Modelings continue   Robert Leverett
  Jan 05, 2006 05:50 PST 

ENTS,

   What does a real ENTS tree fanatic do on New Years? Watch football?
Naw. Why, model white pines - what else? Well, I made it to 60 pines and
I'm mighty proud to say that my regression coefficient now stands at
0.967, but with a high degree of autocorrelation between the not really
so independent variables. However, reducing the number of variables
sends the standard error through the roof.

    I plan to add trees until at least 100 is reached. As stray giants
are found and well-behaved, more modest-sized trees added, it will be
interesting to see if the regression coefficients stabilize. That is
what needs to happen. There were wild gyrations when the sample was very
small, but the changes are much less now.

     The RD 1000 is fast reaching its practical limits on the modeling.
The real challneges must await a more accurate device. That conclusion
is now inescapable. I'll use the RD 1000 for quick modelings. It has
plenty of utility there, but will apply a more accurate instrument for
selected trees such as the one Will and Jess used recently.

     BTW, Will Blozan recently ordered two reticled microscope-telescope
devices that measure the width of openings (or diameters of trunks and
branches) to a high degree of accuracy and at significant distances. One
of the devices goes to yours truly. Yea! Will is currently working out
problems with the eyepiece with the parent company. Can't wait. Once it
comes, it will be time to model the Sunderland sycamore. That great tree
is the easiest for me to get to of the giants. I'll just have to endure
all the gawking passersby.

    Incidentally, a recent visit to the tree with Monica gave me my best
opportunity to remeasure the longest spread. I could see all branch ends
perfectly. The official number is 151.5 feet and that spread is high in
the air. One point is about 70 feet in the air and the other is 30. That
makes the straight line distance between the end points od the spread
157 feet! As our good friend Michael Davie and tree measurer
extraordinaire would say, "that don't suck".

Bob


Robert T. Leverett.
Cofounder, Eastern Native Tree Society
Re: Modelings continue   Jess Riddle
  Jan 05, 2006 17:41 PST 

Bob,

I'm glad to hear the white pine modeling continues to go well. I'm
curious how you're planning to expand to angiosperms; phototropism has
helped put a lot more kinks in those big sycamore limbs, literally. A
monocular with a reticle can certainly provide all the necessary
branch diameters, but determining branch lengths seems a great
challenge to me. With total height measurements, we just look at the
vertical component of the trunk length, and can thus assume a right
angle. However, those darn limbs take much more advantage of all
three dimensions and pay less attention to gravity. If you have a
strategy for determining lengths of branch segments, I'd love to give
you some data from the tuliptrees and oaks down here.

Jess Riddle