Height density analysis and Historical documentation   Gary A. Beluzo
  Jun 06, 2005 10:16 PDT 

Bob and John:

Do you have any geocoordinates or I wonder if we should come up
with a standardized FIELD SHEET which has room to sketch relative positions
and labels of trees on some sort of grid? Perhaps on a simple grid data
sheet you could pencil in the approximate location of individual trees and
write in the dendromorphometry. Has anyone in ENTS come up with such a
standardized worksheet?

RE: Height density analysis and Historical documentation   Robert Leverett
  Jun 06, 2005 13:09 PDT 


   I've been piddling around with a worksheet format. John and I
discussed a simple method of getting the azimuth of each tree in a plot
using my new tripod that has a level and a scale in degrees. I can sight
on a tree and read the angle much easier than I can read a compass. For
the next plot, we'll try to put it all together. The complete process as
we envision it is to:

   1. Locate the center of the plot and set up the tripod.

   2. Put a small tag on each tree to be measured.

   3. Position one person at the center to do the recording and
directing of one or more measurers to the trees.

   4. As a tree is measured, the tag is removed. The recorder would
measure the distance to the tree and its azimuth and record the species.

   5. The measurer would measure girth and height or height class and
call back the numbers. The measurer would also select the age class.

   6. The measurer could also provide other data such as condition.

   I suspect that collecting all these data elements for a half acre
plot will require between 1.75 and 2.5 hours. Despite the work, plots
established with this amount of data should prove very worthwhile for us
in the long run. We would likely measure all trees above a height
threshold very accurately. For instance, in the Bullard Woods plot, we
measured the tallest trees by employing our usual methodology. That is
how we got the 115.3-foot (115.5 by John's calcs) shagbark hickory
identified as the tallest in our plot.

    I can identify approximate GPS coordinates from a terrain map. We
might come even closer using that new aerial photography system.

RE: Height density analysis and Historical documentation   Gary A. Beluzo
  Jun 07, 2005 05:13 PDT 

Hi Bob:

This proposed method seems doable in the field and applying it to many sites
will be more practical than the INTERPOINT method. I think we all realize
that determining the GPS coordinates for each tree in a plot is just not
accurate enough with most of the handhelds and simply takes too long with a
device like a Trimble Geoexplorer. However, if you set up your tripod as
the plot center and record GPS coordinates over a 10-15 minute period we'll
have a good "bench mark" from which we can re-create the locations of the
trees in the GIS from the azimuth/distance measurements as long as they are
fairly precise (0.1 degree and 1 cm, respectively).

I am generating raster grids (cell size 30m, 15m, and 5m)from the MASSGIS
DTM (digital terrain model) files for MTSF. I've started with Mohawk
because so much field work has already been done out there and
ground-truthing the images will be easier. Once we know which cell size we
need to use I can produce raster images for all of our OG sites. From the
raster images we can derive slope, slope position, aspect, TSI, LFI, and
various hydrologic values (e.g. flow direction and accumulation) for each
pixel in any location in Massachusetts. The more of the primary literature
I delve into the more I realize that terrain geometry from GIS can help make
all sorts of predictions about vegetative type and potential maximum tree

Hopefully we can present some of this at the 2005 FOREST SUMMIT (October 13
and 14) this fall.


RE:  Height density analysis and Historical documentation   Robert Leverett
  Jun 07, 2005 13:24 PDT 


     For new members and members with a more casual interest in our tree
measuring discussions, I periodically try to put our collective
ramblings into perspective. I invite Lee Frelich, Will Blozan, Gary
Beluzo, Ed Frank, Tom Diggins, John Knuerr, etc. to join in.

     As many of you have no doubt witnessed, ENTS is dedicated to
historical documentation of important forest sites. This is not to say
that descriptions don't currently exist, but they invariably have gaps.
So our documentation does not duplicate what has already been done, but
typically proceeds along descriptive lines that have received scant
attention in the past. As a consequence of the incompleteness of past
documentation efforts by others, sites that would otherwise have been
acknowledged as exemplary, or historically significant, and thereby
possibly be eligible for special protection status were slipping through
the cracks. Good examples of sites that were once threatened include
Belt Woods, MD; Zoar Valley, NY; MTSF, MA; a private site in
Claremont, NH; and Mackey Mtn., NC. Even well-known sites like Cook
Forest State Park fall into the category of having been descriptively
bypassed. Before the days of Dale Luthringer, what the resource managers
didn't know about the forests of Cook beyond the most superficial
descriptions was eye-opening. I am personal witness to this dearth of
site-specific knowledge. Fortunately, the situation has turned around
for Cook because of Anthony Cook and Dale Luthringer and ENTS's support
of Dale. Another example is MTSF, my forest icon. State resource
managers saw Mohawk as having a convenient campground. A few saw the
aesthetic value of Mohawk, but none had any way of comparing or
contrasting the exceptionally tall forests of Mohawk to other
Massachusetts sites let alone elsewhere in New England or the Northeast.
Consequently, the Commonwealth's tallest trees, icons of a New England
past, went largely unnoticed. The story of Zoar Valley in NY is

