How an inventory of Saint John trees can help prepare city for climate change

Many people may not give a second thought to the trees they pass by on the street, but studies have shown urban forests can do everything from reducing stress and improving physical health to boosting property values.

Now, some people are turning to trees to help mitigate the impacts of climate change.

The Atlantic Coastal Action Program in Saint John has taken an inventory of urban trees in three Saint John neighbourhoods — the central peninsula, the lower west side and the old north end.

"As we look ahead to the impacts of climate change, [trees] will have a significant impact on how we create a resilient community when it comes to stormwater, when it comes to controlling heat, thanks to the lovely shade they provide us in summer, wind breaks, a lot of other great benefits that can actually save, in our case, the city of Saint John, a lot of costs moving forward," said Graeme Stewart-Robertson, executive director of ACAP Saint John.

The purpose of the inventory is to help the city know where it should invest in planting trees.

"We realized there were some knowledge gaps that we didn't have a clear understanding of what Saint John's urban forest contained … the heights or the health or the species composition of many of those trees," Stewart-Robertson said.

The group has been measuring and collecting data on Saint John trees for three years. The three neighbourhoods it started in have now been completely inventoried.

Stewart-Robertson said some streets in the city, like Douglas Avenue, that are renowned for their trees, and others where there aren't many trees at all.

In some cases it is simply a matter of chance as to which streets have trees and which streets don't, but Stewart-Robertson said a lot of it comes down to when a street was built or rebuilt and whether new trees were planted.

"What we want to do is be cognizant of the values that have then grown within those streets, how much more people value those streetscapes, how comfortable they feel spending time outdoors in those spaces, and the value it brings to us as a community," he said.

Another benefit to urban trees is that they are a relatively cheap investment to help mitigate some of the effects of climate change.

In the north end, Stewart-Robertson said there were about 200 trees in the public realm, meaning trees along streets or hanging over intersections, as opposed to being on private property. ACAP's waterfront restoration in that neighbourhood this year added another 300.

"It is possible to make significant growth to our urban forests for relatively low expenses."