[CANUFNET] Healthy tree definition
For Trees
trees at fortrees.ca
Mon Feb 1 00:04:06 EST 2010
I am a professional arborist and run a small company here in rural Alberta.
Every year, we remove hundreds of trees whose only "crime" was being planted
in the wrong place. Trees are too close to houses, buildings, power lines,
streets, new sidewalk construction, fuel tanks, fence lines or other trees,
over hot tubs, decks or patios, block views, create nuisances for
neighbours, get old, are falling apart, or people simply didn't like them or
were afraid of them when they got too big. Now I assume there are dozens of
other arborist companies in Alberta larger than mine and perhaps hundreds of
companies nationwide engaged in similar urban tree cutting activities on a
daily basis. This adds up to thousands upon thousands of urban and rural
trees removed each year, all for preventable reasons. When we, as
professionals, are asked to plant trees whose mature shape and form we know
far exceed the dimensions of the space allotted for them, is it okay to do
so, just because some 'vested interest" tells us to? Are trees to be seen
as community Green Infrastructure, whose purpose it is to filter the air,
store carbon, create oxygen and shade, hold soil and slow down storm water,
to grow as large as possible and last as long as possible, or are they
simply Green Garnish, to be placed by the dry side of a busy road in
compacted soil, surrounded by concrete and asphalt and doomed to die in a
few years?
If trees are Green Infrastructure, then shouldn't everyone on the urban
design team be aware of how to best maximize the tree resource, and plant
the proper trees in the proper spaces, give them the proper care they need
so they can live long and prosper, thereby giving us the return on our
investment that we expect and deserve?
If trees are merely Green Garnish, to be rotated and replaced every so often
as soon as they are too big, sicken or die, then what does it matter what
initial shape or form they may have? I have personally witnessed White
Spruce being planted on the boulevard of a busy Alberta tourist town street,
and how long will they have to last in that environment? Why, just a few
years, at best!
I have heard of arborists being hired to prune new trees after they were
planted so that they might "pass the City's inspection", heading back all
except one of the new trees upper branches, so that the trees might have a
"strong central leader". Physiologically, removal of too many terminal buds
in the newly transplanted tree will hormonally direct new growth away from
the roots, which the newly transplanted tree needs, to the shoots, which the
newly transplanted tree will have difficulty sustaining. If the original
question was how do we, as urban foresters, create policy to ensure the
health of newly transplanted trees, then any policy which forced a
contractor to perform potentially deleterious pruning such as this, was
clearly not pragmatic.
Interesting that the CNLA's Canadian Standards for Nursery Stock should be
referenced. This is a very pragmatic, clear and useful document precisely
because it allows for regional variance with respect to specific trees.
Section 5.2.2, Standard Shade Trees, pages 19-20 of the eighth edition
reads: " trees must have straight sturdy trunks, with a well branched and
balanced head. Branching structure of the head will vary according to
species, height, age and climatic/cultural conditions. A dominant, central
leader will not necessarily be evident or expected at a certain age of a
tree's maturity or be typical of its natural growth habit. This form of
intermediate or diffuse branching should be recognized and considered
acceptable when bid specifications are given."
Furthermore, the spirit of this document is clearly outlined in section A,
General Requirements , page 6, A-7, "Quality must be typical for the species
when grown under proper cultural conditions."
I have been a member of LANTA, the Landscape Alberta Nursery Trades
Association, our provincial affiliate of the Canadian Nursery Landscape
Association, or worked for a member company, since 1984. I am also a nursery
grower, and occasionally attend meetings of the Alberta Grower's group, also
attended by Mr. Harold Voogd, our Alberta representative on the Canadian
Standards committee. This "healthy tree definition" has sparked quite the
debate in recent months! As the current Vice President of the Prairie
Chapter of the International Society of Arboriculture, I have been asked by
that Board to draft a position paper on the substance of a "healthy tree
definition" and outlining our Chapter's position with regard to the Canadian
Standards. As the incoming President of LANTA, I have recieved many
complaints from several different members whose trees have been recently
rejected prior to FAC , based on what looks like literal, arbitrary and
inflexible interpretations of the Canadian Standards. I look forward to the
opportunity to contact you directly, Travis, in the coming days or weeks,
as our schedules permit, so that I may hear more of your side of this
controversial topic.
