==============================================================================
TOPIC: Back to tree modeling
http://groups.google.com/group/entstrees/browse_thread/thread/fc988a81feef3be8?hl=en
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== 1 of 5 ==
Date: Tues, Aug 19 2008 8:53 am
From: dbhguru@comcast.net
ENTS,
Yesterday I went to William Cullen Bryant Homestead in Cummington,
mA to do some crude volume modeling of the largest of the Bryant
pines. The huge tree grows apart form the main stand. It is located
near the western periphery of the area of large pines. The CBH of
the champ on the uphill side is 12.9 feet and it makes 14.1 feet on
the downhill side. At midslope the CBH is 13.4 feet. The height to
a bushy top that has been likely broken more than once in the past
is 135.3 feet. There may be a higher point, but there is too much
intervening clutter to see well. Besides, with such a bushy top, a
higher sprig on an upturned limb could lead to a decpetive trunk
volume.
Using a variety of volume formulas that I won't repeat here, the
volume lies between 785 and 805 cubic feet of trunk volume. Taking
an average of the two figures gives us 795 cubes. However, I think
the 805 is reasonable by simple appeal to the overal shape of the
trunk. I utilized a volume factor of 0.40 to reflect trunk form, a
height of 135.3, and a CBH of 13.4 feet. That combination gives the
805 cubes. So at this point, that's the number I'm going with.
If we add 7% of trunk volume to cover the limbs, we get 865 cubic
feet for the entire tree down to ground level.However, our customary
method of comparison is just the trunk volume. So the figure is 805
for now. When the weather cools and the mosquito population crashes,
I'll do a much more thorough job, using the Macroscope.
The plan for the fall is to model the biggest white pine in each of
the major stands in southern New England and to try to do similarly
for New Hampshire and Vermont. I'll also include isolated field
pines when I can get to them.
So far, in Massachusetts, we have the following pines as members of
the 800cube club.
Tree Trunk
Volume Location
Modeler
Grandfather Pine 967 cubic feet
MSF
Will Blozan
Ice Glen Pine 954
cubic feet Ice Glen
Will Blozan and Bob Leverett
Hiawatha Pine 819
cubic feet MTSF
Bob Leverett
Thoreau Pine 812
cubic feet MSF
BVP
Big Boy 805 cubic
feet Bryant Homestead Bob
Leverett
There are some large opengrown pines that need to be modeled, but
the amount of work is daunting unless the pine offers possibilities
of being a real champion. Multiple trunks are a real pain. However,
we don't want to leave out these big trees and such a tree grows in
a graveyard in Conway MA. It will be the subject of a piecemeal, but
fairly intensive study effort over the coming weeks. It has at least
a slim possibility of exceeding 1,000 cubes, the magic threshold for
an eastern conifer.
Monica and I hope to return to New Hampshire on Labor Day and I'm
hoping I can reconnect with my firiends David Govatski and Sam
Stoddard to see and measure some New Hampshire contenders.
Bob
== 4 of 5 ==
Date: Tues, Aug 19 2008 2:29 pm
From: Larry
Bob, When you buy the new Z8000 Macroscope perhaps you can sell me
your old wore out one. At a well reduced price of course! Larry
== 5 of 5 ==
Date: Tues, Aug 19 2008 2:52 pm
From: dbhguru@comcast.net
Larry,
You can count on it. BTW, it felt good to be able to return to tree
modeling. I still want to get down to the deep South and see some of
those 30footers.
Bob
==============================================================================
TOPIC: Back to tree modeling
http://groups.google.com/group/entstrees/browse_thread/thread/fc988a81feef3be8?hl=en
==============================================================================
== 1 of 1 ==
Date: Tues, Aug 19 2008 9:27 pm
From: "Edward Forrest Frank"
Bob,
Nice to see you back at tree modeling and preparing to scare people
off the list with mathematics.
I have mentioned this before but I want to suggest cylinder
occupation again in this context. In the study of the volumes of
hemlocks in the Tsuga Search Project a ration could be determined
between the actual volume of the tree and the volume of a cylinder
of the same height as the tree and of the same diameter as the tree
at breast height. What was found was that at the lower end of the
scale were outlier percentages representing trees with an abnormally
fat base. The unusually large base diameter would yield a lower than
average % cylinder occupation. Above this was the normal range of
trees with a normal girth to height ratio and generally uniform
tapers. Those at the lower end of the spectrum are tree which taper
rapidly, while at the upper end of the normal spectrum are those
trees that have a slower taper for a much greater portion of the
trees height before tapering to a point. The third group of trees
were those that had their tops damaged or removed. Since these trees
had the profile in their lower portion more representative of larger
and taller trees, and a foreshortened top segment representing the
least cylinder occupation of any portion of the tree, these tree had
an anomalously high % cylinder occupation.
The same could be done for the pine volumes you are measuring. I
would expect, if this tree you measured in Bryant Woods has had its
top removed and regrown that it would be in the anomalously high
outlier or at least in the upper end of the normal spectrum.
What can this tell you? By itself it can indicate that a particular
tree has been damaged in the past. it is a measure nor of size of
the tree but of shape. I am wondering if there would be a general
trend in this value from younger to older trees in an area
indicating that the trees basic shape changes with time and as it
grows? I am also wondering wonder if there might be a regional trend
from south to north that could be determined? The other thing is
would there be a clustering of values from trees in a particular
environment? For example, would the trees nearer the coast that
Andrew Joslin thinks are kept short because of winds, form a
meaningful cluster of data points?
This goes along with the idea of plotting three parameters on a
triangular ternary plot. Initially I was thinking about plotting
girth  height  and average crown spread. This would be a shape
diagram for different species of trees, perhaps also show a
distinction between young and old trees in a species, and perhaps
variations in shape with location or environment. Perhaps the plot
of height  girth  and volume would also be interesting. I have a
basic ternary plot program posted in the measurement section of the
website. Does anyone know or have a macro to create ternary plots in
excel?
I certainly think this is something worth pursuing, and you may have
enough volume measurements at this point to do some preliminary
calculations and plots.
Ed Frank
== 2 of 6 ==
Date: Wed, Aug 20 2008 8:07 am
From: dbhguru@comcast.net
Ed,
Yea, I'm loading up for bear. A set of volume formulas is tumbling
around in my noodle getting ready to spill out and find their way
into emails. I hope that none of the 231 ENTS members will be
driven way, but remind the intimidated, that's what the email
delete button is for.
You make a compelling case for calculating the percentage of a
cylinder occupied by a trunk. Each time you present your ideas on
the subject, they become more appealing. ... I particularly like the
way it would help to capture the volume for of
"decapitated" pines that have recovered enough to present
us with very bushy, indistinct tops. Good stuff.
Bob
