A report out this week by TD Bank valuing the trees in the City of Toronto, in Ontario, at $7 billion adds an interesting perspective to the business of assessing timber stand value. For wood products manufacturers, it has traditionally been the logs — so naturally the trees — most conducive to making dimension lumber products that are of the highest value.
Urban Timber Valuation
City Tree Canopy
Professional foresters, of course, take all kinds of variables into account when measuring timber stands. Apart from the actual trees, foresters examine water, viewscapes, wildlife corridors, and many other values in the forest.
Bank economist Connor McDonald co-authored the report. The TD urban forests report is part of a larger bank initiative. On its site (link: http://www.td.com/corporate-responsibility/tdforests.jsp), the bank has mapped out urban forests across North America.
Carol Walker, manager of forestry policy and planning with the City of Toronto, said she was glad to see a bank validate the importance of the urban canopy.
Urban forests are more than just pretty scenery. The bank’s report said trees are an important aspect of human health and quality of life.
Trees help ease the burden on towns and cities of managing snow and rain and also remove about 25 per cent of all emissions expelled by various industries in a given municipality.
York’s trees soak up the pollution created by millions of vehicles and help manage temperature, both by blocking cold winds in winter, but also keeping communities cooler in summer.
The report looks at Toronto’s urban forest of 10-million trees from an economic perspective, calculating the value each tree provides by saving energy, keeping rain and snow off the streets and absorbing pollution, and lays out a number of ways in which the city’s trees are paying dividends to residents.
“Urban forests represent an important investment in environmental condition, human health and the overall quality of life,” the bank’s chief economist Craig Alexander said in the report.
Although it’s not intuitive to think of a city of almost three million people being anything like a forest, Alexander notes that there are more than 10 million trees of at least 116 different species crammed inside the city limits. A bird’s eye view of the city shows as much as 30 per cent of Toronto’s space — more than 190 square kilometres — is covered by trees or shrubbery.
There are about 16,000 trees in the city limits for every square kilometre of space, or about four trees for every person. And all that greenery is worth a lot of green, Alexander said.
“It’s easy to forget that trees have a monetary value,” he said. The replacement value of the city’s tree cover is about $7 billion, or $700 per tree.
The report’s authors found the trees provide more than $80-million of savings and environmental benefits every year, working out to about $125 in annual savings for the average single-family household.
Alexander came up with that number by adding up both what it would cost to physically replace each of Toronto’s trees, but also by factoring in the economic benefits those trees are quietly performing behind the scenes.
Trees help ease the burden of managing snow and rain, the reports notes. Every year, Toronto’s tree cover intercepts about 25 million cubic metres of precipitation. If they weren’t there to do that, that’s an extra $53 million the city would have to pay out to perform the same task.
“When it rains the water is going to go into the ground, but the trees help the ground absorb the water and it actually takes pressure off the foundations of homes,” Alexander said.
They also remove about 25 per cent of all emissions expelled by the city’s various industries — that’s about 19 million tons of air pollution a year. For context, that means Toronto’s trees soak up the pollution created by one million cars, or 100,000 homes, per year.
It’s also well known that trees help manage temperature, both by blocking cold winds in winter, but also keeping the city cool in summer. Alexander said the net cooling effect on the city of a young, healthy tree is equivalent to 10 room-sized air conditioners, running 20 hours a day.
The total amount of carbon currently stored in Toronto’s urban forest is estimated at 1.1 million tonnes — roughly the amount emitted by 700,000 cars a year.
“Every year, the City of Toronto’s urban forest sequesters over 46,000 tonnes of carbon, which is equivalent to the annual carbon emissions from 31,000 automobiles or 16,000 single-family homes,” Alexander said.
Large, healthy trees absorb 10 times more air pollutants, 90 times more carbon, and add 100 times more leaf area to the city’s canopy.
Toronto benefits from a particularly lush tree canopy, with about one-third of the city covered by trees. In comparison, about one-fifth of Vancouver, BC, Ottawa, ON, and Montreal, QC, falls under tree canopy, according to municipal estimates.
The report didn’t include benefits that are difficult to assign a dollar value, such as beautification, green space for recreation and importance to the community.
“What value is there to a family being able to take their kids to the park in order to play and sit in the shade in the summer? How do you put a dollar value on that? The answer is you can’t,” Alexander said. “We are probably deeply underestimating the value.”
The full report is available here: http://www.td.com/document/PDF/economics/special/UrbanForests.pdf