NTS Book Project on Big Trees of the World

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edfrank
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Re: Historical Douglas Fir heights

Post by edfrank » Sat Mar 02, 2013 8:13 pm

Doug,

The girth height standard is arbitrary based upon a convenient height for measuring girth for timbering considerations. There isn’t any one height that is better than any other. We use 4.5 feet because that is what has always been done. It falls above the basal flair for most normal sized trees, but not all of them.

Why have a standard at all? There is a big difference between girths measured at ground level, or at two feet, from those measured at 4.5 feet. We don’t measure girths at greater heights because it is simply a matter of ease of measurement. The reason to keep the height at 4.5 feet is simply consistency with older standards and compatibility with a large set of existing measurements.

The differences in the measurement heights in different countries is because we are using imperial measurements and they are using metric. People like round numbers. 1.3 meter and 1.4 meters are spaced just a couple inches above and below out own 4.5 feet. 4.5 feet = 1.3716 meters. The human penchant for even numbers isn’t going to disappear. So until we as a country adopt metric measures, we need to use imperial measures to make the process more relatable to the general American population. As primarily an American institution we should try to make what we are doing relatable to the general public. I am comfortable with metric measure, but the general public is not. So for Americans the standard should stay at 4.5 feet as it always has been.

For an international standard, if we were to devise one, slightly higher may be marginally better, so 1.4 feet is marginally better than 1.3 feet, but not a slam dunk winner in my opinion. In the United Kingdom they are measuring at 1.5 feet on the high side of the tree if there is a sloping surface. I can’t argue against that because I essentially made the same argument in regard to 4.5 feet on the high side of the giant western trees, because otherwise part of the girth loop would be below ground level. UK is dealing primarily with really fat old and often pollarded oaks and such so slightly higher and measured from the high side might be more appropriate for them. So if someone wants to argue for one standard international height or another among 1.3, 1.4, or 1.5 meters, I don’t really care what number is chosen.

Again I want to emphasize, in my opinion, that the differences being discussed in terms of girth in almost every case would be small to non-existent. Consider choosing the positioning of the base position as it relates to girth measurement height. I do not believe that in many case, particularly in regard to the fatter trees that two different people looking at the same tree at different times would pick exact;ly the same elevation as the “base” of the tree as it is a judgment call where the pith would intersect the ground surface. Is the tape always wrapped perfectly level around the tree? No. Yes it is good to have an idealized standard height, but people must recognize there will be variations in the girth measurement height and in the tape wrap itself. For major trees we need to work to get these things as well as possible, but they will not be perfect.

I understand your position. I am obsessive about many things myself, but the differences between the girths at 1.3 m, 4.5 feet, or 1.4 feet or even 1.5 feet are not enough to really worry about in my opinion.

Ed
"I love science and it pains me to think that so many are terrified of the subject or feel that choosing science means you cannot also choose compassion, or the arts, or be awe by nature. Science is not meant to cure us of mystery, but to reinvent and revigorate it." by Robert M. Sapolsky

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Larry Tucei
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Re: Historical Douglas Fir heights

Post by Larry Tucei » Sat Mar 02, 2013 8:21 pm

Bob, all, An outstanding idea! I'm in for sure with Live Oak. I often looked at Colby's listing it was outstanding. The Live Oak portion would maybe list 5-10 of the tallest, largest girth, broadest crown, and greatest spread with photos? Whatever you need me to contribute just let me know. Larry

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DougBidlack
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Re: Historical Douglas Fir heights

Post by DougBidlack » Sat Mar 02, 2013 11:11 pm

Bob,

here is my experience with crown spread. When I first started measuring crown spread I just used the max/min method but I was not happy with the results. I was measuring the same couple hundred or so trees every year and I didn't like the fact that the numbers did not always seem to represent actual growth. I mean, if I saw two feet of new growth on all the outer limbs and my crown spread measurement was only a foot greater than the year before you can imagine that I was not happy. So I tried something that looked similar to your drawing. I would measure the radius, take three steps and measure the radius again and so on until I was done. What was the problem here? Imagine a tree growing in an opening on three sides, but say the South side is forested and quite close. In this case what would happen is that I would make far more measurements on the North side than the South side. This, I think, inflates the average crown spread of the tree. Lastly, I would make one crown diameter measurement then I would make a second crown diameter measurement perpendicular to the first. This would give me a pattern that looks something like a plus sign. Then I would make a third crown diameter measurement ca. 45 degrees off from the second one and finally I would make a fourth crown diameter measurement perpendicular to the third. The resulting pattern would look like an asterisk. This method, in my opinion, is far better than the previous two. As you mention in note #4 more measurements would be better, but would the added effort be worth it? At some point there is a very clear inflection point, where adding more measurements makes almost no difference. I don't know where that inflection point lies but I would need to be convinced that making more than 4 crown diameter measurements would be worth the added effort.


