By Blake Jackson
Cornell University has planted ash saplings that may be resistant to the destructive emerald ash borer, making the university the first propagation center for these trees in New York State. This initiative is part of The Nature Conservancy’s Trees in Peril project, which aims to restore ash populations across the country.
Emerald ash borers typically kill every tree in a stand, but USDA Forest Service studies have found that a few surviving trees known as lingering ash show natural resistance.
After identifying several of these trees in its natural areas, Cornell Botanic Gardens is working with conservation partners to propagate more resistant individuals. If successful, these trees and their offspring could help reforest areas in New York and beyond.
“Our goal is to propagate and conserve trees from 50 to 60 unique parents of green, white and black ash species, and we are thrilled that our first cohort of lingering ash have been planted out in their conservation banks,” said Todd Bittner, director of natural areas for the Cornell Botanic Gardens.
Emerald ash borer larvae kill ash trees by tunneling under the bark and feeding on the living tissue. The insect has devastated ash trees in 37 states, causing billions in removal, treatment, and replacement costs. Resistant trees can survive at lower borer populations, but high infestations may still require additional protection, Bittner said.
Cornell collaborates with The Nature Conservancy, USDA Forest Service, the Ecological Research Institute, and other partners to monitor, breed, and propagate pest-resistant ash, as well as American beech and Eastern hemlock. Currently, 139 grafted saplings, between 2 and 7 feet tall, have been planted from 26 lingering ash “parents” in three conservation banks.
“Some lingering ash are able to wall off the larvae faster than they can tunnel through, and once they are walled off, they are stuck and they starve to death, because they can’t move backwards,” Bittner said.
Researchers also suspect a second mechanism for resistance: certain volatile organic compounds (VOCs) may make these trees chemically invisible to emerald ash borers.
Through Monitoring and Managing Ash programs, citizen scientists are invited to help identify lingering ash, particularly the rarer green and black ash, which are culturally significant to Indigenous communities.
“We are looking forward to the day where ash are returned to our forests, strengthening the health of our ecosystems and the communities that depend on them,” Bittner said.
Photo Credit: istock-moneycue-canada
Categories: New York, Education, General