RE: Formulas for points MY MEAGER TAKE ON THINGS    Will Blozan
   Jan 22, 2005 08:33 PST 

Paul and other ENTS,

I find myself with very limited time to respond to such an interesting
discussion. However, I want to present an idea I have discussed with Bob L.
in the past, and it is a system that reflects Paul's desire for a relative
score. It is also independent of units, but is variable as new maximums are
found and does not allow for inter-specific comparisons unless superimposed
upon an absolute maximum "base". Naturally, the system can only be applied
to ENTS measured trees, further limiting it's usefulness in the big tree
lists. Oh well, I will propose it anyway.

With an existing database (ENTS) a set of maximums of girth, height, and
spread are established. The maximums are given a rating of 100, which
represents 100% of the known maximum. For example, let's look three big
tuliptrees; the Sag Branch tuliptree, the Mill Creek Monster, and the
Greenbriar Giant.

Known tuliptree maximums:
Max girth 24.25' =100 pts (Jess may have a larger one)
Max height 178.2' =100 pts
Max spread 113' =100 pts (maximum, not average- treated same
as height which we do not average for separate tops)

With the above numbers, a tree has the potential to have 300 points if it
contained all the maximum dimensions. Here is a comparison of three giants:

Tree Girth Height Spread Points
Sag Branch 91.7 94.3 100 286
Mill Creek 94.4 87.5 88.5 270.4
Greenbriar 100 87.5 85.5 276

How do these trees compare to the best we know of in the east (relative

ENTS maximum dimensions:
Girth 31.8' (Middleton Oak?)
Height 187' (Boogerman Pine)
Spread 154' (Maximum above ground- Cherrybark oak measured last week)

(Max spread estimated) Girth Height Spread Points
Sag Branch Tuliptree 70 89.8 73.3
Pinchot Sycamore 86.8 52.6 94.2
Sunderland Sycamore 81.8 61.8 99.4
Pine Plains Sycamore 75.5 57.8 94.2
Middleton Oak 100 34.8 87.7
Cherrybark oak 61.6 85.7 84.4
Cherrybark oak 62.9 72.2 100

This system gives much more equality with respect to differing tree forms.
It can be modified to compare within a species or within only conifers. The
Middleton oak, with its huge trunk and wide spread compares favorably to the
Sag Branch Tuliptree. The immensely huge Sunderland Sycamore scores high in
all measures, and justly so!

I believe this ranking system is called "hyper-volume" or something, and is
used in ecology to represent three variable niche fulfillments of species
and habitats. I like it because it is independent of units and the above
numbers generally represent my visual ranking of the trees.

Naturally, as we discover new records the numbers will change slightly for
"saturated" species, and more quickly for less measured species (an active
database would be required to continually update the numbers). The relative
ranking for one or more variables may be useful for latitudinal analyses.
For example, the black birch (and birch family in general) may not change
more than 10 points over a huge latitudinal range, whereas white pine,
tuliptree and northern red oak will change by much more within the same
range. A graph of these relative numbers would be very interesting.

Anyway, there it is!

Will Blozan
RE: Formulas for points MY MEAGER TAKE ON THINGS    Edward Frank
   Jan 22, 2005 10:34 PST 


A couple of questions or points. For the species maximums, what about
using the tallest ENTS measured specimen even if it had since died? Thus
the maximum height would still be Boogerman Pine, only at 207 feet rather
than 187.

It will be an annoyance to recalculate the values for each tree every time
a new maximum for that species is established. It will also be a problem to
compare values if there has been one or several adjustments to the base
maximums had occurred between published figures. There is no reason that a
percentage can not exceed 100%. I would suggest a table of maximum values
compiled on a specific date for all species in the dataset. This could
then be used for an extended period of time, perhaps 5 years. Then the
dataset could be recalibrated using the latest values from that calibration
date. The figures could be published for trees listing the calculated
value and the year of the base maximum set used to derive the figures.

This would help fix some of the implementation problems with the proposed
measure. If other datasets listed the height, cbh, and canopy spread
values for trees, we could calculate the same values for them, but there is
still the problem of inaccuracies inherent in other measurement standards.
There is no reason that a new and better standard for calculating big trees
should not be developed by ENTS. I also think this method generates
numbers with real value and not just cosmetic meaning.

Ed Frank
RE: Formulas for points MY MEAGER TAKE ON THINGS
   Jan 22, 2005 11:16 PST 
Will, Bob, ENTS

Using an excel spreadsheet, or even Access, you could group the trees by species, and have a cell dedicated to the current known maximum for each species. I agree it should be historical, as in the example of the Boogerman pine. A master list would be kept, and when a new dimension record is found, the cell that all the formulas use could be changed, then all the calculations would change automatically.

Standardized tree hypervolumes
   Jan 22, 2005 13:16 PST 


I really like the idea that's developing here (Paul started this, I think...) of
standardizing tree measurements in relation to known maxima. Units become
irrelevant (as long as they're consistent for each dimension), unlike in the AF
formula where the use of inches for girth dominates the additive formula.

I have a suggestion - don't add the percentiles for each dimension, average
them. That way the standardized maximum is always 100, no matter how many
dimensions are measured (I presume most people would stay with girth, height,
and crown spread, at least initially).

The cool thing with standardized data is we can now rank trees at different
geographical and/or taxonomic scales. E.g., an insanely big hop hornbeam
(Ostrya) at 9' CBH and 90" tall is ranked right at the top for its species. It
would, however, drop way down when ranked among all eastern trees. A 131' x 11'
CBH x 70' CS northern red oak in Massachusetts would rank near 100% among forest
grown NRO in New England, perhaps ~80% among all forest-grown trees in New
England, some unknown but certainly much less than 100% among all NRO in the
East (forest and open-grown), and so forth. The scale of analysis is set by the
investigator, and could range from "all eastern trees" right down to "all trees
of a certain species at a single site". We also have to remember that with all
biological data, no matter what analyses, manipulations, etc. are performed, the
original measurements can always be reported too.

Re: Standardized tree hypervolumes    Edward Frank
   Jan 22, 2005 14:39 PST 


I don't see any problems inherent in averaging the percentiles rather than
adding them. It doesn't really affect the outcome. One concern would be
trying to mix percentiles derived by 2 parameters, with those from 3
parameters, with those using 4 parameters, and so forth. By adding an
additional parameter the fundamental ordering of the list could be changed.
By mixing the two sets of information the ordering of one set would be
different from the ordering of the other.

For example a tall tree with a small crown spread might rank very high on a
ranking including only height and girth. If a third parameter for crown
spread were added, a forest grown tree with a narrow crown would be
averaging a relatively small percentile for crown spread into the mix,
while an open grown tree that placed farther down the initial list, would
be adding a relatively large percentage for a broad crown spread into its
mix. This isn't bad of itself, but would make it difficult to compare the
two parameter versus three parameter trees in a single listing, even
thought they both are expressed as a single percentage number.

Ed Frank
RE: Formulas for points MY MEAGER TAKE ON THINGS
   Jan 22, 2005 15:10 PST 

What about the whole idea of treating in-forest and field trees separately?
If you really don't like to separate them it would be easy to combine the
two separate tables into one master table. I just think that the form of the two
types is so different and the experience of seeing a tree in the forest or
on a lawn is so different....
RE: Standardized tree hypervolumes    Will Blozan
   Jan 22, 2005 19:22 PST 


I like your thinking, and I did toy with the idea of a "100" max scale. The
300 point scale I proposed gives more depth to the average observer, and a
few more points between trees close in size. It also facilitates separating
the maxima per variable, and better illustrates the relative ranking. A
maximum height ranking of "32" may not mean anything, but a "92" would mean,
"this tree represents 92% of the maximum known for the species, or the East,
or the site..." I.e. - "Wow, Man, that is way tall!"

Roll with it, man!

RE: Formulas for points MY MEAGER TAKE ON THINGS    Will Blozan
   Jan 22, 2005 19:50 PST 


I think the relative ranking equalizes the extremes in growth form, since a
forest grown tree is usually taller and narrower than an open-grown tree
which is typically shorter but wider. The girth may be the most significant
variable between an open-grown and forest-grown tree, and one that may be
equally outweighed by height.

Will B
RE: Formulas for points MY MEAGER TAKE ON THINGS    Will Blozan
   Jan 22, 2005 19:50 PST 


As far as the updating of the "base", I would want to do it regularly, but I
see your point with regard to simplicity. Either way, the "base" should not
change dramatically since we have such a massive set of data for so many
species from so many ENTS measurers. We are certainly talking only a
fraction of a percent in general, with a 2-4% jump being very rare.

I must say though, that Jess Riddle blew the socks off the NA Carpinus
height record last weekend when he spotted a tree nearly 10 feet taller than
anything previously known (except for an unreported tree Ed Coyle measured
in NY recently- post it, DUDE!). Such a jump will be rare, but not uncommon
for species we do not intensively sample.

Will B.
RE: Formulas for points MY MEAGER TAKE ON THINGS    Will Blozan
   Jan 22, 2005 19:55 PST 

The bottom line is, we need to develop a formula that is independent of
growth form. But why? I am nagged by the "need" to quantify trees for a "big
tree list". That is not the mission of ENTS. Quantifications of tree
dimensions over latitudinal or whatever gradients we need are what ENTS is
all about. The understanding of trees, not the competition of superlatives.

RE: Formulas for points MY MEAGER TAKE ON THINGS
   Jan 23, 2005 11:12 PST 

Well, much to my shock, it seems I am alone when it comes to this on this list, but perhaps it could at least be made standard practice to mark down along with other data whether it's in forest or not. It only takes about 2 seconds to make note of this (although certain rare cases might be non-trivial), so it wouldn't seem to be troublesome to make it standard practice, height and spread and stuff are what take effort. So even if the official ENTS and AF tables (not that the AF tables seem reliable enough for anything) don't split lists, others who care about this fact would still be able to make their own customs data tables. 

Personally to me, it seems if you don't split the list then why even bother making separate lists for different states, locations, single vs. multi-stemmed, etc. From an biological or ecological perspective in forest and in front lawn are completely different beasts, as different as Smokies vs. northern reaches of Maine, recent third-growth and old-growth. Plus, isn't it more exciting to say find a tree that is 95% of the known in forest max girth than say only 70%, and where probably 100% of the top ten lists for girth will be from front lawns and 100% of heights from forests? Plus, isn't the experience of a great tree in a front lawn with cars rushing by, the sun beating down, and branching starting at 4' way (not that all lawn tree have this form, some are fairly forest looking in form) different than some forest monarch, not that lawn tree may not be impressive and neat, there are some nice old trees in my town, but still it's such a different thing for so many different reasons. 

Biologically, ecologically, I don't see how it makes much sense (although, granted, various forest disturbances and histories can complicate things, depending upon what you are after). What can we gain about max girth and height in different forests and open parks and lawns and so on if everything is mushed together? Anyway, I'm beating a dead horse. Hopefully people will at least mark the difference so those who wish can look at the relevant data for particular needs.

I agree. I don't like to hear that a tree is open grown, that is why it ranks so high. The capacity of a species is what we are after. Someone had said that we should list forms separately. I think we need to proceed with a formula that doesn't consider form. The trees should equal themselves out, as forest trees are taller and open trees have more girth.


