Rock Elm: A Native Species in Decline?

Carleton University third year Environmental Science students made their group project presentations last week.  One of the projects we sponsored, in partnership with the Ottawa Field Naturalists’ Club, was about Rock Elms (Ulmus thomasii).  The project team examined whether Rock Elm is a species in decline due to Dutch Elm Disease (DED) using data in iNaturalist.  They also reviewed the strengths and limitations of citizen science, the natural history of Rock Elm, tree species recovery programs, and the history of DED in North America.
From the data available, the team concluded that the Rock Elm mortality rate seemed better in 2017-2020 than between 2012-2016; however, they recognized the likelihood of sampling bias.  They also confirmed that the proximity to a dying or dead Rock Elm increases the likelihood that surrounding Rock Elms will also be dead or declining.
We thank the students for their excellent work demonstrating the scientific method and for highlighting the need for a Rock Elm recovery program.
Image of Rock Elm observations in Ontario.
Image of Rock Elm observations from the students’ presentation.

Learn more about Rock Elm.