Ash tree replacement gets growing, Markham says

Yorkregion.com
March 31, 2016
By Amanda Persico

After several years of tree stumps and empty boulevards, Markham streets will once again bloom.

This year, the city will plant some 6,000 trees along boulevards and in parks as part of the emerald ash borer recovery plan.

By 2017, 17,200 ash trees will have been removed and new trees will be planted.

“We are beyond the cusp of tree removal,” said the city’s operations director Barb Rabicki during a recent general committee meeting.

“2016 is on upward swing, with a strong positive replanting program underway.”

But planting trees and beautifying streetscapes in the wake of trees being killed by the emerald ash borer infestation, is not without its challenges.

When the city launched its EAB program, residents were able to see an online map of which trees would be axed street-by-street.

Planting new trees is more complicated, Rabicki said.

“We hear a lot, ‘My neighbour's tree was replanted, why not mine?’” she said. “It’s a difficult process with so many moving parts.”

Markham, along with other municipalities that lost thousands of ash trees, is facing an unexpected challenge – low supply and high demand for trees.

Cities and towns across North America are competing for the same Canadian tree stock, Rabicki said.

Coupled with the low dollar, U.S. municipalities are “buying stock in great numbers,” she added.

Last year, the city made about 800 substitutions for different tree species. That meant reconfiguring where each tree was planted, since Markham’s recovery plan relies heavily on tree diversification – creating small groupings of similar trees.

The lack of tree stock created pockets of empty boulevards.

“It’s not a matter of this tree came out first, so it is replaced first,” Rabicki said. “It could mean planting on one side of the street, waiting for the right tree species then planting on the other side of the street the following year.”

Other tree species come with risks, Rabicki added, noting the Asian long horn beetle preys on maple, poplar, elm and willow trees.

“Everyone loves maples. We can’t continue to just plant maples,” she said. “The only way to move forward is to diversify.”

The city is also looking at planting fruit trees in parks and naturalized areas.

The city also needs to look at rehabilitation programs, especially for Pamona Mills in Thornhill where a large number of trees were removed.

This empty space allows for invasive species, such as garlic mustard to take root, Rabicki said.

The EAB program, costing more than $13 million, also included a tree inventory, which was completed last year and lists all of the city’s 105,000 boulevard trees and 45,000 park trees.

As part of the tree inventory process, 1,800 greenspaces, such as woodlots, parks, easements, paths and trails were assessed and some 4,300 ash trees still need to be removed.

The city also assessed woodlot trees within about 10 metres of private property or public spaces.

“Residents tend to put children’s play equipment or a tree house near shaded areas,” Rabicki said.

Removing ash trees in greenspaces was not part of the initial $13.1 million budget approved by council several years ago. But with favourable prices and savings found in other areas, such as street tree removal, the initial budget would also cover this phase, Rabicki said.

As well establishing a rehabilitation plan, the city also needs to look long-term, beyond 2018.

“We just planted thousands and thousands of trees,” Rabicki said. “We have to make sure these young trees have a good, strong structure. We have to continue to assess and inspect these trees.”