BY WILLIAM STEINBERG AND TREVOR LANE, SPECIAL TO THE GAZETTEAPRIL 28, 2014
Stumps of ash trees line Fielding Ave. in Notre-Dame-de-Grâce on Wednesday, April 23. The N.D.G—Côte-des-Neiges borough has cut down 200 trees to try to slow the spread of the emerald ash borer.
Photograph by: John Mahoney , The Gazette
MONTREAL — The city of Montreal has announced plans to spend millions of dollars to limit the destruction of Montreal Island’s 200,000 ash trees by the emerald ash borer (EAB) beetle.
Much of this money will be wasted.
The EAB first arrived in Michigan in June 2002 and is now in at least 12 states, plus Quebec and Ontario. Some 200 million trees have already been killed by the EAB. The most effective treatment is TreeAzin. It works by sterilizing the female EAB adult (but not killing any EABs) and thus reducing the increase in EAB numbers within the treated tree. It works for two years and then it must be applied again. However, the cost is $200 to $400 per application — and in areas where the EAB has reached high saturation levels, the trees are very likely to die anyway. It will just extend the life by a few years at best.
TreeAzin is not effective when the tree is more than 25 per cent infested. And it is only effective in a small seasonal window between mid-May and August. What’s more, it does nothing to stop other EABs from arriving from other trees within 300 metres.
Montreal’s plan to cut down or apply TreeAzin to trees within 300 metres of an infested tree ignores private trees within the area. EABs will travel from the private trees to the remaining public ones. Furthermore, it is hard to detect the EAB when the level of infestation is just starting — so many trees will be missed until the window for treatment is past, or until they are too infested to be treated.
Montreal’s own experts have told us that they expect virtually all ash trees on the island to be lost within 10 to 15 years. They have told us that cutting infested trees as soon as possible, or applying TreeAzin, will slow the destruction — but not change the final result.
At the rate of EAB spread since 2011, when it was first detected on Montreal Island, it appears that it will be no more than 10 years before we have no more ash trees.
Hampstead has been in the forefront of dealing with this problem.
Unlike Montreal, we have an inventory of all trees (not just ash trees) on our territory — both private and public trees. Montreal has surveyed only public trees. With a complete inventory, we have chosen hardy trees that are under-represented to replace the ash trees we will lose. This will increase our biodiversity and make any future infestations less devastating.
We are removing trees once we detect the infestation, during the legal window from Nov. 1 to March 31. Federal regulations prevent transportation outside of that window. We have put aside $450,000 to eventually replace all 578 of our public ash trees.
We did try TreeAzin last year on 126 larger ash trees in prominent locations like parks. One has already died, and we expect many more to die before it is time to reapply TreeAzin.
For the reasons given above, we are no longer using TreeAzin.
Our money is being spent to remove and replace trees.
Montreal would be wise to do the same.
William Steinberg is mayor of Hampstead. Trevor Lane is public-works foreman in charge of green issues for Hampstead.