If you live in one of 30 states, including those in New England, as I do, you’ve probably heard about the invasive Emerald Ash Borer (Agrilus planipennis) and the destruction they inflict on ash (Fraxinus) trees.  

Ash TreeMany projects have tried to slow the spread of the insects and to prevent further tree damage.    One such project recently published some unexpected results.   The study focused on compromised Black Ash (Fraxinus nigra) found at the test site in the wetlands of Minnesota.  Black Ash trees usually dominate these ecosystems and their demise threatened their entire balance. 

Researchers implemented adaptation strategies including the planting of several different tree species.  The trees were tested under a variety of conditions.  Growth and 8-year survivability were measured.  So far, nothing seems too unexpected.  

However, when the results were calculated, one tree species showed an 81% success rate.  That species is the American Elm (Ulmus americana).  This is the same species that fell victim to Dutch Elm Disease, which was first identified in the Netherland in 1921, one hundred years ago!  By 1970, it wiped out almost all the American Elms within the United States. 

Since then, tree geneticists have succeeded in breeding disease-resistant Elm variants.  Isn’t it ironic that one species under attack could be replaced by another that may be making a comeback? 


Scientific article about the research project— https://www.sciencedirect.com/science/article/abs/pii/S0378112721000475

More about American Elms and Dutch Elm Disease — https://www.thespruce.com/dutch-elm-disease-on-american-elm-trees-2131195