RE: Formulas for points MY MEAGER TAKE ON THINGS   Edward Frank
  Jan 23, 2005 11:30 PST 


I don't think you are alone on this question. I would be in favor of
noting whether a tree was open grown or a forest tree. If that note was in
a sortable field in the database, the list could be sorted to generate
separate forest and open grown lists.   There may be some problems with
annotating the existing database, but there should not be a problem for new
trees, or when trees are remeasured. It would be worth the effort in my
opinion. Bob, what do you think about a forest or open grown field in the

Ed Frank
RE: Formulas for points MY MEAGER TAKE ON THINGS   Will Blozan
  Jan 23, 2005 19:40 PST 
I fully support a distinction. Truthfully, it was not on my mind since I
measure 99% or more forest trees, which is likely true of all the ENTS
members. I take keen interest in yard trees, but focus on the forest
attributes of trees in their "native" habitat and growing conditions.

Great points!

RE: Formulas for points MY MEAGER TAKE ON THINGS
  Jan 23, 2005 14:28 PST 
Ed, Larry, et al:

    It might appear from what we routinely report to the list that we don't record anything about a measured tree but its height, circumference, and maybe spread. That is not the case for some of us. We have room in the database that several of us share to record all the following:

     1. Tree's condition (good, fair, poor)
     2. Age class (young, mature, old)
     3. Number of trunks
     4. Growing environment
           a. forest grown, partially open growth, open grown
           b. old growth, second growth, etc.
           c. moist, dry
     5. Height above base at lowest point of branching
     6. General comments

   We intend to add a terrain index factor when we figure out how we want to go about computing it.
    In truth, I get lazy when it comes to recording the above factors and even under good circumstances, time or location of a tree often precludes recording all the data we want. What some of us have been steadily moving toward is a system of identifying important sample trees on a site for which we will fill all the data fields. Non-sample trees would have some added items recorded, but not necessarily all the above.

     Ed, for ENTS website reporting, maybe we could agree on the following:

     1. The number of trunks at point of major branching
     2. Height at point of major branching
     3. Tree condition
     4. Age class
     5. Growing environment: Open, partially open, forest

   There may be other items we should report, but the above don't require more time or equipment. Tree condition and age class are judgment calls. So we may want to discuss these further. What do the rest of you think?

RE: Standardized tree hypervolumes    Darian Copiz
   Jan 24, 2005 08:03 PST 

I think a relative size scale could definitely be more than a novelty.
During the development planning for forested sites there often is, or
should be, a forest stand delineation in which significant trees are
noted so that they might be preserved. These are always the very
largest trees on the site. It has always bothered me that a site could
potentially have a giant Carpinus, Cornus, Ostrya or such, yet these
giants of their species would be cut down without a second thought. If
a scale relative to species was used, some very cool trees might be
saved. Admittedly, it would be a long time before such a scale would be
adopted as part of the development process, but things always have to
start at some point. My two cents on the scale is that I prefer a 100
point max continuously recalibrated. A percentage based off of 100 is
the most readily understandable. For a better understanding of a
particular tree, the three variables could easily be observed as is the
case in most current lists. I don't like separating forest grown and
open grown trees. There are always gray areas. Trees should be
compared to trees. The challenge would be to balance the variables to
best reflect size - if that's not possible, big deal, we would still get
a pretty good idea of the tree's size.

RE: Standardized tree hypervolumes    edward coyle
   Jan 24, 2005 09:51 PST 


The 'novelty' comparison was for the arbitrary scores for state and other
champion tree lists. This suggested hyper volume scale is a means by which
comparisons may be made to any order. Eastern North America, our focus,
represented by the three largest dimensions we have for height, girth, and
spread, would be the super set against all trees would be measured. Of
course, the number represented by 100% could adjust upward, if a greater
specimen was found.

Additionally, sub sets for regions, states, sites, species could also be
made. Will detailed this in a Jan. 22 post to the site.

Ed C

Will's WAY COOL proposed new system    Robert Leverett
   Jan 24, 2005 10:32 PST 

Will, Ed C., and others:

Oh Man, Will, I've already fallen in love with your proposed 300 max
point system. Look at how it treats the Sunderland, Pinchot, and Pine
Plains sycamores. I may be off a little on the maximum spread of the
Pine Plains tree. Can't find the original max spread measurement, but it
wasn't much off of what is being shown below. Note that the maximum
height for a northeastern sycamore is presently that of the Vanderbilt
Tree and I'm assuming the PA sycamore will yield a legitimate 30-foot
circumference. Scott will have to be the judge on that one, but for now,
we can use the 30-foot circumference as the max.

Comparison of 3 northeastern sycamores against northeastern maximums
Dim -->           Hgt Spread Cir Pts
Maximum ………… 136.1 153.0 30.0
Sunderland………. 114.4 153.0 24.9
Pct Max……………. 84.1 100.0 83.0 267.1

Maximum ………… 136.1 153.0 30.0
Pinchot……………. 98.5 149.0 27.6
Pct Max……………. 72.4 97.4 92.0 261.8

Maximum ………… 136.1 153.0 30.0
Pine Plains………. 114.2 135.0 26.2
Pct Max……………. 83.9 88.2 87.3 259.5

Will, your system is WAY COOL. It has to be adopted .... like, right
now! The Sunderland sycamore rules. YES!

Re: Will's WAY COOL proposed new system    Lee E. Frelich
   Jan 24, 2005 10:56 PST 


I like the 300 point and % max scale you demonstrate.

FYI the University of Wisconsin developed a 300 point scale for comparing
the abundance of tree and herb species among stands in forests during the
1950s, and it is still known today as the Wisconsin School statistics. It
included relative frequency (species present at 0-100% of all points within
a stand), relative density (species accounts for 0-100% of all stems within
a stand), and relative abundance (species accounts for 0-100% of cover, or
in the case of tree, basal area within a stand). For trees they also used
a 200 point scale that included relative frequency and relative abundance.

RE: Will's WAY COOL proposed new system    edward coyle
   Jan 24, 2005 11:21 PST 


I was toying with just how to display the numbers. Your sycamore ranks 267
among known NE max, and the Sunderland would rate 235 against the hypermax.
235/267 or 235.267. Any thoughts on how best to distinguish numbers for sub
sets, ie. region, state, site, species.
Ed C
RE: Will's WAY COOL proposed new system    Darian Copiz
   Jan 24, 2005 11:46 PST 


Not meaning to push a personal preference, but just noting another way
of putting it: 89.0%, 87.3%, and 86.5% of "maximum potential". One B+,
but no A's.


RE: Will's WAY COOL proposed new system- 300 vs. 100 points    Will Blozan
   Jan 24, 2005 12:24 PST 


Ed Frank has proposed that the three scales be combined into a 100 point
maximum point total for all three attributes. I personally like the 300
point scale as it give more readily understandable resolution and where the
tree stands with respect to any given attribute. However, I am open to ideas
and enlightenment. It is just a fledgling idea after all, and free to play

My mind is racing with how many ways we can apply the rating system. It can
really give meaningful depth to the "bigness" a tree can have relative to
it's peers. Much more so than the AF points system can. A 300 AF point
hemlock in New England is way more significant than a 300 point tree in the
Smokies. The new system would illustrate that when it is compared "apples to
apples". Such a tree in New England may score the same as or even surpass a
"larger" 350 AF point tree in the Smokies when viewed against the
appropriate regional scale. Likewise, the 111' "shrimpy" hemlocks of the
Porkies can now be viewed as the relative giants that they are- no less
significant than the Tsali hemlock in the Smokies. That is, when viewed
"apples to apples" against their peers. Neat! Credit where credit is due!

Defining the regional scales is the next hurdle, as is naming this new
system. Much to my surprise, the system seems to have instantly gained
support (even by the stalwart ecologists out there), and may be on the way
to adoption within ENTS. This is exciting! Any ideas for a name? Does it
have a "real" name? Is my memory correct in the "hyper-volume" memory?

ENTS Hyper-volume Rating System? Long, no acronym...
Multivariate Abyss of Confusion...

Maybe something with MASS as the acronym?

Regional assessment of Massiveness?

Regional Magnitude of Massivity?

Burl-belly Hyper-volume Fulfillment Index?

Now we're talkin'...

Will B
RE: Standardized tree hypervolumes    Edward Frank
   Jan 24, 2005 13:01 PST 


Will's Meager Proposal seems to have reached immediate acclaim among ENTS
who have responded. We should adopt it immediately. There are only two
factors I see left to be decided:

1) Should it be the sum of the three percentiles or the average with the
system based on 100%. Tom Diggens, Darian Copiz, and myself have
supported a 100 percent scale. Others, including Will Blozan and Lee
Frelich, favor adding the three figures together.

I like the 100% scale, because as Tom pointed out: "That way the
standardized maximum is always 100, no matter how many dimensions are
measured." Will suggested that the 300 point scale would to an average
person appear to have a greater resolution - 300 versus 100. I would
counter that the percentages should be carried to 1/10 or 1/100 of a
percent, giving a virtual scale from 0 to 1000. If the percentage were
multiplied by 1000, then a perfect tree - one that was the tallest,
fattest, and greatest crown spread - would have a score of 1000. Consider
the three sycamores Bob cited in his post (Jan 24, 2005) the Sunderland,
Pinchot, and Pine Plains sycamores. In the additive formula the scores are
respectively 267.1, 261.8, and 259.5. Using a 100% scale with scores of
89.03%, 87.27%, and 86.5% of "maximum potential" would translate to 890.3
points, 872.7 points, and 865 points.

2) Should the baseline maximums from which a species percentage is derived
be updated continuously, or on a longer term basis?

If they are updated continuously, then the advantage for doing it this way
is that the values for each individual tree are always up-to-date and
represent the most recent findings. If they are updated on a longer term
basis, and a larger tree was found you would have a percentage greater than
100% (not necessarily bad IMHO). The advantage for this method would be
that if the base line numbers were updated continuously, any published
figures would become out-of-date and differ from each other every time the
base line was updated - in general I think a longer term basis for the base
line would provide information that would allow analysis made using it to
be directly comparable over a longer period of time, and hence have a
greater utility.

There was some discussion about whether a separate list should be
maintained for open grow and forest grown trees. This was a concern
expressed by Larry Baum. I also agree that information would be
interesting. However the general tree database includes a field lists
whether a tree is open grown or forest grown. Seagate lists could be
generated from a single master by sorting from the master database using on
that field. So really only one master list needs to be maintained.

Lets hear opinions on these two questions, and if anyone has any additional
questions or concerns I would like to hear them at this initial stage.

Ed Frank
RE: Will's WAY COOL proposed new system- 300 vs. 100 points    Edward Frank
   Jan 24, 2005 13:09 PST 


I think EHR is a fine acronym.

Questions about new system?

3) Should we be using the current biggest tree, or a historical measurement
that is larger if it was an ENTS measurement with good information?

The example that comes to mind is the Boogerman pine. Should we be using
the max height at the current value - 187 estimated, 186 last measurement -
or should we be using the maximum measured height of the tree - 207 feet -
measured before crown loss a few years ago. I would favor the historical
bigger number, but don't view this as a critical question.

