[CANUFNET] Trees and boulevards

[Trevor Thistle]

Hi Ian,

Here in Edmonton I have been working almost exclusively with tree
conservation during Neighborhood Renewal (NR) for 13 years. NR is the
process of reconstructing all sidewalks, curbs and streets in a
neighborhood, as well as adding missing infrastructure.

In our oldest neighborhoods I feel that trees growing in boulevards with
separate sidewalks (curb on one side, sidewalk on the other side of the
tree) have not really been impacted by the perceived restricted growing
area, with the exception of roots literally engulfing curbs or overlapping
sidewalks. I believe that the reason for this is that the construction
standards that were in place decades ago (between neighborhood
establishment and the time the sidewalk was last replaced) allowed for the
construction of sidewalks on top of organic soil. So, in most cases, the
trees had little challenge accessing soil beyond the boulevard.

However, new construction standards include a gravel base and mechanical
compaction under sidewalks. Also, greenfield construction is not what it
used to be. Nowadays developers remove all of the precious topsoil from the
land before building a new subdivision, then bring back enough topsoil to
support the new sod. In these cases, regardless of the sidewalk design
(mono or seperate) the trees do not have enough soil volume to support
them. We do amend soil volumes with trenches in separate boulevards, but
these are trenches in clay with still inadequate soil volumes. So my point
is, depending on construction practices and standards, the configuration of
the sidewalks in relation to the trees may have less impact on soil growing
space than we think.

but I would agree that trees in a more free to grow state, with little or
no barriers to quality soil will outperform a tree in restricted growing
space, and there will be fewer infrastructure / tree conflicts. This means
that we will minimize tree related damages to infrastructure and
construction related damages to trees in order to maintain that
infrastructure.


*Trevor Thistle Bsc. Forestry*
*Urban Forester **| **PR-4760AM | **Tree Risk Assessment Qualified*

OPEN SPACE OPERATIONS

CITY OPERATIONS |  PARKS AND ROADS SERVICES

780-944-5577  OFFICE

780-913-5893  MOBILE

City of Edmonton

12830 58 Street NW





On Wed, Sep 29, 2021 at 9:21 AM Ian Wilson via CANUFNET <
canufnet at list.web.net> wrote:

> All, we are having a bit of an internal debate about standards for
> local/residential roads and boulevards.  My observation is that trees that
> are planted in a boulevard behind a monolithic sidewalk (sidewalk up
> against the curb and planting area next to the property) generally do
> better. They have access to more soil volume in the front yard, they get
> more water and the boulevard is tidier since the homeowner treats it like
> part of their yard. Also fewer issues with roots lifting sidewalks. Some of
> our staff prefer the separated treed boulevard, for various reasons. Note,
> I’m not talking about busier roads where the trees in boulevards help to
> form a barrier from traffic.
>
>
>
> We don’t have a lot of good examples here that directly show a comparison.
> Does anybody have some photos that might show the performance of trees on
> one side of the road in a separated boulevard, vs. trees on the other side
> behind the sidewalk?
>
>
>
> Below is an example that doesn’t exactly show this, but it does show the
> value of soil volume, with the trees on the left side being able to access
> the lawn area behind the sidewalk, vs. the trees in “coffins” on the right.
> These are lindens planted at the same time.
>
>
>
>
>
>
>
>
>
> *Ian Wilson*
> Infrastructure Operations Manager | City of Kelowna
> 250-469-8842 | iwilson at kelowna.ca
> Submit a request for service on the go | kelowna.ca
>
> *I acknowledge that my workplace is located on the traditional, ancestral,
> unceded territory of the syilx/Okanagan people**.*
>
>
>

-- 
*The contents of this message and any attachment(s) are confidential, 
proprietary to the City of Edmonton, and are intended only for the 
addressed recipient. If you have received this in error, please disregard 
the contents, inform the sender of the misdirection, and remove it from 
your system. The copying, dissemination, or distribution of this message, 
if misdirected, is strictly prohibited.*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.web.net/pipermail/canufnet/attachments/20210929/b569148a/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.jpg
Type: image/jpeg
Size: 88879 bytes
Desc: not available
URL: <http://list.web.net/pipermail/canufnet/attachments/20210929/b569148a/attachment-0001.jpg>