Dry soil from summer-long drought caused trees to fall in B.C. storm
A local arborist is saying the high number of fallen trees from the storm in Metro Vancouver over the weekend might be a result of the summer drought and poor planning from the city.
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Owner of Green Crown Tree Care Jason Malysh told Vancity Buzz that poor soil conditions likely lead to more toppled trees that damaged multitudes of parked cars and homes.
“With the drought, the soil changes shape because without the moisture in it you get all these really small fissures, so the roots that are holding the trees up rely on the soil holding to itself,” he said.
“Right before the winds hit, we had some heavy rain and it was enough to change the soil slightly again and I think that played a really big part in it.”
The fact that many deciduous trees still have leaves could have played a part as well, since they act as small “sails,” catching the wind.
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Not only that, Malysh said recent changes to Vancouver city bylaws might have also played a part in the number of trees that have fallen down.
“Once a tree gets to be 20 centimetres in diameter, you’re not allowed to remove it unless it’s an immediate threat of causing serious damage, which in most cases, you can’t really predict that,” he said.
“You really need to think about what you’re planting or making sure and getting some advice on good species for the spot, because once it’s 20 centimetres, no matter where it is, you’re stuck with it until it damages your house.”
Malyish said certain species like Freeman’s Maples are inherently weak and are being planted by the thousands by the city. He said he saw 15 of them having major failures on Sunday alone and recommends anyone considering planting them on their property to rethink their decision.
“The nurseries tend to peddle certain trees, when they’re not necessarily the best species. I think a lot more thought should be put into selecting trees for planting, especially with the new bylaw.”
On the City of Vancouver’s website, it states trees may only be removed from private property under the following conditions:
- The tree on a development site is located within the building envelope
- The tree is located such that a proposed garage or other accessory building cannot be located so as to retain the tree
- An arborist certifies the tree is dead, dying, or hazardous
- An arborist certifies the tree is directly interfering with utility wires and cannot be pruned and still maintain its reasonable appearance or health
- An accredited plumber certifies that the roots of the tree are directly interfering with, or blocking sewer or drainage systems
“Last year the Park Board planted 229 Freeman’s Maples (and about the same number were planted the year before), mostly Autumn Blaze and Scarlet Sentinel,” said Superintendent of Urban Forestry for the Vancouver Parks Board Bill Stephen in a statement.
“They have a very strong root system. We no longer plant Freeman’s Maples that tend to experience branch breakage. Over the years urban forest crews have become acutely aware of what works and what doesn’t and adapts accordingly. The Park Board tends to plant Freeman’s Maples along arterial streets because they are very tolerant of urban stress such as pollution and grow well in constrained areas.”
Vancity Buzz reached out to the City of Vancouver to comment on the tree bylaws but did not get back to us by the time of publication.