Measured Trees - Laser/Clinometers and Tape Drops
ENTS, 

We must not only be able to explain out tree measuring methodology, we need to demonstrate that using older baseline methods often result in tree height measurement inaccuracies.  In addition we must demonstrate that our laser/clinometer methods are more accurate than older baseline methods.  We can demonstrate the accuracy of our measurements by comparing the results of our laser/clinometer tree height measurements with tape drop measurements made during tree climbs.  The table below is the initial compilation of that comparison.  Will Blozan suggested that we also include listings of  the climbers, dates, percent error and the event it which the climb took place. This information, as well as information on when the laser/clinometer measurements were taken and by whom are obviously required to provide adequate scientific documentation of the results. Additional information will be added to the table below as it is compiled.

Ed Frank

latest revision -November 09, 2005
Location Species Laser/
Clinometer Measurement		 Laser Measurement Date Measurer Climb Event/Date Climbers Climb/Tape Drop Percent Error Tree Name Comments
 
Sweetbriar College, VA Southern red oak 95' demonstration/ May 2000 Bob Leverett May 2000 Will Blozan and Rick Van de Poll 95' 0% Unnamed #001
Cook Forest, PA Eastern white pine 172' Cook Forest Rendezvous 2003-04-27 Bob Leverett Cook Forest Rendezvous 2003-04-27 Will Blozan 172' 0% Seneca Pine #002
Cook Forest, PA Eastern white pine 181.1' Cook Forest Rendezvous
2002-04-20		 Bob Leverett Cook Forest Rendezvous
2002-04-20		 Will Blozan and Ron Busch 180.9 0.11% Longfellow Pine #003
Cook Forest, PA Black cherry 138' Cook Forest Rendezvous
2005-04-21		 Will Blozan, Dale Luthringer, Jess Riddle Cook Forest Rendezvous
2005-04-23		 Will Blozan 137.6' 0.29% Davies Black Cherry #004
Ellicott Rock, SC Eastern hemlock 168.7' 2001-12-03 Blozan and Davie  2001-12-13 Will Blozan and Ed Coyle 168.7' 0% Unnamed #005
Ellicott Rock, SC Eastern hemlock 162.1 2001-12-03 Will Blozan and Michael Davie 161.8 0.19% Medlin Mountain #006
Congaree Swamp, SC Loblolly pine 166.4 1997 Will Blozan, D. Riddle, and J. Riddle 1997 Will Blozan 166.6 0.12% Riddle #2 #007
GSMNP Eastern hemlock 167.4' 2003-03-19 Will Blozan 167.0' 0.23% Jim Branch Giant #008
GSMNP Eastern hemlock 148' 146' 1.35% Sequoia #009
Ashville, NC Tuliptree 129.5 132' (felled) 1.9% Unnamed #010
MTSF, MA Eastern white pine 144.9' 146.1 0.82% Massasoit Pine #011
GSMNP Eastern hemlock 176' Will Blozan and Michael Davie 168.8' 4.26% Yonaguska #012
GSMNP Eastern hemlock 173' Before Aug 1999 Will Blozan 169.9' 1.82% Tsali Hemlock #013
Ellicott Rock, SC Eastern hemlock 176' 2001-12-03 Will Blozan and Michael Davie 167.8' 4.89% East Fork Spire #014
GSMNP Eastern white pine 189' 2002-03-29 Blozan and others 185.5' 1.89% Boogerman Pine #015
USFS, GA Eastern white pine 177.7' Bob Leverett before 1999-12-11 Will Blozan 178.7' 0.56% Riddle #1 Pine #016
MTSF, MA Eastern white pine 156.2' 2003-09-23 Bob Leverett Forest Summit II/ 2004-10-24 Will Blozan, Bob Van Pelt, and Ed Coyle 160.2' 2.50% Thoreau Pine #17
MTSF, MA Eastern white pine 162.5 2004-09-14 Bob Leverett Forest Summit I/ 2003-10-24 Will Blozan 160.2 1.43% Tecumsah #18
MTSF, MA  Eastern white pine 160.8' 2001-Oct Bob Leverett/ Will Blozan 2001-Oct Michael Davie 160.9' 0.01% Jake Swamp Pine #19
MTSF, MA Eastern white pine 159.3 2001-01-14 Bob Leverett 2001-Oct Will Blozan and Bob Van Pelt 159.5 0.01% Joe Norton Pine #20
North Carolina Pignut Hickory- east leader 161.8 2003-10-06 Michael Davie 2004-01-17 Michael Davie and John Parmenter 162.3 0.3% Reed Road, Swananoah #21
North Carolina Pignut Hickory - west leader 167 2003-10-06 Michael Davie 2004-01-17 Michael Davie and John Parmenter 164.3 1.64% Reed Road, Swananoah #21a
GSMNP, Sag Branch Tuliptree 164.4 2002-09-11 Will Blozan 2004-02-24 Will Blozan, Bob Van Pelt, Ed Coyle 167.7 1.96% Sag Branch Tulip #22
 

#01:  Bob Leverett wrote (2005-11-07) "Will climbed a southern red oak at Sweetbrier College in May 2000 at a tree-measuring demonstration. I measured the tree by our ENTS methods.  Will's and Rick Van de Poll's taped measurement was 95 feet. My measurement was 95 feet as witnessed by a large group. Difference was zero."

