Don, Thanks for the reference. As you say, definitely something to look into for the book.
Bob -------------- Original message -------------- From: [EMAIL PROTECTED] Bob/Joe-- The water displacement technique for measuring log volume has already been described in research papers--one such paper was recently published in the Southern Journal of Applied Forestry. You can find the abstract of this article at: http://saf.publisher.ingentaconnect.com/search/article?title=volume+measurement&title_type=tka&year_from=1998&year_to=2008&database=1&pageSize=20&index=4 (unfortunately, you need a subscription to get the full article). The unique aspect of this work is that the author took detailed measurements of logs and then translated them so that a computer-controlled system (often used to create miniaturized plastic models) made small versions of the logs to displace, so the large bole wouldn't have to be put into an Olympic-sized swimming pool to displace the water. Definitely a technique to highlight in the Dendromorphometry book... Don ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Don C. Bragg, Ph.D. Research Forester USDA Forest Service Southern Research Station [EMAIL PROTECTED] ~~~~~~~~~~~~~~~~~~~~~~~~~~~ The opinions expressed in this message are my own, and not necessarily those of the Southern Research Station, the Forest Service, or the USDA. -----Original Message----- From: [EMAIL PROTECTED] To: [email protected] Sent: Sat, 27 Sep202008 6:35 pm Subject: [ENTS] Re: Sneak preview Joe, The water displacement process can be used in a piecemeal way to test the closeness of different formulas. Over the years, I've discussed water displacement as the litmus test of volume in emails. The big question for the analyst to ANSWER is how far does the volume of a log or section of trunk or limb differ from the frustum volumes of the more common regular geometrical solids. The frustum formula: V = Pi*F*H*[a^2 + b^2+ a*b] where F = (1/4) for a neiloid, (1/3) for a cone, and (1/2) for a paraboloid and a and b are the radii at the ends of the frustum is the one we apply most commonly these days. The formula assumes a cross-sectional area that is circular. However, the formula can be modified if the cross-sectional shape is more elliptical. In this case we would need to use the semi-major and minor axis from each end of the frustum. The formula would look like the following: V = Pi*F*H*[a1*b1 + a2*b2+ SQRT(a1*a2*b1*b2)] Th e utility of these formulas is their repeated application. We break long lengths into series of short sections. In the aboev formulas, H should not be high or too many changes in trunk shaape can be obscured. In trees that Will Blozan has climbed and modeled (he's done by far the most in the eastern United States), his frustum height are often a meter. He climbs the trees to get girth measurements ever meter of height. In addition, he frame maps trunk splits by using a highly accurate method we developed in ENTS to determine cross-sectional area. We don't just assume circularity or ellipticality where that is obviously not the case. Before leaving the subject I note that log volume charts commonly employed by foresters are of no value to us. They may too many simplifying assumptions. I started out with them years ago, and while they may work for large numbers of logs, I found them to miss individual trees, especially large, old ones. So from that point one Will and I went it alone. All this will be covered in the book on Dendromorphometry that Drs. Frelich and Bragg and Will Blozan and myself plan to write. It is supposed to be under way at this point, I because of my medical situation, I needed time off before taking the plunge. However, when the book is eventually completed, it will include many methods for volume modeling - on a poor man's budget. Tha t will leave plenty of room for high tech wizardry in the future, some of which is already being developed and employed by the likes of Drs. Steve Sillett and Robert Van Pelt in Washington. Bob -------------- Original message -------------- From: the Forestmeister <[EMAIL PROTECTED]> > > BTW, a suggestion- to check how accurate current methods are for > measuring the volume of large trees- I suggest going to a forest that > is about to be logged- no doubt you can find some really big trees- > then measure them- then when that tree is cut, it should be easy to > gather all the crown, in pieces and measure the volume of them by > placing in a tank filled with water (specially designed of course) > whereupon the displacement of the water would give an accuratge > measurement- and the cut logs could easily be measured extremely > accurately before haulded off to the mill. The actual physical measure > by this method should be extremely accurate- then compare that to > various methods now be ing considered (of which I know nothing other > than rough measurements for merchantable logs). > > Joe > > On Sep 27, 4:09 pm, the Forestmeister wrote: > > Well, I don't know what20the accuracy of current methods are when > > estimating tree volumes but it's not likely to be more than plus or > > minus 10% if you're including all the crown. With a digitilized scan > > done by my the