Beating the beetle: Giving ash trees a second life

By Jasmine Sanborn

“Treecycling” is giving a second life to tens of millions of ash trees attacked by one small but powerful beetle.

Instead of chipping fallen ash trees into mulch or chopping them into firewood, groups such as the Illinois Wood Utilization team are promoting a practical approach – “even when you can’t save your tree, you can save its wood.”

Think furniture, flooring, toys and beautiful bowls or baskets.

It’s one answer to the Emerald Ash Borer, named for its vibrant metallic green color. The killer beetle has made a home in 24 states, two Canadian providences and is continuing to spread. In just 10 years, it has become the most destructive forest pest ever seen in North America.

The wood utilization group, funded by a grant from the U.S. Forest Service, is targeting the use of wood from our urban forests. That includes all city trees, street trees, trees in parks and preserves and trees on private property.

The treecycling wood chain now engages entire communities as arborists, sawyers, woodworkers and shop owners to get involved.

Graphic by Jasmine Sanborn
(Jasmine Sanborn/Medill)

“Previously, it has been more expensive to take the wood off site and have it milled. It has been cheaper to chip the wood and have it utilized in close proximity to where it was cut,” said Lydia Scott, director of the Chicago Region Trees Initiative. “Getting the sawyer to the landowner is the key here.”

After arborists remove the tress, they are either sent to sawmills within the quarantine area or sawyers bring their portable sawmills to the site. Once cut into lumber, the trees are clear of emerald ash borer and are safe for travel.

Reclaimed wood from the dead and diseased trees could equal close to 30 percent of the country’s hardwood needs — an equivalent of 3.8 billion board feet, according to the Illinois Wood Utilization Team.

Furniture and flooring are not the only ways ash trees are finding second lives.

Urban timber has tons of possibilities for sustainable lumber projects that can be used local and private use. Emerald ash lumber can be donated to non-profit organizations, K-12 schools for use as theater sets and desks. Other uses could include woodworking programs at Department of Corrections facilities.

“We try to encourage those communities who are taking down thousands of trees instead of mulching them we’re asking them to consider these mills turn them to lumber and put your resources to work,” said Juliann Heminghous, Emerald Ash Borer coordinator for the Illinois Department of Agriculture. “Build fences around your parks, build park benches or picnic tables. Build log cabins for DNR in the state parks.”

In an effort to inspire creativity, the group partnered with the Chicago Furniture Designers Association and local sawmills in 2008 to create a temporary traveling exhibition titled: Rising from Ashes: Furniture from Lost Trees featuring works made out of reclaimed urban wood.

“I think a lot of people forgot how beautiful ash wood is because they’re so used to using oak, maple and pine and they’ve always just thought that ash wood was baseball bats and they forgot it could be used for more,” said Heminghous.

Beneath the bark

Nobody knows for sure how the beetle, native to Asia, migrated to North America, but experts assume it came from insects left in ash logs was used to stabilize shipping cargo.

The adult emerald ash borer surfaces between May and July and the female lays between 40 and 70 eggs between layers of the bark and in bark crevices. In 7 to 10 days, the eggs hatch into larvae who bore through the bark into the phloem layer of the tree, eating away at the tree’s water and nutrient tissues, but leaving the wood unaffected.

 

Emerald Ash Borers go through a complete metamorphosis during their life cycle.
Emerald Ash Borers go through a complete metamorphosis during their life cycle. Click to enlarge. (Jasmine Sanborn/Medill)

It’s similar to when you remove the peel from an orange — just because you’ve removed the skin doesn’t make the inside any less worthwhile.

As the name suggests, the beetle attacks only ash trees.

For many ash trees throughout Illinois, it is too late for them to be saved.

Ash trees are incredibly common area in landscaping as they cost less and grow faster than most trees. Some 8 percent of the tree canopy — 12.7 million trees — in the Chicago region are ash. In the next five years, only trees treated with insecticides will remain, according to the Morton Arboretum in Lisle.

The borer first arrived in Michigan in 2002, but wasn’t detected in Illinois until 2006. Despite the state’s best efforts, the beetle has continued to spread, with 61 of Illinois’ 102 counties now infested.

