The heat wave and unprecedented drought conditions in British Columbia could be the cause of leaf fall from some Vancouver trees this week, according to a scientist.
Social media was filled with photos of trees drying out on the streets of Vancouver last week.
Tree leaves turn brown and fall as a defense mechanism plants use to conserve water in dry conditions, according to the Vancouver City Parks Director.
While June saw its first rains of rain, the province’s record heat wave did not bring rain to the south coast for most of the month and until the first week of July.
Stephen Sheppard, professor of forestry at the University of British Columbia, says cities should be proactive in watering their urban trees and filling tree water bags.
“We probably need better coordination and, frankly, the support of local citizens, just to maintain that number of trees,” he said.
âIt is a huge task for any city to water all the trees on the streets during a two or three week period of drought.
Forest management plans must adapt
Sheppard says municipalities need to consider more heat waves in the coming years as part of their urban tree management plans.
As a general rule, municipalities expect to water new plants and saplings regularly. However, Sheppard says older and more mature trees have been particularly affected by recent droughts.
âI think what we’re seeing with these trends in cities like Vancouver, Surrey and others that are looking very seriously to prepare for greater urban heat is that they will need larger budgets in the future. ‘future,’ Sheppard said.
The City of Vancouver’s Urban Forest Strategy says Vancouver’s trees, whether planted along the road or in parks, highlight the role of tree canopies in cooling parts of the city. the city.
At the height of the heat wave in Vancouver last week, this aspect of tree cover was brought to light as Vancouver’s poorest neighborhood had far fewer trees and suffered a ‘heat island effect. “.
âTrees are a kind of natural air conditioning and the cheapest way to cool neighborhoods,â Sheppard said.
Vancouver’s Urban Forest Strategy also notes that cherry and maple trees âshouldn’t be doing wellâ as the weather warms due to climate change.
Sheppard shares this concern, saying that in his anecdotal experience, maple trees have shed more leaves than usual this year.
Maple is Vancouver’s most common tree, making up almost 25 percent of all trees in the city. Cherry trees are the second most common at around 20 percent.
Sheppard says species that are not used to hot climates, such as the province known during the heat wave peak, could suffer particular “damage” over the next few years.
Vancouver and Surrey are both committed to planting more diverse species as part of their urban tree plans.
For now, Sheppard says residents shouldn’t hesitate to water trees and plants that appear particularly dry.
âWe have to save them so they can save us from heat waves,â Sheppard said.
Vancouver residents can also call 311 or use the VanConnect app to report trees in need of water to the park council.
To listen to Stephen Sheppard’s interview on CBC’s On The Coast, press the play button:
On the coast7:15Trees after the heatwave