Jack,
Good points. I am always curious about the silvicultural data sets used to
generate growth curves. As you point out, conditions can vary a lot even within
yards. Today, Bart's and my walk in Forest Park confirmed once again where the
best growing conditions are.
Obviously we'll never know if there were once 250-foot tall pines. The problem
for us is that we have no way of distinguishing reliable sources from
unreliable ones. Even when a measurer has outstanding credentials, large errors
can be made. I won't go over the many examples we have. You know many of them
as well as I. However, it is fun to think about the possibility that there were
once 250-footers in the East.
Bob
----- Original Message -----
From: "JACK SOBON" <[email protected]>
To: [email protected]
Sent: Tuesday, January 5, 2010 5:21:01 PM GMT -05:00 US/Canada Eastern
Subject: Re: [ENTS] White pine growth rates--something of interest about growth
possibilities
Dear Gaines,
Thanks for keeping the White pine height debate alive.
I read the white pine info at the link you referenced but didn't glean the same
information that you did. First off, nowhere was there indicated a maximum
height potential, regardless of site index. Second, the charts showing growth
increments are for sites in the Southern Appalachians, the Southern extreme of
White pine's range. The historic reports of 250+ trees are all in New England,
at the center of its range. Third, site index does not take into account the
micro climate and topography. We've all seen those damp, sheltered hollows and
ravines where nutrients collect, the ground stays wet all through the growing
season, and mosses cover everything, where trees are protected from wind and
are substantially taller and healthier than those outside the area though of
similar age. That's where the tallest trees are now and would have been
historically. Not a lot of trees in the 250' class, just a handful scattered
across the Northeast but certainly thousands of trees over 180' (our current
Northeast tallest pine).
Also, according to that chart, the height difference between trees growing on
the poorest sites to those on the best is 60 feet, not 20.
As for annual growth after 55 years being about a foot, I've felled trees in
the 55-80 year old class where I've measured the annual height growth for the
last three years over 30" per year. A chart for the Southern Appalachians won't
necessarily apply to New England.
Though the account of a 300 foot pine in Charlemont, Massachusetts may be
stretched, surely some of the other 250'+ accounts must be true. They had
accurate measuring devices then. Though they lacked the techno-gizmo's of
today, they were not primitive. There were surveyors, builders, and others
skilled in measuring then. When I measure old structures from the 1700's, they
are typically within a quarter inch on a sixty foot length. A modern steel
measuring tape can vary that much from winter to summer with thermal expansion.
Just because we don't have them today, doesn't mean there weren't 250 footers
then. Nowhere in New England are there now pines growing in an ideal spot (like
that I mentioned above) where they have been undisturbed for 400 years!
Jack Sobon
From: spruce <[email protected]>
To: ENTSTrees <[email protected]>
Sent: Sun, January 3, 2010 5:18:59 PM
Subject: [ENTS] White pine growth rates--something of interest about growth
possibilities
There is some research about the growth rates of white pines that may
be of interest to white pine enthusiasts. For a bit of background to
make the context of the research I am quoting clear: in forestry,
growing sites for various eastern trees are classed by how tall a tree
can grow in 50 years. This is called the "site index" for each
species relative to each site.
For white pine, the site indices range from 60 feet--for a rather
poor site--to as much as 120 feet for the best sties. It may be
possible that there are some sites with an index of over 120 feet, but
if so, I assume they are very, very rare. In fact, most commonly, the
best white pine sites are between 90 and 100 feet, which I commonly
see quoted for most class II soils. I believe 120 feet is fairly
unusual--I know of one just site, a very rich stream bottomland site
that is probably a class I soil, that may have that kind of potential.
OK, enough for the basic background. Here is the interesting thing
I just learned: If a white pine grows 120 feet in 50 years, this same
tree on this same superior growing site, after age 55, will not grow
any faster than a tree growing on a relatively poor site--index 60. At
age 55, both trees--the one growing on the relatively poor site, and
the one growing on the very rich site, will be growing at the same
rate--roughly one foot per year.
So, all the difference between the height of a white pine tree
growing on an excellent growing site, and the one growing on a poor
site, occurs during the first 55 years. Of course this does not
include any factors that may distinguish sites based on factors such
as ice and wind breakage.
I think this reflects on the question of how tall white pine trees
can grow, in that those growing on the very best sites may not grow
significantly taller than those growing on the lesser, but still very
good sites. Thus, if a growing site is rated at 120 feet, over the
life of a white pine tree, the final height of the tree will be just
20 feet taller than a tree growing on a site of index 100.
To explain a bit more, if we want to speculate on the possibility
of white pines growing to 200, or the oft quoted height of 250 feet,
the idea that the 200 plus trees grew on the very best sites, and
those sites are now no longer available for growing pines because they
are now farmalnd, or whatever, should be less of a factor in our
speculations. The difference in the ultimate height of the trees will
be only 20 feet or so. So even if we want to argue that the best
sites could grow pines taller than what we now see--about 175 feet
max--then the potential was for 195 or so, certainly not much above
200, and certainly not 250 or anything like it.
This research is summarized (with citatiion) in the USDA Forest
Sefvice manual titled "Silvics of North America." The URL is:
http://www.na.fs.fed.us/spfo/pubs/silvics_manual/table_of_contents.htm
This is written from a forestry perspective, but contains a lot of
information about tree growth, etc of interest to any tree lover.
--Gaines Mcmartin
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