Scientists have been studying emerald ash borers since the Chinese insects started killing ash trees near Detroit 15 years ago. They’ve been following the imported insects’ march east, then north and now west and watching the bugs kill nearly every ash tree in their path. But those were mostly green ash, with some white and blue ash, too — the kind of trees that once lined urban avenues, wooded parks and farm woodlots across much of the country.

Now, with ash borers expanding their range in Duluth, the critters are on the doorstep of nearly 1 billion black ash across northern Minnesota’s forests, and no one knows what’s going to happen. “We have some ideas, but nobody really knows. You really are going to be the laboratory for how EAB impacts black ash ecosystems,” said Dan Kashian, a scientist at Wayne State University in Michigan.

That’s why Kashian and more than 170 other scientists and forestry experts will converge on Duluth this week to share their knowledge of the emerald ash borer and the future of ash trees in North America. It’s the biggest emerald ash borer symposium ever, an effort to get as much information out as possible on what researchers know so far about the pest and what questions remain unanswered that need to be tackled.

The group is especially interested in early results from experiments in northern Minnesota and Michigan’s Upper Peninsula where scientists are replicating expected ash borer damage to black ash forests and seeing what might grow in their place.

Because black ash are such swampy ground trees, there are concerns that no other trees will be able to grow there, and vast swathes of northern forest will become scruffy, wet brushlands filled with tag alder and invasive buckthorn. If no big trees grow, scientists also are worried what will happen with the water table in those lowlands.

From The Globe: https://www.dglobe.com/news/4301798-1-billion-black-ash-trees-peril-scientists-invade-duluth-share-emerald-ash-borer