functional circumference

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dbhguru
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functional circumference

Post by dbhguru » Thu Jul 01, 2021 11:06 am

NTS,

Don Bertolette and I will be updating the American Forests Champion Trees Measurement Guidelines Handbook this year and we'll be producing a limited version for the general public next year. Other than tedious, the simple guideline presents few challenges. However, updating the main guidelines is a big deal. We intend to add functional circumference to allow better measurements of multi-stem trees. Measures get away with murder now.

The attachment contains the functional circumference concept applied to some complex forms. Hopefully, the topic will spark some interest. The process isn't that simple except for the first case. nonetheless, maybe some of you have questions or suggestions.

Bob
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FunctionalCircumference-6-28-2021.xlsx
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Robert T. Leverett
Co-founder, Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest
Co-founder, National Cadre

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Larry Tucei
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Re: functional circumference

Post by Larry Tucei » Thu Jul 15, 2021 2:39 pm

Hi Bob-

I looked over the different illustrations you have and believe you have it covered thoroughly.
The most difficult thing will be like you pointed out will be able to follow the pith line.
In some cases it can be well hidden.

The only other thing is that sometimes it is hard to determine the difference between a limb and a trunk.
I say this only because of the Live Oaks I've measured over the years,
Your last illustration of measuring above the root collar is something I've been doing the last few years
and I think it way better for an actual Trunk Circumference.

As these new guidelines come into play they should have a great impact on the current Champion Tree Listings.

Larry

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Don
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Re: functional circumference

Post by Don » Sun Aug 01, 2021 11:01 pm

Good points Larry! One of the 'truisms' that have emerged from Bob and I's focus on measuring circumference, is that at least two things make it very difficult...it seems like most species champions are gob smackers and have had enough exposure to their environment that they approach 'non-standard forms', and yes I'll bet you have some experience with live oaks approaching 'non-standard forms'!
The other thing is that multi-stemmed champion contenders can be difficult to define their pith lines...it's an imperfect art, but no one has come forward with a better solution than the pith line delineation process, that we have laid out in the online AF Measuring Guidelines Appendix.
Last edited by Don on Mon Aug 02, 2021 3:30 pm, edited 1 time in total.

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dbhguru
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Re: functional circumference

Post by dbhguru » Mon Aug 02, 2021 12:13 pm

Don and Larry,

As we move forward, it becomes more and more of a challenge to develop measurement methods that capture the essence of big in the big tree sense. Past American Forests practice was to ignore the complexities if the gob smackers and let the champion tree register devolve to more of a popularity and influence contest. We've ended up with multi-trim organisms like the California Blue Gum.

We've made a lot of progress with the champion tree guidelines, but we're not there yet.

Bob
Robert T. Leverett
Co-founder, Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest
Co-founder, National Cadre

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