Ash trees are being threatened by Emerald Ash Borer (EAB), an invasive pest which has arrived in North America. Ash trees—which make up about 3% of all trees in Maine, an estimated 511 million trees—feed and support numerous species of insects, birds, and mammals, and are vital to Maine forests and communities. Once EAB has infested a tree, 94% of White and Green Ash trees and 99% of Brown Ash trees die within two to five years.
[Above photo: A portion of an ash tree at Gilsland Farm with sure signs of EAB infestation, S-shaped galleries created by Emerald Ash Borer larva as they feed. If bark has peeled away, you may be able to spot these patterns or “galleries.”]
Maine Audubon’s Gilsland Farm Audubon Center in Falmouth has a substantial population of ash trees and provides an excellent place to study the spread of EAB, test various methods to protect ash trees, provide a source of seeds to help preserve genetic diversity, and study surviving ash. Gilsland Farm Audubon Center has participated as an ash treatment demonstration site overseen by the USDA Animal & Plant Health Inspection Service, Maine Forest Service, and, most recently, as a grantee of Forest Stewards Guild’s Sustaining Ash Partners Network.
To test chemical pesticides, 12 trees were injected and tagged in 2024. This June, 12 new trees were injected and three were given a second treatment. Stem-injected systemic insecticides have been shown to be effective at preventing mortality in individual trees.
Lingering ash—mature, untreated trees that are still healthy when 95% of their mature ash neighbors have been killed by EAB—may hold the keys to the future of all three ash species (Brown, White, and Green Ash). This summer, 40 lingering ash trees at Gilsland Farm were flagged and registered with the Monitoring and Managing Ash program (which was developed by and is directed by the Ecological Research Institute), in collaboration with Ash Protection Collaboration Across Waponahkik.
As part of our commitment to providing public education around the EAB crisis, this summer, around the sanctuary, we installed nine signs in our “Conserving Ash Trees Under Threat from Emerald Ash Borer” series. These signs describe: ash trees in Maine; the importance of ash to wildlife, forests, communities, and culture; signs and symptoms of EAB; what can be done to monitor and treat ash; and how you can support this work. (Maine Audubon has also created a single sign that is available for organizations to order; visit maineaudubon.org/EAB for more information on signage.) Look for these informational signs including one inside the Visitor Center displayed with two baskets made from Brown Ash. A narrated video tour of the signs will be coming shortly, for those who are unable to come to Falmouth!
We’re also hosting two community science workshop days in August, where we invite you to join local staff and experts to practice finding and identifying ash trees, and documenting signs and symptoms of EAB and seed collection sites.
Coordinated in collaboration with Ash Protection Collaboration Across Waponahkik and Gulf of Maine Research Institute, these workshops are:
August 13, 4 pm, Fields Pond Audubon Center, Holden (register here)
August 20, 4 pm, Gilsland Farm Audubon Center, Falmouth (register here)
Lastly, we are joining researchers and Wabanaki tribal leaders in asking Maine Department of Agriculture, Conservation & Forestry NOT to lift the quarantine of ash wood. While we are disheartened by the recent discovery of EAB in locations which seem to link previously-documented and seemingly separate infestations, we respectfully request continuing the quarantine for more time to conduct studies like those at Gilsland Farm, to protect the roughly 78% of ash trees in the state which are still healthy, and to conserve ash forests around Wabanaki communities, many of which are near lumber and pulp mills that could take infected wood once the quarantine is lifted. To learn more about the proposed rule change and to submit your own public comments, download the fact sheet and join a public hearing in August.
For more information and resources around ash trees and the Emerald Ash Borer, visit: maineaudubon.org/EAB
