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Re: Measuring Fusions

PostPosted: Sat Jul 25, 2015 8:02 pm
by Matt Markworth

Great spreadsheet! I was thinking of making one to test my numbers, but you've already done the work!

I found two differences in our inputs, and with those resolved, the results created by hand are an exact match to the results created by the spreadsheet.

The first difference is that I found the area at 4.5 units above the base by finding the area of an ellipse (major axis: 7.5 units, minor axis: 6 units), instead of basing area on circumference (I should have mentioned that). So, I used 35.34 square units as the area, instead of 36.44 square units.

The second difference is I used a height for Trunk A of 120 units, whereas the spreadsheet has 126 units.


Re: Measuring Fusions

PostPosted: Sun Jul 26, 2015 8:03 am
by dbhguru

 Soooper! We're cooking with gas. I like the use of elliptical area since that is going to be more typical of those forms. Not sure where I got 126. Typo I guess.


Re: Measuring Fusions

PostPosted: Sun Jul 26, 2015 7:57 pm
by Don

In Bob's interpretation to Zane's
"...discussion of competing forms: (1) a redwood that we interpret to be a main stem plus one or more coppice shoots that have fused to the main stem with a separation at below 1/3rd the height of the main stem, and (2) what we interpret as a single stem that then divides into two stems at 1/3rd or more of the height of the taller stem. As I understand your point, in the case of (1), we expect these coppice stems to increasingly fuse to the main stem and the bark to grow around the assemblage so that the fused region is indistinguishable from a single trunk to the naked eye. Many of the redwood giants are of this form. From this starting point, I understand that you wanted to develop a method to compute a "functional volume" for (1) versus (2), principally to establish parity for big tree competition purposes...",
I have several comments:

a) I like the mathematic portion of this and later discussions in that it deals with more and more accurate means of assessing comparative volumes in multi-stemmed trees. With Matt's addition of an array of geometric shapes ranging from columnar to conic, and mimicking the potential shapes that they take when "pushed" into proximity, a further refinement in volume determinations can be made. As well, it provides a simple model of the primary shape of the base, making it relatively easy to see how over time there is tendency for such a "fusion" to result in increasingly circular cross-sections.

b) I'd like to now segue into a more plant physiologically based discussion (here I'm relying on my own under-graduate and post-graduate forestry classes, from "sometime" back, and will eagerly appreciate updates from current concepts in plant physiology!).  I'd like to refer you to the online Measuring Guidelines, Appendix I, pages 75-81; and the Glossary of Terms, Appendix II, pages 82-85.  
Basically there I gathered, from a wide literature search, that most all trees start from a single seed source, extend a single (apical) meristem upwards from ground level, and with each successive annual increment of growth, adds rings concentrically about the apical meristem (after each years increment, the apical meristem becomes "pith"). In subsequent years, injury or other opportunity can reconfigure the meristematic energy to that of a lateral meristematic growth. This may come in the form of a 'coppice' due to an impact injury, or in the case of redwoods, from a burl (itself a response to injury?), or a 're-iteration' usually a significant distance up the tree, in response to upper canopy disturbances.

c) In my mind, this should have us consider the relationship of the "branching mechanisms" to the seed source at ground level, to the somewhat arbitrary human reference point, that of breast height, to Zane's somewhat arbitrary 1/3 Total Height level.  Functional in traditional forestry for "normal" sized trees, the breast height gets lost in the often millennial growth of the larger species (thinking in terms of the tree's base, of buttressing, large burls, pathogenic growths, and specific to our discussion, fusions). Which is to say branching: pertinent to ground level; breast height; and in Zane's case specifically, branching at 1/3 of the total height.

d) At ground level, at the time of a seed's sprouting, a tree's singularity is a usually a simplistic determination. We've not the longevity as humans to have observed the hundreds and thousands of annual increments, and Zane's point that we cannot know with certainty whether there was a proximity of seedlings that grew together and over time, or morphed like Matt's paper model (kudos Matt, for a scientifically 'elegant' model!) eventually into a circular cross-section, has merit.

e) We can however operate on the assumption (from Wood Science and Technology discipline) that a tree will grow, in the absence of external stimuli, as near a circular cross-section as possible.  And when external input, such as gravity, slope, aspect, solar incidence, and specific to this discussion, obstacles are encountered the tree will respond at the site of such input.  Consider the Scenarios I-IV: Scenario I, two redwood seedlings one inch apart; Scenario II, two redwood seedlings one foot apart; Scenario III, two redwood seedlings ten foot apart; and Scenario IV, two redwood seedlings forty foot apart.  After 2000 years has passed, all other things being equal in Scenario I, it will likely by impossible to tell whether there are one or two trees without destructive sampling; in Scenario II, it will still be difficult to discern the 'singleness' of the origin; in Scenario III, two seedlings growing equally to ten foot diameters will just encounter each other, and as they equally expand to twenty foot diameters, they will first create zones of extrusion to each side of the contact, then as they extend to their full ten foot diameter, they will tend towards a circular cross-section, as the bark of each tree fuses from the base and over time with continued contact up the tree, extend the appearance of bark inclusion, much like that of a tree repairing a wound and eventually disguising the wound; and finally in the case of Scenario IV, after 2000 years, the two twenty foot diameter trees just encounter each other and it's clear to all that we are looking at two magnificent gob-smacking giant redwood trees.

