The City of Ottawa wants 40% of its land to be covered in trees in the future, according to the new official plan, 31% more than in 2017. But after the May law and the 2018 tornadoes destroy many thousands of trees in the area, it is unclear to what extent this goal can be achieved.
As efforts to repair the canopy take shape in the coming weeks and months, and as climate change causes increasingly powerful and frequent storms, a more resilient canopy of trees is needed to cope better, they say. forestry and green space advocates.
A detailed picture of the damage has not yet been shown as the cleanup continues after this latest storm, but it won’t be long before it materializes.
In 2017, an important assessment of the canopy of trees was made for the entire region of the national capital, producing a very detailed interactive map of the canopy as it existed that year (the results were made public in 2019).
It showed that 31% of Ottawa was covered with trees, compared to 45% in Gatineau and 76% of the lands of the National Capital Commission (NCC) in and around the two cities. controlled by NCC are not included in Ottawa and Gatineau). figures).
According to Jason Pollard, Ottawa Forest Department Section Manager, the next detailed assessment, which is being conducted every five years, is expected to begin this month with air flights as long as the weather cooperates.
It will take months to collect and process the data (a combination of aerial imagery and lidar data that reflect everything on the Earth’s surface), but when it is over, it will show us how destructive law and tornadoes were throughout the region. . among other changes.
Wind-blown trees still partially block a road from Goldfinch Drive to Kanata on June 14, 2022. (Francis Ferland / CBC)
Some neighborhoods lost a lot of trees
The city of Ottawa covers a large area and a general fall in the canopy of trees could even represent “a massive number” of destroyed trees, said Paul Johanis, president of the capital’s Green Space Alliance. of Canada. The organization urges the municipality to protect and expand the city’s tree cover.
But zooming in to examine the hardest hit areas, Johanis said neighborhoods that had about 50 percent tree cover could see them reduced by as much as 20 percent.
“I think we will see very measurable impacts … because at the neighborhood level, it really had a big impact on those who were severely affected by the law,” Johanis said.
“Clearly, this is unprecedented. I don’t think we’ve seen anything like this before in terms of damage.”
Paul Johanis, president of the Greenspace Alliance in the Canadian capital, says tools to improve the city’s tree cover are in place, but more money is needed to support them and get more trees on the ground. (Francis Ferland / CBC)
Pollard described the right as “the most significant forest-related forest disturbance in decades,” with damage varying in intensity in each neighborhood.
Some of the hardest hit areas already had little tree cover, according to the 2017 canopy assessment, which was mapped by the Ottawa Neighborhood Study to allow residents to search for specific tree canopy percentages. of their neighborhoods.
Only 15 percent of Navan and Sarsfield were covered in trees in 2017, for example, and Stittsville had a canopy of only 21 percent.
Blossom Park, Merivale Gardens and Greenbelt were also severely affected. They boasted of some of the densest tree cover in the city at around 44, 52 and 40 per cent, respectively, and may see these figures reduced.
How some of the damage to the law looked like from above
This drone video shows heavy damage in the Blossom Park neighborhood of Ottawa after a severe storm on May 21st. (Video by David Johnson)
Researchers are expanding the area of damage on the EF2 descent
Meanwhile, researchers at Western University’s Northern Tornadoes project have continued to assess damage in and around Ottawa from the right and have found that EF2 tornado-induced winds caused damage along a much longer path than it was initially thought.
Although no tornadoes landed in the city, an EF2 descent, with winds reaching an estimated maximum of about 190 km / h, occurred in the southeast along a road that is now believed to be it is about 36 miles long and five miles wide.
The entire damage area on the EF2 descent is now about 36 miles long and just under five miles wide, according to Western University’s Northern Tornadoes project. Yellow indicates intermittent EF2 damage, green indicates intermittent EF1 damage, and blue indicates intermittent EF0 damage. (Northern Tornadoes Project)
The EF2 Intermittent Damage Zone begins just east of Ottawa Airport around Blossom Park, continues east through the rural areas of Navan and Sarsfield and ends beyond Hammond community in neighboring Clarence-Rockland, Ont. Damage includes roads with most trees broken or uprooted, farm outbuildings and felled silos, and broken hydraulic poles.