Ed,

I think that the differences between girth measurements at 1.3m, 1.37m, 1.4m and 1.5m would be small. I'm not going to disagree with you on that. However, there would be measurable differences. This bothers me and it will always bother me. Do you have a big problem with the two measurements of girth that I proposed earlier? If so, what might they be?


Larry,

it's great to have you on board. Of course we all knew you would get to be the live oak measurer. Lucky devil! I have to ask you though, if you could pick only two more species to start with which two would they be? Southern magnolia, the state tree and flower of your great state! How about bald cypress or water tupelo. Or maybe longleaf pine. If you could only pick two more...come on, inquiring minds want to know.

Doug

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KoutaR
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Re: Historical Douglas Fir heights

Post by KoutaR » Sun Mar 03, 2013 4:23 am

Bob,

You suggested Picea abies, Abies alba and Quercus robur for me. I am certainly interested in Picea abies, my favorite European species. I am also interested in Abies alba but I am afraid we have not enough data for the species. But we may be able to get enough data during the project. Jeroen is going to go to the Balkans again. Maybe I will manage to go to Slovakia, for example. However, I don't feel I know Q. robur well enough. Jeroen would be THE specialist with European oaks. If he liked to participate, maybe he would like to take at least plane trees, as well. Larix decidua and Fraxinus excelsior would be additional species that I am interested in. Karlheinz could also be interested in Larix decidua.

I agree that Michael Taylor's participation is indispensable. Indeed, if none of the west coast members participates, the logic of the inclusion of Europe is questionable.

Add to the international section the coming Taiwan exploration by Will et al. (if it is true).

Kouta

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Will Blozan
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Re: Historical Douglas Fir heights

Post by Will Blozan » Sun Mar 03, 2013 8:35 am

NTS,

Great discussion that should now be moved to a separate heading... Tree species perhaps?

I have always been bothered by crown spread and rarely bother to measure it unless nominating a record tree. I do not measure crown spread as a matter of course for every tree. I simply don't like it. Let's face it- crown spread is the most dynamic metric of a tree we take. The crown "foot print" moves and changes nearly daily in multiple directions; girth and height generally go in one direction and at one general point. Crown spread is not really a monitorable dimension unless repeated exactly each time. Even crown area/volume is super dynamic and each measurer will come up with a different result for the same tree.

As for 4.5 feet for BH, yes it is convention so it should stay for our US listings. If we were 10 feet tall BH would be more like 8 feet so it is simply an convention of convenience. I recognize it does not work for all trees and species in every case. We just need to note the exceptions and present as much detail as possible.

Will

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Larry Tucei
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Internet book on big trees

Post by Larry Tucei » Sun Mar 03, 2013 8:50 am

All- I think we should start a separate thread for this project. Many times everyone will not read all the pages in a post and would miss this discussion. Doug, When I measured Live Oak crowns I just do two measurements- example east to west, north to south. I don't have the time to do lengthier crown measurements when I'm doing multiple trees. However when I find a really big Live Oak I sometimes measure 4 ways, north - south, east- west-, northeast- southwest, northwest- southeast, very similar to Bobs diagram. When we were at Congaree measuring the State champs this is how we measured the crowns to get a more accurate idea of average crown spread. Doug I almost put down Magnolia and Cypress on my trees to contribute. I would be happy to do both if no one else wishes to. Ed, Can you bring the postings from the original topic over to this page so everyone will see them together? Larry

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dbhguru
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NTS Book Project on Big Trees of the World

Post by dbhguru » Sun Mar 03, 2013 9:15 am

NTS,

With respect to the shared book project, we now have formally on board Will Blozan, Dog Bidlack, Kouta Rasanen, Larry Tucei, Ed Frank, and yours truly. We need more members to choose a species or two, but this is a start. Kouta, Doug, et al., please feel free to choose the species you want to cover. I proposed that list to just move the project to the next stage.

At this point, I think the best approach is to organize the project as a series of independent coauthored essays. An essay would equal a chapter or part of a chapter in the book. One essay might be a single species by a single author. Another essay could be coauthored for multiple species - however it best works. We might lump several related species for which we don't have much information in one essay. I admit, my thinking here is fuzzy.

