Last updated on April 16, 2014 at 17:34 EDT

Survey of City of Chicago’s Ash Trees Indicates Emerald Ash Borer Infestation Has Reached A “Tipping Point”

July 31, 2012

CHICAGO, July 31, 2012 /PRNewswire/ — Dr. Fredric Miller today announced that his team’s survey of the Emerald Ash Borer (EAB) infestation in Chicago has reached a tipping point. The survey conducted in late June of this year confirmed the infestation in all 50 wards and found its progress advanced. Thousands of ash trees that are treatable today will be lost if not treated in the next ten weeks. The emerald ash borer is forcing a decline in tree health whereby the majority of the city’s ash trees will be untreatable.

“The city’s ash population is at a tipping point. There is still time to save these trees, but treatments need to be applied as soon as possible,” stated Dr. Miller, Board Certified Master Arborist and Research Associate at the Morton Arboretum. Chicago will pay a high multiple of treatment costs if it delays treating its ash trees any longer.”

Dr. Miller, who is a noted tree canopy expert, and his team of research aides and interns, conducted the two-day citywide canvass that inspected ash tree health in all areas of the city. The findings are reported in his report “The Current Status of the Emerald Ash Borer Infestation on Chicago Parkway Trees.” The City of Chicago has approximately 90,000 parkway ash trees and has a policy to treat trees every three years. Treatment began in 2009 but was severely curtailed after only 18 thousand trees were treated, due to resource constraints. The City estimates that 11,000 ash trees are “undesirable” but Dr. Miller’s survey found that number will increase significantly in 2013 if there is no action taken in 2012.

The survey found that currently 60% of the 238 blocks surveyed have some level of EAB infestation and this number will increase in the immediate future to 100% with the number of tree deaths increasing exponentially throughout the city. Today, 40% of the blocks surveyed have trees with greater than 20% canopy thinning and 11% have greater than 40% canopy thinning. Once trees reach 50% canopy thinning they are not treatable, according to scientific consensus. The City of Chicago’s criteria for treatment are far more stringent than 50%.

“The time period to aggressively treat Chicago’s ash trees has begun and to wait too long to treat ash trees for EAB will lead to their rapid and certain demise and result in the unnecessary use of millions of taxpayer dollars,” Dr. Miller added.

The report indicates that it is less costly over the long-term for the city to treat trees than to let them die. Chicago spends approximately $1,100.00 to remove and replace one tree. That same tree can be treated for approximately $60.00 or 1/20th of the cost of removal and replacement. Expressed differently, trees can be treated for more than 50 years for the same cost as removal and replacement.

The study also explains that there are additional economic losses incurred by homeowners if these trees are lost. They provide shade that keep energy costs down, improve air quality and increase property values.

“If city parkway ash trees are not preserved, many areas will have virtually no tree cover. This will have significant effects on local neighborhoods and communities.” Miller concluded, “Delaying this action, even for a year or two, is a financial, environmental and risk management mistake.”

As Miller explains, dead ash trees do not maintain their structural integrity compared to other tree species like American elms that were killed from Dutch elm disease. With thousands of trees dying all at once, the city’s resources will be overwhelmed, creating major safety and liability issues.

“Once an ash tree dies, it can drop large limbs and may fail in wind or ice storms. Property damage, human injuries and possible death and power outages may occur.”

About Dr. Fredric Miller

Dr. Fredric Miller is an ISA Board Certified Master Arborist and Professor of Horticulture at Joliet Junior College. He is also a research associate specializing in Entomology at The Morton Arboretum in Lisle, Illinois.

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SOURCE Dr. Fredric Miller

Source: PR Newswire