In residential neighborhoods hit hardest, homeowners are losing more than just sidewalk aesthetic. Residents have complained of lower property values and higher water and electric bills, according to natural resources and agriculture officials. Roots hold water on a landscape and shade from trees keeps buildings cooler.

The Illinois Department of Natural Resources and the Department of Agriculture have tried to combat the spread of the beetle by establishing quarantine zones and firewood bans.

“The problem is that once you know your tree is infested with emerald ash borer, it’s been there probably for four to seven years,” said Heminghous. “If you’re a regular traveler with firewood and you cut down your ash trees and you’re taking it to this county or the next, you don’t know that you have it.”

Detecting the beetle has proved to be a big problem. Due to the 300 to 500 day incubation period of the larvae, beetles in most trees aren’t detected until it’s too late. Ashes with a low density of beetles may show no external symptoms at all.

Another problem results from the egg laying pattern of the beetle and possibility of spread. Females often lay eggs on nearby trees, i.e. within 100 yards of the original tree they infested. Some beetles have a much wider flight pattern and can take their eggs anywhere from 0.5 to 3 miles.

“There may be only one beetle, but that’s enough for her to lay her eggs and infest another county,” said Heminghous.

In an effort to naturally combat the beetle population, local and state governments are looking at introducing one of their natural predators.

“There’s only so many years of research that have gone into this, so they don’t have a silver bullet chemical. Probably the silver bullet is the biological approach, bringing their nemesis over from Asia,” said Heminghous.

Welcoming in wasps

The USDA has approved three species of parasitic non-stinging wasps for import from China.

The wasp eggs develop inside of the ash borer larvae, killing it in about a week before they eat their way out of the corpse. After they emerge from the trees, the adult wasps continue to feed on larvae and eggs in the area. Woodpeckers are the wasps only natural competition.

According to the USDA, the wasps are not attracted to pets or people and have no stingers. What looks like a stinger is actually their egg-laying organ.

Currently, scientists are breeding and releasing them. As of fall, the wasps have been released in 19 states. But their population still has to catch up to the immense borer population and Illinois doesn’t have the wasps as yet.

“It’ll be years before that balance comes back into the ecosystem until then, there’s no silver bullet to save those ash trees,” said Heminghous.

Another method of control in urban areas or for high value trees is the use of insecticides.

Insecticides are only effective while trees are still healthy enough to carry poison through the vascular system of the tree and into the branches and canopy. Multi-year studies have shown that if more than 50 percent of the canopy appears to be thinned out, that the tree is most likely too sick to save. According to the Illinois Department of Agriculture, if treated soon enough, it is estimated that insecticides can save infested trees  20 to 40 percent of the time.

Saving trees can be an expensive process. Applying pesticides every two years costs on average of $250 per tree and rates can vary if you call in a tree specialist. But removal and replacement can average $750 – $1200 a tree.

In the end, it all comes down to the way we see trees and their contributions to society.

“I don’t think people think about trees as living,” said Scott. “People need to understand that trees are growing, living plants in need of our help so that they, in turn, can help us.”

Ten key organizations, such as Openlands, the Morton Arboretum and the USDA Forest Service, joined together in 2013 to establish the Chicago Region Trees Initiative to educate people about trees and expand tree diversity in the region. By building more robust and diverse forests, the initiative hopes to not run into a problem like the emerald ash borer again.

“The Morton Arboretum has developed a species list that enables landowners and managers to select from about 214 different species that are appropriate in northern Illinois. If we can get people to plant broadly diverse species then we are less likely to run into a problem similar to the ash problem in the future,” said Scott.

The initiative is working with more than 100 partners who have committed to “up their game” in growing healthier forests in the region.

They have also developed eight work groups to meet the goals of the initiative. Their work ranges from collecting forest data to assist in diverse tree planting, management training for those with little to no forest training and green infrastructure work groups.

Scientists have also been working to collect seeds of the fallen ash trees. Some labs are researching a hybrid that is more ash borer resilient species as they anticipate the reintroduction of ash trees into the North American landscape.

“There are a number of things that can be done with this wood and I think that’s where we want to go because it’s a very conscious effort to have a small carbon footprint. There’s only so many wood chips you can put into a playground,” said Heminghous.

Photo at top: An ash tree in Michigan that survived Emerald Ash Borer. (Wayne White/Save The Ash Trees)