The first time--and place--anyone was aware that the emerald ash borer was going to be a problem for ash trees in Chicago, according to arborist Clayton Ruyle, was five years ago at the intersection of 29th and State--just two miles south of my house. Ruyle is district sales manager for The Care of Trees, a Davey Company--my own personal tree trimmers that you can read about here.
The first I heard that something was up was a few weeks ago when several trees were cut down on my block of South State Street and replaced. Then I heard the same thing was happening just east of me on Indiana Avenue where several trees were also cut down and replaced. What was going on? Just money-wasting by the city? A friend of Rahm's suddenly in the tree business? Or what?
Or what. The fighting of an infestation of emerald ash borer. Before this little Asian beetle came on the scene, Ash trees made up eight percent of the tree canopy in Chicago, according to Davey.
The little nonnative insect from Asia arrived in our area via packing material from China, Ruyle contends. It burrows under the bark of a tree and hatches its larva, which ultimately eat away and destroy the vascular system of the tree--which is the delivery system for food and water. If caught early enough, some trees can be saved with an injection of insecticide, says Ruyle. "The tree can't be damaged too much if it's going to work."
So what are the arborists in town replacing the ash trees with? Native species like the Kentucky Coffeetree. And nonnative species like Ginkgo. The latter drives my friend Charlotte Adelman nuts. And the former makes her heart sing. She is co-author of "The Midwestern Native Garden" and expert on the whys and wherefores of planting only native species in all things plantable.
She recently looked at a list of some of the tree species that are replacing the affected ash trees; and declared that only about half of them passed muster. Here's some of what she had to say:
With all the wonderful native Illinois trees to recommend, I cannot understand tree experts recommending trees from Asia, including a disgusting smelly tree like Ginkgo which reduces the quality of life of those living near it. Surely there are enough lllinois species to plant without needing to resort to Asian trees. It is time for experts to pay attention to the role that native trees play in the ecosystem. Native trees are the species that host native butterflies. And while Chinese trees host Chinese butterflies in China, they don't host them in Chicago. It's because of evolution. Chinese trees and Chinese butterflies co-evolved. North American butterflies did not co-evolve with Chinese trees or other nonnative plant species and most can only lay their eggs and reproduce on the plants with which they co-evolved.
Definitely gives us all something to think about.
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