The emerald ash borer are destroying ash trees all over North America. In order to save as much as possible and preserve the species, in Ohio, researchers have created a real Noah’s Ark of the ash tree.
There are a total of 16 species of ash trees growing in North America, all threatened by the borer beetles. For the American biologist Jennifer Koch, it is midnight minus one. If nothing is done, many of these native species could completely disappear from the surface of the Earth.
In collaboration with other American researchers, Koch has created a real nursery of ash trees.
The loss of ash trees has a direct impact on ecosystems and, consequently, on the services they render us. When we lose an ash, we do not lose a tree, we also lose all the fauna and flora that are attached to it.
Jennifer Koch, Researcher Biologist, Department of Agriculture, United States
In 2008, researchers discovered here and there some ash trees still standing in the middle of forests devastated by the borer. Ash trees that resist the invader longer. The genetic makeup of trees in the forest is much more diverse than that of trees planted in the city.
Thanks to these survivors, the strongest trees and best equipped to fight the borer, Jennifer Koch believes to be able to save the ash trees.
[Here we give] a helping hand to Mother Nature. We accelerate the natural selection process by taking the most resistant trees for breeding.
Jennifer Koch, Researcher Biologist, Department of Agriculture, United States
To test the level of resistance of her young shoots, Jennifer Koch and her team plant eggs of borer on the trunk and let the larvae develop there. The trees are peeled eight weeks later and that’s when researchers find out how many new generation larvae succeed in killing.
The latest test of trees obtained by crossing two surviving ash trees shows encouraging signs, according to the researcher.
Some of the trees were able to kill more larvae than the previous generation. The results are promising. We believe that in 5 to 10 years we will be able to produce seedlings of good quality to begin replanting ash trees.
Jennifer Koch, Researcher Biologist
The ash trees saved by Asia
In case of failure, Jennifer Koch has another card in her sleeve to save at least one American ash tree. The salvation of black ash could go through Asia. There, different species of Asian ash trees have evolved with the borer and have developed over time a defense mechanism against this insect.
Few ash trees succumb. It is precisely this defense weapon that the biologist hopes to develop by creating a hybrid ash, crossing the black ash - the only native species that genetically resembles a species of Asian ash that is resistant to the borer - and the Manchurian ash .
Our bioassays show that the first generation of hybrid ash resists as well as Manchurian ash when the level of borer infestation is moderate. But she falters in front of a stronger infestation.
Jennifer Koch, Researcher Biologist, Department of Agriculture, United States
Jennifer Koch’s team plans to continue testing with second-generation hybrids.
Whether by hybridization or by crossing the most resistant ash trees, the goal of Jennifer Koch and her collaborators is ambitious. But the results so far suggest that all hopes are allowed.
Molly Rielly was born and raised in Cleveland. As a journalist, Molly has contributed to many online publications including The Street and The Inquir. In regards to academics, Molly earned a degree in business from St. John’s University. Molly covers economy stories here at Cleveland Post Gazette.
