Bringing habitat back to hydro corridors

Nature is increasingly hard to come by for Canadians as greenspaces — and the wildlife that depend on them — are squeezed out of the urban and suburban areas where we’ve concentrated our housing, transportation, agriculture and industry.

This is particularly true of the area stretching from Quebec City to Windsor, Ont., the country’s most densely populated region which boasts half the people, most of the big cities, and the highest number of at-risk species.

Encompassing around 6.3 million hectares from southern Quebec to southwestern Ontario, people have converted most of this region’s natural landscape for our use, fragmenting the rest.

But as our Restoration Analysis shows, even in places where most land is privately owned and parks and conservation areas aren’t enough, there are still opportunities to create, connect and improve wildlife habitats (and sequester carbon while we’re at it).

And with the biodiversity loss crisis increasing, every opportunity must be seized, from marginal agricultural land to vacant urban land that’s low priority for development. This includes hydro corridors for electrical transmission lines, which is has brought us to Montreal’s South Shore suburbs.

What WWF-Canada is doing

Since 2021, WWF-Canada has been working with municipalities to identify and restore habitat within hydro corridors, using various management practices such as modifying mowing schedules — delayed mowing or no-mow zones (NMZ) — sowing native seeds, removing invasive species and planting native plants.

We piloted this project with Saint-Constant and Brossard before adding Sainte-Catherine and Salaberry-de-Valleyfield to the mix, whose leaders all recognize the value healthy greenspaces bring to their communities and enacted plans to carry out this work.

With the support and collaboration of Hydro-Québec, our team identified 160 hectares of appropriate restoration sites along their transmission corridors: spaces that, aside from parks, are often the only connected green areas left.

Even when surrounded by houses and other private or municipal infrastructure, these sites are still large and diverse enough to provide benefits like food and shelter for wildlife as well as sequestering carbon and helping to mitigate the “heat island effect” of dense urban development.

In fall 2021, Saint-Constant removed 3.1 hectares of turfgrass, improved the soil structure by adding compost and planted seedlings grown by a local native plant nursery.

Nearby, an NMZ was also established, reducing mowing to once every 2-3 years (except near bike paths for visibility and safety). Brossard focused on establishing a 5.4-hectare NMZ in 2021, and in fall of 2023 the first native seedlings were planted directly into the turf throughout half of the zone, along with signage to raise awareness.

NMZs have several advantages: the long stems of grasses and herbaceous (non-woody) plants provide safe shelter and nesting habitat for many different animals, including insects, birds and reptiles; a variety of native plants grow throughout the growing season and develop seeds, thereby increasing the abundance and diversity of plants; and mowing less helps decrease gas emissions.

To find out how advantageous the NMZs really are, monitoring was carried out by WWF-Canada interns during the 2022 and 2023 growing seasons, focusing on abundance and diversity of invertebrates and native plants, as well as how community members reacted to the NMZs.

The data showed twice as much insect diversity throughout NMZs compared to mowed zones — higher pollinator populations as well as more food sources for birds, bugs and mammals — while plant diversity was more than 150 per cent higher. And over 80 per cent of the community members that the interns interacted with liked the addition of the NMZs in the hydro corridors. As a result, the NMZs were expanded in the 2024 growing season.

Resulting in the restoration of 14.3 hectares so far, this collaborative work is made possible by Hydro-Québec, the manager and steward of these corridors, by providing access to key sites.

Their biodiversity specialist team also worked with WWF-Canada’s biodiversity experts to create a  Francophone guide for municipalities on management techniques to promote biodiversity in hydro corridors and habitat restoration standards, including innovative and rarely used techniques, which will be published this spring.

Collaborations like these are increasingly key to providing wildlife access to stretches of habitat with the resources they need to thrive, especially in densely populated areas where greenspace is precious and every piece of restored nature really pays off.