f) In the Scenarios that involve contact, they respond to that contact with displacement of the circularity expected of trees [in the absence of any other external input], the only difference is the length of time the trees have to "disguise" themselves as one, and the height at which they "emerge from their disguise".

g) In the case of redwoods' and their ability to "re-iterate" some significant distance up the tree, these typically take the form of a coppice, initially growing out (phototrophic?) then up, and while it would be expected that they would be necessarily included in a redwood tree's volume, it's not reasonable to consider reiterating stems in an AF formulaic point assessment.

The means by which one can work chronologically backwards, conceptually from Scenarios IV, III, II, and I involves the "circularity" assumption as described in the online Measuring Guidelines, page 75 in Trunk Development section.  External inputs cause the tree(s) to adapt, in what are referred to as adaptive or reactive responses.  The cross-sections of such trees demonstrate Reaction Wood. "Angiosperms put tension wood on the uphill side of the tree to pull the tree back up straight [response to change in gravity input], whereas gymnosperms produce compression wood on the downhill side of the tree to push the tree back up straight." (Fritts 1976). Working chronologically backwards, or more to the point, from the top of the tree down, one could expect that the trees would go from essentially circular cross-sections, to (at the point of contact or "fusion") increasingly eccentric  cross-sections at the base.  The degree to which the bases are eccentric, determines the displacement of the pith line from what would have been a central axis in a circular cross-section.

This requires judgement on the part of the observer, and multiple images or views of the complete circumference of the base, but a better estimate of a tree's singularity or their multiplicity is obtained by delineating the perceived pith lines, than merely making the judgement of what happens 1/3  or more of the way up the tree.

Another way of stating this might be better, that is, for mathematical estimates of a tree's volume or of "fused trees" volumes, Zane's formula is perhaps the best yet.  But in terms of plant physiology and wood science, the assumptions referred to here in the online Measuring Guidelines (and included Literature Citations) provide a better determination of single tree versus multiple trees issues than any I have yet seen.

I remain open to and encourage other views, theories, citations...I have made a reasonable search of literature available to me (I don't have extensive availability to Inter-library Loans, etc. here in Anchorage) and would look forward to additional discussions and literature on this topic!

Re: Measuring Fusions

PostPosted: Thu Jan 26, 2017 1:50 am
by mdvaden
yofoghorn wrote:Hi everybody, .... SNIP ...  Why should we discount large 30000 cubic foot trees like Howland Hill Giant, an undisputed single-stem redwood, by adding up all the volume of fusions? Another issue are disadvantages to fused trees as far as the ranking.

Howland Hill Giant is 100% a fused coast redwood. With the right light this month, I was able to find, identify and photograph exactly what was needed to recognize it as a double redwood. 100% certainty ... no shadow of doubt.

If we ever get a chance to meet at the tree sometime I'll show you what to look for. Chad Olson gets down to the park fairly often from Grants Pass and he may be the first one I show and teach about this type of formation. I'm sort of surprised that a couple of researchers missed it, but after thinking about it, I realized that they've worked on far fewer trees than arborists who are often hands-on with tens of thousand of trees in their work.

Re: Measuring Fusions

PostPosted: Sat Feb 18, 2017 6:24 pm
by Don
I'd like to open up discussion to a broader spectrum of tree species, than just redwoods, if you folks don't I'm in the 'business' of trying to find as 'standard' a rule as is possible for almost all species.
For example, in an image of two ponderosa trees that Mario offered up some years back, I have taken the liberty of delineating it, based on my understandings of the physiology of tree growth, as follows:
Two "fused" ponderosa pines, image is courtesy of Mario Vaden

The orange lines represent the assumed pith lines, extended down from the central axis of each ponderosa pine here. The curvature that starts roughly about waist high on Mario's friend, represents the curvature of the pith lines as the two trees pushed against each other as they grew together.  The red dashed line represents the Zone of Extrusion, where the cellulose, lignin, cambium and phloem extruded out with each annual increment of growth. While I don't have an image of the back side of these two ponderosas, I would expect a very similar Zone of Extrusion on the back side.  These trees have begun the process of inosculation, and after another hundred years, I would predict the bark would attain a uniform appearance that one would expect of a single tree, and a generally circular apparent cross-section.  The yellow lines represent the two locations where the diameter could be tape wrapped, with respective heights that they were taken at.
What sayest you?

