By Michael Gill
Cleveland, OH (December 16, 2009)- Cleveland’s plan to repel the emerald ash borer invasion?… Cutting all the ash trees down. But there are other ways. When, eighteen months ago, a neighborhood wasn’t ready to accept the eventual complete removal of the trees, they began asking, ‘Why can’t we have these trees treated?” But they couldn’t get the city interested in trying a still-new chemical treatment. The urban forestry director was unwilling to risk the cost.
In Norse mythology, a great ash tree called Yggdrasil holds up the world. Inside the tree, a serpent- Nidhogg, the tearer of corpses- gnaws away at the wood and roots, weakening the tree. Living beneath the tree are giants, who guard the wells of wisdom and fate that feed its roots. At stake is the fate of the world: If the gnawing serpent weakens it enough, the great ash tree, and the whole world, will come crashing down.
All that might sound like prophecy on West 50th Street, between Bridge and Franklin, where the entire block is lined with ash trees, the only species susceptible to a particular tiny serpent- the larval form of an Asian beetle known as the emerald ash borer. As an adult, the emerald ash borer gleams like a Faberge hat pin and is as almost harmless as it is pretty. The real troublemakers are their babies. Maggot-like things, as ugly as the adults are beautiful, they attack the thin green layer beneath the ash’s bark, its vascular tissue. They’re worse than vampires- instead of drinking blood, they eat their victims’ veins. Once they strike, the tree is left brittle and dead in just two to three years.
The emerald ash borer has not yet surfaced in Cleveland. The more immediate threat to the city’s ash trees- in particular, the big old stands like those on West 50th and a few other streets- is the city’s plan to cut them down before the insect gets to them.
On the early November day when Matthew Fehrmann got a letter from the city about his ash tree, its leaves had already fallen. The letter, from Michael E. Cox, director of the city’s Department of Parks, Recreation and Properties, was to tell him his tree’s time had come: “Your tree has been selected for removal and replacement at this time under the provision of the City of Cleveland’s Emerald Ash Borer Management Plan.”
The city’s plan to cut the trees before the arrival of what’s seen as an inevitable wave of infestation is rooted in safety and legal liability. A 30-foot ash trunk can weigh 1,000 pounds. The city’s concern: A dead ash tree in the city’s care could fall on a house, car or person. Cox explains: “We’ve been, for the last three years, cutting down larger trees. It is a precautionary measure that if the tree does die, it won’t injure a resident. We have a population on every street on this city, where children are playing and cars are driving. We’re looking to make sure everyone is safe.”
To that end, his department will spend $300,000 each year for five years in an effort to remove the danger. By Parks, Recreation and Properties’ count, there were 7,134 city-owned ash trees in the city in 2007, about 6,500 of which are on tree lawns. The Van Curen Company has the contract to remove the trees, grind up the stumps, repair the tree lawns and re-plant with trees a little larger than broomsticks the following year.
Since 2007, 749 ash trees have been felled on Cleveland tree lawns. The city plans to cut another 293 this year. Even though the mature trees being cut are not infected, the wood they harvest can’t be recycled into custom cabinets for urban condos or even traditional uses for ash, like baseball bats and axe handles. Instead, it gets ground up into chips, to ensure that no ash borer larvae survive.
Pesticide treatments to protect ash trees were available when the city was planning its strategy. Councilman Matt Zone says he asked about treatment at the time, but the city was concerned about the cost and the fact that the treatments were still new and had only been tested for two seasons.
Other council members spoke up too. Collinwood councilman Michael Polensek – who says he lives in an “heavily tree-ed ward” – recalls asking when the department revealed its cutting strategy whether it wouldn’t be worth looking into treatment instead.
“I even submitted stuff on it,” he says. “They didn’t want to get into that. But a quality tree adds at least $2,000 to your property in value. If the tree is in the right spot in summer time, it cools your home and can cut your air-conditioning bill. I know it can be easy to tear it out, but sometimes you have to do things differently.”
There are people living on West 50th Street who remember when the ash trees were planted. Fehrmann figures they were planted to replace elm trees that fell victim to Dutch elm disease, which swept through Ohio in the ’50s. Towering roughly 40 feet above the pavement, the West 50th Street ashes are like public art on an architectural scale: sculpture that blooms, shades the houses and helps clean the air. If the city were to proceed with its Emerald Ash Borer Management Plan here, the block would be nearly clear-cut and completely changed. So when he got that letter from the city, the 33-year-old photographer joined an effort that had gotten under way in 2006, when the city’s plan was to simply cut the trees all at once.
