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)? 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] <[EMAIL PROTECTED]> wrote: From: [EMAIL PROTECTED] <[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-CONE ratio ENTSPTS ratio ENTSPTS2 ratio Champ Tree Pts ratio 50 8 84.8 400 32 146 50 12 190.8 2.3 600 1.5 72 2.3 194 1.3 50 16 339.2 4.0 800 2.0 128 4.0 242 1.7 100 8 169.6 2.0 800 2.0 64 2.0 196 1.3 100 12 381.6 4.5 1200 3.0 144 4.5 244 1.7 100 16 678.4 8.0 1600 4.0 256 8.0 292 2.0 150 8 254.4 3.0 1200 3.0 96 3.0 246 1.7 150 12 572.4 6.8 1800 4.5 216 6.8 294 2.0 150 16 1017.6 12.0 2400 6.0 384 12.0 342 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 modified ENTSPTS tracks perfectly with conical 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 the largest tree to the smallest would increase slightly - perhaps 2.5 to 1. I've discussed the new system of ENTSPTS with Ed off list. Ed is solidly behind it. Ed also mentioned that John Eichholz had once before pointed out the value of C^2 versus C as the factor dealing with circumference. I mentioned the proposed new method briefly to Will in a recent phone conversation and told him I'd shortly present some analysis. The above table is the first step in that direction. Thoughts anyone? Bob --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