Ed Frank
RE: Will's WAY COOL proposed new system- 300 vs. 100 points    Robert Leverett
   Jan 24, 2005 13:26 PST 


At this point, I would vote for historical maximums since they tell us
a specie's story over time much better than current maximums do. The
concept of historical maximums should be apply to local, regional, or
eastern wide maximums.

In response to your prior e-mail, I'm still thinking about the 100%
scale versus the 300 point maximum scale. I'm also developing a sample
of 20 New England white pines that I know very well. I plan to put the
scores earned by these pines on each of the 3 point systems ( AF, ENTS
Pts, and EHRS) side by side with comments. I'll pass the results to you
in a spreadsheet in a couple of days so maybe you can post it to the
website for others to look at and comment on.

RE: Will's WAY COOL proposed new system    Robert Leverett
   Jan 24, 2005 13:32 PST 

Ed Coyle:

Good questions. We may want to consider breakdowns of eastern wide,
region, state, and site. We would have to agree on the regional
definitions. That can get messy. The Northeast is commonly consider to
include New England, New York, Pennsylvania, and New Jersey. I'm unsure
of what states belong to what other regions. The pie can be sliced in so
many ways and for so many differing purposes.


RE: Standardized tree hypervolumes   Darian Copiz
  Jan 24, 2005 14:55 PST 

Ed and ENTS,

In regards to topic of discussion 2 below, I think there are some
problems with not continuously updating a database. If a larger tree is
found, and given a score of say for example 303 or 101 or 1001 (whatever
is decided), the maximum potential score of all other trees of the
species are immediately out of date. The new discovery is up-to-date in
comparison to the old base tree/trees. However, although all the other
trees are also accurate relative to the baseline, they do not reflect
the new discovery and a new potential maximum. How clear would it be to
the reader that the tree maximums are set by a baseline, which might or
might not be the actual known maximums for the species. Additionally, a
score above a set maximum implies that the tree's size is actually
greater than the maximum for the species. But the tree in question, by
existing, has displayed otherwise. I think that in order for published
material to never be out of date, scores would have to be chosen that
the species could probably never actually attain so that the baseline
wouldn't change. That, however, doesn't sound like a very appealing
option to me. I think part of the nature of published material is for
it, at some point, to become out-of-date. A web based database,
however, could always be up-to-date. One way to help solve the problem
of an old base line would be to use the scoring system in conjunction
with the actual measurements. Almost all big tree lists I can think of
list the measurements in addition to the final score.

My vote would be for a 100 point system (with possible decimals), second
would be a 1000 point system, and third would be a 300 point system. I
think most people immediately understand a scoring system between 1 and
100 and can more quickly grasp the relation between a given number and
100. I immediately have a good idea what 89.03 is in comparison to 100.
It takes me a little longer to understand the relationship between 267.1
and 300 and even after thinking about it for a while, its still not
quite as clear as on a 100 scale. That's my vote, although it should
probably not be weighed very heavily since I have not regularly
contributed in the past and I don't think anyone in ENTS knows anything
about me.

So as a real quick introduction, I'm a landscape architect/urban
designer living in Maryland right outside Washington D.C. I have a
great interest in trees (of course) and nature in general. I am also
interested in photography and history. Sorry for the tardiness in the

Will's WAY COOL system - problems
  Jan 24, 2005 15:19 PST 

I mostly like where this is leading, but you are not there yet.

The new system makes the three measurements equal - are you sure you want that?

I still think average crown spread is arbitrary and not very useful.

All of the methods that convert what a tree is into some arbitrary point system will always have problems with certain trees. The AF system favors big trunks over tall trees and falls apart with super large trees.

What is your objective - do you want this new system to reflet volume? If not, then what else?

In my scientific research I must predict volume all of the time. My equation for Piea sitchensis, for example takes the form of:

This is based on 61 trees that run the full range of size to 401 cm diameter and 92.7 m tall.

Enough for now.

Re: Will's WAY COOL system - problems    Edward Frank
   Jan 24, 2005 16:09 PST 


I wanted to address your general comments. I am sure others have opinions
to express as well. The question of whether tree canopy should be given
equal weight was ask earlier by Larry Baum.

I don't think this formula is intended to reflect volume, but to reflect an
overall generic idea of "bigness." This is perhaps not a tightly defined
concept, but reflects a balance of all the parameters that contribute to
the aesthetic concept of bigness.

Should all of the factor be weighed equally? For a couple of reasons I
would argue that yes they should be treated equally. You think average
crown spread is arbitrary and useless. I am not sure it is. The crown
spread represents to some degree the size of the tree canopy. This is
where all leaves are located, where all of the branches are located, where
all of the photosynthesis is taking place. It is hardly a trivial area of
the tree in a biological sense, although it may be in terms of volume. 

You certainly know far more than I do about tree canopy
structure from your detailed mapping of giant trees around the world. If I
were to look for an expert on the subject, you would be the one I would
call, but on this question about whether canopy spread is a useful
measurement or not, I still disagree with your assessment.

For the trunk dimensions and the canopy dimensions the formula is using
linear dimensions. Using a volumetric measure might be more appropriate,
but a canopy does not form a perfect cone or sphere, the trunk tapers (as
per your formula). Compromises must be made. I feel the simpler method is
adequate for defining the space. This is especially so considering that we
are considering each the measurements as a percentile of the maximum. For
giant trees the formula may or may not breakdown. For a detailed modeling
of tree form, certainly a more complex set of descriptors might be needed,
but as a measure of overall bigness this formula is excellent.

We can calculate an index using just circumference and height as the only
parameters, and we can calculate a figure using circumference, height, and
crown spread. We could calculate a figure using those three plus an
additional undetermined parameter using this methodology. If we base the
numbers on a 1 to 100 or 1 to 1000 scale, all of these would generate
numbers in a comparable range. This would let us see how inclusion of each
of these different parameters affected the overall picture. Part of the
beauty of the formula is that all values are treated equally.

I agree that whatever method is chosen, there may be problems with
certain trees. The formula by comparing the measured parameter with the
largest known measure of that parameter, I believe minimizes that problem.
Please post additional thought you have on the issue, or propose an
alternate formula. I am sure many of us are interested in what you have to
say on the subject.


RE: Standardized tree hypervolumes
  Jan 24, 2005 16:20 PST 

1) 300 point scale. I think it will appeal the masses, but is that what we want.

2) I think the data base should be updated at the find of a new champ. I don't think it will happen that often, after the initial year or so. As mentioned before, the data could be calculated easily using a spreadsheet. If not, then at least annually. I know the 10 year span for the Pa tree list probably frustrates alot of people who find a new tree one year after the latest results come out.

RE: Will's WAY COOL proposed new system- 300 vs. 100 points   edward coyle
  Jan 24, 2005 16:46 PST 


I too am inclined toward the tri-measure. I think more reduction leads to
a lesser impression, or picture, of an individual tree.

Ed C
RE: Standardized tree hypervolumes
  Jan 24, 2005 17:15 PST 

So all the coefficients are going to be 0.33333 (or 1) each? No more
thought of testing out various weights for the final output?
a(% of max species Height) + b(% of max species Width) + c(% max species
Spread) and a+b+c=1.0 (or 3.0)

anyway I suppose it doesn't matter anyway, as long as height, situation,
etc. anyone can make up there own tables
as they see fit, renormalizing % of each factor to max for location type
and setting coefficients as they desire, there isn't a way to make one
single list that's good for every purpose or desire anyway. 

one thing
though with officially keeping open and forest completely tied together,
well won't this, with equal coefficients case in particular, mean that a
great many in forest trees might not even make it onto the table and
perhaps in other cases notable lawn trees, how many of each type will
appear? if just one from each region then obviously there will be no way to
rebuild the table since you'll loose whatever % of species for each table
type. even if say 5 of each species get in the list, maybe it is a species
that gets exceptional girth and spread in the open and so much less so that
no amount of height will let any forest tree make the list. what exactly is
going to be plugged into the list, all significant finds from each region
(many entries per region) or just one tree per region, etc.?

  3) Sould we be using the current biggest tree, or a historical measurement 
that is larger if it was an ENTS measurement with good information?

I would also favor historical.

  1) Should it be the sum of the three percentiles or the average with the
system based on 100%. Tom Diggens, Darrian Copiz, and myself have
supported a 100 percent scale. Others, including Will Blozan and Lee
Frelich, favor adding the three figures together.

if we did go to varying coefficients, I might set spreads coefficient=0.0,
heh. In some ways I can see it being quite worthy though. In other ways it
seems more problematic and rather a pain. I think overall I could easily
live without it. I would certainly scale it way down at least, to be no
more than a modest tie-breaker (of course there are truly horrible counter
examples, one the worst of which would be the Live Oak, in general though,
I think it might make more of a mess than help, I can think of scenarios
were it could mess things up as badly as it would help for Live Oak, not sure.)


Re: Will's WAY COOL system - problems
  Jan 24, 2005 17:37 PST 

They are good points.
OTOH, I keep envisioning this fat white-ash that grew to immense spread
open-grown, branching exceptionally low to the ground and how while it
seemed big it just didn't seem nearly as big as this one I saw off-trail in
Pine Orchard that just towered up soooo high, but a very narrow crown. I
think with the 1,1,1 (1/3,1/3,1/3) factors it would not even make the list
though and would appear to be almost incomparably smaller by these #'s which
isn't the feel that I get around them. And say there was some redwood 50'
taller and similar diameter to one that, for some reason, and maybe it
doesn't occur to this extent, had exceptional enough spread to come out as
high or even much higher in final score. still, I do see your valid points
regarding spread.

  From: Edward Frank 
This is perhaps not a tightly defined
concept, but reflects a balance of all the parameters that contribute to
the aesthetic concept of bigness.

Should all of the factor be weighed equally? For a couple of reasons I
would argue that yes they should be treated equally. You think average
crown spread is arbitrary and useless. I am not sure it is. The crown
spread represents to some degree the size of the tree canopy. This is
where all leaves are located, where all of the branches are located, where
all of the photosynthesis is taking place. It is hardly a trivial area of
the tree in a biological sense, although it may be in terms of volume.

You certainly know far more than I do about tree canopy
structure from your detailed mapping of giant trees around the world. If I
were to look for an expert on the subject, you would be the one I would
call, but on this question about whether canopy spread is a useful
measurement or not, I still disagree with your assessment.

RE: Standardized tree hypervolumes   Edward Frank
  Jan 24, 2005 17:37 PST 

Three equal measures seems to be the way almost everyone wants, but nothing
has been decided yet. I noted in my last email that you wanted to weight
canopy spread less than the other factors, and BVP ask about whether we
were sure we wanted to give all three values equal weight. I favor giving
them all the same weight, but it is not universal. I will be happy to
repost the questions, or post a new message, asking whether all factors
should be weighed equally or weighted in some manner.

It is my understanding that every tree with measurements will be included
in the list so that there won't be any forest grown or open grown trees
with measurements left out.

