Thousands of kilometers of highway in Ontario are lined with non-native legumes, which are ecologically useless for pollinators, and have shallow roots that aren’t as good at filtering water or preventing erosion as are native plants.
|By Haljackey at English Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31335717|
Roadside revegetation with native plants
Roadside revegetation with native plants is being studied by Stefan Weber, a PhD student in the Biology department at McMaster University. In 2016 the Ontario Ministry of Transportation put out a request for proposals for their Highway Infrastructure Innovation Program Fund to study the best practices for establishing native roadside vegetation. Now, Weber’s project has two sites on highway number 3 outside of Tillsonburg and Norfolk county, and two sites in Saint Mary’s on highway 7.
Weber says the primary step to restoring habitat is preparing the site adequately. It can take two years to get rid of most of the invasive and noxious weeds, and even then the weeds and invasive species can persist. “I love the phrase ‘undressing a salad’,” he says, “It’s impossible to undress a salad. If you want to undo changes that have been made to the biotic community, it might not be possible; so many things have happened in terms of changes to soil structure and soil chemistry. It may not actually be possible to revert some roadsides back to the native landscape.”
Weber says that we can keep our tallgrass prairies around by keeping these communities in an early state. This can be done by managing them with grazing or mowing. Historically, these prairies were maintained with fire by First Nations people. In a roadside setting, mowing is an essential activity for keeping prairie plants thriving. It helps eliminate competition from fast growing weeds which can shade these prairie species out.
“A successful project requires choosing species that are most appropriate for the physical characteristics of the restoration area,” says Weber. “The goal is to build what we want to see into the future, not recreate some historical scene that doesn’t exist anymore. We can’t travel back in time, so that’s not really the point.”