volume estimates (fwd)
15, 2003 17:46 PDT
I'm forwarding a thought-provoking communication from Colby
Rucker about calculating tree volume. Colby, Will, and I are
always talking about ways to compute tree volume.
---------------------- Forwarded Message: ---------------------
From: "Colby Rucker" ;
Subject: Total volume estimates
Date: Wed, 15 Oct 2003 00:29:09 -0400
I like to limit volume calculations to the main trunk and
heavier leads so
that modeling of hypothetical cuts also provides a total in
This allows comparisons with the historic record of trees that
12,000 to more than 20,000 board feet.
I think it's unwise to add some trifling percentage for brush to
carefully calculated trunk volume of some conifer. It become
oranges, and guesswork always ruins good numbers.
All that said, there are some monstrous open-grown trees that
much in board feet, but would displace a great deal in total
course, there's no decent way to calculate the volume of all the
branches, but it's all wood. One interesting exception was the
Wye Oak, a
white oak that stood on Maryland's Eastern Shore. Although the
somewhat of a composite, we can get a pretty good idea of volume
weight of a fallen limb weighed at the feed mill across the
For any kind of argument, I'll say the volume reflects the tree
as it was in
1953, with its major limbs intact. Although limbs were weighed
after that, a great deal of live wood was removed from the tree,
year, in an attempt to reduce the weight and sail area of the
suggests that the major components maintained a fairly constant
volume, despite unavoidable increases in diameter. I have not
counted a low
limb weighing perhaps ten to fifteen tons removed as part of the
upgrade to auto traffic ca. 1912.
So, not perfect, but here goes anyhow:
10/6/53 Large limb fell
across road 20.0 tons (est.)
Preston, pp. 110-111.
8/29/56 Largest limb fell 30.0 tons
Preston pp. 5, 111.
6/10/84 Largest remaining
limb fell 37.0 tons (feedmill) Balto
pruning 2.5 tons
Balto. Sun 3/20/85
6/6/02 Tree fell; main
Balto. Sun 6/23/02
6/6/02 Limb wood 19.25
Balto. Sun 6/23/02
Total weight of tree 139.50
The estimates were probably from state foresters. The 1984 limb
heavier than the 1956 limb, which was immense, and the longest.
suggests the estimate of 30 tons may have been somewhat low, or
the limb was
simply less fully branched. The 6/6/02 limb wood tonnage is
derived from an
estimate of 100,000 pounds for the entire tree. Leaves and
rakings were not
included. 19.25 tons seems reasonable. Although less than the
weight of the three earlier limbs, much of the trunk was removed
wide-load piece, with portions of the heavier limbs still
139.5 tons = 279,000 lbs. Dividing by 60 lbs./cu. ft. = ca. 4650
Circumference at grade was 51 feet, cbh was 31' 10". The
bottom of the
trunk was a hollow shell, accessed via an iron port. This air
no weight, receives no volume from the 61,500 lbs. A broad void
feet up, tapering abruptly to ten feet up, it amounted to about
350 cu. ft..
Thus, quite conveniently, the total volume was 5,000 cubic feet.