Vancouver Island trees are losing their limbs as drought conditions aggravate existing health problems, and experts warn the consequences could be seen into the storm season this fall.
Arbourist Trevor Coey pointed to a massive branch that broke away from an oak tree last week, scraping past two vehicles and narrowly missing a pedestrian when it fell.
“It’s a phenomenon called sudden limb failure or sudden limb drop,” said Coey, who works with Bartlett Tree Experts.
“The issue right now, of course, is this prolonged drought we’ve been having. … We’ve seen quite a few different species decline or die as a result of the drought.”
The branch blocked traffic for more than five hours on Aug. 19 at Foul Bay Road and Granite Street, said Oak Bay Police acting Sgt. Rick Anthony.
Chris Hyde-Lay, Oak Bay’s manager of park services, said most sudden limb failures occur on horizontal branches and are tied to an internal flaw. In this case, a poor pruning cut in the tree’s past was the main problem, but drought made it worse.
Falling tree limbs aren’t unusual toward the end of summer, but Coey said he began seeing them as early as June this year.
He attributed that to dry conditions, which make trees more vulnerable to root diseases, vascular diseases and insect attacks. A dry tree is like a human with a compromised immune system, he said — it’s more susceptible to threats.
Limb failure has struck Garry oaks, elm, willow trees and other varieties. In some cases, apples and plums have grown so heavy that fruit-tree branches have broken, too, Coey said.
Native species and introduced species are both experiencing health problems, he said.
Coey recommended that homeowners have mature trees regularly inspected by a qualified professional, monitor root temperature and prune trees.
Taking care of trees when they’re young is critical to their structural development, he said.
B.C. Hydro spokesman Ted Olynyk said trees and branches have fallen on power lines up and down Vancouver Island this summer — especially maples.
Olynyk observed similar dry conditions in 2006, which was followed by heavy storms.
“Otherwise healthy trees came down. That caused a real problem for us. Our customers experienced some severe outages,” he said.
British Columbia has more trees per kilometre of power line than any other province, Olynyk said, and the highest concentration is on Vancouver Island.
B.C. Hydro responded by investing more resources in its vegetation-management program, which monitors tree growth near power lines, he said. It has also re-routed certain lines, so that power can be restored more quickly.
The challenge is that even if B.C. Hydro identifies an unhealthy tree, it is restricted from using chainsaws in many areas because of the fire risk.
“There is a restriction on chainsaw use in rural areas, so it’s an ironic twist,” Olynyk said.
Residents should prepare an emergency kit in case of power outage, he recommended.
Like an earthquake kit, it should have a radio, batteries, food, water, a flashlight, candles and other resources, he said.
“Small storms can be the snooze alarm for an earthquake. Are you prepared?” Olynyk said.