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TOPIC: Example use of formulas
http://groups.google.com/group/entstrees/browse_thread/thread/c01b76e4cadaa70f?hl=en
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== 1 of 1 ==
Date: Mon, Dec 31 2007 8:44 pm
From: dbhguru@comcast.net
ENTS,
As an early 2008 communication, I plan to work up an extended
example that utilizes many of the formulas that I've been throwing
at the list as of late and will be shown in an article in the
upcoming Bulletin. My hope is that a concrete, extended example will
showcase the utility of the volume formulas (or the opposite for
some) with the objective of boiling our bag of formulas down to the
most useful set. As a brief preview of what is to come, expect to
see the formula set:
(1) r = R*[(Hh)/H]^p and
(2) V = [1/(2*p+1)]*[pi*R^2*H]
where (1) is the taper equation that leads to (2), the volume
equation. In these equations,
r = radius of trunk at height h above the base,
H = full length of trunk
pi = 3.141593
R = radius at base (or 4.5 feet above base in some situations)
V = volume of solid
If we examine (2) more closely, we quickly see that:
p = 1 gives the cone
p = 1/2 gives the parabola
p = 3/2 gives the customary neiloid shape
In our experimentation with exotic volume formulas, we must not lose
sight of our primary objective and that is to model the volume of
the trunk of a tree. For symmetrical, compliant trunks, forestry
provides log rules that do well enough, especially when large
numbers of logs are involved, but ENTS focuses more on individual
trees, especially the giants. As to form, the latter are seldom
wellbehaved if opengrown. It is with these big opengrown trees
that we need the most help and help is on the way.
Bob
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TOPIC: Excel Workbook
http://groups.google.com/group/entstrees/browse_thread/thread/743348eb8e4d5167?hl=en
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== 1 of 1 ==
Date: Wed, Jan 2 2008 10:08 am
From: dbhguru@comcast.net
ENTS,
If anybody has opened the Excel workbook I sent earlier as an
attachment to an email, and are confused by it, I apologize. Please
feel free to ask questions about it and I will happily clarify.
Communications such as the Excel workbook are often presented by me
without any strong expectation of responses from fellow and lady
Ents , although I'm happy when I get responses. My main purpose with
the technical emails is to provide a continuous stream of
infromation and data that will become available to researchers when
Ed posts the communications threads to the ENTS website. For me, it
is easier to present material on these technical subjects in bits
and pieces via th email process. However, I hope that some of the
material will stimulate interest in others to join the measuring
mission of ENTS.
In presenting technically oriented emails, there is usually a set
of priorities that I am attempting to implement. The first priority
is to produce a more accurate statistical description of a forest
site and/or individual tree. Rucker analysis and its spinoffs does
that. The description priority is usually suffiicient to justify the
effort. The second priority is to perfect our measuring craft, push
the envelope as it were, but always in a direction of our own
choosing. Development of formulas meets the second priority. We
don't have the market cornered on tree measuring, but at this point
we're by far the best show in town within the geographical East. I
don't want us to lose that edge. The third priority is to build
databases of scientifically useful research data. I have faith that
the Tsuga Search database and my reports on MTSF will eventually be
courted by serious scientific researchers. The fourth priority is to
provide a means of distinguishing exemplary forest si
tes and individual trees through measurment methods that highlight
differences. In the past Tom Diggins has spoken eloquently to this
point. The exemplary status of Zoar Valley, NY, was virtually
invisible to the local DEC people. Their techniques were (and still
are) too crude to reveal the exemplary features of Zoar. About all
the DEC representatives have done has been to add up board feet and
to misrepresent the true nature of the resource at Zoar Valley (Ooh,
my bad).
The above having been said, I still plan to produce a set of
examples to help interested Ents explore the value of formulas,
methods, and protocols.
Bob
