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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*[(H-h)/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 well-behaved if open-grown. It is with these big open-grown 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 e-mail, 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 e-mails 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 e-mail 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 e-mails, 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 spin-offs 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