An approach to the whole project could be to break it up into volumes. The eastern U.S. would be a volume, and the West, another. Europe would be a third volume. Australia, New Zealand, and Tasmania would be a fourth and so on. This would keep the project alive by completing and showcasing parts as inducements to continue. The tropics represent an enormous investment in time and resources. A volume there would likely come last. We certainly would want a volume on the tropics, but it wouldn't hold up the project, awaiting its completion. Ed is very good at thinking of logical ways to proceed, but it seems to me that the idea of breaking the project up into volumes makes it more doable.

While I've got the podium here, let me address some aspects of project design that are especially important to me. I really want to address mis-measured trees as a general topic, especially where mis-measurements confuse the public about what a species can achieve, or has. I don't mean that we should call individuals to task for having contributed to the deluge of mis-measured tree data. That would be a tremendous mistake, but we should be able to find ways of explaining what is reasonable and what isn't in terms of numbers for a species throughout its range. A tuliptree is someone's yard in suburban southern New England is very unlikely to reach a height of 158 feet. If planted and basically lawn-grown with a fairly prominent spread, a height above 130 feet is unlikely, though not impossible. Above 150 feet is extremely unlikely. Move to a nearby ravine that affords protection, water, and deep soils, and add competition from companion tuliptrees, and the 150 becomes quite plausible. Move from say 40.5 degrees latitude in southern New England to 41.5 degrees and the likelihood of the 150-footer drops considerably even in the best growing conditions for that species. This is the kind of information I would hope we could include in the essays where we feel confident in our data.

My next step is to begin an essay on the white pine. As it progresses, I'll post drafts to the BBS and ask for critiques. In this way, Ents who would like to participate more casually can make contributions. Others can do likewise, if they choose for their essays. Thoughts, ideas, suggestions?

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

Joe

Re: NTS Book Project on Big Trees of the World

Post by Joe » Sun Mar 03, 2013 9:41 am

Bob, I'm curious what sort of book you're thinking of- a big coffee table book with photos in addition the essays you mention? Or something more intellectual, mostly text? Is the audience meant to be the general public or mostly the environmental intelligentsia or more specifically for tree measurers? Perhaps this has all been discussed but for some reason I missed that discussion.

In the past- a few times- I've sugested that a very serious essay on exactly why this work is important- would be valuable- such an essay should be in the book, IMHO. After all, it's not important just to provide the best methods of measuring trees so we know what the biggest trees are, as mere facts- I should think knowing the full potential of nature is something important to the human race for many reasons- it could even get philosophical. Of course I'm merely a lowly field forester, so I wouldn't know anything about such deep thinking.
Joe

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tomhoward
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Re: Historical Douglas Fir heights

Post by tomhoward » Sun Mar 03, 2013 10:14 am

NTS,

I like the idea of a list limited to species that are accurately (by NTS methods only) to 40 m height or 5 m girth. All the world's biggest and tallest trees would be covered by this list. In the discussion of Western tree heights I noticed that one very significant species is missing - this is the Western Red Cedar, one of the world's largest trees. Does anyone in the group know how tall the tallest Western Red Cedar is? I think it must be over 200 ft.

Tom Howard

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dbhguru
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Re: NTS Book Project on Big Trees of the World

Post by dbhguru » Sun Mar 03, 2013 10:44 am

Joe,

Your past suggestions about why this type of book is important have not gone unnoticed. I greatly value your contributions. I could see a forward by a well-known scientist covering the ground you describe. I don't see this as a coffee table type book because there is just too much detailed information that needs to be included and coffee table books are hideously expensive to produce. Nor, is it intended as a book about how to measure trees. It would be more descriptive, laying out the case for what each of the profiled species has done in the past, is doing presently, and on a trajectory to do what in the future. Some of the information would be silvicultural in terms of what a species needs to grow to maximum size. Forestry sources would be not only important, but critical to telling this part of the story. For the white pine, I plan to interview members of the forestry community who are willing to discuss their experience with white pine, in terms of where and how it grows best. This book is not meant to be confrontational, but it would point to what may be lost when a species is "not treated with respect".

Other Ents are free to express their ideas about the overall style of the book, but as I see it, a guide to tree measuring would be something entirely separate. So, in terms of the audience, it would be aimed at that part of the lay public that enjoys details and facts presented in a reasonably entertaining way. Should we absolutely feel the need to explain some of our measurement methods, they could be included as an appendix.

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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