     ENTS has championed exceptional forest sites that have otherwise
gone largely unnoticed. a small contingent of us have spent many hours
roaming the sites measuring trees and trying to get a handle on what we
are seeing. Concepts like the Rucker index and now height density
distributions have evolved to fill the voids. Our measurements and
protocols won't tell the whole story, but they are not intended to do
that. However, future generations interested in qualitative and
quantitative descriptions of say Bullard Woods and how it compares to
the forests of the past and present will have far more to drawn upon.

     Our latest foray into height density analysis holds promise of
providing the detail that serious scientists want to gather on trees
populating a site. However, unlike the more typical plot-based data that
produces reliable quantitative measures from breast level to the ground
and compromises on height data, our heights will be completely reliable.
But the height density documentation and analysis that we've begun to
explore will be time consuming. However, with John Knuerr, Gary Beluzo,
Susan Scott, myself and hopefully John Eichholz perfecting the process,
we'll be able to pass on the lessons we learn to save others time. A
recap of the process as we now envision it follows.

        1. Locate the center of a circular plot with a radius of 28
yards (25.6 meters).

        2. The recorder records the start time.

        3. The recorder or measurer gets GPS coordinates for the center
of the plot.

        4. The recorder, positioned at the plot center with a laser
rangefinder, clinometer, device to measure horizontal angle, and
recording worksheet proceeds to direct the activities of one or more

        5. The recorder sends the measurer to each tree within the plot
as determined by the rangefinder of circumference 1.0 feet. The trees
are tagged for easy subsequent identification. This process is crucial
to keeping accurate tabs on what has and has not been measured. Trust

       6. The recorder sends the measurer to a tagged tree and requests
the following information:

                a. species,
                b. circumference at breast height,
                c. full height or height class,
                d. crown exposed or understory,
                e. age class,
                f. condition,
                g. max crown spread (optional)

      7. The recorder records the above information along with the
distance to the tree and its azimuth.

      8. The recorder requests the tag to be removed.

      9. Steps 7 and 8 are recorded for each tree in the plot until all
trees have been measured.
    10. The recorder records the ending time.

     The above process can be enhanced by expanding the concept of step
6c to include added stratifications. If each tree is accurately height
measured, we can develop whatever height stratifications we wish.
Otherwise we might us the following system:

       0 - 49.9 ft
       50 - 74.9 ft
       75 - 99.9 ft
       100 - 124.9 ft
       125 - 149.9 ft
       150 - 174.9 ft
       175 and over

   The above documentation/measurement protocol would be employed
selectively, at least at first, to provide data on the best places
within our best sites.


Robert T. Leverett
Cofounder, Eastern Native Tree Society
Re: Historical documentation and height density analysis   Edward Frank
  Jun 07, 2005 16:12 PDT 


Your proposed methodology seems to be right on the button. Large cave
rooms are often mapped from a central position and shooting to the walls
much like you are proposing for the site documentation.

1) In your initial HDA at Shunpike, MTSF you used a larger area
(greater radius) than in your summary outline below. Circumstances at a
particular locality may serve to dictate what radius is used. I don't see
any reason why a larger radius could not be used where appropriate. More
data is always better than less data, providing there is time to do a
larger area. Site size might be based upon the particular feature you are
trying to document or analyze.    

2) With regard to the height divisions. It is easier and quicker to break
a site down into broad height groups. This also allows easier comparisons
between sites. Do the natural breaks vary from site to site, and if so what
is the best way to deal with it?
What are the natural breaks in the tree heights in the forests being
studied? I am wondering if the suggested heights best conform to the
natural height groupings found in the forest, or should the breaks be made
at less arbitrary heights? My thinking is if the typical canopy height is
100 feet, then a break between a 99 foot high tree and a 101 foot high tree
may not be the best place to break the data set, as both represent the same
naturally occurring height grouping. There is no real need to have every
height grouping be exactly 25 feet.

3) I would strongly suggest that a detailed site description be made for
the area in addition to measurements. Numbers are very important to
understanding what is happening in a forest section, but a good site
description forces you to analyze what you are seeing in real time, while
you are at the site. I made a list of things to consider when examining a
site last November:


This discussion could be adapted to more of a checklist for use in
conjunction with on-site height density measurement analysis.

Ed Frank
RE: Historical documentation and height density analysis   Gary A. Beluzo
  Jun 07, 2005 17:18 PDT 


I would suggest that since multiple recorders will be present and so many
tree measurements are being made that TERRAIN GEOMETRY also be assessed at
the same visit. The plot aspect, slope, and slope position could be
determined very easily.

In addition, the Terrain Shape Index (TSI) and Landform Index (LFI) should
also be determined. The reason for doing this is threefold:

1) As the recorder has an assistant move around the plot 360 degrees from
center to perimeter it would be very easy to also record the % slope from
the plot center to the plot perimeter (for TSI) and plot center to horizon
(for LFI) with the clinometer at 45 degree intervals starting with North.

2) The resulting terrain information may then be used to statistically
examine the relationships between the various terrain factors (i.e. slope,
aspect, slope position, TSI, and LFI) and the tree variables measured such
as maximum tree height. This can be done most efficiently with a Geographic
Information System (GIS). For example, in many of the primary literature
studies I have reviewed, terrain variables collectively influence maximum
tree height more than do nutrient levels, A-horizon depth, or total soil

3) As ENTS folks begin to employ GIS-based analysis of their sites, the
field-based measurements of terrain variability will prove to be invaluable
for model calibration.


Gary A. Beluzo
Professor of Environmental Science
Holyoke Community College
303 Homestead Avenue
Holyoke, MA 01040
RE: Historical documentation and height density analysis   dbhg-@comcast.net
  Jun 08, 2005 03:49 PDT 
   The TSI and LFI are easy additions to the list, especially with the leveling tripod graduated in degrees.

    The height classes I suggested are admittedly arbitrary and should probably be adjusted for the forest being measured. I'll give some examples in my next e-mail that would use different classes.

Plot survey methods   lwin-@hampshire.edu
  Jun 08, 2005 04:28 PDT 

I've tried both the Interpoint and the circular plot/polar coordinates
methods with students in my classes and the plot center method goes much
more smoothly. We use plots the same size as CFI plots, so data are
comparable. We've used exactly the method you've described - one person
at the center coordinating, rovers out "calling" trees (dbh, condition,
crown class), "taggers" out tagging trees, numbering them and noting the
species on the tag. We found that shooting the back bearing to the
center, using a sighting compass, was easier the using a rotating plane
table in the center - almost as accurate. Using a laser or a sonic
rangefinder is of course infinitely superior to pulling a tape,
especially in a brushy plot. The sonic rangefinder works a little
better, with a transponder in the plot center - signal goes through
trees, while the laser is of course blocked - the distance through trees
is actually underestimated, since the speed of sound is different in wet
wood than in air!

When possible we also have one student using a laptop computer to record
the data directly into an Excel spreadsheet - I can send along a copy of
one file as an example - the spreadsheet converts polar to Cartesian
coordinates and maps the plot as you go (could also now use a polar
plot, not an option back when I firat started doing this kind of survey)
, so you can walk around and check things - pretty easy to get confused
with a group of students - but once teams get the hang of it they can
really move. But 3 or 4 plots in a full day was the most we ever did,
and that was estimating height visually, not shooting the tops.

If the plot center is marked (PVC pipe, witness trees, locust stake
painted red) it's pretty easy to resurvey, given the detailed map. No
need to mark trees directly, which has been a problem. GPSing the center
is also a very good idea, although I have had little success using GPS
to return to a plot without witness trees or some other visual signs. In
winter good fix has  been possible - summer harder. Sometimes we set a
pin in a clearing or a nearby road, then survey in to the plot the hard
way with a level or transit.

Additional measures that you may have already thought of: core the
tallest dominant tree or two to get data for Site Index or to recover
site history; use a steel rod about 1/4" in diameter as a soil depth
probe - drive it in in 20 places or so until you hit rocks, then measure
that depth - you'll need a vice grips to get the rod out on occasion. We
also note ground cover vegetation and saplings -

Sounds like a wonderful project - I'm teaching Old Growth Forests again
this Fall and Forest Ecology in the Spring - perhaps we should get
together and coordinate plot locations and survey methods and data formats!


Lawrence J. Winship
Professor of Botany, Hampshire College
RE: Plot survey methods   Robert Leverett
  Jun 08, 2005 05:13 PDT 


   Gary Beluzo, John Knuerr, Susan Scott, and I (the current team) would
be delighted to "coordinate plot locations and survey methods and data
formats". Absolutely! Incidentally, we have many white pines tagged in
MTSF, courtesy of Lisa Bozzuto and Susan Benoit, that could be used in
plots toward several objectives.
Just say the word.

