Hatfield Sycamore in Winter

    On Saturday, I visited the Hatfield Sycamore in Hatfield, MA, near a
former home of Don Bertolette's. The Hatfield tree is one of 5 great
sycamores that I routinely visit and measure in New England-New York.
The others are the Sunderland sycamore (MA), the Pinchot sycamore (CT),
the Pocumtuck Buttonwood (MA), and the Pine Plains sycamore (NY). The
Hatfield sycamore is a street tree that was probably planted about 200
years ago. I have a reproduction of a drawing of it from 1898 given to
me by the family whose house the tree is close to. The tree was large
then. But today it really is a whopper and continues to add volume. It
has grown a foot in circumference since I've been tracking it. That must
be around 13 years. Its current measurements are as follows:

     Circumference at base:            28.5'

     Circumference at breast height:   24.2'

     Circumference at 10':             22.3'

     Circumference at 20':             19.4'

     Circumference at 25':             21.4' (below limb separation)

     Point of limb separation:         27'

     Height:                          118.2'

     Average spread:                  130'

     Limb separation comes at 27 feet above the base on this sycamore
and at that point 4 large limbs emerge. The largest limb starts at an
initial girth of 12 feet, but then expands to 14 feet around at just
below the branching of the limb at 35 feet above the base. It has
further branching, but the subsequent levels of branching have not been
modeled. Instead this limb structure is treated as a cone to a height
level of 100 feet above ground level. The second limb starts at a
circumference of 10.6 feet and is carried to a height level of 118 feet.
The second limb is 7.5 feet around at 61 feet above the tree's base just
before the bulge leading to a split. There is a lot of wood in these
first two limb structures The third limb starts out at 8.5 feet in girth
and is carried in the calculations to a height level of 95 feet. The
fourth limb starts at a girth of 7.2 feet and is carried to a height
level of 90 feet. The trunk and 4 limbs yields 2101 cubes. Given that
this is only a partial modeling, is this a reasonable projection of the
total volume? Please consider the following.

        1. Each major limb structure branches several times and builds
up wood volume below each branching point. The expansion of the first
limb from a girth of 12 feet to 14 feet is an example of the wood
build-up. There are probably 15 extra cubes of wood in these bulges over
the entire tree - if not more. I didn’t include the bulges in the first
modeling.

        2. Small lateral branches were not modeled. There are a couple
dozen such branches with at least a cube of volume in each. Then there
are numerous ¼ to ½-cube limbs. It is not hard to build a case for 40
cubes in these subordinate branches. There may be more volume, but for
the present, I've settled on 40 cubes.

        3. The limb length is greater than actually modeled because
crown spread has not been factored into calculating limb length. The
limbs were treated as if they were vertically aligned, which, of course
they aren't. For example, the limb structure modeled to a height level
of 118 feet above the base of the tree starts at 27 feet up and angles
outward. The modeled length is 91 feet (91+27=118). However, the tree's
great spread gives the limb structure a horizontal component of at least
50 feet, creating an actual limb length of more than 104 feet.
Comparably conservative lengths were computed for the other three limb
structures. There are at least 40 more cubes than modeled due to the
added limb lengths.

       4. I treated the area between 25 and 27 feet as a cylinder using
the area at 25 feet. However, the width at 27 feet up is greater than at
25. The difference is at least 15 cubes.

     So, I would estimate that a good 110 cubes were not modeled.
However, the RD 1000 was used for the modeling and that’s a problem.
Based on lots of tests, the RD has a probable over-calculation of
between 4% and 5% on large trees even when conservative readings have
been taken on the trunk and limbs. If liberal readings are taken the
over-calculation can easily reach 10%. I took conservative readings. So
taking my calculated volume of 2101 cubic feet, adding in the 110 missed
cubes, and reducing the result by 5% gives 2100 cubes. We'll see how
well this calculation holds up with additional measurements. But at this
point, I believe the 2100 cubes for the Hatfield sycamore is reasonable.
That's a lot of wood, but the tree starts off at 28.5 feet in girth at
the base, which is taken at between 0.5 and 1 feet up. The Hatfield
sycamore is not a cheater in any way.

    As for the other great sycamores, I would guess that the Sunderland
sycamore holds between 2400 and 2600 cubes. I think the Pinchot sycamore
holds a comparable amount, as does the Pine Plains sycamore. These 4
distinguished trees form the 2000 club. The Pocumtuck Buttonwood
probably has about 1700 cubes, so I’m not including it as a candidate
yet. But a lot of work remains, folks. The horizontal extension and
twisting of the limbs, the many branchings, the elliptical parts, etc.
all introduce the possibility of errors on the order of between 100 and
200 cubes more or less. The Hatfield sycamore is a giant, but it won't
match the other three. It really is going to be a horse race between
them. Then there is that huge sycamore Howard measured in southern NY.
Howard's measurements suggest a 2000+ cubic-foot volume.

    Well, I guess the 2000 Club of the Northeast has officially been
born. Are there other northeastern candidates? Someone sent me a picture
of huge sycamore in eastern Massachusetts next to a bank - I think. I
have to retrieve the image. But I believe the tree may be a candidate.
There may be a cottonwood or two that will make it into the club, but
I'm unsure if cottonwoods develop the limb volume necessary to make the
2000 mark. We'll see.

    My compulsion to measure these big trees is not of recent origin.
Twelve years ago, a friend of mine Dick Matthews, a retired English
professor from the University of Illinois wanted to do a freelance
article for Yankee Magazine on the largest tree in New England. Dick
thought I had the answer. I had not. I had no clue and told him so. I
also told him that the champion tree lists would be of no real help. I
thought to myself that one day I would answer that question. Well, 12
years later, an answer seems far more feasible.

Bob


Robert T. Leverett
Cofounder, Eastern Native Tree Society