Allowing dogs to roam off-leash is damaging fragile ecosystems like urban forests, two scientists interviewed by The duty. By straying from trails, dogs trample young tree saplings and native plants, which harms forest regeneration and contributes to the emergence of invasive species.
At Summit Woods in Westmount, one of the three peaks of Mount Royal defined as a “wildflower and bird sanctuary”, dogs, accompanied by their owners, can walk without a leash for several hours of the day, which has created debate (see other text).
“Mature trees are little or not affected by [la présence de chiens sans laisse]but it is the future of the forest that is mortgaged,” maintains Alain Paquette, professor of biology at the University of Quebec in Montreal and holder of the Research Chair on the Urban Forest.
Young trees, like understory plants and spring plants, suffer from trampling — whether caused by dogs or by walkers who stray from the paths. “This is a big issue for the regeneration of understory flora and for the eventual replacement of trees.”
At the same time, trampling creates gaps in the forest that form an environment conducive to the appearance of invasive species, explains the professor who has studied in more detail the Papineau woods in Laval, an ancient forest where dogs were also walking without leashes a few years ago.
“When an undergrowth is intact, it tends to resist the appearance of invasive exotic plants because it occupies the space,” he says. But the appearance of gaps creates entry points for these plants, which are more resistant to trampling. Buckthorn or wood anthriscus, for example, then take the place of native plants, such as trillium.
Although these changes in the forest are slow and difficult to see for walkers, they represent “a profound transformation of the dynamics of a forest which will mean that we will eventually no longer have a natural forest.”
Multiple pressures
A concern shared by Emma Despland, professor of ecology at Concordia University and member, like Alain Paquette, of the Centre d’étude de la forêt. “We see that the woodland is deteriorating,” says this Westmount resident who walks through Summit Woods. A degradation that is partly caused by the same pressures that other woodlands in the region are experiencing, due to the emerald ash borer, the arrival of invasive species and climate change, among other things.
“But dogs are an added pressure,” says the researcher, also pointing out the harmful effects of trampling. No other major park in Montreal allows dogs without a leash, she notes. SEPAQ and Parks Canada parks also prohibit the presence of dogs that are not on a leash.
“I understand that dog owners want to have a place where they can walk their dog. It’s a completely reasonable request. But does it have to be in the only old forest that exists in Westmount?” wonders Emma Despland.
The fact that dogs have been allowed off-leash in Summit Woods for decades is not a sufficient argument in her eyes. What was possible in the 1990s or 2000s is not necessarily possible today in the era of climate emergency, she argues. “If we are serious about mitigating the biodiversity crisis and protecting our old-growth forests, it is not really consistent to allow dogs off-leash. Yes, it is unfortunate for those who lose this privilege, but it is a privilege that is no longer really realistic.”
Preserve
In an interview at DutyWestmount Mayor Christina Smith says she is convinced that it is possible to preserve Summit Woods and allow dogs to walk there without a leash.
“People love it. It’s a part of Westmount [le fait de pouvoir promener leurs chiens sans laisse] that people really appreciate,” she said. To date, the City has not conducted an environmental assessment to analyze the impact that dogs have on Summit Woods. But next year, the Municipality will complete a master plan for its three major parks, including Summit Woods. “That will cover environmental protection,” assures the mayor.
Until now, the debate over the presence of off-leash dogs has been “relatively civilized” in Westmount, reports Ralph Thompson, a journalist for the weekly Westmount Independent. He notes, however, that the degradation of the forest is noticeable in several places, particularly along the paths, which have widened over the years, gaining ground on the forest.
“If changes need to be made in the future, we can look at that,” says Christina Smith. Already, to promote the preservation of Summit Woods, the mayor plans to block the unofficial trails in the woods that have appeared during the pandemic. She also mentions the possibility of closing sections of the forest, on a rotating basis, to promote its regeneration, as is the case on Mount Royal. An effort is also being made to combat invasive species, she assures.
“It’s an urban forest, so there are challenges that come with that,” the mayor said. “I know we need investment.”