[CANUFNET] hybrid poplar tree hazard

[Anita Schill]

I concur. I read Plant Biomechanics by Karl J. Niklas many years ago. If I remember correctly he describes wood strength at a cellular level and at a tissue level... Periods of drought can definitely affect individual cell strength permanently and as you say, probably magnified over time.
Anita Schill, PAg
Instructor Olds College
RCA #421 (ASCA)
Certified Tree Risk Assessor # 95

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From: canufnet-bounces at list.web.net [canufnet-bounces at list.web.net] On Behalf Of pwynnyczuk at richmondhill.ca [pwynnyczuk at richmondhill.ca]
Sent: Wednesday, June 16, 2010 10:06 AM
To: Canadian Urban Forest Network
Subject: Re: [CANUFNET] hybrid poplar tree hazard

If the limbs are shed randomly, ie., no wind, only in summer, or no evidence of decay, at one time I remember a comment related to Poplars, particularly Carolina Poplar, Populus canadensis, in terms of moisture levels in the wood affecting structural soundness.
Rapid changes in weather,  wet to dry and vice versa can lead to significant fluctuation in the wood cell size. If there are preexisting weak points in the limbs,  these are magnified over time until breakage.

Any one have similar information?

Regards,
Peter Wynnyczuk

Urban Forestry Supervisor
Town of Richmond Hill
Community Service Department
Telephone:  905 780-2930
Fax:  905 780 -2928
Internet: pwynnyczuk at richmondhill.ca



From:   Vince Rutter <vince at rutterurbanforestry.ca>
To:     Canadian Urban Forest Network <canufnet at list.web.net>
Date:   06/16/2010 11:43 AM
Subject:        [CANUFNET] hybrid poplar tree hazard
Sent by:        canufnet-bounces at list.web.net

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A client's neighbour owns two large hybrid poplar (similar to cottonwood) trees that overhang his property.  They are healthy vigourous trees, both with many codominant stems and are quite large (2 metre DBH).  That's pretty big for here in Thunder Bay!  Over the past several years there have been many occasions where branches have snapped and fallen which is typical of the species.  The branches are anywhere from 2 inches to 5 or 6 in diameter.  They are truly concerned about the tree and would like to compel the owners to take action.
At best, we could clean the crown, reduce long branches and support included branch connections by cabling but I don't feel that would greatly reduce the risk of occasional limb breakage.  That said, have any of you condemned a tree based on its species characteristics like these poplars?
This problem comes up fairly frequently here and it usually leads to tree removal but in this case all parties involved can't come to an agreement.

Any insight would be greatly appreciated.
--
Vince Rutter, RPF
ISA Certified Arborist
www.rutterurbanforestry.ca<http://www.rutterurbanforestry.ca/>
807-627-6201