Until then, perhaps we could all agree with Bill Mollison, the founder of
Permaculture, who states: "The only ethical decision is to take
responsibility for our own existence and that of our children."?
Yours truly,
ForTreeslogocolour
Gerard Fournier
Board Certified Master Arborist #PR-0130BT
Tree Canada Community Advisor-Southern Alberta
President
For Trees Company Ltd.
1-877-390-TREE (Alberta toll-free)
<http://www.fortrees.ca/> http://www.fortrees.ca
From: canufnet-bounces at list.web.net [mailto:canufnet-bounces at list.web.net]
On Behalf Of Travis Kennedy
Sent: January-28-10 11:03 AM
To: 'Canadian Urban Forest Network'
Subject: Re: [CANUFNET] Healthy tree definition
Gerard makes several salient points, in particular that trees are not
naturally high headed. There is no disagreement here that low branches aid
trees in many ways. It's foolish to dispute Darwin. But trees don't
naturally grow beside concrete driveways or within 1.5 metres of roadways.
It's great to propose a tree utopia, but in reality there are strongly
vested interests that do not always agree with what is best for trees. In an
urban setting, we as arborists must make pragmatic choices if we hope to
nurture our urban forests. A low headed deciduous tree in a busy urban
boulevard setting will at worst be torn apart in the first few years as it
begins to grow out into streets and sidewalks. Homeowners are callously
unappreciative of the optimal growth requirements of trees if they perceive
those trees to be in their way; moving trucks and roadway resurfacing
vehicles even less so; perhaps it is the classic case of the wrong tree in
the wrong location.
Note that I referred to a blvd setting in the comment. Perhaps I need to
clarify: the comment is not the standard, it is in reference to a particular
site. The comment changes, the standard, which does allow for decurrent
habit, does not. Furthermore, I urge you to read the standard that I cited
in depth. It expands greatly from form to reference the old CTLA (Now CNLA
standards). In particular 2.1.1: "All materials shall meet the horticultural
standards of and comply with, all sections of the latest edition of the
Canadian Landscape Trade Association (C.N.T.A.) planting specifications". I
believe that these standards are national and developed in direct
consultation with Nurseries. There you will also find reference to the
importance of height of branching in street tree bid specifications.
Gerard, please feel free to contact me directly.
Regards,
Travis Kennedy, BSc, AIT
River Valley, Forestry and Environmental Services
12304 - 107 Street
Edmonton, Alberta
T5J 2R7
p 780 496 4954
-----Original Message-----
From: canufnet-bounces at list.web.net [mailto:canufnet-bounces at list.web.net]
On Behalf Of For Trees
Sent: Wednesday, January 27, 2010 10:46 PM
To: 'Canadian Urban Forest Network'
Subject: Re: [CANUFNET] Healthy tree definition
With regard to Travis' comments, it seems to me that this wording leaves it
completely open to whatever subjective interpretation your inspectors may
have on any particular day, with no recourse whatsoever for the contractors
or nurseries that have their trees rejected. You are basically saying that
a tree must conform to your standards, whatever they may be, right or wrong.
In point of fact, trees are not normally high headed, and must be pruned
that way in the nursery. Such pruning is clearly detrimental to the health
of the tree, and in most cases, stunts the growth, reduces taper and trunk
strength, and invites disease and poor compartmentalization, which can lead
to trunk cracks, sunscald and several other defects that I can think of.
This is all well researched and documented in Alex Shigo's book 'A New Tree
Biology" 1989 and in "Modern Arboriculture." 1990. Other researchers such as
Gilman have since written excellent books on the topic of pruning and
pruning trees for urban areas in the nursery, which have been universally
accepted by most of the rest of North America and the world.
