Recently, there is interest in using trees in stormwater control systems to manage the contamination levels of the stormwater that flows from streets and roads into downstream watersheds. Using trees for these systems can provide additional benefits such as shade and enhanced habitat connectivity for avian and ground-dwelling fauna. However, in Quebec, where winters yield large quantities of snow and frost, the use of de-icing salts presents a chemical stress that impacts the livelihood of street trees. In general, soil microbial communities can shift and adapt with salt exposure and subsist under high salinity. However, the point at which these changes can no longer support tree health is unclear. Therefore, understanding the feedback between soil communities and street trees in response to de-icing salt presence can serve to minimise tree death in these stormwater control systems, all while ensuring their lasting establishment.

The project is two-fold: we will be deploying a controlled, mesocosm study at the Montreal Botanic Gardens, and an in-field study along Rue Bélanger, in the Rosemont-La Petite Patrie neighbourhood of Montreal. Using metagenomic sequencing, the microbial communities of the soils associated with the experimental trees in both studies will be quantified.