There may be situations where differences in girth overwhelm those of
height or crown spread, or the opposite. We just need to wait and see what
the data shows. If the results turn out to be too skewed for reasonable
rankings, the list can be sorted by forest or open grown, or the weight of
each parameter could easily be adjusted by changing a number in a
calculating cell. All factors being equal seems the most appropriate way
to start.

the formula is really:

(1/max height) specimen height) + (1/max girth) specimen girth) + (1/max
canopy spread) specimen canopy spread) = Points, the choice then under
this scenario would be raw points as listed, or a percentage value derived
by dividing the result by 3. (I also suggested expanding the percentage
derived by multiplying by 1000 to give a larger, more appealing, number

One of the ideas for the database is to give people access to the raw
information so that they can manipulate the information to whatever need
they have. So the information can be reprocessed to reflect whatever
sorting or weighting of the parameters you want.

Ed Frank
RE: Standardized tree hypervolumes - Weighting Parameters   Edward Frank
  Jan 24, 2005 17:40 PST 


Larry Baum and Bob Van Pelt have both questioned whether or not we wanted
to weigh all three of the parameters under discussion evenly - Height,
Girth, and Canopy Spread. What are your opinions, please try to explain
the pros and cons of each option in your reply. I have previously stated
my opinion.

Ed Frank
RE: Standardized tree hypervolumes   edward coyle
  Jan 24, 2005 18:16 PST 


As I understand your concern for 'losing' a species, due to its being
forest or field grown, I can only think that it would depend on the list.
All trees would not, and should not, make a national list. It would be
exhaustive. However, a plot or site, might require recording every species
As the list jumped in scope to state, or regional level, your particular
trees may be lost due to their relative unimportance. For example a state
champion something might disappear from an East coast listing.
The list can be made to any level you want,plot, site, state, region. It
will have ultimate comparison with the hyper volume tree values. The number
of each species listed could be unlimited, but would more likely, it would
be reduced to a managable number,and be representative
of the best the sub plot has to offer.

That's how I understand the concept at this juncture.

Ed C
RE: Standardized tree hypervolumes
  Jan 24, 2005 18:17 PST 

  Darian Copiz wrote:
In regards to topic of discussion 2 below, I think there are some
problems with not continuously updating a database. ...

One way to help solve the problem
of an old base line would be to use the scoring system in conjunction
with the actual measurements. Almost all big tree lists I can think of
list the measurements in addition to the final score.

I guess it would be easy enough to keep up to date. Each % for the three
values would be calculated based off of excel cell location for that
species max girth, height, spread so it could automatically update for every
tree of that species without any work at all, since it is is recording all
the data for each tree. You could have a function that goes down the list
automatically finds the largest for each of the three values and stick it
in the storage box for that tree which the percentage boxes would then make
their calculations based off of. You'd have functions to grab this for
state, region, location type etc. and then other telling which to use.
actually this msg is getting garbled i don't have time to be coherent now,
back to work.
RE: Standardized tree hypervolumes - Weighting Parameters   Paul Jost
  Jan 24, 2005 18:18 PST 


I never liked spread since it assumes nicely symmetrical trees. It
penalizes trees with asymmetrical crowns. It usually doesn't tell you
anything about growth potential since trees shed branches too easily.   
BVP once mentioned using the length of the longest branch. If we needed
to add a third dimension to the scoring parameters, then I believe that
the third dimension of longest branch is probably the fairest. Also,
the longest branch measurement is as easy to make as the height and
girth measurements, while spread may be difficult to make on steep
grades or on trees overhanging rivers. Spread on a line through a tree
trunk is also more prone to error to those not careful in their
measurements due to the fact that the measurer uses his opinion and
perspective to assume the axis of greatest spread. Average spread then
takes the spread of the axis at a right angle to the axis of the
maximum spread. In a large data set with many measurers, it is just
too sloppy of a measurement to consider of equal weighting to girth and

As far as 100 vs. 300 points go, who cares - it's all relative anyway.
But the advantage to a 100% scoring system over a 300 point system is
that you can take a preliminary measurement without spread and see where
it lies. Most of us may never take spreads on the majority of trees
anyway unless we find that it's score warrants fine tuning due to it's
large size. Otherwise, large trees missing one dimension will be too
far down the list in a 300 point system. This has been one of my pet
peeves on the AF scoring system.

Paul Jost
Parameters - Max Crown Spread or Longest Branch   Edward Frank
  Jan 24, 2005 19:02 PST 


Question(4): What should we be using to measure crown spread: Average
crown spread, maximum crown spread, or longest branch?

Paul Jost suggested the following: "BVP once mentioned using the length of
the longest branch. If we needed to add a third dimension to the scoring
parameters, then I believe that the third dimension of longest branch is
probably the fairest. Also, the longest branch measurement is as easy to
make as the height and girth measurements, while spread may be difficult to
make on steep grades or on trees overhanging rivers."

Bob Leverett stated in a previous post: "It's my understanding that we
would be using maximum spread for a tree instead of average spread. How
does that impact your thinking about the 300 point system? If we were to
use weights, do you have a feel for how they should be determined to do
justice to volume?"

Average crown spread is a different concept than longest branch or maximum
crown spread. Much of the existing data may be in the form of average
crown spread, but we could dig out a longest branch approximation for many
of them. The biggest are remeasured frequently and could be redone using a
revised measure criteria. So this should not be an overwhelming factor.

Ed Frank

Re: RE: Will's WAY COOL proposed new system- 300 vs. 100 points   Jess Riddle
  Jan 24, 2005 20:17 PST 

I often think of ENTS tree measuring as investigating the potential of
different species, and I believe several others have placed measuring in
the same context. From that perspective, this new point system makes
great sense. Keeping potential in mind suggests that we use all ENTS
measurements not just the greatest current dimensions of known trees; that
is, we should use historical data. That view also supports updating the
reference values continuously to best reflect the species' known
potential. That process would diminish the value of posting old trip
reports on the website, so I'm not nearly as firm in my position on this
point. If the list were updated with each new record, that event would be
a fairly common as evidenced by six new records in one day recent day of
measuring in the Congaree.

A 300 point system seems a significantly more useful format than a 100
point system. Reduced intuitive appeal has been cited as the main
drawback of the 300 point system, but no one on this list has requested
further explanation of how the 300 point system world work and it seems
unlikely that the system would remain perplexing to anyone after a moments
consideration; the 100 point system may be more intuitive, but the
difference is too small to cause any real difficulties. On the other
hand, the 300 point system does provide some unique flexibility. We have
little spread data for many species, so if we add the height and girth
percentiles for those species we essentially have a scoring system out of
two hundred points. Looking at those score would immediately reveal that
one dimension had been left out whereas with a 100 point system how much
data had contributed to the point score would be unclear. The 300 point
system would be analogous to the use of the Wisconsin School statistic or
Importance Values where three percentiles are normally combined to obtain
a value but the frequency value may be omitted if only one plot is used
and a note is simply made that the scores are out of 200. Anyone more
familiar with those systems feel free to correct me, or elaborate if that
is incorrect.

I'm still undecided on long branch vs. no spread vs. long spread; however,
if spread is used I would argue for long branch or maximum spread over
average spread. Again, either of the latter two dimensions relay
information about the structural potential of a species while average
spread obscures the raw data.

Having something to refer to the point system by rather than "300 point
system" would be nice. Hyper-volume doesn't appeal to me since I keep
thinking of hyper as a prefix, and that meaning does not apply well to
this use. Also, volume is not actually being measured, so that term could
easily be misinterpreted. Alternatives include percents of potential
scale (POPS), relative maximum dimension score (RMDS), or some other name
using percent, relative, maximum, or potential. Don't know if score or
scale should be kept on the end or not. Fortunately, that concern is
relatively trivial.

Jess Riddle
Re: RE: Will's WAY COOL proposed new system- 300 vs. 100 points
  Jan 24, 2005 22:01 PST 

  On the other
hand, the 300 point system does provide some unique flexibility. We have
little spread data for many species, so if we add the height and girth
percentiles for those species we essentially have a scoring system out of
two hundred points. Looking at those score would immediately reveal that
one dimension had been left out whereas with a 100 point system how much
data had contributed to the point score would be unclear.

   Personally, I don't really care much whether 100 or 300, since it is the
exact same
thing and 300 isn't something pain in the neck weird like out of 967.8,
although 100 seems a little
bit more natural since it has been normalized to a more natural mode for
our typical base 10 way of thinking.
But it's a very minor point, maybe 300 sounds bigger and more grand, maybe
100 sounds like perfect score, I don't know.
I don't see that your arguments make all that much sense though in
supporting either 100 or 300, a tree might be
70%,75%,40% for a 170% total and another might easily be 80%,95%
for a 175% total, so I don't see how this 300% system automatically reveals
whether one aspect has been left out or not, here both are below 200 AND
the one with only two
components is larger. Sure, in many cases if it has less
than 200 it would mean that, but I don't think it would be all that uncommon
for it not to either, it would be entirely unreliable way to tell at a
snap, although perhaps trees of such low triple
points would be rare (but then again a forest tree might have low spread,
big but not tops girth and decent height and often apear less than 200).
Also, with the 100 points then you just look if its under 66, same as
checking if its under 200. So whether you add the three (two)
together or add the three together and then divide by 3 (2) they both seem
equally easy and clear. OTOH, if we tracked all three, but very or mostly
only used 2 in the end, then 200 is more natural than 66 to deal with, so
that might favor the 300 system since there would be less converting thigns
back and forth, although then again if we deal mostly with out of 200 could
make the 200 a 100 and the few times you use 300 make that out of 150.
Jess weighs in
  Jan 25, 2005 03:57 PST 
Thanks for weighing in on the alternatives. Your writing is crystal clear. You've done a service for the less numerically focused on our.
   Even though, I support the 300 point system slightly over the 100 and am partial to the longest limb slightly over the longest spread, we shouldn't rule out some weighting umtil we've applied the formula to lots of trees. I'm presently comparing 16 white pines in New England on all 3 systems: the proposed one, AF, and ENTS Points. From my perspective the new system is a slight improvement over the other two for reasons that are as subjective as objective. More to come on this topic.
Re: Jess weighs in   Lee E. Frelich
  Jan 25, 2005 06:28 PST 


I agree with Jess. 300 points is more honest, since it tells you right
away that three factors were used, and for those trees where you only have
2 measurements, you can compare them using the 200 point scale. This is
probably the reason that most indexes based on multiple factors, such as
the plant abundance system I explained in a previous e-mail, use 200 or 300

The longest limb is probably the best measurement to take for purposes of
comparing big trees.

I take the crown radius in several directions and use elliptical formulas
to calculate crown area, since I am usually interested in area occupied by
trees in different age classes. However, that is much more detailed data
than necessary for big tree comparisons.

Random thoughts on measuring and formulas   Robert Leverett
  Jan 25, 2005 06:32 PST 


   The unprecedented burst of e-mails on where to take the measuring
game has been music to the ears of those of us who have been wanting to
see us have a good debate on the subject for a long time. This morning
John Knuerr and I discussed the direction we seemed to be heading and
John made the observation that ENTS is in the business of collecting raw
measurement data on trees using sound techniques and then making the
data available for the portrayal of results for any number of purposes.
John is absolutely right. We are about the processes of data collection
than about achieving a particular end result. Science, big tree beauty
pageants, and historical documentation all fit the bill, provided we
collect enough data.

