[CANUFNET] ash tree question

Thu Nov 4 09:17:20 EDT 2021

In my practice as a Registered Consulting Arborist, I have been called in to inspect EAB infested trees. Just last year in the middle of Toronto I looked at a large indigenous White Ash that was treated with Treeazin more than 10 years ago and twice every 2 years. Yes the tree died back and suckered but id recover. Why did it not get reinfested? My belief is once the hoard  has past through then the likelihood of reinfestation is much less. Proof is in the pudding.

Also as Oliver suggests I maintained over one hundred Blue Ash (Fraxinus quadrangulata) in my past career and never lost one from EAB. Also Fraxinus mandshurica which I had planted in the Mount Pleasant Arboretum was also quite resistant as the genes got the taste obviously. I say to all do not give up hope.

Jack Radecki RCA 342

From: CANUFNET <canufnet-bounces at list.web.net> On Behalf Of Susan Mentis via CANUFNET
Sent: November 3, 2021 5:53 PM
To: Canadian Urban Forest Network <canufnet at list.web.net>
Cc: Susan Mentis <mentis41 at gmail.com>
Subject: Re: [CANUFNET] ash tree question

Lorraine thank you for voicing a pertinent question to the Urban Forest Network especially with your twenty five years of “Growing Wild”! I commend you Andrew for not “mudding the waters” but being forthright in the policy and practises Urban Foresters should challenge. 

I suggest being farsighted, not short-sighted. Over the centuries the ash tree has survived from a range of pests, diseases, floods, and ice and wind storms. We don’t know yet if the Emerald Ash Borer will be eradicated from Canada or if a cycle of infestation and mortality will continue forever. “For the time being” attitude stops the clock for future generations who may never know the benefits of a mature ash tree for community or diversity in ecosystems. 

“Planting a young tree only to see it succumb just as it reaches some stature” can be a property owner’s or municipality’s option - a choice. Ash trees provide shade, excellent leaf mulch, food source for frogs, habitat for wildlife and their harvested wood is a renewable material of the future.  We can advocate an approach to value and invest in our trees whatever their lifespan.

I say invest because it will involve components of time, energy and money. Resources are being used to bank ash seeds for fifty years in hopes that the Emerald Ash Borer will be eradicated from Canada.  Time lost. It is the time frame needed to document and research the resilience of ash species from prolonged Treeazin treatment and / or natural controls and / or whether their seedlings have developed a resistance to EAB, pests or disease or the effects of climate change. Is scientific research over and out for the ash species? 

For those of us with ash on private property who have ventured down the costly Treeazin path, we live through the seasons with the future in mind and a hypothesis to address. To treat or not treat our mature trees who have contributed to the urban forest for 100 years? To recognize impending mortality from EAB and plan plus save dollars for removal? Harvest the wood instead of chipping its old growth of unique properties into mulch? Maintain the new generation of seedlings that have found their place in the garden and surprisingly grow as saplings taller and healthy each year? Utilize the saplings to monitor for the pending cyclical return of EAB? Wait and watch? Remove or not?

Decisions on a small scale, yet these trees are the last of our dwindling legacy that still and should have a role to play in natural history. Without action and applied knowledge now, is the entire Fraxinus genus to be buried as “once were” in horticulture and arboriculture documents and as an extinct footnote in Trees in Canada? 

This is happening on our watch, our timeline when forests are impacted by devastating climate effects and all urban trees are under added pressure from land development and especially infill development in neighbourhoods. If Urban Foresters and Arborists don’t demonstrate the value of the ash today, then their significance within cultural history is lost to next generations.  

Don’t rely on government resources and take some action. “Right tree, Right place!” Go ahead, plant an ash tree there. Nurture it, monitor it, document it, share the experiment and pass it on to next generations. Use your knowledge and speak to youth, neighbours, students and community about tree plant health and the dynamics of ecosystems. Show them a live majestic mature ash tree today. Afford them the opportunity to embrace one as it may never happen again in their lifetime and woefully in mine too!

Willing to share ash seedlings.

Susan Mentis

Mississauga, ON

On Wed, Nov 3, 2021 at 4:09 PM Oliver Reichl via CANUFNET <canufnet at list.web.net <mailto:canufnet at list.web.net> > wrote:

If you can find any, I’ll suggest that its okay to plant blue ash (F. quadrangulata), which EAB doesn’t seem to like, but pass on the rest.

On Wed, Nov 3, 2021 at 3:20 PM Andrew Almas via CANUFNET <canufnet at list.web.net <mailto:canufnet at list.web.net> > wrote:

Hi Lorraine,

Based on the conversations that I have had with numerous municipal employees in southern Ontario, I would say that there is nearly a consensus that planting ash trees is a waste of resources given the extremely high mortality due to EAB (within 6 years of infestation, more than 99% of the ash trees are dead (Klooster et al. 2014; Knight et al. 2013), and I think many of us are still feeling some PTSD from seeing so much of our urban canopy destroyed in such a short window of time. 

There is another intriguing point of view which has been espoused by some, such as University of Delaware entomologist Doug Tallamy in his 2020 book "Nature's Best Hope" that we should continue to plant ash and retain non-hazardous ash both on public and private property as a means of retaining ash based aspects of our food web (for instance, insects which can only be found on host ash trees), but also to identify and maintain natural resilience so ash trees may thrive in the future. I recognize that this is a difficult scale of objective to manage when making site specific planting decisions, but it is an argument against policies such as you have outlined in the City of Toronto which takes an extirpation approach to ash, which if expanded to all Ontario municipalities, counteracts any attempt at identifying natural resistance. The challenge of course is that realistically there is almost never going to be resource-based support for planting something which has a less than 1% chance of surviving once infested.....

I hope that helps to 'muddy the waters'!

Andrew

On Wed, Nov 3, 2021 at 7:24 AM Lorraine Johnson via CANUFNET <canufnet at list.web.net <mailto:canufnet at list.web.net> > wrote:

Hi all,

Apologies if this question has already been addressed by the group.

I'm wondering whether or not you are recommending (or advising against) the planting of ash trees in Ontario at this time?

I'm aware that some municipalities (Toronto, for example) have bans on the planting of ash trees on City-owned property, but my question relates to recommendations for private land-holders.

Ash trees are still for sale at nurseries. Should people plant them or not in Ontario? 

I'm assuming no, but wonder if there is consensus on this.

With thanks in advance for your thoughts,

Lorraine Johnson

Toronto, Ontario

-- 

Andrew Almas

Assistant Professor of Teaching

University of British Columbia

Department of Forest Resources Management

Bachelors of Urban Forestry Program 

(647) 529-8867

-- 

Oliver K. Reichl, B.E.S.(Hons)
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