York University Grounds Department continues to deal with its biggest threat the Emerald Ash Borer.
It has been 3 ½ years since Tim Haagsman and his Grounds staff identified and initiated a strategy for dealing with Emerald Ash Borer, which has proven to be as serious a threat to our urban forest as predicted back in 2012. The key elements of the strategy were 1. Assessment and monitoring, 2. Conservation, 3. Tree removal and replacement, 4. Restoration through home grown nursery stock, and 5. Information and Education. For additional information refer to the York University Strategic EAB Management Plan.
A big part of the assessment and monitoring role has revolved around our tree inventory system. As of this spring all the trees at both the Keele and Glendon Campus with the exception of those in wood lots now have a specific identity tag affixed to them as per the enclosed photo. This tag allows Grounds to track each tree’s attributes, including it’s size, health and exact location, using GPS coordinates, as well as all maintenance that has been performed on the tree. In total, 7,029 trees have been tagged at Keele Campus and 849 trees have been tagged at Glendon Campus. The complete inventory is available for use by anyone interested, simply click on the Keele Campus Tree Inventory.
Tree with Identity Tag Affixed
A big part of the conservation endeavors have been the continued use of Treeazin a systemic bioinsecticide chemical recommended for use on infested trees with 30% or less foliage loss. In 2012 when we began the injections it was believed at the time that applications every other year would be adequate to ensure tree survival with minimal insect damage. Of the approximately 600 ash trees on campus the original goal was to preserve 90 high quality trees. Unfortunately as a result of significant damage that occurred during the ice storm on December of 2013 and the ineffectiveness of the Treeazin in some trees we are now down to 43 trees. The plan now is to continue to inject the these 43 trees on an annual bases and hope we can sustain the trees through the 12 to 15 year infestation period, as predicted by urban forest experts .
With reference to the remaining 510 trees, we have already removed approximately 250, including the removal of the stump and below ground root system and hope to remove the remaining non injected trees over the next 12 months. The goal of our strategy is to replace every ash tree with a new tree which is being in done in conjunction with the removal program. The replacement trees are all species that are native to Canada and include oak, tulip tree, cedar, maple, birch, ironwood, amur cork tree and butternut, some of which we are provided from our own on campus nursery.
Another element of conservation initiatives is the utilization of the wood from the trees that are removed. The trucks from the larger trees with appropriate form as being stock piled with the hope that we will be able to attract a future buyer, and a number of trees has been given to our Fine Arts Faculty for use by York student who are enrolled in the Sculpture Program. The remaining the trees are ground into wood chips that is used as mulch to dress up the shrub beds and existing trees on the campus.
If you have any question or concerns beyond the information that is available on the website you can contact Tim Haagsma, York University Grounds Manager at haagsma@yorku.ca.
File: EAB Strategy\ July 2015 website update