   From our growing base of raw data, we can compute all kinds of scores
and indices and array them for a variety of potential purposes. For
instance, in comparing two trees with an eye toward crowning one an
overall size champion, we also are inclined to stray into troubled
waters. We too calculate composite tree scores based on a single
compromise formula. And we observe over and over that the results are
entirely unsatisfactory for a substantial percentage of comparisons.
Given the impossibly varied forms taken by trees, this will always be
the case. However, if we expand our measurements by taking circumference
at the base, at the traditional 4.5 feet, and another at 6.5 feet if
tree shape allows, height at the major branching point, maximum limb
length, average radial crown spread, total height, number of trunks,
number of major branches, etc. we can make a variety of meaningful
comparisons. We may reach an overall conclusion that one tree is bigger
than another or we may not. But the data will all be there and available
to mull over ad infinitum. We lse no detail, disguise no features. So
John's reminding me this morning that ENTS is in the business of
collecting accurate data and making it available for a variety of
presentation purposes and anaylses really does speak to our mission.

   Contests will always be fun and there is no harm in us having a tree
ranking system of our own, of building a slightly betetr mouse trap - so
long as we don't take it too seriously.

Re: RE: Will's WAY COOL proposed new system- 300 vs. 100 points   edward coyle
  Jan 25, 2005 06:57 PST 


I have been thinking about this nonstop since its idea was brought forth.
Many probative questions have been raised, and this is great! I believe we
are on the verge of having a universally usable, and comparable, dimension
relativity index.
I will list my thoughts, for what they're worth, regarding some of the ideas
put forth.

I favor using maximum spread.
Though this may give some edge to field grown specimens, many examples of
forest monarchs could be given. Combining field and forest grown does not
present a problem for me. Using max spread, as opposed to longest limb
extension, might better show species potential, rather than a forced, errant
branch. Either method used does not indicate canopy mass, or volume
potential. Neither does averaging a perpendicular crossing. It is only for
max spread potential, one of our index criteria.

I favor using the 300 point scale.
We use three measurements, and always have, to obtain a size ranking.
Beyond that application more involved measuring is needed, and beyond the
scope of the index. Examples, volume, biomass-to whatever extent, etc.
The weighting of the three variables is best done by applying 100% to
each. How can applying a handicap to one aspect of three, more indicate the
value of that measure? It cannot.
There is no more accurate way to judge relativity than by using the
maximum example known, not 60% of that value, for example.
Surely, if one can understand a percentage of 100, a simple combination of
three of these should present no difficulty. Reducing the three to a single
number does not change the tree, but it is an unnecessary step. Perhaps it
is a matter of perception. I clearly understood how Bob L's sycamores rated
for the Northeast, better I think, than if I had a single 89% number given.
Maybe too, it is because I look at every tree in three dimensions as a
matter of course.

Historical measurements.
ENTS measurements should be our base. That would include past ones, ie.
Boogerman. Species potential does not change due to physical breakage.
Though they are undoubtedly related, we have an accurately measured 207'(~)
tree as a max height value.

Ed C
RE: Jess weighs in   Robert Leverett
  Jan 25, 2005 07:07 PST 


   Taking it one step further, in the data we present, I think we should
always present the raw data, never just the end score. Then other
calculations can be readily performed.

   Back in the middle 1990s when Will Blozan, Jack Sobon, and I were
working on "Stalking the Forest Monarchs - a Guide to Measuring Champion
Trees", we experimented with a couple of techniques to compute average
crown spread. Shooting the spread from the periphery to the trunk as a
system of radii taken at intervals of perhaps 45 degrees was my
favorite system. From those data, minor and major axes can be derived
for purposes of crown area as well as average crown spread. Then looking
for the single longest limb adds that additional piece of data about the
growth potential of the particular tree.

   Oh, but that's a lot of measurements to take and not apt to be done
on every tree - at least not by me. I know myself pretty well. So it has
occurred to me for ENTS purposes, we may want to identify three classes
of trees: (1) special ENTS trees that we measure fully, (2) a second
class that we measure partially, and (3) other trees. Any thoughts along
those lines?

RE: RE: Will's WAY COOL proposed new system- 300 vs. 100 points   Darian Copiz
  Jan 25, 2005 07:18 PST 


Although I was a previous proponent of a 100 point system, the arguments
for a 300 scale are very good - particularly that it is more honest, and
reflects three measurements.

I agree with Ed on the max spread being used over a single branch.
Otherwise a tree with one single very long branch could beat a tree with
a large, uniform canopy. Of course a tree could also have two very
long branches that just happen to be opposite each other with no other
branches, but that seems highly unlikely and even if it was the case it
would still be a pretty impressive tree. Also, I don't know if it's
actually so, but I think a tree growing in the forest would have a
better chance of competing with an open grown tree if the max spread is
used rather than an average spread.

There was one name for the index that had a particularly beautiful ring
to it: "Magnitude of Massivity", although I don't think it was
necessarily the most accurately descriptive. I think the word
"potential" and similar could be important.

Point System Spreadsheet   Edward Frank
   Jan 25, 2005 11:04 PST 


I have posted a spreadsheet compiled by Bob Leverett showing the rankings
using various point systems for some select trees from the NE to the ENTS
Website. I have links to the spreadsheet on the ENTS index page, Newest
Updates page, and on the Measurement page, so you should be able to find it.

January 25, 2005

Measuring and formulas   John Eichholz
  Jan 25, 2005 12:39 PST 


I have been reading these emails with interest and finally have some
time to contribute. First I would like to state that I favor the 300
point percentile ranking, or more accurately, any number of percentile
rankings scaled to the maximum (ENTS recorded) measurement available.
It seems to me each measure should be reported separately, then
combined. The spread measurements are less likely to exist for most of
our historical data and probably future data as well, simply because it
it more time consuming and less intuitively important. Perhaps thinking
about spread is taking us into the arena of modeling or diagramming? I
am reminded of the beautiful drawings made by Bob Van Pelt. Surely if
we are interested in maximum limb or spread we are going to appreciate a
well composed photograph or scale drawing, to see the mechanism by which
the tree achieves its score. But that sets the bar too high for casual
measurements or or site surveys. I guess the longest limb is an honest
metric in that it is absolute. But, are we to take the reading along
its length, or along the ground? Are we interested in canopy area or
mass of wood? This adds another twist to the multiple stem discussion,
as each stem could be considered a limb in its own right.

The percentile scale ranking has interested me from the start. I first
used it when comparing Mount Peak measurements to those from Mohawk
Trail State Forest. I found most instructive the comparisons of
rankings by species. I was able to see which species excelled at my
site, and which lacked, even though I could tell the overall index was
lower. When I saw Mount Peak Shagbark Hickory at 97% of MTSF, I decided
to keep studying the site! From an ecological standpoint, the age class
is another important variable. The 120' white pines at Mt Peak are only
55 years old. What percentile of 55 year old white pines do they fall into?

Another thought that comes up is the need to have a widely available
master list, like Colby maintained, of the reported maxima by species
and region. Without this, none of us will be able to accurately report
the percentile scores with our raw data. The Rucker indices by site are
a ready starting point for site based height maxima. Until we canvas as
heavily for girth as we have for height we probably can't say with
certainty much about the site based percentile scores there. (Although
the global maxima may well have been found out on the AF lists.)

As for the circumference/ basal area discussion, from a data collection
standpoint I feel we should freely collect girth at whatever heights we
wish, as long as the height of measurement is reported and the 4.5'
measurement is included if possible. If we have enough girth
measurements for a tree, we begin to allow for modeling of the volume of
the trunk in a meaningful way. What sequence of girth measurements
would be enough to get a good feel for the trunk volume?

We ENTS have such an important role to play in documenting our forests,
it is great to see such a lengthy discussion about what they mean and
how to best do it.

Ruminations on scoring systems...   Don Bragg
  Jan 25, 2005 13:11 PST 

I'm not sure my first posting of this made it, so here it is again
(sorry if it is redundant)...

Some ruminations about the recent discussion on the new scoring system
for big trees...I would presume the ENTS records would still maintain
the individual measurements of diameter/circumference, height, average
crown spread (or whatever measure of crown size), rather than just the
ENTS score.   Thus, it would be possible to calculate any of a number of
indices using this raw data, including the AF bigness index, or one
scaled on 100, 300, 1000, etc.   I have always been partial to
percentile scaling, probably because of years of experience with school
grades.   Obviously, any of the systems could be converted from one to
another using a simple multiplier. All that I would ask is that the
final system make more intuitive sense than that used to evaluate
quarterbacks in football, where a "perfect" or maximal score is
something funky like 158.3.   Call my vote as a lukewarm one for the 100

I would also say that retaining past tree data (if known to be accurate)
is more appropriate than constantly changing what is supposed to be a
maximal dimension with whatever trees we happen to find. "Shrinking"
champions would not be as informative as the long-term body of
information.   That is why I would also suggest keeping as many of these
records in the database as possible, but identifying them with a column
that indicates alive versus dead. I would also recommend keeping as
many of the live big tree records in the dataset as possible, even if
they are not that close to champion size.   From a research perspective,
the more information available, the more useful the dataset.

The arguments about crown spread (longest branch, average spread, etc.)
should not necessarily be couched as reflective of crown volume, and
hence a further direct indication of tree size. Crown length is also
vital to determining crown volume, especially for many species with
pronounced apical dominance.   This is particularly true of some of the
tallest conifers in the western U.S. (e.g., Doug-fir), that can reach
extreme heights without producing a wide crown. They maintain their
massive biomass by spreading their crown vertically along their extended
stem, rather than reaching out horizontally.   Eastern analogs would
include most spruces and firs, which have a large amount of crown
biomass in a narrow form. Simply including crown spread would fail to
recognize the vertical dimension of crown volume. Measuring crown
length would also require determination of which aspect of this
attribute to include (first live branch, or continuous crown, etc.), but
these could be use to calculate a basic estimate of crown volume
directly that may be much more relevant to total tree dimensions.

I would guess that at some point, a consensus should be reached that
identifies which parameters are to be measured, establishes acceptable
protocols, and these should be posted as the requirements for inclusion
on the ENTS lists. We should not rush to judgment (good or bad) on any
of these aspects, lest we fail to adequately describe the trees in the
most appropriate manner, and thereafter institutionalize a flawed
process.   It would be most difficult and awkward to try to change the
process decades down the road, as AF has to face. After all, we also
need to consider that our records of tree measurement should set the
standard and be as valid to researchers and tree lovers in 2105...

Don Bragg

Research Forester
Monticello, AR
RE: Ruminations on scoring systems...   Robert Leverett
  Jan 25, 2005 13:27 PST 


   Valuable post. I agree completely that there should be no rush to
judgement and posting the raw data is a must so that any number of
indices can be calculated. Your point about the verticality aspect of
crown development is a good one. Food for thought. I wonder what are Lee
Frelich's and Bob Van Pelt's thoughts on this.


