these pruning events small and intimate so that each volunteer gets more hands-on experience. Pruning can feel like an art as much as a science, and it’s something that takes a lot of practice before you feel comfortable with it.
Check out our event calendar to sign up for our first planting event of the season at Northwest Expressway, or to train to be a Crew Leader!
“We started having smaller pruning events because of Covid,” says Taylor Glass, Eugene-Springfield Program Manager for Friends of Trees in Eugene. “We decided to keep them small because the pruners really appreciate it.”
Each pruning event has just up to 15 volunteers, and they split into four or five groups, with one Friends of Trees staff member on each team. They prune to provide clearance over the sidewalk and the road, and they prune for good structure. In many but not all species, this includes encouraging a strong central leader.
One reason that Eugene prunes in late summer, rather than in the dormant season, is that it slows the trees down. “Here, fast growth is a bigger issue than slow growth,” says Eugene Director Erik Burke. Fast growing trees are tougher to manage for strength and stability, and will often have weaker wood more prone to failure, particularly in snow or ice storms, which is something you don’t want in the urban environment.
“Young tree pruning is the most cost effective thing you can do for an urban forest,” Erik says. Pruning helps create a lasting form that won’t suffer as much damage from storms and trucks.
When you walk up to a tree that needs to be pruned, it can be tough to know where to start. Every tree is different. You have a number of goals you want to achieve, but you can only prune so much. Each pruner might make different little decisions toward the same overall goal of forming the tree.
“It’s so personal, the approach each person takes,” Erik says. “We all do it totally differently and no one way is right.”
The small pruning teams allow for a collaborative decision-making process, which grows a volunteer’s experience and confidence. And with experience and confidence, a small team can accomplish just as much as a big group.
“Volunteers can be anxious, because they want to do it right,” says Erik. “But the trees are resilient, and they’ll be fine in the long run.”
Ideally a tree gets pruned every three years for the first fifteen years of its life. We’re not always able to provide every tree with the ideal number of prunings, but thanks to volunteer efforts, we can often give trees pruning attention that they need.
Pruning a tree can be really satisfying, when you step back and see its form take shape. And it can be especially rewarding when you see the tree grow into that form over the years. Giving volunteers hands-on involvement in the process creates a special bond to these community trees, and volunteers always want to come back to do it again.