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TOPIC: FW: Confirming the Exact Height of the Tallest Tree in New England:
http://groups.google.com/group/entstrees/t/3d544f31adb1c553?hl=en
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== 1 of 2 ==
Date: Wed, Dec 3 2008 6:30 am
From: dbhguru@comcast.net


Lynn,

On November 1st, Will Blozan climbed the Jake Swamp Pine in MTSF and we did a tape drop measurement to get an exact height. Will used a pole to get to the tip of the highest sprig. The tape drop measurement yielded 168.5 feet as compared to my ground-based measurement of 168.6 feet. Shucks, I missed it by 0.1 feet. Losing my touch, I guess.
Joking aside, we in ENTS have the measuring process down pretty well. Our challenge has been to bring other tree measurers on board. Many, if not most, want to stick with the clinometer and tape measure because it is easier - but unfortunately, it leads to lots of errors. Dr. Lee Frelich, Dr. Don Bragg, Will Blozan, Dale Luthringer, and myself are writing a paper on the comparative accuracy of measurement methods. Lee is actually doing the writing. The rest of us supplied the data. BTW, Monica and I are still planning to visit you next summer.

Bob

-------------- Original message --------------
From: "Lynn Rogers" <lrogers@bearstudy.org>

Marshall, here is an example of what I was saying about Bob Leverett, the dbh guru. Lynn


Confirming the Exact Height of the Tallest Tree in New England:

The effort that ENTS has put into measuring the Jake Swamp white pine in Mohawk Trail State Forest has, by any reasonable measure, been extraordinary - excessive to non-quantitatively inclined tree lovers, no doubt. I, alone, measure that great white pine as many as 20 times in a year and I have no thoughts of hanging up my lasers. Jake will continue to receive attention.
However, I am not alone in lavishly heaping numerical attention onto Jake. Over the years, our tall tree champion has been measured by such notables as Jack Sobon, Colby Rucker, Bob Van Pelt, Will Blozan, John Eichholz, Gary Beluzo, John Knuerr, Howard Stoner, and probably others assisting one of the foregoing. In terms of members of the A-team, I don’t specifically recall if Ed, Dale Tony, or Carl measured the tree, or if superstar Jess Riddle measured Jake. Regardless, the list of stars who have is long and impressive.
Beyond ground-based measurements, the Jake tree has been climbed and tape-drop measured twice and it will be climbed and measured a third time this fall. Will Blozan made the initial climb in 1998. Michael Davie climbed and tape-drop measured Jake in 2001. Will Blozan and possible others (Andrew Joslin?) will climb Jake on November 1st. 2008. So, suffice it to say that Jake has garnered ample attention from a host of distinguished tree measurers working on the ground or aloft over the years and this state of affairs is guaranteed to continue so long as Jake performs for us as he has done so outstandingly since 1992.
So, it was appropriate that on Thursday, I went to Mohawk to test my new Nikon Prostaff 550 and chose Jake as the logical tree to measure. The day was crystal clear and Jake’s highest leader stood out cleanly against the background of a bright blue sky. Unfortunately, blue sky bodes poorly for using my expensive TruPulse lasers. They do much better when the sky is cloudy. They do not return accurate bounces when the target is small and framed against the background of a bright blue sky. You have to aim lower in the crown to a spot where the foliage is thicker and broader, and of course, that means you don’t measure the highest spot in the crown.
However, on Thursday I was fully prepared. I took three other lasers: my new Prostaff 550, the older Prostaff 440, and the really aging, but still useful, Bushnell 800. For angles, I decided to use the clinometers built into the two TruPulses. You can get clinometer measures regardless of the target’s clarity or background illumination. The clinometer in the TruPulse is just a tilt sensor.
I decided to use all five instruments in one way or another to see what kind of results I would get comparing the different readings. It was in this respect a thought experiment. I would use three of the five instruments for distance ( 2 Nikons and the Bushnell) and the remaining two for angles (the TruPulses). I decided to use the tape measure to establish the distance to the base. A tape-measured result to the base would eliminate the problem of trying to get good laser returns from the base through the clutter. With this plan, I was set. The following table gives the results.