Re: Ruminations on scoring systems...   Edward Frank
  Jan 25, 2005 15:30 PST 


I would like to say a few words in favor of average crown spread. I really
think the purpose of a big tree formula is to represent the tree as it is.
There has been alot of talk about the longest branch or maximum crown
spread as an indication of the potential for the tree. The big tree
formula should be about the actuality of the tree being measured, rather
than it's potential. Average crown spread is the best representation of
the size of the crown in a particular tree, not longest branch or maximum
crown spread. It may be more difficult to measure, but is most

Don Bragg talked about how some trees have a narrow crown spread but a long
vertical component to the crown. This is true, and by comparison these
species will suffer in a regional compilation including a variety of tree
with a broader crowns.

However for determining the largest tree of a particular species, the
comparison are between examples of that species. Small crown spread to
small crown spread, like to like. The number for a particular tree is a
percentile of the largest of that species. A strength of the proposed
system is that it works no matter what the shape of the tree for
comparisons within a species.

Ed Frank
Re: Ruminations on scoring systems...devils advocate   edward coyle
  Jan 25, 2005 16:46 PST 


Don't take offense, but I must play the devils advocate on this. The max
crown spread, or an averaged crown spread, show only 2 or 4 points on a
trees crown. They really tell nothing of the form, condition, or volume of
the canopy. What the measurements are is a linear measurement to define
crown width. Why would this measurement be averaged, when the other two are
not? We go for the highest sprig, not the average of the three top sprigs.
To be fair, I understand the rational. In my mind, there is no difference in
either...except, the longest measurement is diminished when averaging. I
would prefer to keep the maximum width, and add it to the other two

Ed C
RE: Ruminations on scoring systems...EXCELLENT   Will Blozan
  Jan 25, 2005 18:08 PST 

Well said! Great discussion and comments!

For big tree lists, crown length would not be needed, but would certainly be
a feature to track, but one that I personally will not generally gather data
on. Also, considering we have, when all compiled, 5000+ ENTS measured trees
in the database, virtually none of these will have canopy length data. We
can start, but what for? The proposed ranking system is not an attempt to
calculate volume of the tree or canopy. Models such as these can be derived
as BVP has done, but is beyond the immediate scope of a simple and fair
rating system. Maybe I am missing something... It would be cool to be able
to predict the height of a tree based solely on the lowest branch height!

I do like the idea and the thoughts behind it.

RE: Ruminations on scoring systems... CROwN SPREAD   Will Blozan
  Jan 25, 2005 18:08 PST 


Honestly, crown spread has always been the last thing on my mind since the
AF formula trivialized it to the point of "why bother". We do not take an
average crown height or an average girth at various points so I see no
reason right now to "muddy" one of the three dimensions.

I'll think more on it...

RE: Standardized tree hypervolumes - RESPONSE TO PAUL JOST   Will Blozan
  Jan 25, 2005 18:24 PST 



"Also, the longest branch measurement is as easy to make as the height and
girth measurements,"


" while spread may be difficult to make on steep grades or on trees
overhanging rivers."



Enough capitals! Will
RE: Point System Spreadsheet   Paul Jost
  Jan 25, 2005 18:34 PST 

I was wondering how the spreadsheet would score the trees on a national
scale with our all time reliably measured limits. Does anyone know our
ENTS verified greatest eastern white pine dimensions other than the 207'
height record?

I've measured forest grown pines up to around 17-19' in girth and one in
northwestern Wisconsin to about 20' (although only about 60' tall - a
real freakish wind blown taper from 40' to the top.) I haven't measured
a lot of pine spreads but think that I have them up to 40-50'. I have
to dig through some old boxes in the attic to get to the real
numbers.... what does the database show?

Paul Jost
RE: Standardized tree hypervolumes - RESPONSE TO PAUL JOST   Paul Jost
  Jan 25, 2005 18:51 PST 

Actually, a branch length would be measured from one spot. Move with
the clinometer to a point directly beneath the end and then use the
rangefinder and clinometer to calculate the range times the cosine of
the clinometer angle to the bark collar.

The real problem with spread measurements or longest branch measurements
is that to take them accurately, you usually need to spend a lot of time
taking many measurements to accurately determine the longest branch and
even more difficultly find the greatest spread. Most people would take
shortcuts and just measure one or two points that appear to be the
greatest spread. Spread is the most subjective measurement in the
database and the most likely one to be mismeasured and diminish the
quality of the database. Girths and heights are relatively easy to
measure quickly. Few people with spend the time to correctly measure
spread. I agree that I'd rather just not take the spread measurement
into account for the score for that reason. It should be taken only as
extra data for future use but not included in the score. 

Even, if it is
determined that spread or longest branch are going into the score, I
still will not measure it on any tree that isn't near championship
status or part of a study plot. I have just too much territory to cover
and too many trees to measure in places that are too far away to return
to frequently -- and I'm not getting any younger. That is a primary
reason why I prefer the 100 point scoring system. On a 300 point
system, you can't tell if a tree is a medium sized tree with 3 data
components or a large tree with 2 dimensions recorded. Most of Will's
trees won't show up on the list either since only height and girth are
recorded for most of them. A 100 point system will allow trees with
only 2 dimensions recorded to be fairly represented. To be truly fair
and consistent, the third dimension shouldn't even be considered in the
score. Save the three dimension scoring for study plots where there is
adequate time to properly obtain all the data required.

Paul Jost

Re: RE: Point System Spreadsheet   Jess Riddle
  Jan 25, 2005 18:53 PST 

Those circumferences are impressive. I've never seen anything like them
in the southern Appalachians. In the southeast, the largest I know of is
15'3" cbh.
RE: Ruminations on scoring systems... CROwN SPREAD   Edward Frank
  Jan 25, 2005 19:16 PST 


We measure girth at a particular arbitrary point on the tree at 4.5 feet.
It is not the maximum as it is measured above the root flair. It is taken
at a point that fairly represents the best and highest circumference of a
tree. Height is a discrete characteristic of a tree, not really something
to be averaged. Crown spread is something different. It is not a single
entity like the trunk. It is made of a composite of all of the branches in
the tree at varying heights. It includes large branches and small of
varying complexity and lengths.

I think cbh and maximum height are fair representations of those aspects of
the tree. They are characterized by individual measurements representing
discrete elements of the tree. Crown spread on the other hand seems to me
to be more of a composite characteristic. I think that simple measuring
the longest branch (from the base of the trunk) or even the maximum crown
spread is a misrepresentation of the crown of the tree.

Average crown spread doesn't "muddy" one of the three dimensions. It is a
fair representation of a more complex part of the tree. With dozens to
hundreds of branches involved in the canopy, selecting a single longest
branch to represent the whole, gives a distorted view of the crown
structure. I understand that we are not attempting to model the tree
structure. However it is still not right to use an inappropriate number to
represent an aspect of the tree simply because it is a bigger number.

I cetainly will be willing to go with whatever parameters and formula that
is determined to be best by the group. I do want to make arguments to
everyone so that they may be considered before a final decision is reached.

Ed Frank

Re: Ruminations on scoring systems...   Jess Riddle
  Jan 25, 2005 19:18 PST 

I completely agree with the ideas you base your arguments on, but I reach
different conclusion. I believe most people using the term potential are
referring to the potential of the species rather than the potential of an
individual tree. Even if a tree were allowed grow till the end of its
natural life without any storm damage, anything from soil conditions to
what species grow next to it could prevent an individual from approaching
the maximum dimensions of the species, the species potential as best we

I also strongly support measuring the tree as it actually exists;
consequently, I favor longest branch or max spread over average spread.
The average spread of a tree is a value calculated from two measurements
of the physical tree, one of which is the max spread. One could calculate
the average spread of a tree without ever knowing which two limbs produce
a spread of that length. Conversely, the maximum spread and longest
branch are each a direct measurement of a physical attribute of the tree.
Paul Jost's arguments for not placing any more emphasis on measuring
spread than we already do sound reasonable to me, so this discussion may
be trivial anyways.

Jess Riddle
Paul's caution to us and the ENTS Olympics   Robert Leverett
  Jan 26, 2005 05:31 PST 


   Your caution about dropping the spread dimension from the point
system is certainly one we've all considered. As you know, ENTS Pts
doesn't use spread. Trunk circumference is considered a surrogate for
spread, however calculated. It is food for thought. And while we are
brainstorming, for purposes of comparison, I've often wondered why we
don't move farther up the tree to take a circumference measurement. BVP
once told me that he needed to get as high up the trunk as he could
reach to get a better idea of trunk taper. That 4.5 feet corresponds to
breast height on most people and is therefore convenient to quickly
popping a tape measure around a trunk an reading of the result might
have more than just a little to do with the use of 4.5 feet.

   The question is where would we stop in terms of including new
measurements. We I could easily see the following as a minimum.

    1. Circumference at 1.5 feet to capture basal area
    2. Circumference at 4.5 feet to allow comparisons to other systems
    3. Circumference at 6.0 feet to get a better handle on trunk taper
    4. Height to point of major branching or to the first conspicuously
large branch
    5. Full height
    6. Length of longest observed branch
    7. Average trunk to crown spread by the radial method

   Of course, we wouldn't collect all the above measures on each tree,
but how efficiently can the measurements be taken for trees of major
interest to us? Good question? Well, as soon as this miserable weather
(ugh, toasty warm weather by your and Lee's experiences) lets up, maybe
the Mass-Eastern NY A-team can hit the ground measuring. We can time
ourselves on getting different combinations of the above. Uh, oh, is
this the introduction of a time factor to measuring suggesting of real
competition? Okay, how about a tree obstacle measuring course set up at
Cook Forest, with qualified judges watching to insure that the measures
are actually being taken. Of course! It would be the start of the ENTS
Olympics. OMG, with long-legged fellows like Will Blozan and young
whipper-snappers like you, Dale, Scott, and Jess, I'm in a heap of
trouble. Gotta have a system of handicaps for old geezers like me and
Howard. Course, I'm a young fellow compared to Howard. Right Howard?    

RE: Point System Spreadsheet   Robert Leverett
  Jan 26, 2005 05:36 PST 


   It looks like you hold the girth record for the largest white pine.
For purposes of including an absolute maximum, what might your number
be? BTW, where you find the huge pines, are they extreme rarities, or
are there lots of big trees in the vicinity, e.g. lots of 4-foot
diameter trees, with the occasional 5 to 6-foot diameter tree? I guess
I'm looking to understand what kinds of averages are to be expected in
places known for individual giants.

RE: Ruminations on scoring systems...   Lee E. Frelich
  Jan 26, 2005 05:46 PST 


I usually measure the heights to the base and widest part of the crown as
well as total height and crown radius in several directions. That way I can
use 3-D ellipse formulas to estimate crown volume, although I have not
found that to be as useful for characterizing forest structure over large
stands as crown area.

RE: Point System Spreadsheet   Paul Jost
  Jan 26, 2005 05:59 PST 

Well, the MacArthur pine was 17.5' in girth when accurately measured as
a champ in the distant past and was slightly larger when I measured it
before it was likely burned down by vandals.

There also was a comparable one the I measured crudely to over 17' with
no bark remaining while falling off the dangling roots over what was a
riverbank before it washed out. It was the national champ in the early
1970's on the Little Carp River near Memenga Creek in the Porkies so an
old AmFor book should have accurate girth numbers.

It was just downstream from the recent Porkies national champ which was
at or just over 17' (the ENTS group measured the recent one, too Bob,
and it's in the recent AmFor book.)

