The Chicago Park District is removing some 400 trees from Austin's Columbus Park this fall due to an infestation of the Emerald Ash Borer beetle.
The Ash trees to be removed are "dead" as a result of the metallic green critter responsible for tree infestations across the country.
"We have known for quite a number of years, probably seven or eight, that the Emerald Ash Borer was going to be coming," said Adam Schwerner, director of Cultural and Natural Resources for the Chicago Park District.
The Emerald Ash Borer is native to Asia, namely China, Japan, Korea and eastern Russia. Until 2002, the bug was unfound in North America, according to the website emeraldashborer.info, which monitors efforts to combat the critter in more than 20 U.S. states as well as in Canada.
Millions of trees have been destroyed since '02 when the insect first appeared in southeastern Michigan. By 2006, it had spread to the east coast and other Midwestern states, including Illinois. The first sightings in the state were in Kane County in June of that year, according to the Illinois Department of Agriculture. The bulk of infestations in the state are in the northeast, mainly around the Chicago area, according to the department.
Chicago's Columbus Park, meanwhile, covers 135 acres in the Austin community — a significant number of its trees are Ash.
Four hundred of the trees are being removed this winter. Other city parks have also had trees removed because of infestation. And although there's a significant gap in the park's landscape, new trees have already been planted and are growing, Schwerner said. More trees will go in next spring.
"We've stopped planting Ash Trees around the same time we knew they were going to be dying," Schwerner said. "We plant about 2,000 trees a year in the park district and over these last seven or eight years, we have been planting diligently to make sure that when this hit us we would be ready to have less of an impact in the parks."
Ash trees are known for their robust fall foliage, which is why so many are planted throughout Columbus Park. But hundreds have died due to infestation, with thinned out canopies, lifeless limbs and toppled tree tops.
According to agriculture experts, the beetle is believed to have been unintentionally imported to America in wooden packing materials from oversees more than 10 years ago.
The bug tunnels under the bark of Ash trees. Over the course of one to three years, it interferes with the tree's ability to transport water and nutrients to feed itself, thus the tree dies. The Emerald Ash Borer only affects Ash trees.
Some of Columbus Park's trees have stood for more than 50 years. Now, many have been reduced to leaning towers of brittle branches waiting to be ground-up and replaced. Schwerner said the beetle has no known predators here, so they've run wild, and there's no way to keep the critter from infesting Ash trees.
About 40 million Ash trees have been lost in the Midwest alone, according to Schwerner, who points out that the problem goes beyond Austin's corridors. So far, in Chicago, 550 parks have been grappling with this problem.
"Ten to 12 percent of the tree population have the Emerald Ash Borer in the tree right now, or will at some point in the future," Schwerner said.
He noted that this is not the first time Chicago has had to put up with a tree-killing pest.
According to the Forest Preserve District of Cook County, back in 1954, a mold-like fungus called Dutch Elm Disease was spread by a beetle to Chicago, wiping out the entire population of the American Elm tree. Schwerner maintains that the city has learned much from that experience.
They've learned that a mixed population of trees is healthier to have. The park district is planting different types of trees and, perhaps, will incorporate a "hybrid Ash tree," if available, in the future.
"We are very lucky, in that of our 8,300 acres we have about 180,000 trees and there's no one series of species that's hit more than 15 percent," Schwerner said. "We will not be planting one-tree-for-one-tree. We will be planting where we think it's appropriate for a tree."
The Columbus Park tree removal is expected to have little impact on the park's activities, Schwerner said.