"Lingering Ash" Research Began in Ohio and Michigan
In 2008–2010, researchers at the US Forest Service's Northern Research Station began monitoring, testing and grafting the rare healthy ash trees that survived EAB to learn why they were surviving. FGCA began to hear of similar "lingering ash" reports in Ontario around 2016. The NRS's early research provided the theory and a template for action. Until Fall 2018, there was no group working on mapping and DNA testing surviving ash trees in Ontario.
Thanks to Dr. Nathalie Isabel and Marie-Claude Gros-Louis at the Laurentian Forestry Centre in Sainte-Foy, Quebec, FGCA was able to send 36 leaf samples inclusive of all five species in October 2018 for DNA testing. 3 seed collections were made (1 blue ash, and 2 green ash) far into SW Ontario. This is the beginning of our understanding to why some trees have survived and what implications it may have on species recovery.
Explore the NTSC's Ash Seed Bank & DNA Survivor Map (Species at Risk and rare species locations are obscured)
Exceptional Survivors Found with FGCA & Partners October 2018All photos by Melissa Spearing 2018. Thank you to John Enright, Don Craig, Jeff Sharpe, Sara Rowland, Mark Brown, Mark and Roberta Buchanan, Justin Bell, Tammy Dobbie, Allan Fretz, Jill Croswaithe, John Ambrose and Sean Fox for their assistance, stewardship and reports of lingering ash. The photos below are not representative of all survivors found.
Green Ash Seed Collection, Bridgen
3 natural trees, all approx. 15 cm DBH, remaining woodlot dead, woodpecker/bird feeders hanging from them, healthy crowns, no sign of EAB. Handful of seed, low seed percentage viable but let NTSC decide.
Blue Ash Seed Collection, Alvinston
Natural tree seeded in from stands nearby, lots of seed! >60% appears viable on cut test, approx. 5-6L sent to NTSC.
Green Ash Seed Collection, Wardsville
Stand of 10-15 healthy ash, all approx. 10-15 cm DBH, full crowns, minimal and healing EAB damage, larger natural trees in area alive.
White Ash, Wardsville
Very large roadside tree, 90 cm DBH+, perhaps planted by landowner but at least 75+ years old (prior to nursery tree availability?), full healthy crown, a few EAB exit holes on trunk.
Green Ash, Talbot Trail Hwy
Large full crown, approx 80 cm DBH+, evidence of EAB damage on large limbs but healing, minor epicormic shoots, no known history of TreeAzin from previous owner, other large green ash nearby succumbed in 2012-2013.
Black Ash, Point Pelee NP
Only a few saplings and poles remaining in the Park, heavy EAB damage but callusing and full crown to the top. Largest one sampled 8-10 cm DBH likely regen since the parent trees died and last seeded.
Is this tolerance or luck?
Pumpkin Ash (ID?), Newbury Area
Very large leaves, possibly still a green ash, natural near vernal pool edge, approx. 20 cm DBH, very healthy full crown near dead white and green ash.
Blue Ash, Point Pelee NP
Largest healthy treee, 75 cm DBH+, some EAB exit holes on trunk and minor larval damage on twigs pulled from crown.
Green Ash, Point Pelee NP
Ideal EAB survivor, 30 cm DBH+, many dead in the area, very little EAB damage and almost completely healed over, lots of regeneration in the vicinity.
Green Ash Seed Collection, NCC Florian Diamante, Pelee Island
Several surviving trees in wet Phragmites swale, maybe mown by ag equipment in the past, healthy full canopies and many seedlings invading abandoned field. 20% viable?
White Ash, Talbot Trail Hwy
Healthy crown, approx 20 cm DBH, epicormic shoots appear more from ditch mower damage than EAB.
White Ash (Planted Local Stock), Thorndale Rd, London
Planted roadside tree but from Seed Zone 37 nursery stock (local), all others dead in planting, full healthy crown with minor epicormic shoots, approx DBH 18 cm. John Enright has been watching this tree for years. Thorndale woodlot also yielded several Ag survivors.
White / Green Ash Regeneration, London
Meadowilly Woods Park, London. No surviving large trees but many patches of regeneration like this.
Dead White Ash, London
Meadowilly Woods Park, London. Parent of seedlings on the left likely.
Heavy ash mortality at Fox Lagoon, Fish Point Nature Reserve, Pelee Island. All five native ash species are historically reported to occur on Pelee Island. 3 survivors found amongst the dead (one crown obvious from a distance at the far right end).
What are the chances of establishing seed production areas (SPAs) of tolerant trees on Pelee Island? What has happened to the EAB population?
Can we graft? Need to learn more from USFS-NRS researchers! Need money too!
Amazing road trip for tree nerds! Pelee Island October 14, 2018, in the glorious and poison-ivy-brave company of John Ambrose, Sean Fox, Kristen Sandvall, and Melissa Spearing.