The ~20' one no longer exists and I measured even more crudely since I
was without measuring gear while deer hunting as an 18 year old. It was
about 3.5 tight hugs with my 6' wingspan, so that number can't reliably
be used.

I can up the real numbers when I find my old notebook - which I failed
to find in my last attempt last night. I've got a few more boxes in the
attic to go through tonight.

Paul Jost
RE: Ruminations on scoring systems...   Paul Jost
  Jan 26, 2005 06:05 PST 

Lee, Bob, et al,

You may do the additional measurements, but probably only in study
plots, right? When you were with me, we only did heights and girths,
the same as Bob or Will when I measured with them. We all shrugged off
suggestions at taking spreads whenever anyone mentioned it. Spreads and
additional measurements were only seriously considered for use on
prospectie champs and future use in study plots. How many of the trees
in the ENTS database have any spread data? This scoring system should
be applicable to the entire database for proper usage and an improved
score used on enhanced data from study areas in the future phases of
ENTS. For now, we are still scouting for prospective study areas for
the later phases of the ENTS mission. So, really, only the two variable
formula is applicable now.

Paul Jost
Crown volume and area   Robert Leverett
  Jan 26, 2005 06:13 PST 


   I presume that total crown volume correlates pretty well with trunk
cirumcerence. Given the lateral squeeze on tree crowns from competition,
how well does crown area correlate with crown volume? I'm struck by Don
Bragg's reference to the startegy of Doug-fir to increasing the
photosynthetic material of conifers. I've seen hickories that seem to
mimic the conifer system. I'm often struck by the narrowness and
verticality of hickory crowns.

RE: Ruminations on scoring systems...   Lee E. Frelich
  Jan 26, 2005 06:44 PST 


Yes, the detailed measurements on tree crowns are only for study plots. I
don't think most ENTS are going to measure these attributes for large
numbers of trees.

Re: Crown volume and area   Lee E. Frelich
  Jan 26, 2005 06:49 PST 


Yes, crown volume is well correlated with cbh and with crown area within
one species and within one region. Within the Porcupine Mountains, you can
predict just about everything about a sugar maple tree just knowing either
its crown are or cbh. However, when you compare sugar maples in Upper MI
and northern WI to those near Paul's house in southeastern WI, there is a
big difference. Sugar maples in southern WI have much bigger crowns than
trees with the same cbh in the north. That is a common pattern--trees
develop narrower crowns in cooler climates and high latitudes.

thoughts on spread   Darian Copiz
  Jan 26, 2005 08:35 PST 


Perhaps this thread is on pause, but I have been thinking about spread
measurement and just wanted to post my thoughts before I forget them.

Measuring Longest Branch:
I like the idea of measuring the longest branch of a tree to the branch
collar. It is appealing to know what the potential maximum for a single
branch of a particular species of tree is. It would then be interesting
to compare this to other trees of the same or different species. This
measurement would also give a good indication of the potential maximum
spread of the tree. However, there are problems with it. A single
branch may not accurately depict how wide the overall crown is. Some
trees have strongly arching branches that look like an extended tree
stem. It could be difficult to determine where the branch actually
starts - I'm thinking Black Walnut and Elms. Additionally the actual
length of the branch would not be measured, but the horizontal distance
from the base of the branch to the tip of the branch. This brings up
the question of what the intended measurement is - potential branch
length, or potential horizontal spread.

Measuring Longest Spread from Base:
Some of the difficulties in measuring a branch could lead to just
measuring the maximum horizontal distance from the trunk base. This
would be appealing as far as determining how far a tree can grow out
from it's base. One benefit of this would be that trees that are
strongly leaning would then be partially compensated for not having as
great of a height. However, strongly leaning trees could also be
misrepresented as having a very wide crown because it would imply that
the theoretical maximum spread of the tree was twice the longest spread
from the base.

Measuring Longest Spread:
By measuring the maximum spread of a tree it solves the problem of crown
misrepresentation due to leaning and measures actual maximum spread
instead of theoretical maximum spread. However, it could still
misrepresent overall spread, although not as much as the previous two
methods. Another problem is the measuring difficulty.

Measuring Average Spread:
The average spread would give the best indication of of the tree's
crown. However it would not indicate what the potential maximum spread
of a species is. As has been stated by others, if maximum height is
being measured, why not maximum spread? Of course it could be said that
dbh is not the maximum trunk diameter, but then again it is also
standardized at a given height. Average spread would also be the most
difficult to measure.

My personal favorite is maximum spread, at least for an index of maximum
potential. I think it would be unfortunate not to include the spread in
the final score. However, the difficulty in measuring and the lack of
this information for previously measured trees definitely seems a
problem. I sure don't know the answer.

RE: thoughts on spread   Robert Leverett
  Jan 26, 2005 10:09 PST 


   One of the advantages of my OptiLogoc laser is that it will measure
the distance to a target that is as close as 4 or 5 feet. For a tree
that is fairly accessible, I can walk around the tree at the periphery
of the crown and shoot distances to the trunk. The analogy that comes to
mind is taht of creating the spokes of a bicycle wheel, except that the
spokes are different lengths because the rim is shaped more like the
extensions of an amoeba than a circle. At any given spot, with the
clinometer aimed upward, you can move forward or backward until the
outermost extension of the crown at that point is at a 90 degree angle.
Hopefully, as you circle the tree, you can spot the greatest horizontal
crown extension and include it as one of the spokes. This method can
then be used to create a graphical portrayal of the projection of the
crown in shadow form. It allows for the calculation of average crown
spread to trunk - as opposed to through the trunk and to the other side
of the tree.
    On rare occasions, I've successfully used this method. Limitations
abound in cities and towns where tree crowns extend over structures or
you suddenly find yourself in the middle of traffic with people honking
their horns at you and casting aspersions on the marital status of your
    Where there's a will (and a Will) there's a way. In hunting for the
most extreme examples of a species to better understand its genetic
potential in varying environmental conditions, there's no such thing as
too many measurements. We need lots of direct measurements of ideal
trees so we can establish factors to use when dimensions can't be
obtained such as when in-forest conditions obscure the limits of a crown
   In terms of calculating branch length as opposed to horizontal
extension, so long as the branch isn't to crooked, you can use any of
several trigonometric methods to calculate length. Line yourself up with
the branch so that you, the tip of the branch and where it grows out of
the trunk are in a straight line. Shooting distances to the end of the
branch and its point of origin and shooting the angles to the tip and
point of origin sets up a situation to use the law of cosines to compute
the branch length. I'll draw a diagram on an Excel spreadsheet and pass
it to Ed Frank. Here, I'm speaking of a well-behaved branch that doesn't
curve to the side.


ENTS Big Tree Formulas   Edward Frank
  Jan 28, 2005 09:11 PST 


Another weekend is here, so perhaps people will again be interested in
continuing the discussion on Will's proposed big tree formula. This is a
summary of the questions to be considered, with a brief note on some of the
arguments. I am trying to be fair to all sides and trying to make sure
everyone gets their viewpoints considered. Please post any additional
concerns to the discussion list.

Will Blozan on Jan 22 presented the following proposal: "I want to present
an idea I have discussed with Bob L. in the past, and it is a system that
reflects Paul's desire for a relative score. It is also independent of
units, but is variable as new maximums are found and does not allow for
inter-specific comparisons unless superimposed upon an absolute maximum
"base"... With an existing database (ENTS) a set of maximums of girth,
height, and spread are established. The maximums are given a rating of 100,
which represents 100% of the known maximum." He goes on to explain that
for each tree a percentile rating for each of these three parameters would
be calculated in which the dimensions for that particular tree would be
represented as a percentage of the maximum size for that species in the
database. The sum of these three percentiles would then represent the
trees total points out of a possible three hundred point total. This is
also known as a hypervolume rating.

The proposal generated one of the most active discussions in the history of
the discussion list. Most people liked the basic premise and discussions
relate to details of its implementation. There are a number of points that
have been raised in these discussions.

1) Do we want to include height, girth, and canopy spread in the formula,
or do we just want to include height and girth? The premise is that many
of our tree measurements only include height and girth, and some have
questioned the utility of canopy spread in the overall size calculation.
There is a spreadsheet published on the website that illustrates the
different rankings generated in a sample set of 24 white pines using these
two options. I have links to the spreadsheet on the ENTS index page,
Newest Updates page, and on the Measurement page, so you should be able to
find it.

2) Do we want all three parameters - height, girth, and crown spread to be
given equal weight in the final formula? If they should be weighted
differently, what weight should each be given.

The argument in favor of doing so include the idea that by giving them all
the same weight the formula is more shape independent than similar formulas
from AF and others. Overall it is a simpler, more straight forward system,
and more elegant in its implementation. It may be more ecologically
representative if all are given the same weight.

There are arguments in favor of weighting the parameters differently. Some
question the value of the canopy spread component at all, and would limit
it to tie-breaking or eliminate it completely. Height is viewed by many as
a more critical dimension than the other two in determining the biggest
tree. It can be pointed out that using the base formula in which all
values are equal, the Boogerman Pine, the Longfellow Pine, and the Seneca
Pine, the three tallest trees in the dataset, rank 7, 9, and 11
respectively using the base formula. The sample spreadsheet shows the base
calculations, and has a column in which height is given a 2x weight in the

3) Should we have two ratings, one based upon 2 parameters - height and
girth - and a separate rating based upon height, girth, and crown? If we
choose this option should the parameters be weighted to force a similar
ranking between the two measures (in this case one example would be h + g,
versus 2h + g + c)?

4) Should we use the historical maximums from ENTS measured trees or the
current maximums? The prime example is the Boogerman Pine which was
measured at 207 feet, while its current height is about 187 feet. Most
people have seemed to favor historical maximums.

5) If we use crown spread as one of the parameters, should we be using
average crown spread, maximum crown spread, or longest limb length (as
measured by horizontal distance from the base of the trunk - I assume).
This has received a great deal of discussion. Please refer to the old
posts sent to your computer, on the topica website, or posted as a thread
on the ENTS website.

6) Should we be using a three hundred point system ( or 200 if canopy
spread is eliminated) or should everything be converted to a 100
point/percentage system?

Many people feel that a 300 point system is a more honest representation of
the fact we are using three parameters in the calculation. Other people
feel that a 100 point system is simpler to understand and would allow trees
that have been ranked using different numbers of parameters (2, 3, or more)
to be directly compared. Please refer to the spreadsheet to see how the
rankings change whether two parameters or three parameters are used in the
calculation. Overall either option can be converted to the other with a
simple multiplier of 3 or 1/3.

7) What would be a good acronym for the formula(s)?. It can be basic like
HG Rating, and HGC Rating to something more complicated like standard
hypervolume index total.

8) Should the database maximums be updated continuously or on a longer
term basis? Note that percentages higher than 100% are allowed in the

9) How does this new formula affect the idea of ENTS points calculated by
multiplying the girth in feet by the height? This formal is still valid
because it is calculating something different. In essence the bigger the
tree, the larger the overall number. The question is whether we want to
keep using this formula or not?

Many of you have expressed opinions on some of these matters already. If
you have additional thoughts on these issues, have changed you mind, or
have more points to consider. Please post them to the discussion list.
Please try to explain why you have a particular opinion as that lets the
rest of us understand your thinking.

