University of Ottawa study: Roadside management boosts pollinators by 45%

A study led by the University of Ottawa has found that modifying roadside maintenance can significantly boost pollinator populations. Researchers discovered that reducing mowing frequency and using herbicides more selectively on rural roadsides increased the number of pollinators by 45% and the variety of species by 23%.

The research team compared rural roadsides in jurisdictions surrounding Ottawa, such as Lanark County, which employs low-intensity management, against Ottawa and Leeds & Grenville County, which use more conventional methods. Lanark County mows twice a year and uses spot-treatments for invasive plants, whereas the other jurisdictions mow four times a year and use widespread herbicide spraying.

Over two summers, researchers identified 153 species across 3,773 specimens. Professor Jessica Forrest noted that the results suggest land managers can support biodiversity without compromising road safety or invasive species control by simply making modest adjustments to mowing and herbicide application.