09/08/2020
Making the most of a tree epidemic
A large portion of North America’s 8.7 billion ash trees are now infested by a beetle called the emerald ash borer.
Since its discovery in the U.S. in 2002, the emerald ash borer has killed hundreds of millions of ash trees, drastically transforming entire forest ecosystems in the process. As of October 2018, infestations have been found in 35 U.S. states and several Canadian provinces.
Ash wood is used as a material for furniture, flooring and baseball bats, and in the past, was used in heavy timber construction. The larvae of the emerald ash borer hatch underneath the tree’s bark, which hinders the plant’s ability to transport nutrients throughout its trunk, causing it to decay.
The infestation has left arborists, researchers and scientists scrambling to find a way to slow the spread or repurpose the infested trees. With emerald ash borers creeping into Cornell University’s Arnot Research Forest in upstate New York, we wanted to see if we could figure out a method to make use of dying ash trees as building material.
Ash trees rendered worthless
As with the spread of other invasive species, global trade brought the emerald ash borer to American shores.
It likely arrived in Michigan in 2002 via shipping crates from East Asia, where ash trees are resilient to the beetle and its larvae. The beetles soon proliferated. In New York, almost 8% of all trees are ash trees, and, since the beetle was first discovered in the state in 2009, the infestation has been impossible to contain. While a number of mitigation strategies are currently being developed, the dying off of native ash trees is expected to continue for the foreseeable future.
Once an ash tree has been infested, there are really only two outcomes: You can let the trees slowly decay in place or use them for firewood. Neither is ideal, especially since each process releases more carbon into an atmosphere already choking with excess carbon dioxide. Furthermore, the sale and distribution of firewood is actually one of the main ways the infestation spreads.
