Seeing Urban Forests Instead of Just Trees

If you live in an urban setting, then whether you know it or not that tree on your property big or small, is part of an urban forest. And while many of us have difficulty grasping the concept of an urban forest (we literally can’t see the forest for the trees), the fact is the trees and woody plants that make up an urban forest have a dramatic impact on quality of living.

One of the most important benefits is heat mitigation. Trees provide invaluable shade and a much-needed cooling effect – which couldn’t be more timely with global warming and heat waves this year that have affected cities across North America and Europe.

The new normal – especially in major urban centres is that as you venture into the core of a city and higher density areas, a phenomenon known as heat sinks occur, with temperatures several degrees higher than outlying areas. Not surprisingly then, cities are placing much greater importance on having healthy tree canopies. One of the more ambitious tree canopy programs in the world is currently taking place in Melbourne, Australia, which has a noble goal of going from a current tree coverage of 22 percent of the city’s footprint to 40% by 2040. Toronto is no slouch either, with the target of going from 19.5 percent (according to a recent MIT study) to 40% by 2050.

I recently had the opportunity to attend an urban forest conference in Mississauga, organized by GTA consulting firm Urban Forest Innovations and following the conference had a chance to speak with principal consulting arborist Philip van Wassenaer. From his perspective, which goes back to the forest and trees analogy, all too often the question city dwellers ask is what’s the city doing about our trees? But failing to recognize the bigger picture and the fact that not just the city but residents and businesses have a shared responsibility for urban forests. “City trees typically only make up 15-20 percent of an urban forest,” observes Wassenaer. “The rest are on private, commercial and industrial property on land not owned by the city.”

So why should we collectively care more about our trees and begin to embrace the forest mindset? Wassenaer is quick to reference health and mental well being as a strong function of urban forests. “There are more than enough studies on the green calming effect of trees. For instance, if you take a walk in a ravine in Toronto, after 15-20 minutes, you feel better. You feel more relaxed. In fact, it’s such a recognized benefit in places like Japan, that they call it ‘forest bathing’.

Yet another benefit is cleaner air. “Trees are quite good at trapping particulate matter as small as 10 micrograms,” says Wassenaer. “They get caught on the surface of trees and needles and when the rain comes, those particles get washed out.”

Tree Canada (www.treecanada.ca) lists several other urban forest benefits that tie in with ecological, climactic, psychological and monetary gains, including: a habitat and food source for wildlife, noise mitigation, reduced dust levels, carbon sequestering, conservation of energy and flood relief.

Despite the multitude of benefits, Wassenaer says what’s often lacking is a long-term comprehensive urban forest management plan that addresses everything from the health of existing trees that aren’t cared for properly (or are being killed by pests and disease), to the failure of many communities to replace trees that are being needlessly cut down.

Toronto to its credit does have an urban forest management plan of its own, that ties in with its 40% canopy by 2050 goal. But without public support, it could be an uphill battle to reach this goal. “If you’re trying to grow your canopy but you’re losing maybe 5% of your trees a year due to disease and if residents are letting their trees die, it’s pretty hard for the city to manage,” says Wassenaer.

In response to that challenge he says, residents, businesses, politicians and professionals need to stop acting in silos and work together in support of more comprehensive, long term urban forest management programs – as opposed to sitting back and expecting municipalities to do the heavy lifting. Considering the numerous benefits, it’s time we all take a more active interest in growing our tree population and promoting greener communities. 

Author's Note: This article was originally written for Postmedia and appeared in the Aug. 18 issue of the Toronto Sun. For more articles like this, visit Mark's blog Sustainable Community Builder.