Block-club leader Roger Scheve says Heather Tonsing Volosin spoke up for the trees back then. When she learned of the city’s plan to cut the trees, she contacted councilman Zone and arranged a meeting with representatives from the city and neighborhood, as well as an arborist from the Ohio State University Agriculture Extension. Eventually, by lobbying the city with concerns about what the wholesale cutting of trees would do to home values, its environmental impact and the rising energy cost that would result from the loss of shade and shelter from the wind, Volosin was able to persuade the city to cut the trees in phases, removing and re-planting just a few a year so that the change would be gradual and the new trees would have a chance to get established.
When he joined the effort to preserve the trees, Fehrmann researched online, reading reports and sending out queries. There’s no shortage of information available. Interstate and international coalitions have formed around the Great Lakes states to study and share information about the pest and strategies for fighting it. The exotic beetle was first discovered near Detroit in the summer of 2002. It came from Asia, probably in wooden packing material. Since then, entomologists at universities throughout the affected region have cooperated in a race to find what might stop the predatory bug.
Fehrmann says it was “a lucky e-mail” that opened the door that might ultimately save their trees. One of his e-mail queries was to Arborjet, a Massachusetts-based company that treats trees with emamectin benzoate, a chemical that is injected under pressure into the trunk of the tree with a compressor attached to a fat syringe. Fehrmann sent a photo of the ash trees on his street to the company’s general-contact address.
A salesman from Arborjet called him that night. The salesman, Rob Gorden, would eventually make an offer that Fehrmann, his councilman and his neighbors hope the city can’t refuse: to treat the ash trees on West 50th free of charge for 10 years. It’s the classic promotional move: try it for free. But it’s worth noting that, while Cleveland cuts down its trees, some cities are opting for treatment, rather than face the loss and the huge upfront cost of cutting. Chicago began treating its 81,000 ash trees last spring. Milwaukee recently began treating its 36,000.
Scheve credits Fehrmann for resurrecting the neighborhood’s conversation with the city about treating the trees. Zone hopes West 50th Street can serve as a test case and example for other blocks interested in keeping rather than cutting their ash trees.
Scheve says that if the treatment works, the block club is willing to raise money, either through grants or by donations from neighbors who want to see the trees live. “We aren’t asking the city to pay for anything,” he says. “We’re just trying to keep these trees from getting cut down.”
Cox says the city has agreed at least to stay the execution of the trees while his department learns more about the product. If the city allows the free trial to proceed, a contractor would apply the chemical to the trees starting in May or June, when leaves are open and the vascular system is active and will carry it throughout tree.
The record of success for emamectin benzoate in the two years since Cleveland settled on its removal and replacement strategy has been promising. A study by researchers at the Ohio State University Extension, Michigan State University, Purdue University, the University of Wisconsin-Madison, and the University of Illinois at Urbana- Champaign, evaluated emamectin benzoate and other trunk-injected pesticides, as well as pesticides applied by drenching the soil around the roots or spraying bark and foliage. They found that injecting emamectin benzoate into trunks was nearly 100 percent effective at keeping emerald ash borer larvae out of the trees for at least two years, even as adjacent untreated trees were infested with hundreds of larvae. It can be reapplied every two to three years indefinitely to keep the tree immune. That’s startlingly good news when just a couple of years ago the near extinction of the species was assumed to be the emerald ash endgame.
Rick Tyler, senior natural resource manager for the Cleveland Metroparks, is familiar with the research. The Metroparks system isn’t cutting trees until they are found to be infested, and then only when they are close to a road or parking lot. Those trees don’t inspire defenders like urban ash trees, which residents see every day and associate with their homes and neighborhoods.
But the Metroparks’ mission of conservation has Tyler and his colleagues hoping researchers will eventually win the battle against the bug. As the emerald ash borer makes its way into the park, there may be a time when the Metroparks might treat especially large or noteworthy ashes.
“There’s a silent prayer going on that research will find the silver bullet, whether it be a pheromone or an insecticide,” says Tyler. “We’re doing anything we can to buy some time. The trick is, how long does [the treatment] last, and how many times do you have to do it? Once you commit to injecting the stuff, you are basically committed to life-long treatment.”
That would cost $75 to $120 for large trees, every two to three years.
Gorden weighs the cost of that commitment against the cost of cutting down the trees. The city will spend an average of nearly $1,000 for the removal of each tree. He says for that money, a contractor could treat the West 50th ashes – which are on the unusually large side and therefore more expensive to treat – for 20 to 30 years.
That sounds like a no-brainer to Fehrmann and his neighbors, several of whom said the trees were among the reasons they chose to live where they do. As they await official word on whether the city will allow the pro bono treatment of their ash trees, they’re keenly aware that once they get cut, they are gone forever.
Cleveland Scene- The Emerald Dilemma