February 2022

Hello and welcome to the inaugural newsletter for the Great Lakes Basin Forest Health Collaborative (GLB FHC)! We’re glad you’re here. 

In this issue, we’ve got the latest news from the Collaborative, ways you can get involved, and a roundup of some of the latest research on ash, hemlock, and beech. Together we can help conserve these tree species!

Did someone forward this to you? Sign up for our email list by contacting us here. Know someone who might be interested in joining the GLB FHC? Please forward this email.

Thanks for joining us!

 — Rachel Kappler
The Latest
Sun through Boll Woods at Holden Arboretum by Joe Aber.
We’ve hit the ground running since our launch in January 2021. Here’s a snapshot of what we’ve accomplished in the last year:

  • Added 50 partner organizations across ten states and provinces — MN, WI, IL, IN, MI, OH, PA, NY, NJ, and Ontario.

  • Formed an executive board to ensure the Collaborative’s efforts continue to reach our goals. The executive board includes representatives from the US Forest Service (FS) Northern Research Station, FS Region 9 Invasive Species Coordinator, FS Forest Health Protection, FS Regional Tribal Relations Program Director, FS State & Private Forestry, Holden Forests & Gardens, and the Northeast-Midwest State Foresters Alliance. Additional technical advisory committees will be formed this year as we invite input from experts to provide guidance and scientific expertise to species-specific projects, ensuring that our work is science-based and meets quality standards.

  • Launched our training programs in August with a workshop on identifying lingering ash trees for DNR forest stewards volunteers in Michigan, which has already resulted in 4 reports from locations that have 2–6 lingering ash each, two of which scientists at the Forest Service have already evaluated for resistance.

  • Have had eight additional lingering ash trees reported via the TreeSnap app. 

  • Added 62 new seed collection locations for eastern hemlock with partners in OH, NY, WI, and PA.

Thank you for all your contributions in 2021! We’re looking forward to what 2022 brings.
Get Involved
Rachel Kappler presenting materials at an outdoor training in Michigan on identifying and reporting lingering ash trees.
There’s much to do to help increase the resilience of our native trees to invasive pests and diseases! Here’s how you can help:

  • Spread the word. We’d love for more interested organizations, agencies, and individuals to know about the GLB FHC! Please forward this email to someone in your circles that you think might want to join in.

  • Join the mailing list. Keeping up-to-date on GLB FHC happenings is a great way to tap into resources that will help you on your mission for sustainable forests. If this message was forwarded to you, send us an email to request being added. You’ll only hear from us a few times per year!

  • Become a partner. If you haven’t already, we’d love for you to formally join the GLB FHC! We’re constantly adding new partners who are interested in:
  • Monitoring forests for pest and disease progression
  • Reporting healthy trees from infested locations
  • Seed and scion collection
  • Grafting and propagation
  • Providing land for tree planting trials
  • Request a workshop for your group. Part of the GLB FHC mission is to provide training on the newest techniques, developed by research, in all phases of breeding. Visit the GLB FHC website for the full list of trainings and workshops we offer, and stay tuned for announcements of upcoming online events!

  • Search for lingering ash in forests near you, and encourage your volunteers and stakeholders to search, too. A lingering ash tree is a mature (>10 cm diameter at breast height), native, untreated ash tree that has remained healthy in a stand where ash mortality levels have been 95% or greater for more than two years. Lingering ash trees are not “immune” from emerald ash borer attack and often have bark cracks from EAB galleries that have healed over. Despite this, these trees maintain a healthy green canopy. There are a number of ways to report lingering ash sightings:
  • Email us tree canopy & leaf photos and coordinates/location info
  • Upload photos and data to Treesnap, online or using the Treesnap mobile app
  • Upload photos and data to the Monitoring and Management of Ash (MaMA) Lingering Ash Search on Anecdata, online or using the Anecdata mobile app

  • Establish a forest monitoring plot. If you are in a location where >90% mortality has not occurred yet from EAB, consider establishing monitoring plots. This helps prepare for when the time comes to start looking for lingering ash. Plus, establishing plots where mature ash has died is important for monitoring regeneration — critical for understanding the future of ash within your forests. 

  • Collect tree seeds. We are trying to increase seed collection for natural populations of our target trees, especially from locations that are not currently represented in National Seed Storage. For instructions and forms, please visit the USDA Forest Service’s genetic conservation pages for ash and other trees. 
Research Roundup
Image Credits: Ash in the lab, Rachel Kappler; Beech leaf disease, Mary Pitts; Hemlock in pot, David Burke.
  • A new way to propagate ash (without grafting onto EAB-susceptible rootstock): Work led by Jennifer Koch with the U.S. Forest Service has developed a faster way to propagate ash via cuttings (photo above, left). The new technique trims leaves to focus the plant’s energy on rooting and uses a chemical solution to stimulate root growth. It’s much faster than previous best practices of grafting with EAB-susceptible rootstock!

  • The nematode that causes beech leaf disease is a new subspecies. Research led by Lynn Kay Carta at the USDA-ARS and David Burke at the Holden Arboretum identified the culprit behind beech leaf disease as Japanese nematode Litylenchus crenatae, though morphological and range differences suggest the North American populations are a distinct subspecies from their Asian counterparts, Litylenchus crenatae mccannii. (Read more)

  • Tree leaves infested with beech leaf disease have distinct microbiomes. Work led by David Burke at the Holden Arboretum and Jennifer Koch with the U.S. Forest Service found that symptomatic and asymptomatic beech leaves have different bacterial communities (photo above, center). Notably, infected leaves had a bacteria called Wolbachia, which is known to associate with insects, and may be an important clue to understanding how beech leaf disease spreads. (Read more)

  • What about the cost? Stopping the EAB is still economically beneficial. Researchers with the Canadian Forest Service crunched the numbers and found that managing for EAB is economically justified — the costs are less than the economic benefits. In case you ever need to provide more reason for your efforts! (Read more)

Have something to share in the next GLB FHC newsletter? Email us!
In the News


The Great Lakes Basin Forest Health Collaborative is an initiative co-sponsored by Holden Forests & Gardens and the USDA Forest Service, funded through the Great Lakes Restoration Initiative
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