Jack,
One fallout benefit of this discussion/investigation is to identify ever more
precisely where we find our tallest trees and the gradient of heights as we
move up/down a ridge. It's a worthwhile discussion. Let's keep it going. Did
you read about the 131.5-foot white pine in Forest Park? I think that is about
as high as we're going to find them at this point in time.
We're gradually locating the pockets of tall pines in the Valley and I think we
can safely say, they will never (in our lifetimes) rival those in the
mountains. The mountain great whites rule.
Bob
----- Original Message -----
From: "JACK SOBON" <[email protected]>
To: [email protected]
Sent: Wednesday, January 6, 2010 3:08:26 PM GMT -05:00 US/Canada Eastern
Subject: Re: [ENTS] Re: White pine growth rates--something of interest about
growth possibilities
Dear Gaines, Ed Frank, Bob, ENTS,
I would be highly suspect of historical white pine height measurements of
standing trees, but I believe all the reports are of felled specimens. As for
measuring felled trees, I have dropped thousands of white pine in the 80-120'
range and measured a few hundred. The trunk occasionally fractures at upper
branch whorls and the top 3 or 4 feet might have to be looked for nearby but
the tree's trunk is still intact and easy to measure after limbing. I think
that if someone wanted bragging rights to an exceptional tree, they probably
had it verified.
The other stumbling block to this maximum height issue seems to be the exposure
and canopy height issue. Most of you are envisioning a typical forest canopy on
gently rolling ground. In such forests, I doubt the trees would have reached
200 feet. However, in a rugged landscape there are occasional pockets where
trees can be much taller without being unduly exposed. In these rare cases, a
pine could reach 250 feet and still be protected. I attach a sketch
illustrating my point. The top drawing shows a forested ridge with the sun
behind it. As you will see, the canopy height is not parallel with the ridge
but tends to even out the profile. It is shorter at peaks and higher in
hollows. Check this out for yourself at sunrise or sunset. It is easier this
time of year with the leaves off and the sun so low. The lower drawing shows
how a single 250 foot pine growing in a ravine can be way above other trees and
still not be too exposed. The moist, fertile environment and quest for sun
would encourage such growth. This would be a rare condition of course hence the
relatively few historical reports of such trees. To my knowledge, none of the
tallest pines measured recently (MA 169', CT 172', PA 182', NC 207') are
growing in such a protected site and none are of the diameters of the historic
examples. For instance, the Charlemont, MA pine felled in 1849 was seven feet
in diameter 10' from the stump and 5' diameter 50' from the stump. Our tallest
pine today has a 44" DBH!
Every one is looking for reasons why it couldn't be true instead of how it
might be true. Is 250' really that far-fetched? Where are the optimists?
Jack Sobon
From: spruce <[email protected]>
To: ENTSTrees <[email protected]>
Sent: Wed, January 6, 2010 11:23:12 AM
Subject: [ENTS] Re: White pine growth rates--something of interest about growth
possibilities
Jack, Ed, ENTS:
A few more thoughts/responses about white pine growth/measurement:
As for the capability of people 200 years ago to measure the
heights of standing trees—that is unquestioned. The main question is
“did they?” Often the reports of these very tall trees came from
loggers, who, although I have worked as a logger at various times in
my life, and believe at its best it can be a noble profession, I have
not seen them much interested in taking precise measurements of any
trees before they cut them down, nor in measuring trees after,
especially when the top of the tree shatters and it would have to be
carefully reconstructed to get an accurate measurement. I would think
that if some one with a “scientific” mind did careful measurements,
these would have some down to us in a quite different way than in the
style I have seen them, i.e. “early lumberman reported that….” etc.
One thing I have seen in reports from early lumbermen of the trees
they cut down, is a focus on data such as, “at a height of 120 feet
the tree had a top diameter of 20 inches,” or some such thing. They
report this way because they are interested in how many logs the tree
has produced.
So here is what MAY have led to some of these reports. If a
gigantic white pine is 200 feet tall, and at a height of 160 feet
still has a diameter of something like 20”, someone could read that
report and say, “Oh at 160 feet the tree was still 2” in diameter, so
then it must have been 250 feet tall. Yes, many younger white pines
have a rather gradual taper. A tree 20” in diameter in a young forest
can be 100’ tall. But with very old trees, the taper at the top can
be very, very rapid. A very old white pine could have a diameter of
20” near the top, and be only 40 feet taller, or perhaps much less.
As for amount of light required—the amount of crown exposure above
adjacent trees—for white pines to make maximum growth: This is an
important factor. Tree crowns are usually classified by foresters into
basically 4 crown classes: dominant, co-dominant, intermediate, and
suppressed. Added to this I believe should be “emergent.”
A dominant crown has a good portion of its crown exposed above the
surrounding trees, but this does not require that the crown be
“emergent,” meaning far above the surrounding trees as many white
pines in NE, especially on ridges where the hardwoods they are often
mixed with, cannot really compete.
The next crown class, the co-dominant, is a bit lower in relation
to the surrounding trees. Here the crowns of a group of trees are more
or less equal in height, but they do have good space between them, and
they receive plenty of direct sunlight. An issue here is also grown
length. A dominant crown will be somewhat longer—extend further down—
than a co-dominant tree.
The next crown class is the intermediate. Here the tree is closely
pressed on all sides by other trees. In some cases the crown can be
at nearly the same height or more usually somewhat lower than those of
its competitors. The crown is narrow, and depending on the species
and the kinds of trees it is competing with, it can be either rather
short, or rather thin foliaged.
White pines are classed as a moderately intolerant tree, meaning that
they require more direct sunlight than a tolerant tree. This means
that to grow well in height, a white pine needs to be in either a
dominant or a strong co-dominant crown position. To grow well in
diameter, it should be in a dominant crown position.
Norway spruce is more tolerant than white pine, and therefore can
grow better in an intermediate or marginal co-dominant crown position
than white pine. White pines that are in an intermediate crown
position, or perhaps also in a marginal co-dominant crown position,
usually will lose vigor and be overtopped.
Well, sorry, I see I am giving too much background here. The basic
answer to the question about the amount of crown exposure a white pine
needs to grow the tallest is dominant or strong co-dominant. Emergent
crowns get so much light that a great deal of the growth energy of the
trees goes into creating a very large spreading crown with heavy
branches. White pines, and most other forest trees grow tallest when
they are in competition with other trees as in the usual dominant or
co-dominant positions.
Finally, occasionally a white pine tree growing far above the
surrounding trees did not in fact grow as an emergent tree, but grew
in a forest with other trees in a dominant or co-dominant crown
position, and then, either because the surrounding trees were removed,
or died for some reason, this tree will stand in a very, very strong
emergent position. That does not mean that it grew to its present
height as an emergent.
--Gaines McMartin
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[email protected] Visit this group at
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Send email to [email protected]
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