The combined pressure of habitat loss, climate change, and the ongoing threat of EAB has contributed to significant black ash mortalities. The species was classified as endangered on the Species at Risk in Ontario (SARO) list in 2022, due to the projected decline of > 70% of black ash over the next 100 years, resulting from the combined effects of EAB infestations and climate change. It was previously believed that black ash trees at the northernmost extent of their range were protected from EAB invasion due to the insect’s inability to survive winter temperatures below -26°C and -35°C. However, recent findings show that EAB can withstand extreme cold as low as -50°C. Combined with warming winters, this suggests that the northern expansion of the invasive insect may no longer be limited by cold temperature – putting black ash populations in the northernmost parts of their range at risk of invasion. With as high as 25% of the global population occurring here in Ontario, the province plays a critical role in the conservation and recovery of this species. 

Black ash typically grows in swampy, seasonally flooded areas, such as fens, riparian forests, and shorelines where few other tree species can thrive, though it can also occur in moist microsites within upland habitats. Its presence supports a rich diversity of plant and animal life, helping to stabilize soil, regulate water flow, and maintain wetland health.  

The loss of black ash from these ecosystems could have cascading effects, altering water dynamics, increasing erosion, and reducing habitat quality for numerous wetland-dependent species. The native Canadian Sphinx Moth (Sphinx canadensis) for example, is believed to rely almost exclusively on black ash for larval development and survival, highlighting the fragility of interspecific species interactions and the broader ecological consequences that can arise when a single species is threatened. Additionally, the loss of black ash due to EAB can have lasting impacts on habitats where the species is dominant, creating conditions for habitat conversion and increasing the risk of invasion by other invasive species. 

Sphinx canadensis feeding on black ash foliage. Photo by Alexandre Laberge, via Breedingbutterflies.com

Valued for its flexibility and strength, black ash has been used for thousands of years by the Anishinaabeg, Haudenosaunee, Wabanaki, Ho-Chunk, and Menominee peoples for a wide range of purposes, including basketry, tool handles, snowshoe and cradle frameworks, fuelwood, and wigwam construction. For many Indigenous communities across Ontario and beyond, black ash is deeply tied to cultural identity, traditional knowledge, and intergenerational practices.  

Historically, black ash wood has been valued for its strength and workability, making it ideal for tool handles, furniture, and various handcrafted products. Its growth conditions produce strongly ring-porous yet flexible wood, well-suited for items such as baskets, snowshoe frames, canoe ribs, and more. While not as commercially widespread as white or green ash, black ash has played an important role in local economies—particularly among craftspeople and small woodlot operators. 

Amid the ongoing threat posed by EAB, the value of black ash extends beyond its ecological and cultural importance to its genetic potential. While EAB has devastated ash populations across North America, a small number of ash trees—often referred to as “lingering ash”—have demonstrated an ability to survive even in areas of severe infestation. These trees may possess natural tolerance or resistance to the invasive insect, offering a potential key to the species’ long-term survival. As such, lingering ash are the focus of ongoing research and seed conservation efforts. Their unique traits could not only support black ash recovery but also provide valuable insights for enhancing the resilience of broader forest ecosystems. 

Our initiative supports efforts to identify, map, and collect seeds from black ash populations — especially those that have survived past EAB infestations. By preserving this genetic material, we are complementing existing efforts to build a foundation for long-term recovery and potential breeding for resistance.