Frequently Asked Questions
Is there still time ahead of the EAB front?
Yes, but not much. In a few years EAB may spread throughout the entire Great Lakes–St. Lawrence forest of Ontario.
Is there hope for ash on the landscape after EAB goes through?
Yes. FGCA's 2018 road trip searching for lingering ash in SW Ontario provided some evidence of persistance. Not all species or individuals are affected equally. Conservation of surviving trees and monitoring regeneration may hold clues to EAB tolerance, breeding and future reintroduction.
Why is there still ash regeneration long after the EAB front?
Anecdotal theory is that the stressed parent trees put on heavy seed crops a year or two before they died. The ash seed on the forest floor or in the duff layer may actually persist 5–10 years before germinating in higher light conditions when the canopy is dead. Some foresters suspect the EAB population crashes after most ash are dead, and the regeneration is too small to be attacked. This window of time with low levels of EAB presence may give natural regeneration a chance to grow again. This is similar to how American elm (Ulmus americana) has persisted on the landscape afer Dutch Elm Disease, but nowhere near the record sizes it regularly attained. This is promising for SW Ontario and looking ahead of the EAB front, in areas where mature trees are allowed to persist (not be cut in advance) until natural mortality occurs. This DOES NOT mean the regeneration is genetically tolerant or resistant to EAB.
Is there any proven natural genetic resistance to EAB?
Not yet, but potentially. The search and investigation continues, notably with 0.05% of surviving green ash in Michigan/Ohio. Like American chesnut back-crossing, an alternative strategy comes from cross-breeding our native ash with Asian cousins that have coexisted with EAB for much of their evolutionary past. Work is also being done at Purdue to insert Bacillus thuringiensis (Bt) genes into tissue cultured black ash shoots in hopes of testing efficacy against EAB.
What are Ontario municipalities doing about EAB and ash conservation?
Mostly what has been done is an analysis of which urban ash trees to invest TreeAzin injections in, and subsequent removal of dead and dying hazard trees around municipal assets. Most large urban forestry departments have an EAB mitigation plan that involves diversifying replacement tree species in urban plantings on municipal and private land, regular TreeAzin treatments of the best trees and educational awareness about the factors that spread EAB. If the ash trees on municipal land were planted from horticultural stock, they would not qualify for seed or survivor analysis. Naturally-occurring trees are of interest however.
Only a few municipalities (Peterborough County, Northumberland) have inquired with FGCA about incorporating seed collection and survivor assessment in rural areas into their mitigation plans. We welcome any municipality that has some funds to dedicate to the targets provided on the seed page. Strengthening partnerships on EAB management between local municipalities, Conservation Authorities and local landowner groups to get involved in seed and survivor monitoring now is important.
Some select research and management plans are listed here and will be added to as FGCA's communications about ash spread:
- CONFORGEN Seed Collecting Guidelines
- USDA Ash Seed Collection Resources
- Optimized seed sample sizes in green and black ash (Julia Hendrickson, University of Minnesota thesis)
- Forest's Ontario EAB FAQ
- OMNRF Forest Health Review (Dan Rawlinson) 2016
- US Northern Forest Research Station Researcher: Jennifer Koch
- Monitoring ash (Fraxinus spp.) decline and emerald ash borer (Agrilus planipennis) symptoms in infested areas
- County of Renfrew EAB Update 2016
- 2017 FGCA & ISC Efforts – TVO Article
- UK Native Tree Seed Collection Project ~ 10 million seeds later