City Trees

January/February 2011

City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!

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Page 22 of 39

R O U N D T ABL E Preparation, Detection, and Planning Strategies for Emerald Ash Borer Photos by Steve Cothrel except where indicated (EAB) in the Oakville, Ontario’s Iroquois Ridge South Community in July, 2008. This would seem to confirm our early speculation that the EAB population had been building undetected for several years in this neighbour- hood—not unlike the pattern throughout EAB’s range to date. The next month, we began treating approximately 100 ash street and park trees with TreeAzin. Today, the only ash trees which are alive and healthy in this neigh- bourhood are those which we treated. Our treatment results indicate a 99.9 % efficacy rate. F But where else was EAB in Oakville and at what levels of infestation? With no formal urban forestry support program in place in Canada and Ontario, lower tier municipalities like ours were on our own to find out. I did not realize at the time that we would play a role in creating the detection and delimitation surveys to answer these questions. My understanding is that the current Canadian Food Inspection Agency (CFIA) guide- lines for detecting EAB, published in 2006 and 2007, miss three out of four infested ash trees because they rely on visual survey techniques that often only show late stage infestations. How were we going to reliably map EAB in time to man- age it? Should we treat more trees? Should we follow the CFIA protocol successfully employed for Asian Long- Horned Beetle at the City of Toronto in 2003 and begin sanitizing the host and replacing the canopy? Furthermore, where are Oakville’s 177,300 public and private ash trees located? Fraxinus represents 9.3% of the Town’s urban forest, according to our 2005 Urban Forest Effects Model Project with the U.S. Forest Service. The ecological services these ash trees pro- vide include $108,300 in annual pollutant removal and contribute towards the Corporate Urban Forest Canopy objective outlined in the Town’s Official Plan. As the town’s urban forester I had a sinking feeling in the pit of my stomach that the future for EAB was going to be like that described to me by some of my colleagues in southwestern Ontario: chaos. Was this Dutch Elm Disease (DED) all over again? Ironically, I gained confidence by speaking with some of the people involved with success stories of DED; specifically the city of Fredericton, New Brunswick which After removing most of the large old ashes along streets, Upper Arlington, Ohio is beginning to remove younger trees before ash mortality overwhelms the City’s limited staff. saved approximately 80 % of its elm canopy (I am also aware of similar successes in the District of Columbia and Winnipeg, Manitoba). If they could do it, perhaps we could too? The town retained BioForest Technologies as our EAB consultant. BioForest developed an EAB Emergency Response Plan that Council approved in the fall of 2008. It outlined the following key areas for the town to build in order to fight this long-term battle: (1) Inventory; (2) Strategic Management Plan; and (3) Budget. All three components need to complement each other in order to be effective. It also stressed that this insect should 23 ollowing a discovery by a private citizen, the Canadian Food Inspection Agency confirmed Emerald Ash Borer

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