| Modeling
Results and #77 |
Robert
Leverett |
| Oct
24, 2005 08:29 PDT |
ENTS,
For me, the weekend was rainy
(enough, enough), but otherwise
productive. I was able to remodel the Tecumseh tree and do 5 new
trees.
The multiple linear regression coefficient from 31 trees now
stands at
0.935. The independent variables for the model are: total
height, CBH in
ft (I just like the number), dbh in inches at 50 feet, and dbh
in inches
at 100 feet.
The biggest technical challenge with the
Rd 1000 is to get reliable
measurements at heights of 100 feet up the trunk. So, much works
remains
to be done to refine the numbers taken aloft. From about 75 feet
down,
we're in good shape, but reliability goes way down after that.
After remodeling the Tecumseh
tree, I turned my attention to
another big tree in the Elders Grove. We call it the Benchmark
Tree. As
of this growing season, it has just made 11 feet in
circumference and is
now 150.2 feet tall. Yep, that's #77 for MTSF in terms of white
pines
and #78 for all species in the 150 Club. Not bloody bad folks. I
also
measured a white pine at the upper leach field to potentially
serve the
same purpose as the Massesoit pine did this past ENTS rendezvous
at the
lower leach field. The new pine, which I called the Boulder
pine,
because it has several large boulders close by, is between 146.0
and
147.0 feet. My actual measurements of yesterday of the tree were
146.1
feet, same as the Massasoit tree, and 146.8 feet. The 146.1 is
in the I
put in the books - staying on the conservative side. The tree's
horizontal offset is -3 feet, i.e. high point is slightly behind
trunk.
This new tree has even better climbing visibility than the
Massosoit
Tree. Measurers are 20 feet above the base and around 70 yards
distant
from the crown points being measured. Seventy yards is a better
distance
to minimize angle errors than the 100-yard distances we were
shooting
for the Massosoit tree. The modeled volume of the Boulder Pine
is 343
cubes. It looks to be a little more, so I'll do several more
modelings
of it, but if understated, I doubt that additional measurements
will add
more than 20 cubes. The regression prediction is 360 cubes. BTW,
the
remodeled volume of the Tecumseh tree is 720 cubes with a
predicted
750.
Here are some interesting comparison of
the dimensions for 5 white
pines that have been modeled.
Tree Height CBH' DBH"-50
ft DBH"-100 ft Tot
Vol ft^3
Ice Glen 154.3 13.0' 39.1 26.0 1041
Tecumseh 161.3 11.7 35.0 24.5 720
Massasoit 146.1 9.0 27.9 13.0 466
Boulder 146.1 8.7 23.0 13.9 343
HQ Hill 117.0 7.8 17.3 5.3 182
The Ice Glen pine is probably 270 years old.
The Tecumseh tree about
180 and the HQ Hill pines is about 90 years old. The age ratio
of max to
intermediate to min is 3 to 2 to 1, using the min as the base.
The CBH
ratio is of max to min 1.7 to 1.5 to 1. The total volume ratio
of max to
min is 5.7 to 4.0 to 1. Of course these are different trees and
there is
no way of knowing what the dimensions of the larger two trees
were at 90
years. The HQ Hill is growing in a favorable spot and it is
tempting to
believe that in time it will reach a girth of 11 feet and has
the
potential for reaching 160 feet in height. It is also tempting
to
project a volume increase of at least 3 to 1 in a doubling of
its age.
A linear extrapolation based on age would place the volume of
the HQ
Hill pine at 121 cubes at 60 years. It might have been even
less. An
objective of the modeling is to develop separate volume, height,
and dbh
curves regressed against age for stands at 60, 120, and 180
years. We
have plenty of pines to model in the 60 and 120 year age
classes, but
only one stand in the 180. We have plenty of isolated trees in
the 180,
but they often don't have a history of stand development
influence.
Bob
Robert T. Leverett
Cofounder, Eastern Native Tree Society
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