#03:  Longfellow pine - Bob Leverett wrote (2002-04-22) "Confirmation of the Longfellow Tree's height by Will and Ron's climb
was the highlight of the occasion and was attended about 110 spellbound people. The great tree is now officially 180 feet 11 inches tall...My 4 trigonometry-derived heights varied from 180.4 to 181.9 feet - all within in +/- 1.0 feet of taped height.

#04:  Davies Black Cherry - Dale Luthringer wrote (2005-05-02) "The best measurement we could get was from directly underneath
at slightly over 138'. The best I got for this tree was right at 140' about a year and a half ago, but that was before multiple wind events. Last Fall the best I could get was a bit over 137', but I wasn't sure I had the same window. This tree is a bugger to measure at a distance away from the tree. The interlocking branches and multiple canopy layers make it quite a challenge.

#05:  E. Fork Chatooga R., Ellicott Rock Wilderness, 1.5 mile west of Walhalla State Fish Hatchery, Andrew Pickens Ranger Dist., Sumter NF, Oconee Co. 168’11” (laser/clinometer) Blozan & Davie 12/3/01.    168’9” (taped) Blozan & Coyle 12/13/03

#06:  Medlin Mountain Monarch - East Fork Chatooga River, Ellicott Rock Wilderness, 1.5 mi. west of Walhalla State Fish Hatchery, Andrew Pickens Ranger District, Sumter NF, Oconee Co.        (161’ 10” taped) Blozan & Davie 12/3/01

#07: 

#08:  Jim Branch Giant - Jim Branch (west side), Cataloochee Valley, GSMNP, Haywood Co. Blozan 3/29/03.   Will Blozan (2002-07-26):  169.5' "Jim's Giant" (I discovered a bees nest at the base..) Two laser readings from vastly different angles and slope positions were within a few inches; 169.9 and 169.1).

#010:  Tree was cut down and removed.

#011:  The Massasoit Pine was measured by a group of eight (?) different people, some of whom have limited experience, at an ENTS event held Oct 15, 2005 at Mohawk Trail State Forest.  The numbers presented represent the numerical average of 47 different readings, with an absolute difference of 2.0 feet.

#12:  Laser/Clinometer readings measured with poor equipment - rough clinometer

#13:  Tsali Hemlock - Winding Stairs Branch, Cataloochee Valley, Haywood Co., dead by 11/6/01.  Laser/Clinometer readings measured with poor equipment- rough clinometer

#14:  “East Fork Spire.” East Fork Chatooga River, Ellicott Rock Wilderness, 1.5 mile west of Walhalla State Fish Hatchery, Andrew Pickens Ranger District, Sumter NF, Oconee Co.  167’ 10” (taped) Blozan & Davie.  .Laser/Clinometer reading measured with poor equipment- rough clinometer

#15:  “Boogerman Pine.”  Near eastern end Boogerman Loop Trail (off Caldwell Creek Trail),   Laser/clinometer reading measured with poor equipment- rough clinometer

#16:  “Riddle Pine.”  Laurel Creek, Chattahoochee National Forest, Rabun Co.   Bob Leverett wrote (2005-11-07) "The Riddle Pine in Georgia was measured by yours truly to 177.7 feet before Will announced his 178.6 feet for a difference of 0.9 feet. I should point out that I took multiple measurements of the tree with its double top. One measurement was 174.9 feet. I settled on the 177.7 only after about 4 independent measurements."

#17:  Bob Leverett wrote (2005-11-07) "The 9/23/2004 measurement of the Thoreau Pine by yours truly was 156.9 feet. The Thoreau pine has a very complex top and the highest points can't be seen from a location where the base can be seen. I had struggled with the tree for years before calling for help in the way of a climb. I was convinced that climbing was the only way to get an accurate measurement of the Thoreau pine. Although higher numbers were frequently obtained for the Thoreau pine, I discarded them because I could not establish a convincing pattern. You can show a legitimate difference between the laser measurement and tape drop as (160.2 - 156.9) or 3.4 feet difference."

#18:  Bob Leverett wrote (2005-11-07) "The Tecumseh tree is another difficult to measure tree from the ground. That is why I asked Will to climb it. The 160.2 is a tape drop measurement. My measurement of 9/14/2003 was 162.5 feet. A subsequent measurement of the tree by Howard Stoner prior to Will's climb were around 161 feet if I recall. But for the record, we have (162.5-160.2) = 2.3 feet difference."

#19:  Bob leverett wrote (2005-11-07) "Jan 8, 2001, we measured the Jake Swamp tree to 160.3 feet in height.  Both Will Blozan and I got heights around 160.8 in Oct before Michael Davie climbed the tree. We taped it to 160.9 feet. For all practical purposes, we hit this tree dead on. Call it off by a tenth of a foot."

#20:  Bob Leverett wrote (2005-11-07) "On Jan 14, 2001, I measured the Joe Norton tree to 159.3 feet. In the following October Will Blozan and Bob Van pelt climbed the tree and tape-dropped it to 159.6 feet. That's a difference of 0.3 feet. Other measurements of the Joe Norton tree just prior to measurement differed from the tape drop by 1 to 2 feet."

#21, #21a Swananoah Pignut Hickory:  Michael Davie wrote (2009-01-04)  "It's really a beautiful tree, obviously pretty old and with great structure, though the trunk is hollow at about 110 feet or so- you can look into a racoon-sized hole and see the shell of wood about 4 inches thick. There are two leaders at the top, nearly equal in height, so we measured both. The west leader measured to 162'4", the east leader was 164'4"

#22:  Sag Branch Tulip - Detailed 3-dimensional  mapping completed February 24, 2004.