technique I'm fantasizing about - I should think it > > would be accurate to plus or minus a tenth of a percent which would be > > orders of magnitude better. > > > > Regardless of that issue- I think it's urgent for us to start putting > > real dollar signs on all the currently intangible values- which are > > more likely to be significant for large trees- the larger the trees, > > the greater for those intangible values. Though there ma y not yet be > > market values for these considerations- if we pretend that there are- > > maybe they'll happen. > > > > For example, let's say we do come up with a value system- then say, > > the state wants to buy a property to add to an existing state forest/ > > park- when they negotiate with the owner they should have to factor in > > such values- because we'll all demand it. After all, when people > > appraise something like antiques- there is no logic to it other than > > supply and demand. If a landowner were told that the value of their > > property was something beyond what some real estate appraisser says- > > then it will be so if they believe it. Much of our economic system is > > "faith based", not logical- so we must all have faith in the true > > values of large trees and old growth forests, c'est nes pas? > > > > Joe < BR>> > > > On Sep 27, 10:50 am, "Will Blozan" wrote: > > > > > > > > > Joe, > > > > > What do you mean by "orders of magnitude"? That would imply at least ten > > > times more accuracy, but in what units? > > > > > Will F. Blozan > > > President, Eastern Native Tree Society > > > President, Appalachian Arborists, Inc. > > > > > -----Original Message----- > > > From: [email protected] [mailto:[EMAIL PROTECTED] On > > > Behalf Of the Forestmeister > > > Sent: Friday, September 26, 2008 3:58 PM > > > To: ENTSTrees > > > Subject: [ENTS] Re: Sneak preview > > > > > Hey Bob, I know next to nothing about the sophisticated methods ENTS > > > people use to determine tree vol umes- I only know standard, basic, > > > simple methods of tree measurements used by field foresters. But, I > > > should think that there must be some way using the best technology in > > > the world today to get an exact 3 dimensional image of any tree- using > > > something like radar or some other electromagnetic radiation- by > > > moving the energy generator AROUND the tree- sort of like a giant scan > > > of a hospital patient. > > > > > The scan could scan the shape to great detail in 3-D, then incorporate > > > that into data into a holograph in order to project it- and I'm sure > > > mathematical geniuses could easily then use that data to calculate the > > > volume of the tree to an order of accuracy orders of magnitude beyond > > > current ENTS methods. > > > > > And, while at it, why not use pene trating energies such as the > > > hospital scan to give a true internal image of the tree which could > > > then be studied for whatever reasons, such as the work done by Alex > > > Shigo to determine the course of "discoloration and decay"- or to > > > discern the value of the tree for wildlife habitat (assuming some > > > hollows in the tree). > > > > > And, if this is done for many trees close together- it could be useful > > > to Gary Beluzo who I recall is interested in the emergent properties > > > existing in forests- a nd for that, having such information and > > > modeling tools- might be significant in such research. > > > > > Just a crazy thought. > > > > > Joe > > > > > On Sep 25, 9:06 am, [EMAIL PROTECTED] wrote: > > > > Beth, > > > > & gt; > The proposed ENTS point formula admittedly works best for trees > > with > > > long straight trunks that can be modeled with a regular geometrical form, > > > principally a neiloid, cone, or paraboloid. I chose the cone for > > > illustration purposes, but either of the other two forms would have > > > worked > > > just as well. > > > > The question of what kind of formula works for a big spreader like > > > the live oaks that Larry measures is probably not going to be adequately > > > determined for a long time. There is just too much wood tied up in the > > > complex network of limbs. The ENTSPTS formula is not the answer for trees > > > of > > > that shape, but then neither is the champion tree formula. Consider the > > > table below. > > > > > > HGT CIR SPD CHP PTS ENTSPTS > > > > 50 12 12022472 > > > ; > 6 524120383374.4 > > > > 13024120448748.8 > > > > > > For trees with spreads of 120 feet, we know there is lots of wood > > > committed to the limbs. Looking at the entries in the table, it is > > > apparent > > > that ENTSPTS does not capture limb wood. The champion tree formula > > > actually > > > does better, but going from rows 2 to 3 is just not logical for the > > > champion > > > tree formula. A 130-foot tall tree with a 120-foot crownspread implies a > > > lot > > > more wood than the spread of points of 383 to 448 indicates. > > > > The problem we're experiencing in calculating an absolute number of > > > points for a tree stems from the one size fits all approach. I understand > > > that it was for simplicity's sake and to try to get the general public > > > involved, but the formula doesn't work well enough for a group like ENT > > > S. &g t; > > > For a system of relative comparisons, TDI works well and we may > > > never get beyond that, i.e. relative comparisons. However, for white > > > pines > > > in New England, I need more of an absolute measure. The amount of limb > > > mass > > > for a tall, straight conifer may not be more than 5% or 6% of trunk > > > volume. > > > So, I don't have to worry too much about the limbs and can apply the > > > proposed formula. By contrast, the limb volume versus trunk volume ratio > > > may > > > approach 50% for live oaks. I wouldn't apply to formula to trees of those > > > shapes. So, the search must go on. > > > > I apologize to the list for not making it clear that I had conifers > > > in mind for the proposed formula. Very clumsy of me. > > > > Sorry you won't be able to make it to the rendezvous. The one in > > > 2009 will be in Cook Forest . That is considerably closer to help for > > > time > > > and expense travel. > > > > > > Bob > > > > > > -------------- Original message -------------- > > > > From: Beth Koebel > > > > Bob, > > > > > > Not being a math major (I had to drop CAL I because I couldn't > > > > understand > > > it), it looks like you are using a cone to measure the volume as the > > > "gold > > > standard" and then using the new ENTPTS2 to get the measurements that are > > > often taken, height and circumfence, to match it. If this is the case, > > > then > > > would this work also for trees like palms or any other tree in which > > > there > > > is a trunk without branches for say 50 or so feet then a relatively flat > > > crown(umbrella shaped)? How about the classic hardwood shaped tree (golf > > > > > > ; ball on a tee)? > > &g t; > > > BTW, I am not going to be able to make it to the ENTS gathering in Oct. as > > > it is too close to my projected closing. Sorry, I wish I could've made > > > it. > > > Maybe the next one. > > > > > > Beth > > > > > > "Information is moving--you know, nightly news is one way, of course, > > > > but > > > it's also moving through the blogosphere and through the Internets." > > > > Washington DC, May 2, 2007 George W. Bush > > > > > > --- On Wed, 9/24/08, [EMAIL PROTECTED] wrote: > > > > > > From: [EMAIL PROTECTED] > > > > Subject: [ENTS] Sneak preview > > > > To: [email protected] > > > > Date: Wednesday, September 24, 2008, 9:25 AM > > > > > > ; ENTS, > > > > > > Folks, it is time to reconsider our two ENTS methods of ranking the > > > size of trees: ENTSPTS and TDI. The TDI system is sound. No modifications > > > needed there, but ENTSPTS is ailing, the reason being that the number of > > > points awarded does not track well enough with increases in trunk volume > > > . > > > The following table compares the effect of tree size increases using the > > > old > > > way of calculating ENTSPTS ( height x circumference) , a proposed new way > > > of > > > calculating ENTSPTS ( [height x Circumference ^2]/100), and an > > > abbreviated > > > version of the champion tree formula ( 12 x circumference + height). > > > > > > Height Circ VOL-CONEratio ENTSPTS ratio ENTSPTS2 ratio > > > Champ Tree Pts ratio > > > > 50884.8 400 32 146 > > > > 5012190.8 2.3600 1.572 2.3194 1.3 > > ; > > 5016339.2 4.0800 2.0128 4.0242 1.7 > > > > 1008169.6 2.0800 2.064 2.0196 1.3 > > > > 10012381.6 4.51200 3.0144 4.5244 1.7 > > > > 10016678.4 8.01600 4.0256 8.0292 2.0 > > > > 1508254.4 3.01200 3.096 3.0246 1.7 > > > > 15012572.4 6.81800 4.5216 6.8294 2.0 > > > > 150161017.6 12.02400 6.0384 12.0342 2.3 > > > > > > Looking at the table, we see that the ratio of the volume of the > > > largest tree to the volume of the smallest is 12 to 1. The ratio of > > > ENTSPTS > > > of the largest tree to the smallest is 6 to 1. The ratio of modified > > > ENTSPTS > > > of the largest to the smallest tree is 12 to 1 (just what we want), and > > > the > > > ratio of modified champion tree points of the largest to smallest tree is > > > 2.3 to 1. The change in m odified ENTSPTS tracks perfectly with co nical > > > volume. Each ratio in the above table is the current entry divided by the > > > first entry in the respective column, not the preceding entry in the > > > column. > > > The purpose of the ratio columns is to show how points track with changes > > > in > > > volume as measured by a form such as the cone or paraboloid. > > > > The reason I chose a scaling factor of 100 for modified ENTSPTS is > > > to bring the point total more in line with numbers that come from the > > > champion tree formula. Additionally, it is computationally simple. I > > > leave > > > out hypothetical crown spread in the table. However, were we to include > > > realistic crownspreads for the size trees indicated by height and > > > circumference, the ratio of the points of > > > > ... > > > > read more »- Hide quoted text - > > > > - Show quoted text - > Find phone numbers fast with the New AOL Yellow Pages! --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org You are subscribed to the Google Groups "ENTSTrees" group. To post to this group, send email to [email protected] To unsubscribe send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/entstrees?hl=en -~----------~----~----~----~------~----~------~--~---