Investigations also reported intermittent damage to EF0 (104-137 km / h) and EF1 (138-177 km / h) over a much wider strip of eastern Ontario and western Quebec.
They used satellite imagery taken just before and after the storm (May 18 and May 25) to examine changes in tree cover. Some dramatic differences could be seen in McCarthy Woods; the forest along the Rideau River on the west side of Ottawa Airport; a wooded area between Frank Kenny Road and Delson Drive in Navan; and along the northeast shore of Mer Bleue Bog, among other places.
Researchers created this map of tree damage to satellite trees visible in southeast Ottawa and beyond after the law. Each black X marks identifiable changes to the tree cover, and the red X indicates worse damage. (Northern Tornadoes Project)
Build a resilient canopy in the face of climate change
Some patterns have begun to emerge on what went down to the right: many coniferous trees (many fir trees and large white oriental pines), as well as linden trees, according to Pollard, the city’s ranger.
Plans to replace the fallen trees have yet to be made with the cleanup still underway, Pollard said, but discussions will take place in the coming weeks and months.
“Maybe we should look for ways to increase the number of trees that are planted,” he said. “Once we get past this initial phase of removing dangerous trees, we will have time for … staff to examine areas that need a specific planting effort in response. We are not there yet.”
Jason Pollard, manager of the City of Ottawa’s forest services section, says Ontario’s forest departments need to build more resilient canopies to withstand the effects of climate change. (Francis Ferland / CBC)
Replanting efforts will need to focus on strengthening tree tops to better manage the most powerful and frequent storms, he added.
“Looking to the future, I believe that for any Ontario municipal forestry organization … we all need to think about how to create a forest canopy that is resilient to climate change and the harshest climate,” Pollard said.
“This will include things like species diversity, but also diversity in … the age of the species and the age of the treetops.”
It’s really a matter of decades before the canopy is restored. – Paul Johanis, Greenspace Alliance of the Canadian capital
Johanis of the Greenspace Alliance said the city has moved in the right direction in recent years with a strengthened tree regulation and a relatively new forest management plan, but more money is needed to see these changes. and get more trees on the ground.
“It’s really a matter of decades to get the canopy back to the way it was. facing the canopy replacement more effectively, “Johanis said.
After the law, a new challenge: how to make “more resistant” forest canopies.
Jason Pollard, Ottawa City Department of Forestry section manager, says the severe storm in late May raised concerns about how to protect the treetops from future weather events.
How to replace trees
Want a free tree seedling to plant on private property, perhaps to replace one that fell in the storm? Ecology Ottawa is giving away 20,000 seedlings this year and there are three gift events today and this coming weekend. After June, more gifts are expected for the fall planting season.
The city of Ottawa is trying to plant about 100,000 trees in a normal year, according to Pollard. The spring planting season usually occurs between May 1 and June 30, but the remainder was canceled after the storm to allow crews to concentrate on cleaning. All scheduled spring plantings have been extended into the fall.
“While postponing planting and canceling events is disappointing, I want to assure council members that we will look closely at how to restore forest cover to the community once the storm cleanup efforts are complete,” Alain wrote. Gonthier, general manager of the city. of public works, in a note dated June 1 in the town hall.
Arborists in the city of Ottawa will clear fallen trees and branches in Aladdin Park, south of Ottawa, near the airport, on June 17, 2022, almost a month after the May 21 law. Crews are still focused on cleanup efforts and will later focus on replanting efforts in the hardest hit areas. (Jacques Corriveau / Radio-Canada)
In the parks, staff are working on a list of significantly damaged trees to replace in 2023 and beyond, according to the city.
Anyone who wants to replace a city tree on their property across the street, or plant one where there is space, can apply online for the city to plant a tree. It’s free, but there are conditions and criteria to be met, such as the owners agreeing to water the newly planted trees …