As many of you know, the American Forests National Cadre was created to provide AF with a corps of expert tree measurers to certify national champions and train others to correctly measure trees for championship contests. The Cadre was originally conceived by Don Bertolette and has since been developed by Don and yours truly. The Cadre drew most of its initial membership from NTS. The majority of members are still in NTS. However, the Cadre is a separate organization. Cadre members carry a special membership card from American Forests, and act under its authority. But NTS and the Cadre continue to share a base of common measuring interests. One of those is how to accurately measure trees for championship competitions.
We still have plenty of room in the Cadre for members and any of you who are NTS, but not Cadre, have a leg up in joining us in the Cadre. With this promotional pitch out of the way, I’ll turn to the real purpose of this communication – measuring trunk circumference and the multi-stems.
Arguably, the biggest challenge that American Forests has faced since the beginning of the national champion tree program in 1940 has been defining what a tree is for measuring purposes and specifying the rules to be used in measuring circumference. That challenge has been exacerbated by the fact that most of the national champion tree program coordinators have not been expert tree measurers. Until the current measuring guidelines were published in 2014,http://www.americanforests.org/wp-conte ... nes_LR.pdf
the instructions for measuring height, circumference, and average crown spread amounted to a measly three Internet pages. Basically, the national coordinator left it up to the state coordinators to certify nominees to the National Register. The state coordinators used a combination of state forestry personnel and independent volunteers, i.e. big tree hunters. This has led to what we have now, a combination of the good, the bad, and the ugly, with the ugly becoming more the rule than the exception (Yes, beauty is in the eye of the beholder, but ….).
In May 2017 we’re planning to hold another tree measuring workshop in Virginia with Virginia Tech as the administrative sponsor and the AF National Cadre members doing the instructing. We’re looking at holding the workshop in Charlottesville, VA, but that location is not yet firm.
In contrast to previous workshops we have held where measuring tree height took the lion’s share of the time, in this event, we’ll concentrate on measuring circumference. We’ve got height down to a fine science, but circumference remains hostage to the battle between single and multi-stem forms. We’re going to try to crack this tough nut for American Forests, and hopefully for those state programs trying to get in sync with the national program.
We plan to consider: (1) the definition of a tree for AF measuring purposes, (2) methods of handling tree forms with multiple stems at 4.5 feet above ground level, and (3) rules and techniques for determining whether nominees are single or multiple tree forms.
It is (3) where most of the trouble lies. Under the current rules, if you can keep a tape in contact with a bark surface as you encircle the trunk at the chosen measurement height, you may treat the result as though you measured a single trunk regardless of how many pith lines might be included internally. Basically, the rule had been if the tree form is divided into separate stems at 4.5 feet, the measurer finds the smallest circumference between 4.5 feet and the ground and use that, again keeping the tape in continuous contact with bark - even if there are seams along the trunk suggesting that multiple trunks (stems) are pressed together with an outer covering of bark that hides the individuality of the stems.
Now we perform a pith analysis. If the stems extend down to the root collar and if tracing their assumed pith lines result in the lines reaching ground level before coming together in a point, then we treat the result as multiple trees. If a trace has the pith lines coming together before the base is reached, we have one tree. This new method provides for a resolution for clear-cut cases, but there are always tree forms that don't submit easily to pith tracing. That occurs more frequently than we'd like because the pith lines are seldom in the centers of trunks that press together. Still, the new rule is a vast improvement. Here is why.
The old rule for measuring circumference led to a lot of mischief and gave multi-stems a huge advantage over even the best, most perfectly formed single stems. However, in fairness, the old rule also enabled forms for species like willows that prolifically sprout multiple stems from the root collar to be treated as a single organism. There is still a legitimate difference of opinion as to whether or not the multi-stem willow form should be treated as a single tree. But how far do we go in this direction? In the past, the practice basically was that if you couldn’t conclusively prove that a candidate was actually multiple trees via someone's challenge, the candidate was given the benefit of the doubt.
In his AF Measuring Guidelines Working Group capacity, Don Bertolette, has shown what the prevailing practice has led to in his recent analysis of the forms that have been accepted into the National Register - forms that have many of us rolling our eyes and shaking our heads. Even with pith analysis attempting to distinguish forms that represent what started as different trees that subsequently began pressing together with bark growing around and over the areas of compression. We still have unresolved issues.
We are soliciting ideas from the NTS membership on how to deal with the multi-stems. BTW, NTS President Will Blozan, who is also AF National Cadre and MGWG favors the normal form that a species assumes as a qualifying criterion. A tree may be injured multiple times in its life giving rise to additional stems developing from the root collar, all of which may eventually press together at some point giving the appearance of a single trunk to untrained eyes. Will rejects these forms as eligible for championship status. At least, he rejects including all the stems in calculating circumference points. I agree with Will for species that are not prolific at stump-sprouting. However, I leave room for species that take on shrub-like forms more frequently than development as single stems. Some of the western junipers appear to fall into this class. Many members of this class are the small trees, but if I understand our friend Larry Tucei, live oaks can develop as a multi-stem form when grown from a single acorn. When they get to be enormous, we admire them and are less concerned about their origin, but I’d hate to see one rejected because there was some doubt about how it began life. Either way, there is lots of room for discussion.
Also, tree appearance plays a big role in these debates, at least informally. The peach-leaf willow champ from California (I’ll leave it to Don to supply an image) does not look remotely like a champion to me. I would not nominate such a shape regardless of what might eventually be proven about it genetically. I could give other examples, but I prefer my champions to have forms that we can all admire, forms that do justice for the species. For me, choosing our champion trees should not devolve to a contest among the bizarre and deformed. Let me offer an example based on one of my favorite species.
For a historic and charismatic species like the white pine, shouldn’t we seek its Olympian ideal? White pines are subject to being deformed by attacks from the white pine weevil. The result is an asymmetrical, contorted form that lumbermen reject as worthless. It is certainly not the normal shape of the species, but because it becomes multi-trunked at the point of weevil damage, it can develop a large crown. This leads to more photosynthesis and a larger lower trunk. This in turn leads to a higher point total on the champion tree formula. So, we can end up with an almost grotesque national champion that is rejected by the forestry community and violates the notion of the Olympian ideal. Is this really what we intended?
One way we plan to better analyze what appears to be multiple stems is to collect photographs of cut stumps. Ideally, we'll take before and after shots where the opportunity prevents itself. Actually, Will did that with a red maple several years ago, if I remember. It was a good start.
Well, I’ve rambled enough. Although, this is primarily Cadre business, the MGWG is happy to keep the discussion going here in our NTS BBS if enough of you are interested. Any thoughts? Who votes for what? Where do we draw the lines?
Robert T. Leverett
Co-founder and Executive Director
Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest