TOPIC: old growth density
== 1 of 9 ==
Date: Mon, Oct 13 2008 6:13 am
From: "William Morse"
I have a friend working on a project for school regarding stand
densities/ trees per acre. Does anyone have any information
tree spacing or density in unmanaged/old growth forests,
broadleaf and mixed forests of the northeast? Is there an old growth
characteristic that includes spacing or density?
== 2 of 9 ==
Date: Mon, Oct 13 2008 6:36 am
From: "Joseph Zorzin"
Good question- I can't answer it definitively but I suggest 50-75
trees per acre is a good general purpose rule of thumb- the figure
would vary greatly depending on species, location, etc. Conifers
generally will have more trees per acre in old growth and more
volume and they can, generally, withstand higher density. This sort
of info exists in forestry textbooks.
Forest researchers have plotted the growth of density, size, growth
rates, etc. for all sorts of forest types. Your friend needs to find
a good library. In addition to the textbooks, the Journal of
Forestry has countless such research papers.
I'm sure others here who specialize in studying old growth have
better info and can direct you to specific research papers.
== 3 of 9 ==
Date: Mon, Oct 13 2008 8:15 am
Densities vary greatly in old-growth forests, responding to the wide
variety of disturbance regimes. One of the best sources of
information on the subject is:
"Information About Old Growth for Selected Forest Type in the
Eastern United States" by the USDA Forest Service. Principal
research scientists include Lucy E. Tyrrell, Gregory J. Nowacki, and
Thomas R. Crow.
From my own research, I can easily verify a wide range of densities
with the conifer stands most densely packed as Joe Zorzin points
out. As a general rule 50 to 125 trees per acre in the range of 4
inches in diameter and greater covers the majority of old growth
The person to really weigh in on the density question is Lee Frelich.
Don Bragg and Don Bertolette will also have excellent insights.
== 4 of 9 ==
Date: Mon, Oct 13 2008 11:02 am
This text is found online at:
== 5 of 9 ==
Date: Mon, Oct 13 2008 2:17 pm
From: "Joseph Zorzin"
I just downloaded that file- it's 473 pages and took about an hour.
I haven't read it yet- but I'm sure there must be a vast amount of
info there worthy of discussion in this forum. Has anyone read it
through? Is it well written by the standards of the ENTS community?
Did anyone in this forum contribute to that report?
== 8 of 9 ==
Date: Mon, Oct 13 2008 2:32 pm
From: Lee Frelich
The density in old growth stands (i.e. multi-aged stands) is
within one acre, there would be patches that are very dense and
with few trees. The density in younger stands is more uniform
of the trees are about the same size.
The most interesting factor that changes is the shape of the
distribution, which goes from unimodal (close to normal) with a
dbh and small variance in young forests to unimodal with large mean
wide variance in older forests of the stem exclusion stage of
(say 100-120 years old), to unimodal with a second peak on the left
forests in the transition to uneven aged (120-150 years old), which
clumps of small trees entering gaps and the remnants of the unimodal
even-aged peak, to almost negative exponential in old-multi-aged
that there are a lot more small trees than large trees.
Density goes down as even-aged stands age and the remaining tree
larger and larger, it reaches a minimum in old even-aged stands and
goes up in old multi-aged stands, but not quite as high as a young
even-aged stand, as gaps vacated by the death of large trees are
with clumps of saplings.
== 9 of 9 ==
Date: Mon, Oct 13 2008 2:57 pm
Many contributed to the document. I was one of them.
TOPIC: Old Growth Forest Document
== 1 of 1 ==
Date: Mon, Oct 13 2008 7:55 pm
From: "Edward Frank"
Paul Jost posted this link:
Title: Information about old growth for selected forest type groups
in the eastern United States.
Author: Tyrrell, Lucy E.; Nowacki, Gregory J.; Buckley, David S.;
Nauertz, Elizabeth A.; Niese, Jeffrey N.; Rollinger, Jeanette L.;
Crow , Thomas S.; Zasada, John C.
Publication: General Technical Report NC-197. St. Paul, MN: U.S.
Dept. of Agriculture, Forest Service, North Central Forest
Abstract: Compiles information about old-growth attributes for nine
forest type groups that occur in the eastern United States. A range
of values for each old-growth attribute for each forest type is
summarized regionally from published and unpublished sources.
This is a large file that is 244 MB in size. If you have a fast
modem I would encourage you to download the full document. It should
take less than an hour on a cable modem. The file is an Adobe
Acrobat pdf file. Essentially there is an image of every page put
sequentially into the pdf document. You can't cut and paste text
from the file to another application. The total file is 433 pages in
length. Of this total over 300 pages are tables of one sort or
another, and another 40 are bibliographies and other appendices.
Much of the useful information in the document is compiled into
these tables and appendices. However, if you just want the text of
the document, and the key diagrams, I have posted two files totaling
12 MB file temporarily to the ENTS Google list site: http://groups.google.com/group/entstrees?hl=en
The first OG_forest_types1.doc contains the introductory material.
The second OG_forest_types2.doc includes the breakdown of the
information by forest types. They total 88 pages, a much more
printer friendly total to read through. The data in the tables can
be perused in the complete pdf file listed above. My file also is a
cut and paste of images of the pages included in the pdf file and
not in a text format. it shall be up for only a limited time as I do
not want to hog the file sharing section of the Google site.