[CANUFNET] Urban tree mortality rate

Fri May 27 12:21:48 EDT 2016

Thanks for your response Julian.  When you take into consideration newly planted trees, you’re right, mortality rates/replacement rates are quite high.  In our case, Richmond Hill has undergone a lot of growth in the last few decades so a lot of newly planted trees are covered by a warranty in their first two years so the municipality is responsible for the replacement tree.  Our Urban Forestry section is telling me that their replacement rates are not as high as what I’m hearing from others and I think that may be why.

Ann Marie

________________________________________________________________
Ann Marie Farrugia, B.E.S., MA.Sc., EP
Manager of Natural Environment
Environment Services  |  Environment & Infrastructure Services
905-771-5509 |  annmarie.farrugia at richmondhill.ca<mailto:annmarie.farrugia at richmondhill.ca> |    RichmondHill.ca

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From: CANUFNET [mailto:canufnet-bounces at list.web.net] On Behalf Of Julian Dunster
Sent: Tuesday, May 24, 2016 12:16 PM
To: Canadian Urban Forest Network
Subject: Re: [CANUFNET] Urban tree mortality rate

I suspect mortality varies by region. At the first or second Urban Forestry conference (now a long time back) there was a paper delivered that showed 7 years as the typical life expectancy for street trees in Canada. The number stuck with many of us simply because it was so small. But, it is likely a lot longer on the west coast than the east coast or even interior Canada regions simply due to differences in winter / summer weather. With climate change all bets are off. The west coast continues to suffer drought conditions in the summer - I think this is the 7th or 8th year now and mortality rates are high in street and native trees as a result.

Replacement numbers are very variable. With luck it would be at least one for one, often 2 or 3 for every tree removed but that depends on the agency involved, the reasons for removal, private vs city land etc. 'Not enough' is probably the most likely de facto standards now in play, although the numbers planted are usually not of much use anyway. How many actually survive and get established, and how many are maintained would be a far more useful metric. Again, the answer is almost certainly 'not enough.'

 jd

On Tue, May 24, 2016 at 8:42 AM, Ann Marie Farrugia <annmarie.farrugia at richmondhill.ca<mailto:annmarie.farrugia at richmondhill.ca>> wrote:
Good morning,

I’d like to ask if anyone is aware of any information or research that defines standard urban street tree mortality rates and/or tree replacement rates (pre/post EAB) .  Is there a rule of thumb the industry follows?

Thanks in advance for your help,
Ann Marie

________________________________________________________________
Ann Marie Farrugia, B.E.S., MA.Sc., EP
Manager of Natural Environment
Environment Services  |  Environment & Infrastructure Services
905-771-5509<tel:905-771-5509> |  annmarie.farrugia at richmondhill.ca<mailto:annmarie.farrugia at richmondhill.ca> |    RichmondHill.ca

[RH_Logo_CMYK_email]

--
On Behalf of Dunster & Associates Environmental Consultants Ltd.

Dr. Julian A. Dunster R.P.F., R.P.P., ISA Certified Arborist,
ASCA Registered Consulting Arborist,
PNWISA Certified Tree Risk Assessor #1.
ISA Tree Risk Assessor Qualified.

Honourary Life Member International Society of Arboriculture (ISA) and PNWISA

North American Distributor for Rinntech
Canadian distributor for Air Spade

email: jadunster at gmail.com<mailto:jadunster at gmail.com>

www.dunster.ca<http://www.dunster.ca>
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