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<DIV>In my experience there is no reliable rule of thumb for tree age vs
diameter. You can have two trees planted at the same time of the same
species that have dramatically different DBH right beside each other, and this
routinely happens with even-aged stands in the wild. If one is getting more sun
and the other is suppressed there will be a large difference in diameter.</DIV>
<DIV> </DIV>
<DIV>In a even aged stand, say red oaks, you can have one dominant tree in the
middle of the grove that is taller and thicker than all the others growing
around it. The others may all be growing sideways to try to get to the
sunlight as the centre tree spreads it’s crown out to capture all of the sun
above them and are a lot different in diameter but all close to the same
age. In a conifer plantation in the early stages there can be a narrow
range of sizes so easier to make age estimates from size, but as the plantation
ages the dominant trees grow much larger than the suppressed ones, which die out
eventually.</DIV>
<DIV> </DIV>
<DIV>If you have some local data from core samples or counting rings of cut
trees to compare with you could make up a rough table of age vs size that could
be a fair estimate for each species most of the time. It has to be local
data – trees in Toronto or Niagara grow a lot faster than on the shield north of
us. You know that pines can be aged by counting the branch whorls
eh? There are also old MNRF publications that have age/height curves by
species and site class that are based on good data and can be a good tool for
estimating.</DIV>
<DIV> </DIV>
<DIV>You hear people all the time describing 60cm+ trees as ‘100 year old trees’
that are often silver maples or willows that can’t be more than 60 years old
since the area was developed then.</DIV>
<DIV> </DIV>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000">Stephen
Smith<BR>Urban Forester, ISA Certified Arborist<BR>Qualified Tree Risk
Assessor<BR>Urban Forest Associates<BR>www.ufora.ca<BR>off 416-423-3387/cell
416-707-2164<BR></DIV>
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<DIV style="BACKGROUND: #f5f5f5">
<DIV style="font-color: black"><B>From:</B> <A title=canufnet@list.web.net
href="mailto:canufnet@list.web.net">Andrew Almas via CANUFNET</A> </DIV>
<DIV><B>Sent:</B> Wednesday, October 03, 2018 1:23 PM</DIV>
<DIV><B>To:</B> <A title=geospatialniagara@gmail.com
href="mailto:geospatialniagara@gmail.com">geospatialniagara@gmail.com</A> ; <A
title=canufnet@list.web.net
href="mailto:canufnet@list.web.net">canufnet@list.web.net</A> </DIV>
<DIV><B>Subject:</B> Re: [CANUFNET] Tree Growth Factors
Question</DIV></DIV></DIV>
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<DIV dir=ltr>Hi Darren,
<DIV> </DIV>
<DIV>There is no extra mathematical step to applying the growth factor. It is
just that trees grow differently in different settings. So in the case of the
growth factor provide by the Morton Arboretum they are only considering trees
that are "landscape specimens", these tend to grow in diameter far more quickly
than trees in a forest setting that tend to grow taller. Most growth factors you
will find are associated with that species growing in a forest setting. That is
the source of the discrepancy. Another source of discrepancy could be locale - a
red maple in Quebec will grow more slowly than a red maple in Georgia...</DIV>
<DIV> </DIV>
<DIV>Best,</DIV>
<DIV> Andrew</DIV></DIV>
<DIV> </DIV>
<DIV class=gmail_quote>
<DIV dir=ltr>On Wed, Oct 3, 2018 at 12:00 PM Darren Platakis via CANUFNET <<A
href="mailto:canufnet@list.web.net">canufnet@list.web.net</A>>
wrote:<BR></DIV>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<DIV dir=ltr>Hello everyone,
<DIV> </DIV>
<DIV>I was hoping to be enlightened with regards to tree growth factors and
estimated tree age. I am not a arborist by trade so be gentle with me.</DIV>
<DIV> </DIV>
<DIV>I'm trying to apply growth factors to an inventory of trees to estimate
age but some things do not make sense.</DIV>
<DIV> </DIV>
<DIV>By way of example, the growth factor for a Norway maple is noted as being
4.5 so in essence, a Norway maple with a diameter of 20 inches is estimated to
be 90 yrs old - Diameter X Growth Factor (this number doesn't seem right to
me). <BR><BR>However, there are several charts available that provide this
information, such as one released by The Morton Arboretum that state a Norway
maple of 20 inches in diameter is estimated to be 52 years old. This would be
a growth factor of 2.6 (Estimated age / diameter = Growth Factor). My question
is, why the big discrepancy? Am I missing a step somewhere?<BR><BR></DIV>
<DIV>This is an exercise that I may like to take into a classroom but with the
wide chasm of results I'd be wary of doing so. <BR><BR>Thanks in advance,
</DIV>
<DIV> </DIV>
<DIV>Darren Platakis</DIV>
<DIV>
<DIV class=m_8998232209122420274gmail_signature dir=ltr
data-smartmail="gmail_signature">
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<DIV dir=ltr>
<DIV dir=ltr>
<DIV><FONT color=#000000 face="helvetica, geneva, sans-serif">BSC., GIS(PG),
FRCGS</FONT></DIV></DIV></DIV></DIV></DIV></DIV></DIV></BLOCKQUOTE></DIV>
<DIV> </DIV>
<DIV> </DIV>-- <BR>
<DIV class=gmail_signature dir=ltr data-smartmail="gmail_signature">
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<DIV><SPAN lang=EN-CA
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Almas</FONT></B></SPAN></DIV></SPAN><FONT size=2
face="Times New Roman">Lecturer</FONT></DIV>
<DIV dir=ltr><SPAN lang=EN-CA style="FONT-SIZE: 12px"><FONT size=2
face="Times New Roman"><SPAN style="LINE-HEIGHT: 115%">University of Toronto,
Mississauga</SPAN></FONT></SPAN></DIV>
<DIV dir=ltr><SPAN lang=EN-CA style="FONT-SIZE: 12px"><FONT size=2
face="Times New Roman"><SPAN style="LINE-HEIGHT: 115%">Department of Geography
and Programs in the Environment </SPAN></FONT></SPAN><SPAN
style="FONT-SIZE: 12px"></SPAN></DIV>
<DIV dir=ltr><SPAN lang=EN-CA style="FONT-SIZE: 12px"><FONT size=2
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