The terms tree canopy and urban forest has come into the forefront lately, and for good reason. The city of Toronto has undergone a devastating setback with our own tree canopy.
In 2007, Toronto City Council under then mayor David Miller, adopted a plan to significantly expand the city’s tree canopy to between 30-40%. It was one of the more ambitious goals the city had set for itself, but now it looks like it will be an impossible task and here’s why.
A study conducted back in 2008 by Toronto Urban Forestry determined that the city of Toronto had a 20% forest cover representing 10.2 million trees with an estimated structural value of $7 billion. (Source: Every Tree Counts)
Maintaining the existing canopy, that is, saving the trees that we already have is growing more and more difficult. The Emerald Ash Borer (an introduced insect pest) poses a significant threat to Toronto’s tree canopy. The loss of all ash trees in Toronto would reduce overall forest cover in the city from 19.9% to about 18.3%. In 2013-14, a particularly harsh winter followed by an ice storm was thought to have damaged tens of thousands trees or up to 20% of the existing tree canopy. That is well below the North American average, and more than 50% less than David Miller’s target.
It doesn’t help when municipal politicians cannot even agree on how to address the situation. Mayoral candidate John Tory says he would double the city’s tree-planting budget, investing an extra $7 million per year in a campaign to plant 3.8 million more trees (380,000/yr)over the next decade. (note to readers that the math doesn’t add up). Olivia Chow has agreed to commit 1 million trees (200,000/yr). She said that as mayor, she’d pay for the new trees and hire 500 youth over five years by “changing the way polluting businesses pay for the city to treat environmentally harmful discharges in the sewage system.” (Source: The Star)
Just after the December ice storm at the 2014 budget vote, current Mayor Rob Ford suggested cutting the $7-million budget earmarked to plant 97,000 trees. “If you want to go plant trees, knock yourself out. But don’t use taxpayers’ money,” he said to fellow city councillor Mary-Margaret McMahon. In February, on his broadcast on You tube he said, “I do not support planting 97,000 trees at a cost of $7 million. Would you rather have your road paved – more than one, for $7 million – or plant 97,000 new trees? We can’t even take care, as you saw during the storm, of our existing canopy.”
From 2004-2009, an average of 84,000 trees/year were planted through City programs. Forest cover would start to decline if tree planting in Toronto stopped. Loss of tree canopy would range from 8% to 16% over the next 100 years depending on tree mortality rates. (Source: Every Tree Counts)
Toronto’s tree canopy is not only beneficial to the life and vitality of our city, but it also saves us money. Toronto has approximately 20% forest cover representing 10.2 million trees. Toronto’s urban forest provides the equivalent of at least $60 million in ecological services each year. The benefits derived from the urban forest significantly exceed the annual cost of management (Source: Every Tree Counts)
Some of the benefits that we derive from the urban forest are (Source: Faculty of Forestry, U of T):
Improved air quality: Some of the more problematic gaseous pollutants in our cities are: sulphur dioxide, nitrous oxide, carbon dioxide and ozone. While individual trees may remove only small amounts of pollutants from the air, the urban forest as a whole can have a significant mitigating effect on air quality. The trees in Toronto store 1.1 million metric tonnes of carbon annually or the equivalent of annual carbon emissions from 733,000 automobiles.
Energy conservation: Trees provide natural cooling in summer and winter winds can cause substantial energy loss from buildings, but strategically planted trees and shrubs can act as windbreaks to lessen these effects.
Improved Water quality: The high percentage of hard surface in the urban environment reduces the ability of storm water to infiltrate the soil, and thereby increased the level of runoff into storm sewers.
Reduced Noise pollution: Substantial tree buffers (greater than 30 metres wide) along highways and industrial sites can reduce the harmful effects of noise pollution.
Improved Wildlife Habitat: Trees and shrubs along streets, in parks, and in our yards provide crucial nesting and other life functions habitat for resident bird populations, as well as stopovers for migratory birds.
Increased Property value: Evidence from Canada and the United States suggest that residential properties with substantial tree cover may sell for between 5% to 25% more than similar properties without trees. Similarly, homes in well-treed communities tend to sell more quickly.
Improved appearance: A diverse urban forest can break up the hard lines of built structures, reduce glare from hard surfaces, and provide a more pleasing “natural” appearance.
Enhanced Psychological well-being: Research in hospitals has shown that patients in rooms that overlook green space tend to recover more quickly than those with rooms that overlook hard surfaces.
If this is something that interests you and you want to get involved, here are some resources: