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In the past 10 years, millions more ash trees have died, and the invasive buckthorn now makes up 36% of the Chicago region’s trees, census shows

  • A sign hangs on an ash tree near that may...

    Jose M. Osorio / Chicago Tribune

    A sign hangs on an ash tree near that may be removed soon near Winnemac Park in Chicago, April 29, 2021.

  • Shirley Davis, 72, who is a TreeKeeper in Chicago, stands...

    Jose M. Osorio / Chicago Tribune

    Shirley Davis, 72, who is a TreeKeeper in Chicago, stands with a linden tree she cares for in her neighborhood on April 30, 2021. The TreeKeeper program from the conservation group Openlands trains volunteers to care for trees.

  • Permaculture designer Annamaria Leon plants sugar tyme crabapple trees at...

    Terrence Antonio James / Chicago Tribune

    Permaculture designer Annamaria Leon plants sugar tyme crabapple trees at Douglas Boulevard and Central Park Avenue in Chicago, April 30, 2021.

  • Shirley Davis, 72, who is a TreeKeeper in Chicago, stands...

    Jose M. Osorio / Chicago Tribune

    Shirley Davis, 72, who is a TreeKeeper in Chicago, stands with a tree she cares for in her neighborhood on April 30, 2021. The TreeKeeper program from the conservation group Openlands trains volunteers to care for trees.

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When Shirley Rounds Davis moved to her home on the Far South Side decades ago, she could see a maple tree through the window. Over the years, she watched it grow.

“And the birds would come,” Davis said. “In the morning, they would wake me up, and my children too, they’d wake us up with their song in the morning.”

The tree reminded her of the mulberry tree she passed by on the way to Bible class growing up, with berries sweet enough to eat — until the day it was cut down.

“I grew up loving trees,” Davis said.

Recently, she watched the last ash tree go. Now, she’s hoping the invasive tree of heaven, which has taken hold across the street, doesn’t reach her home.

Davis is one of many Chicagoans caring for the trees that make up the regional canopy coverage, which has increased by 2% since 2010, according to a new tree census from the Morton Arboretum. But that finding comes with some caveats.

Shirley Davis, 72, who is a TreeKeeper in Chicago, stands with a tree she cares for in her neighborhood on April 30, 2021. The TreeKeeper program from the conservation group Openlands trains volunteers to care for trees.
Shirley Davis, 72, who is a TreeKeeper in Chicago, stands with a tree she cares for in her neighborhood on April 30, 2021. The TreeKeeper program from the conservation group Openlands trains volunteers to care for trees.

A jewel-toned beetle fond of ash trees is killing Chicago’s canopy. An invasive tree is eclipsing other species. Some neighborhoods continue to enjoy tree-lined sidewalks while others long for shade as temperatures climb and climate change threatens more warmth.

Like the layers of a forest, the view from the top doesn’t tell what’s happening below.

In Chicago — where the tree canopy has actually decreased 3% — people who care about trees are fighting to save them, plant them and care for them. Because, when trying to solve big problems feels impossible, one place to start is with what’s outside the window.

Rapidly spreading invasive

In 2010, the first regional tree census from the arboretum helped create a blueprint for where trees were most needed and what was happening with the forest. The new census is a marker of what’s happened since.

Lydia Scott, director of the Chicago Region Trees Initiative, a partnership of more than 200 organizations, said this census reconfirmed priorities, but the canopy increase was a welcome finding.

“We expected the canopy to have dropped a couple of percentage points because of the loss of ash trees,” Scott said. “But the ash haven’t disappeared as quickly as we thought they had.”

The canopy across Cook, DuPage, Kane, Kendall, Lake, McHenry and Will counties increased overall, from about 157 million trees and shrubs in the region in 2010 to 172 million today, a 2% increase bringing regional canopy coverage to 23%, according to findings from the census. Chicago has about 4 million of the trees, with the other 168 million in the seven-county region.

But the area is also blanketed by European buckthorn, a rapidly spreading invasive tree accounting for 36% of stems — by far the most pervasive species in the region. Coming in next is the box elder, which makes up only 4% of trees. Buckthorn made up about 28% of trees in the last count.

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Its spread is worrisome, scientists say, because the modestly sized trees often win out against native plant species and make regeneration difficult with sun-blocking thickets.

“If we don’t do anything, it will proliferate,” said Chai-Shian Kua, urban tree science leader at the Morton Arboretum. “For invasive species like buckthorn, they are very good at proliferating.”

More than 40% of the region’s tree species are invasive, according to the census. Amur honeysuckle is another common species with increasing numbers.

The Chicago Region Trees Initiative’s Healthy Hedges program aims to remove and replace buckthorn with noninvasive options.

“Most people just don’t have a clue about it,” said Scott. “They don’t know that it’s a problem. And so we need to really generate this huge public education campaign to get everybody aware that buckthorn is something we need to get a handle on.”

In addition, the region’s ash trees are down to fewer than 7 million from about 13 million a decade ago. About 4 million of the 7 million are either dead or on their way.