Re: Measuring Fusions

PostPosted: Sun Feb 19, 2017 12:01 pm
by edfrank

As you know I have been well into the discussions of single trunk versus multitrunk for years.  I even wrote the Wikipedia document on the subject.  As time passes and after my break from daily participation in the group, I am having heretical thoughts on the subject. Yes they grow faster and a multitrunk is not the expression of the best a single trunk might perform, but...  Big is big and multitrunk trees with fused trunks seem to pretty much function as a single tree in ecological terms.  Multitrunks are the standard for many species.  At some point the distiction between fused multitrunk trees and single trunk trees becomes almost indistinguishable and it becomes a exercise in futility to try and determine if something is a single or double short of cutting the tree down.  They are valid tree forms.  The ideal option would be to have a list of the biggest tree whether single or multiple and a separate list for largest single trunk tree, where the tree is clearly single trunk.  The goal should be to promote the idea of two valid listings rather than trying to unravel the mystery of fused trunks.  In the mutitrunk tree all of the fused stems at breast height would be considered part of the tree's diameter.


Re: Measuring Fusions

PostPosted: Sun Feb 19, 2017 9:08 pm
by Matt Markworth

Great example. It's a strong reminder that nature is "wiggly" - seldom in straight lines or geometric shapes and in a constant state of change. As an avid tree measurer I definitely think it's worth the effort to try to straighten out this wiggly world:)

I used to get concerned about the validity of trying to compare multi-stems to single stems for champion tree lists (which is why in the past I was a proponent of having two separate lists), but I've come around on that quite a bit. In the past I felt that deriving a certain number of points for a multi-stem would always have an element of being arbitrary, but, after all, even the big tree formula itself is quite arbitrary (with a mixture of inches, feet, etc). In the end, the number of big tree points that a tree has is simply a concept - in other words it's not an absolute truth of nature, but rather a conceptual truth of humans - and finding a way to more equitably compare various tree forms is just an addition to the concept of the big tree formula.

All that being said, can you provide us with a general snapshot of where the effort stands right now on trying to grapple with how to best compare multi-trunks to single trunks for the purposes of a champion tree list? The ongoing discussion over the past few years on this topic is probably the best example of all that it may not always be possible to find a perfect solution when trying to straighten out a "wiggly" world.


Re: Measuring Fusions

PostPosted: Mon Feb 20, 2017 2:08 am
by Don
You both make good points, many that I've voiced at different times and ways, myself. If you don't mind, I'll reply to them, in a private message.

Re: Measuring Fusions

PostPosted: Tue Feb 21, 2017 1:54 pm
by dbhguru
Ed, Matt, Don, et. al.,

  I think we all recognize that applying one formula to capture "bigness" in tree form, given the wildly differing shapes, produces mixed results at best. However, it is my perception that most big tree competition participants continue to want a simple measurement/evaluation process. While the National Cadre is doing its best to honor this wish, I doubt if we can continue the one size fits all approach that we've been using. Something has to give.

 In the 1920s, a Maryland Forester created the big tree competitions, and from Sheri Shannon's research, he weighted the big tree formula to reduce the impact of open-grown trees. He was attempting to call attention to forest-grown forms and the loss of those big single-trunk trees with their precious genetic heritage. The Maryland competition became nationalized in 1940, and evolved into what we have today. Were that Maryland forester to come back and see many of the trees that are presented as champions of their species in the National Register, I don't think he'd be a happy camper.

 As we have extended the big tree competitions to tropical forms, we have recognized that there needs to be an expansion of the measuring process to cover their forms/shapes by creating parity with more conventional forms. We are moving in that direction satisfactorily, but mainly with respect to tropical forms that have huge buttress roots, below and a single trunk above. Species like banyans with their complex aerial root systems elude us.

 Outside the tropics, we still need to agree on which species express themselves through multiple shape changes over time, leaving us to judge if we have one or multiple trees. We want to be able to better distinguish coppices from trees that started separately. Then of course, there are forms that represent both. I think several of those have made it into the National Register and leave us scratching our heads. Don has done a yeoman's job offering exercises to get input from the participants on where they stand on about 50 or 51 trees/tree-forms in the National Register. We need to see how we individually and collectively evaluate these problematic champions.

 I try to stay flexible, but so far, arguments for accepting, as one, multiple trees that over time become joined at the root collar are not persuasive to me. This means that I would vote no on the California live oaks national champion. However, while I have a voice, I'm only of many who does. Who are the others? The National Coordinator (presently, we don't have one), the National Cadre members, and the state coordinators. These are the main players. Don and I are presently communicating with as many of these folks as we can. Actually, it is Don who has been doing the heavy lifting. My time is more devoted to methods of measuring and establishing parity.

 Over the coming months, we will periodically revisit the origins of the  big tree competitions, the factors that we want to consider today, and very importantly how we want to weight them (do we like ugly trees?). We're going to be at resolving the single versus multi-stem debate for a long time. NTS is not a direct player, but an important indirect one. After all, the National Cadre was born from NTS. So, we'll continue using the NTS BBS as an important discussion forum on the subject. It may eventually come down to voting involving the three parties mentioned above.