Hi Luke,

I looked into this question over the winter for a black ash project in the Kawarthas.

There is quite a bit of research happening on the south side of the great lakes. Some examples from research are listed at the end of this message.

Below is potential replacement species list.

Of course you need to match the replacement species with the site conditions and silvics of the replacement species (soil, shade tolerance etc.)

Elm species

American Basswood

Bitternut Hickory

Black Willow

Musclewood

Eastern Cottonwood

Black Walnut

Hackberry.

You can also consider shrubs such as spicebush, buttonbush, bladdernut, elderberry or white meadowsweet

Elliott

Iverson et al (2015) https://research.fs.usda.gov/treesearch/49775

This paper from Minnesota identifies replacement species within the context of EAB and climate change. 

see attached Table from this study

Palik et al. (2021) https://research.fs.usda.gov/treesearch/62033

This more recent study from Minnesota analyzes survival rate after 8 years of replacement species. Note the research site does have a high water table, which is discussed as a potential factor in lower survival especially in the clearcut treatments.

see attached Figure 3 from this study

University of Minnesota Extension note

https://extension.umn.edu/forest-pests-and-diseases/replacement-trees-ash#wet-forests-1804161