Unlike the overall trend, Chicago’s canopy decreased from 19% to 16% in the last decade, in part because of the loss of ash trees.

“The reason the ash was so prominently planted is because it’s such a hardy tree that can be planted and grown almost anywhere,” Scott said, looking out at the three ash trees in her backyard that have been treated and are surviving. “It does well in areas that are wet, it does well in areas that are dry, it was the perfect street tree.”

There are at least 194 different species in the region, researchers found, and 103 in Chicago alone. But the entire range is not distributed throughout the entire region. And three-quarters of the trees and shrubs are small.

“When you lose a mature tree and you replace it with another tree, it’s not quid pro quo, it’s not the same thing at all,” Scott said. “As the tree gets larger it provides more benefits across a wider range, and the little trees just don’t have that. So that’s why it’s really important to try to preserve and protect the existing trees that we have, because that’s where we’re going to get the most benefit for our canopy, but it’s also where we’re going to get the most benefit for us as humans.”

The forest provides a series of benefits: natural cooling on hot days, carbon and pollution removal, safeguards against flooding, homes for creatures of all sorts, a daily boost to our physical and mental health.

The report estimates the regional forest is worth more than $416 million. The Chicago region’s trees remove 18,600 tons of pollution a year and more than 500,000 tons of carbon. They assist in avoiding more than a billion cubic feet of runoff.

“The No. 1 goal is to inspire people to value trees,” Scott said.

Working to save the ash

The white ash tree in front of John Friedmann’s house is part of a dying class, but he will care for it as long as he can.

He wheeled it home from the local garden store and planted it after his daughter was born. Now it brings up fond memories of his kids jumping into heaps of autumn purple leaves.

“It’s very rewarding to know that you are responsible for that thing still being alive,” Friedmann said.

Most native ash trees in the Midwest are expected to fall prey to the emerald ash borer — a giant problem less than an inch long.

Discovered in 2002 in Michigan, the beetle is believed to have hitched a ride on ash wood, and today is responsible for the death of millions of trees. The beetle’s larvae maze through bark, eating their way through the tree’s survival system until it’s choked. Large trees can die within a few years, depleting the canopy and releasing stored carbon back into the atmosphere.

Ashes once made up about 17% of the city’s street trees, with about 85,000 trees, and a few hundred thousand additional trees could be found on private property.

In 2010, white ash and green ash trees were among the most common in Chicago. Today, white mulberry, white ash and the invasive European buckthorn lead the pack.

Across the region, about 5 million green ash trees are gone from the 9 million a decade ago. Another million white ash trees, now numbering about 3 million, have been lost.

But on the Northwest Side, a growing number of communities are working to save the ash. Friedmann was among the first to take up the cause, helping to spread the word years ago about the vulnerable trees. He pushed for permission from the Chicago Park District to treat the trees in Horner Park, and covered treatment with craft beer fundraisers.

“We still have all our ash trees,” Friedmann said. “Now we’ve collected seven of the eight species that are native to this area. We’re actually setting it up as a living seed bank for ash trees — an ash tree preserve, if you will.”

In 2019, the city stopped treating the trees. Some residents found the decision to be shortsighted and removal potentially more costly.

A sign hangs on an ash tree near that may be removed soon near Winnemac Park in Chicago, April 29, 2021.
A sign hangs on an ash tree near that may be removed soon near Winnemac Park in Chicago, April 29, 2021.

Friedmann, president of the North River Commission, helped fuel a series of neighborhood campaigns to “Save Your Ash,” allowing residents to donate to cover treatment costs. Hundreds of trees were treated last season, Friedmann said. The prime treatment months, May and June, are coming up.

“Saving the tree down the block isn’t very high on the list but people typically don’t notice until they’re gone, and then it’s too late,” Friedmann said. “So we’re trying to intervene when things can still be done.”

The key goal is preserving the canopy, Friedmann said, and ash trees are just one component.

“The shift now is that we’re not trying to treat the ash trees forever. We’re actually trying to do a phased replacement of ash trees, but maintaining all the healthy ones as long as we can, giving the saplings time to take hold,” he said.

Nancy Wade, a leader of the Lincoln Square effort, was inspired by Friedmann — and the ash tree outside her window that turned every color last fall.

“I think a lot of us can imagine, think, what would it be like if three to four of the largest trees on your block died and were cut down two years from now?” Wade said. “It might be a forest fire, but nobody can see that it’s happening.”

Wade connected with the Heart of Lincoln Square Neighborhood Association to organize an effort to inventory the ash trees in the neighborhood, attach signage to the trees to alert people to the problem and raise funds for insecticide treatment, which she said costs about $100 and generally lasts three or four years.

Friedmann said he’s returned to the Southwest Side neighborhood where he grew up, and the lack of trees compared with his current neighborhood is stark.

“The Northwest Side is relatively affluent compared to other areas of the city, and homeowners have the money and the wherewithal and the organizations to treat their own trees, whereas you go to the South and West sdes and there’s just blocks and blocks of treeless parkways,” Friedmann said. “Environmental injustice, I guess, if you will.”

