Why Toronto's Urban Forest is a Critical Infrastructure Asset

Urban forests are vital infrastructure that provide $125 million in services to the GTA each year. But with little support from senior governments, municipalities are stretched to nurture their green assets.

Photo by Doug Smith from the Torontoist Flickr Pool.

When a resident from Kleinburg, a heritage district in York Region, proposed a plan to build an underground garage on his property, the City signed off with little dispute.

The car park, complete with a hydraulic lift, would be close to the property line, but would offer just enough clearance from the neighbour’s mature trees to avoid causing any damage. Soon after the resident started excavating, however, the City was inundated with calls from a frantic neighbour.

Major roots that stretched from their property into the excavation area were severed, cutting off a significant means of water and nutrient uptake, and the neighbour feared, correctly, that their trees would die.

It turns out the resident building the garage had mislead the City by submitting plans for the above-ground area of the project—a fraction of what was being excavated below the surface.

But according to Philip Van Wassenaer, a seasoned arborist and tree consultant for municipalities, knowing the construction would have damaged the roots wouldn’t have mattered anyway.

“What’s below ground—40 to 50 per cent of the tree’s biomass—is the most important part,” says Van Wassenaer, “But if my tree is growing a metre away from the property line and you get permission to excavate to that point, then you’re going to be doing significant damage to a portion of the roots in my tree, and I have no recourse.”

Indeed, while municipalities have the mandate to protect the trunks, branches, and leaves of mature trees, the vital root systems remain largely ignored by policy, leaving them vulnerable to development.

It’s just one of the many limitations in the efforts to protect the GTA’s urban forest—a critical asset for healthy cities, and one that is increasingly under threat, from climate change, disease, and the built environment.

“The urban forest isn’t a nice-to-have, it’s a critical infrastructure asset,” says Michelle Sawka, a project manager with TRCA and manager of the Green Infrastructure Ontario Coalition. “But often trees are seen as an afterthought. Our work is getting them integrated into all decision making at the municipal level, and valuing them for the services they provide.”

It’s easy to appreciate the benefits of trees upon stepping into one of Toronto’s many parks or ravines: your anxiety lifts, your breathing becomes easier, and in the summer, a cool calm sweeps over you as you take in the canopy’s beauty.

At the same time, trees are working to offer less overt benefits, like stormwater management and climate change mitigation. In total, the urban forest provides about $125 million in services to the GTA every year.

Photo by Cameron MacMaster from the Torontoist Flickr Pool.

Still, municipalities struggle to get the resources necessary to support the urban forest. And a major barrier, says Sawka, is the outdated terminology we use to describe trees. “Using the term ‘infrastructure’ is really important. It’s saying you need to integrate urban forest and urban trees into the fabric of our cities, just like we do our roads, and pipes, and all of our grey infrastructure,” she says.

“That’s a new way of thinking about these assets.” While Ontario municipalities are staring to adopt this perception, the provincial and federal governments are slow to catch on.

The concept of changing our language around urban trees is more than symbolic. In fact, it’s essential for getting the funding trees need to continue providing their services. Currently, municipalities can’t apply for infrastructure funding to support their urban forests “even municipalities that do manage trees as assets,” says Sawka.

Last year, for example, the Ontario government earmarked $137 billion over the next 10 years for infrastructure spending—the province’s biggest contribution to the fund to date—with none of that money allocated for urban trees. “It’s because they’re undervalued for the services they provide to our communities,” Sawka adds.

One may argue that the GTA’s urban trees need extra support now more than ever. A string of misfortunes in recent years, namely the ice storm of 2013 and the invasive emerald ash borer that’s poised to kill off the region’s ash—a tenth of the total tree population—in a matter of a few years, have gobbled up much of the urban forest funds, leaving little for regular upkeep. Limited resources means cities and townships have to react to problems rather than prevent them.

The current plight of the ash tree is one example of how poor planning on the part of underfunded, understaffed urban forest management teams can breed devastating results.

When Dutch elm disease wiped out 80 per cent of elm trees in the GTA, those trees were replaced with ash. “There were streets with beautiful elm coverage, 50 to 150 years old, and then nothing,” says Van Wassenaer. “Eventually, those same streets had beautiful ash coverage, and now nothing.”

Originally, regional governments chose ash for its ability to thrive in gritty urban environments. “They’re like the raccoon of the tree world,” says Janet McKay, founder and executive director of LEAF (Local Enhancement & Appreciation of Forests). “They can survive amid intense human development. They can coexist with us in areas that have a lot of paved surface and low soil volumes and drought and salt and air pollution.”

But too many of any species in a given area, no matter how hardy its stock, invites pests and disease. “When an insect that has a target host comes along in a population with low diversity, it’s got tons of opportunity and it can just spread like wildfire. That’s a large portion of your tree canopy gone,” McKay explains.

It’s widely accepted that it’s too late to save southern Ontario’s ash trees. Success of injection treatments for early stage infestations is tepid, and removal is often the only option. At this point, “the best defense is replanting with a diversity of species,” says Van Wassenaer, who has consulted 12 municipalities on urban tree management to date.

While Van Wassenaer agrees that Ontario’s municipalities need greater support for their tree management strategies, he says local governments are doing remarkably well with what they’ve got. “Southern Ontario is a fairly forward moving jurisdiction in that realm,” he says. “The fact that urban forest management plans are in place at all is a step in the right direction.”

The TRCA plays a pivotal role in that progress through several greenspace management initiatives, like the pioneering Terrestrial Natural Heritage program. And this past June, in partnership with the Green Infrastructure Ontario Coalition, they released the State of the Urban Forest Report [PDF], which brought together data from 17 regional and municipal governments in the GTA—a call to action encouraging higher levels of government to support their urban trees.

What Ontario lacks compared to jurisdictions with even stronger urban forest supports (like Seattle and Portland, for example) is that essential acknowledgement that trees are vital infrastructure, Van Wassenaer notes.

“The provisions of the planning act and our ability to protect a tree are often at odds. And in my opinion, the planning process is fairly stacked up against trees in this moment,” he says. “The most progressive work can be seen once we give trees equal importance as grey infrastructure and put them in the forefront of design and management and investment efforts of the municipality.”

Sawka says that crucial change is slowly happening. Last year, nudged by the Green Infrastructure Ontario Coalition, the federal government amended its clean water and wastewater fund to make green infrastructure projects eligible for funding from the $2 billion pool.

“That’s the first time a senior level of government has acknowledged this type of work within an infrastructure funding stream,” says Sawka. And while the Province has yet to extend infrastructure dollars to urban trees, in 2014, they updated the Provincial Policy Statement to include the definition of “green infrastructure” for the first time.

“It’s finally getting into the provincial policy lexicon. We’re seeing it in the updated Growth Plan, the Great Lakes Act, and the Climate Change Strategy,” says Sawka. “It’s a great first step.”

BY TORONTO AND REGION CONSERVATION.

BY CATHERINE MCINTYRE

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• Urban Drainage
• Smart City
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• Urban Water
• Climate Change Adaptation
• Climate Change Resilience
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