Posted: Wed Jan 25, 2017 11:02 pm
by Don
Darian Copiz wrote:Although the examples I've seen appear to be pretty clear to me and I'm not sure why there is so much debate about this, I think there are some potential complications if one is using the root collar for determination, as that area can be somewhat muddled. At 4.5 feet above the ground there is less room for interpretation and things are even clearer. Breast height is where circumference is measured, so that should be where the number of trunks should be determined. Otherwise we might as well measure circumference at the root collar.


Darian/Will-
Are we not approaching a circular argument? When you say "Breast height is where circumference is measured...", Breast height is measured FROM the perceived location of the root collar (the proverbial positioning of the original seed that set it all in motion).
The point is, physiologically, a seed sends up a single meristem. Whether or not it chooses to subsequently branch in response to its new environment is another issue. Those that retain a single stem form get measured 4.5' up from that 'seed'; and if the seed branches before 4.5' in height, the multiple stems get measured at 4.5', then get 'normalized' to achieve parity with single-stem contenders. This is fair to both single and multiple stems, and serves as a intermediate step in using 'volume' as a measure of bigness.
This 'normalization' method is sound, and we'll soon be sending out a package for all National Cadre Members that will include, among other items, the Normalization Formula and it's derivation, and an Excel spreadsheet that automates the calculations.
-Don

I meant to introduce the "after" image of the Quad Sugar Maple which was felled a few years after the "before" image...the attached image is of it's cross-section, very near ground level. For scale, note the 8" x 11" sheet of paper in the middle of the cross-section. I've copied it below at the highest resolution I can, you should be able to zoom in far enough to discern multiple 'meristems'/piths, at (or very near) ground level...I can't see them coalescing into a single stem maple within inches further down...methinks this was a cluster of four to five maple seedlings planted together to insure at least one came up...it doesn't take much imagination to see the 'before' image looking evermore AS IF IT WERE a single stem tree that has inosculated its own base, had it lived another hundred or two years.

Does it matter? That is the question we have before us, to arrive at a consensus...may the discussion broaden and continue...: > } [Including the role of measuring girth at breast height!] As Bob would say, we're about to cook with gas!


QuadSugarMapleXsection.jpg

Quad Sugar Maple Cross-section