He’s hopeful the city may change its position. Or young people could be trained to treat the trees as part of a new Civilian Conservation Corps. Or an energy company might be willing to step up and provide funding.

“The parkways belong to everyone in the city,” Friedmann said.

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Fostering an affinity for trees

Trees in the Chicago region are unevenly distributed, which means some communities may be more vulnerable to threats like warming temperatures. After the last census, an analysis showed areas of North Lawndale ranged from high to very high priority for future work.

In the neighborhood, a yearslong effort is underway to fill out the canopy and foster an affinity for trees.

The Oaks of North Lawndale kicked off in 2017 with a goal to plant 7,000 trees in the neighborhood, an effort inspired by the German artist Joseph Beuys, and led through a partnership between the School of the Art Institute and community groups and stakeholders.

About 500 trees have been planted so far.

Annamaria Leon, a North Lawndale resident and project participant, said she got to show Yo-Yo Ma how to plant a tree.

“When I go outside and it’s hot, I can go under a tree,” Leon said. “And it’s a very simple act. But that simple act of just sitting under a tree, it provides a moment of reflection and of peace in an extremely uncertain world right now, that just seems like nothing’s going well.”

Permaculture designer Annamaria Leon plants sugar tyme crabapple trees at Douglas Boulevard and Central Park Avenue in Chicago, April 30, 2021.
Permaculture designer Annamaria Leon plants sugar tyme crabapple trees at Douglas Boulevard and Central Park Avenue in Chicago, April 30, 2021.

The project has branched out and transformed in recent years, Leon said, and now there’s a focus on deepening community roots with a program called “Treemendous.” During the pandemic, webinars have covered topics on everything from the economics of trees to the climate crisis — even the anatomy of a tree. The Trust for Public Land is now lending support to the effort.

“Oaks of North Lawndale is still going, and it’s growing, and we’re expanding it through deeper community engagement,” said Leon.

Planting a tree might sound simple, Leon said, but some community members have brought up fears of gentrification. Some of the trees have also been lost to neglect.

“If we could have people really understand the value of the tree, and the value of who they are, that would be a big accomplishment,” Leon said.

Kevin Sutton, executive director of the Foundation for Homan Square, has also been an enthusiast of the project, going back to the trip to Germany. He’s looking forward to a possible peace garden installation, where people can rest, relax and reflect.

“I recognize this extreme difference that the absence of trees creates,” Sutton said. “They scrub the air, they make things cleaner and safer and healthier, in my mind.”

But, Sutton said, “Planting trees is not a cheap thing.”

He’s hoping for more funding for the project, to bring it to the pace and scale stakeholders would like to see.

“We’d love to be able to come in and do 1,000 trees on this street,” Sutton said. “This doesn’t need to be a 20- or 30-year effort. We just don’t have the time to wait that long.”

On Friday, a sunny Arbor Day, across from Stone Temple Missionary Baptist Church, you could stick your head through a hand-painted tree pop-up, pick up some seedlings and read up on local trees.

A little girl in a Minnie Mouse jacket picked out a begonia and a pot to paint. A group gathered around a mulberry tree, where a woman climbed up into the tree to scope it out, and another team filled out a card about the tree’s benefits — $38 for the year.

Across the street, three freshly planted crabapple trees with tiny white buds stood with some support. The community hopes the corner will become a plaza with plants and trees and a cafe.

Barbara Stewart came out to the event and said she wished more community members joined. Any help is good, but community support is vital, she said.

“I’m finding new ways to discover North Lawndale from when I was a kid,” Stewart said. “The place is starting to flourish and bloom again.”

A more resilient canopy

Researchers say a diverse canopy is important for forest health. The ash massacre is an example of what can happen when a city leans on one species. Silver maple and Norway maple trees are ranked as having the highest importance value in Chicago, according to the census report, but both could be decimated by pest infestations.

“We have to acknowledge that our regional forest is very important green infrastructure,” said Kua, the arboretum’s science leader. “But of course, everything has two sides. You have this important green infrastructure, but then there are some problems.”

Different kinds of trees can also help create a more resilient canopy to withstand threats — including climate change.

“Right tree, right place, with the right care,” said Kua.

Unlike some rugged invasive trees, native trees including maples, elms and oaks are more likely to be stressed by shifting weather patterns, including the wetter springs and hotter, drier summers projected for Illinois, making them more susceptible to havoc-wreaking insects and diseases, the report says.

Oak trees — which make up only 4% of trees but 13% of leaf area — alone support more than 600 animal species in the state.

Davis, the Far South Side resident who is a TreeKeeper trained as part of the program from the conservation group Openlands, has witnessed the effects firsthand.

There were about 100 trees near her home, with no one to tend to them, so she and another resident took the course and became the local groundskeepers, mulching and pruning — work that has paused throughout most of the pandemic.

Some crowns were smaller after last summer, Davis said, and budding timing has changed, along with when the trees are dropping leaves — even their fall colors seem different.

“Changes brought about by the change in climate have made their effect,” Davis said. “The trees feel them.”

mgreene@chicagotribune.com

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