The above, latest determination of Jake’s height stands in opposition to the more common ENTS approach that uses the highest values returned for distance and angle. However, I chose the above route for good reason, especially considering the mix of equipment.
If I were to selectively choose maximums, e.g. from the TruPulse 200 for angle and the Prostaff 550 for distance, or some other equipment combination, I could get values as high as 169.68 by one selection, 169.58 by another, etc. Close!
From the above data, I could make a good argument that a defensible height based on the maximums is around 169.6 feet. Following a similar strategy, using the minimums, I could go as low as 167.6 feet. Using the average of maximums and minimums, I get 168.6 feet as the midpoint between the minimums and maximums.
I should point out that all three distance measuring instruments gave return bounces off Jake’s high point of 72 yards at times and 73 at others. I shot repeatedly with all three instruments and consistently got either 72 or 73 yards with each instrument. No bounce registered as low as 71 or as high as 74 yards.
I settled on an average of 72.5 yards. That seemed reasonable to me because all three instruments can shoot long or short as demonstrated in my tape measure comparison studies. Also, the use of the average is consistent with the literature on the lasers that quotes accuracies in terms of +/-. I would further point out that my Prostaff 440 often shoots long by half a yard. So using 72.5 seems justified.
Experimenting with the various combinations points to 168.6 as the most probable figure, with arguments for 169.6 feet duly acknowledged. BTW, on two recent occasions, I got exactly 169.1 feet as the height of Jake, and prior to this latest exercise, I had settled on 169.1 as the most probable height. I abandoned 170 from an even earlier measurement. That stretches my luck a little too far. So, until Will proves otherwise, it’s 168.6 feet for celebrity Jake, the tallest tree in New England.
For new members of ENTS who don’t know the history, Jake was first measured in November 1992 by Jack Sobon and myself and was 155.3 feet at the time, based on careful cross-checking transit measurements. Then, Will Blozan taped dropped Jake in Nov 1998 and got 158.6 feet. In the 16 years that have followed the first measurement, Jakes average growth rate has been 0.83 feet per year if we consider the current height as 168.6 feet. However, if Jake is 169.6 feet, then the average growth rate is 0.89 feet per year. I do have other input on annual growth rates.
Based on Macroscope 25 measurements made in three successive years of the new-year growth candle, Jake is putting on height at about 13 inches per year, a much higher annual rate when compared with the growth rate between 1992 and 1998, which averaged only 0.5 feet. Crown damage over the course of 16 years is highly probable.
Now to an important question: Why are we spending so much time specifically on the Jake Tree? There are several reasons. First, the white pine is a key economic and aesthetic symbol of a bygone New England. Henry David Thoreau spoke of the loss of the great virgin white pines, towering 150 feet and more along the banks of New England’s rivers. In “Tall Trees, Tough Men”, author Robert Pike speaks of the great pines of the past with almost religious reverence. The use of the species by the Royal Navy for ship masts is well documented and led to violent conflicts between colonists and British authorities. The great whites are embedded in our New England history. White pine sap runs through New England’s arteries and veins. A few stalwarts still romantically search for symbols of the King’s Pines, hoping to find some huge old snag that shows the three hatchet marks. Jake is our best symbol of that history, interest, and admiration. Viva La Jake!

Bob

== 2 of 2 ==
Date: Wed, Dec 3 2008 1:18 pm
From: James Parton


Bob,

1/10th of a foot. That is incredible accuracy! It reminds me of an
offline conversation Will and I had a few weeks back. I have been
carrying the decimal point to 100ths. The sine method is good but not
that good so my future measurements will be done to the first decimal
point. Tenths of a foot. We also exchanged comments on fractions of an
inch when measuring tree girths.

You guys are still edumicating me! AND thank God for calculators! My
math stinks!

James P.