   I'm especially interested in establishing the kinds of plots we've
been discussing in the high performance areas of:

   1. MTSF
   2. MSF
   3. Ice Glen
   4. Mount Tom SR
   5. Bullard Woods
   6. Mount Greylock SR
   7. William Cullen Bryant Homestead
   8. Broad Brook (Monica's Woods)
   9. Canary Island
10. Mount Everett SR

Other high performance forests could be added to include a plot or
two in Quabbin. I saw Bruce Spencer over the weekend and I'm sure he'd
be happy to authorize us to do it.

More on plot survey methods   Robert Leverett
  Jun 09, 2005 07:40 PDT 

   One point to mention in determining the distance from a center point
to a study tree using the laser rangerfinder is that when the base to
eye level is obscured by underbrush, the simplist solution is to find
the lowest visible point on the trunk, shoot that distance, take its
angle, and calculate the eye level distance to the tree using the simple

     D = distance to point on tree
     A = angle to point on tree
     H = horizontal (eye-level) distance to tree

     H = Cos(A)D

   Even if the tree leans toward or away from the observer, the error is
usually minimal for trees in the East.

   To the protocol previously listed, we could add the slope angle to
the perimeter of the plot at the 4 cardinal compass points. The average
of the 4 slope angles or their equivalent slope percentages can be used
to compute the Terrain Shape Index (TSI) of the center point of the
plot. A similar calculation can be done for the Land Form Index (LFI).
Gary, please correct me if I am wrong in my use of these terms.

Re: More on plot survey methods   foresto-@npgcable.com
  Jun 10, 2005 10:28 PDT 

Bob's comments on ways to characterize the immediate landscape has me thinking
of an old solution that might be "hopped up" to work out...are you familiar
with plane table mapping? In the 'good old days', a plane table (on tripod),
an alidade (linear "gun sight"/straight edge/compass), a couple of under grads
running abneys (clinometers/laser hypsometer)and rag tapes and you'd end up
with a surprisingly good landscape characterization...
RE: Ash tree seed collection and Lee's observation   Robert Leverett
  Jun 10, 2005 13:04 PDT 


   Have we taken site and individual tree measuring to the point of
diminishing returns? From some perspectives and for some purposes, I
imagine we have. Squeezing another decimal point out of our methods
would seem to be overkill. But for a certain class of unprotected forest
sites, courtesy of our intense, and to some, fanatical focus, we have
become uniquely qualified to recognize and quantify their special
attributes. Who else does it or has done it? There is no other game in
town. Our over-focus, and that is my term, has recently allowed us to
help others see what they didn't see before. They acknowledge that
unprotected sites like Mohawk truly are exceptional and worthy of
special protection. But we have a special situation developing on our

    The State is currently engaged in a laudable program of identifying
forest reserves on public lands. I should be elated. Initially I was and
still am pleased, but from what I've seen so far, the program is
endanger of going astray. At the least, environmental organizations must
come together to push (or shame) bureaucrats into doing the right thing.
It's a long story, Don.

    Believe it or not, neither MTSF and MSF are presently included in
the proposed system of reserves. They were bypassed ostensibly for
political reasons to give the Fish and Wildlife Division its "fair
share" of reserves. Why the heck does Fish and Wildlife need a share of
the reserves? While the fish and wildlife folks do a pretty good job of
managing the resources under their control, they, nonetheless, stay
almost singularly focused on raising revenue from deer, bear, turkey,
grouse, and timber. To them, resources always need to be managed. In my
view, Fish and Wildlife has not shown sufficient understanding of the
value of reserves to be trusted as a proponent and reliable overseer.

   MTSF and MSF may yet qualify when the smaller reserves are
identified, but it is obvious to me that even with all the work that
FMTSF and ENTS has done in the past, and presented to the state, a
sizable percentage of those involved still don't understand the unique
attributes of the forests of the Deerfield River corridor, which
includes MTSF and MSF. Fortunately, lack of appreciation is not
universal. Some state officials have been receptive to our message and
in recent years have become strong advocates for protecting sizable
parts of MTSF and MSF by whatever method. Forest reserves fit the plan
based on their understanding of the exemplary state of the Mohawk and
Monroe forests. Guess what/who has shaped their perceptions?

   So back to the question about site variables. We'll be trying to
understand forest productivity in the Deerfield for years. Of that I
have no doubt. I won't see adequate answers in my lifetime, but
hopefully, I will see a wider appreciation for what those forests
represent and a commitment by EOEA and DCR to protecting them in

Re: Ash tree seed collection and Lee's observation   Don Bertolette
  Jun 12, 2005 09:41 PDT 
Just now back from Scandanavia,