And what of trees that do not normally have a central leader in the Edmonton
area? Trees like Green Ash, Mayday, Schubert, Amur Cherry and Ornamental
Crabapples very rarely possess a "single dominant, well developed leader." I
can only imagine that very few otherwise healthy trees of these varieties
survive your inspection process!
Even if any particular Urban Forestry department actually knew what a
"healthy tree" was and could specify this in a way that was "not open to
interpretation", there is no guarantee that picking a tree simply on the
basis of "good" form will guarantee future good health, especially in a
place where trees are notoriously difficult to grow, such as the Western
Prairies. Planting methods are the single biggest factor influencing the
success of a tree. And while you are perfectly right not to accept a tree
with obvious signs of abuse such as scrapes and broken branches, we continue
to plant the healthiest of trees in the worst of places and blame the tree
when it dies. Trees need room to grow both above and below the ground to
sustain themselves, and usually have neither in most Urban Areas in the
world today.
Fixating on a tree's form, especially when the form is entirely unnatural to
the species or variety, certainly should never be considered the only
attribute of potential good health!
We obviously need to rethink the whole notion of "tree health" when Urban
Areas are still in the design process. I believe it is possible to shape
cities to conform to nature, but nature cannot be retrofitted to fit our
cities, if our cities are to be sustainable.
Food for thought.
ForTreeslogocolour
Gerard Fournier
Board Certified Master Arborist #PR-0130BT
Tree Canada Community Advisor-Southern Alberta
President
For Trees Company Ltd.
1-877-390-TREE (Alberta toll-free)
http://www.fortrees.ca <http://www.fortrees.ca/>
From: canufnet-bounces at list.web.net [mailto:canufnet-bounces at list.web.net]
On Behalf Of Travis Kennedy
Sent: January-27-10 4:17 PM
To: 'Canadian Urban Forest Network'
Subject: Re: [CANUFNET] Healthy tree definition
Our Design and Construction standards touch briefly on "healthy" but add a
number of other quality measurements to reinforce our intent:
Refer to section 02930 2.2 and 2.3 in Volume
<http://www.edmonton.ca/city_government/documents/PermitsLicences/D_and_C_la
ndscapsng.pdf> 5: City of Edmonton Design and Construction Standards.
A design review comment that we like to make on submitted drawings from
developers usually contains some or all of the wording below (this
particular case is in reference to deciduous blvd. material):
"All trees to be high headed and exhibit a full and uniform crown, with a
single dominant, well developed leader. Trees with broken or damaged or
missing leaders will not be accepted. All plant material must conform to the
City of Edmonton Design and Construction Standards."
This comment in combination with the standard helps prevent confusion about
what is and isn't acceptable during our CCC / FAC inspection process.
Regards,
Travis Kennedy, BSc, AIT
River Valley, Forestry and Environmental Services
12304 - 107 Street
Edmonton, Alberta
T5J 2R7
p 780 496 4954
-----Original Message-----
From: canufnet-bounces at list.web.net [mailto:canufnet-bounces at list.web.net]
On Behalf Of Kowalyk, Bohdan (MNR)
Sent: Monday, January 25, 2010 7:05 PM
To: Canadian Urban Forest Network
Subject: Re: [CANUFNET] Healthy tree definition
There are various tree classification systems depending on intent. For some
purposes, it may be appropriate to require confirmation by a qualified
person, subject to an authority's approval, that a healthy tree is not
likely to degrade in health and functional attributes for at least the next
15 years.
Bohdan
_____
From: canufnet-bounces at list.web.net [mailto:canufnet-bounces at list.web.net]
On Behalf Of SVescio at thunderbay.ca
Sent: Monday, January 25, 2010 1:02 PM
To: canufnet at list.web.net
Subject: [CANUFNET] (no subject)
Hello out there,
Is there an accepted or standard definition for the term "healthy tree"? We
would like to revise the wording for acceptable condition of trees at final
inspection and do not want the health of a tree open to general
interpretation. Thanks.
Shelley Vescio RPF
City of Thunder Bay
(807) 625-2473
(807) 625-3258 (fax)
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