Trees have been making a lot of news around Vancouver lately — between last year’s big wind storm bringing down some of the larger specimens along 12th Avenue, vandals topping trees near Spanish Banks and, more recently, on Langara Golf Course. So when Peter Francis saw two mature oak trees near his home on East 43rd slated for removal, he sounded the alarm.
He said he was told by city staff the trees were rotting, but he questioned that statement after the first one was cut down last month. He said he didn’t see any signs of rot. He also noted the trees survived December’s windstorm that toppled more than one tree and brought down branches across the city.
The two oaks were cut down in mid-January.
“These recent actions have denied us the shading these 60-ft [tall] trees provided, homes and foods for the squirrels,” Francis said in an email.
“My house and our block is much poorer for this.”
City arborist Amit Gandha said the trees had to be removed because they had “extensive fungal fruiting bodies” on the trunk, which caused concern about the stability of the trees.
“Every tree has different diseases that attack it, but for oak when you start to see fruiting bodies, then there’s major concerns about the root system underneath,” Gandha said.
“Sometimes from above ground it doesn’t look like much, but what happens is the roots are actually dying and so the stability of the tree is being undermined… if we wait too long for oaks they basically just fall, they don’t die back.”
The two oaks were among the more than 147,000 trees lining the streets and boulevards of Vancouver, and each and every one is inspected on an annual basis.
“What we’re looking for is anything that is obviously hazardous, dangerous or [signs] of disease, and also just maintenance,” Gandha said.
Staff also responds to calls from residents with concerns about particular trees, and sometimes when there is construction on a street, a private arborist will alert the city to any concerns about a nearby tree. In those cases a city arborist will follow up and do another inspection of the tree to corroborate the claims.
Any work that needs to be done is then prioritized based on the level of risk and potential damage.
“We want to take care of anything that’s hazardous prior to any, say, cosmetic pruning,” Gandha said. “We want to make sure that we get those things done first prior to anything else.”
Trees are removed if they are dead, diseased, or if major sections are split or cracked. If more than a third of a tree is considered “ready to fail” it’s removed.
“There’s no point in sometimes leaving a tree that’s going to be half removed… you’re better off to just remove the tree and get a new one in so we can get it growing,” Gandha said.
Roughly one per cent of the total number of street trees in the city are removed on an annual basis — that number includes trees that are diseased and/or dying, those that come down, or are heavily damaged, during storms, or in car crashes.
Gandha added that occasionally trees need to be removed due to conflicts with underground transmission lines or gas mains.
“Sometimes when there’s issues with the systems underground the tree needs to come out,” he said. “That’s infrequent but things like that could happen.”
Any tree that comes down is eventually replaced as staff looks for any opportunity to increase the number of street trees in the city.
“So if, say, the spacing wasn’t quite adequate and now we can fit two trees into the same area, we’ll try to do that as well,” Gandha said.
There are more than 500 species of trees planted throughout the city and maintaining diversity in the types of trees is a way to keep the tree stock healthy and minimize the risk of one disease coming in and wiping out a large swath of trees. However, in some cases where a neighbourhood has historically had more of one type of tree, staff will try to maintain that aesthetic.
“There are certain streets that we would probably keep that look because it almost identifies some parts of Vancouver, for example cherry trees line certain streets,” Gandha said. “Things like that we try to retain that as much as possible but for any new blocks or streets, redevelopment, we’re always trying to diversify the species.”
As for what happens to the trees that come down, most of the wood is chipped and reused for pathways or restoration where staff is trying to eradicate an invasive plant.
However, since most of the street trees in the city are hardwood, Gandha said staff is currently looking at ways to make some of it available to local residents.
“If there’s people that are interested in woodworking or doing things like that we’re trying to figure out a way to actually have a site where we can take it to and then people can basically take the wood and use it.”