Ed Frank
Big Tree Formula - My Preferences   Edward Frank
  Jan 28, 2005 09:13 PST 


These are my preferences for how this formula should be calculated. I have
went over many of these ideas in greater detail in previous posts.

1) Do we want to include height, girth, and canopy spread in the formula,
or do we just want to include height and girth?

I want to have a both basic formula including just height and girth, and an
expanded formula including all three parameters. Most of our measurements
include only two parameters, our basic formula should consist of just those
parameters, and an expanded formula for trees for which we have more data
including all three parameters.

2) Do we want all three parameters - height, girth, and crown spread to be
given equal weight in the final formula? If they should be weighted
differently, what weight should each be given?

3) Should we have two ratings, one based upon 2 parameters - height and
girth - and a separate rating based upon height, girth, and crown? If we
choose this option should the parameters be weighted to force a similar
ranking between the two measures (in this case, one example would be h + g,
versus 2h + g + c)?

In the basic formula height and girth would be given equal weight. In the
expanded formula I would use the formula [2(h) + g + c]. I think that
height should be the most important factor in a big tree formula. In this
scenario height is weighted as 50% of both totals. The rankings generated
by the two parameter formula and the three parameter formula above are much
more similar than they are if the expanded formula has all three parameters
weighted equally. I will admit that I am also drawn to the idea of
weighting all three parameters equally.

4) Should we use the historical maximums from ENTS measured trees or the
current maximums?

Historical measurements for maximums should be used if they have been
measured accurately. In a table with historical data the height for white
pine would be the historical height achieved by the Boogerman Pine at 207
feet. Present trees, including the Boogerman itself at it's present
height, would be compared to this historical maximum.

5) If we use crown spread as one of the parameters, should we be using
average crown spread, maximum crown spread, or longest limb length?

I would like to see the parameter for the crown to be the greatest
horizontal spread from the base of the trunk of the tree. Yes, this might
give slanted trees an advantage, but it is the most straight-forward
measurement of crown size even given these possible exceptions.

6) Should we be using a three hundred point system (or 200 if canopy spread
is eliminated) or should everything be converted to a 100 point/percentage

I still favor converting the final result to a simple percentage/100 point
number for the tree. It is a more basic representation of the relative
size of a tree than a 300 point or 200 point system. It would also allow
direct comparisons to be easily made between evaluations using either 2 or
3 parameters. However, overall either option can be converted to the other
with a simple multiplier of 3 or 1/3.

7) What would be a good acronym for the formula(s)?. It can be basic like
HG Rating, and HGC Rating to something more complicated like standard
hypervolume index total.

ENTS HG Rating (for height and girth) and ENTS HGC Rating (for height,
girth, and crown). Perhaps they do not make up a fancy contrived word, but
they are descriptive. A Blozan Index and Expanded Blozan Index would also
be appropriate.

8) Should the database maximums be updated continuously or on a longer
term basis?

I would favor the database maximums not be updated any more frequently that
once a year, and preferably on a longer rotation. Values greater than 100%
are perfectly valid, and I believe it would give the results a greater
utility to have a longer time period of stable base numbers.

9) How does this new formula affect the idea of ENTS points calculated by
multiplying the girth in feet by the height? This formula is still valid
because it is calculating something different, the bigger the tree - the
higher the ENTS points. The question is whether we want to keep using this
formula or not?

I have no opinion on this matter.

Edward Frank
Tree Dimension Index   edward coyle
  Jan 28, 2005 10:27 PST 


I have taken a break, looked everything over, and remain bumfuzzled.

It seems the open grown/ forest grown combining presents no difficulty,
with the proviso that open grown be noted. Since most of our trees are
forest grown, it makes sense to mark the exception only.

3 point, or 2 point dimension rating index

Here's the thing. Most ENTS measurers don't take spread, of any kind, for
most trees. The big ones of every species usually get a more thorough exam.
I suspect this is a holdover from nominating/comparing to other lists.
Whatever the motivation, data beyond height and girth are great for all
sorts of reasons.

Although I am in favor of the 3 point index, it can't practically be done
for every tree. As well, the data can't be used in conjunction with a 2point
index on a common list. Many of our trees, already recorded, have only
height and girth. Do we dump all these, or revisit every site to homogenize
the data? No. It is simpler to adopt a 2point system.

So perhaps we should adopt a 2 point dimension rating index. It allows for
seamless continuity in the records we have. The raw data could still be
compared against the greatest known height and girth known (200%, 100%?).
Further, we could gather more information for the champions of every
subset (region, state, site). It could include max spread, lowest limb
height, terrain, condition, orientation, associated species, gps grid,

I think historic ENTS measurements should be used- 207'height.

Update the list yearly, I guess. I don't know too much about spreadsheets. I
assumed the raw data would remain with a particular tree, while the
percentile score would shift automatically, if a greater tree were added.
I would think waiting to change a years findings at one time would create
a monumental task.

ENTS points- no opinion, or use for them myself.

Ed C
Re: Crown Spread
  Jan 28, 2005 11:09 PST 

    The crown spread information in my database is weak. I often estimated crown spread. Very little information has been included about maximum limb length. Crown spread is the weak link. I have racked my aging brain to think up shortcuts for compiling acceptable canopy data and each time I have ended up abandoning whatever I was working on.

    Your summary of our point system discussions is very useful. Fine job as usual. I'll respond to you request for additional thoughts in a day or two.


Re: Tree Dimension Index
  Jan 29, 2005 10:15 PST 

How about those situations where you have a tree that started as a stump
sprout in a clearcut or became established in a pasture to become one of the
founding members of a patch of old timber.

I encountered a 56" DBH/14.7' CBH yellow poplar this past fall while
planning a timber sale in central WV. The tree broke into multiple stems about 15
feet up and the live crown extended over 70 feet in at least three directions.
Most dominant poplar trees in the stand were over 130' tall and the same
general area yielded a pitch pine that was 7.9' CBH and nearly 105' tall.
Despite the poplar tree appearing to have been a "pioneer" that became
established in a stone pile in the middle of a corn field in the early 1900's, it is
now in the middle of a stand of mature poplar and oak with many poplar trees
having a maximum size ranging between 7.8' and 10.5' CBH.....this tree and
several surrounding individuals were retained as "legacy" trees.

The unusually large spreading yellow poplar I encountered would have never
survived undamaged in an open pasture for as long because wind or lightning
certainly would have whacked it. I have seen hundreds of exceptionally large
poplars in pastures, meadows and fence rows throughout WV but the very
largest, especially open grown individuals have a largeness that is extremely
tenuous and tends to be a fleeting condition at best. The largest or maximum crown
spreads for individuals of several species might actually occur in the is just easier to spot monster crowns when they are in open spaces.

Russ Richardson
Re: Tree Dimension Index   Edward Frank
  Feb 01, 2005 19:02 PST 

I don't know which Ed you are talking to but I think the ideas you present
are worth talking about. Essentially there are two ideas: 1) What about
trees with a complex mixture of Open Growth and Forest Growth, and 2) Are
crowns really bigger on the Open Grown trees than on Forest Grown trees or
is that just an impression because we can see them better? I will hazard
some ideas and the real experts can pick them apart and enlighten us.

What is generally considered as an Open-Grown tree is a result of a more
anthropogenic activity than a natural origin.

A tree in an open area tends to increase girth rapidly when compared to a
tree in a like environment in a forest. You can see this by wider rings
formed by shade relief when an opening occurs near a forest grown tree.

Observations have tended to show that forest grown trees tend to grow
rapidly upward toward openings in the canopy or because of competition
with adjacent trees. This rapid upward growth is reflected in a tree form
that tends to be taller with a slimmer trunk. Once a tree reaches maturity
at or near the upper end of its height potential for an area, the upward
growth slows and the trees tend to gain girth. Even with a wide variation
in overall girth, it can be seen from plots of white pine in both Cook
Forest and MTSF that average girth increases with height and that the slope
of the increase is greater with greater height.

Overall then the main difference in shape between open grown and forest
trees is that at the same age forest trees tend to be taller and slimmer,
while open grown tree tend to be shorted and fatter. Observations suggest
that the open grown trees also have larger crown spreads for their height
than do forest grown trees. The rationale for this process is that
competition from adjacent tree limits the areal extent of the crown in
forest trees, while open grow trees are able to spread out to maximize leaf
area without being limited by nearby trees.

I don't know for a fact that this is true. I don' think we have enough
data in our database to prove or disprove this hypothesis. You suggested
that damage from wind, weather, lightning, and other factors serve to limit
the crown spread and perhaps the height of open grow trees, and that forest
grown trees might be able to retain a larger crown because nearby trees
help protect each others crown from similar damage. So really it is a
question about which is a greater limitation on crown spread: Weather and
like damage to open grown tree canopies, or competition from nearby trees
in forest grown specimens.

Mixed history trees: These are trees that are found in the forest that
have some characteristics of Open-grown trees. To have these open grown
characteristics, the tree must have spent a substantial period of time
growing in open conditions - I don't know how long 50 to 60 years? What
could be the origin of these open areas. There are several possibilities -
both natural and man-made. Forest Fires: A tree may have survived a
forest fire while its nearby competition was killed. With a head-start on
the competition the tree may gain several decades of open growth before
the competition catches up. Similarly a tree that survives a blowdown, or
a river side flood could have a naturally occurring period of open growth.
Man-made activities can also result in a tree of mixed origin. The tree
may have been left behind by selective logging. It may have grown by
stump-sprouting from a clearcut forest. It may have been a tree left in a
pasture for shade. It may be a tree left in a residential area. Or a tree
left behind after clearing for a whole variety of reasons. (Trees of good
size are often found in the bottom of sinkholes in the sinkhole plain area
of Kentucky south of Mammoth cave. The steep sided depression 20 to 80
feet across and 10 to 30 feet deep are areas that are not farmable so
trees are left behind on farms. They also serve as shade for animals, and
unfortunately as dumps fro garbage.) If the forest surrounding this
isolated tree grows it becomes part of the resulting forest - it becomes a
mixed history tree. This may be regrowth after clearcutting, regrowth
after a fire, old field changing into forest through succession.

How to distinguish these trees: I have a couple of examples to suggest,
and would like to hear other characteristics. Trees grown in the open from
early age may have branches or branch stumps near the base of the tree. In
forest grown trees lower branches are soon shed as the tree grows upward.
In open grown trees they can persist and grow to significant size. The age
distribution of the trees in the stand. Old growth forest stands will have
trees of mixed ages. There may be large numbers of late succesional old
trees, but interspersed throughout will be younger trees that have grown in
openings formed in the canopy by various natural processes. Forests may
also be very uniform in age, as would occur if there was a large scale
forest destruction from fire, a blowdown, or even logging occurred at one
time. Mixed history trees on the other hand would tend to be much older and
or larger than the surrounding forest. There will be a distinct gap
between the ages of these lone wolf trees and the age of the other trees in
the stand.

You can get a mixed history tree when an individual tree was left behind in
a recent clearing of a forest to create a pasture, or a housing
development. Only in this case the tree would have forest characteristics
- tall, thin trunk, high lower branches in an open setting. I don't know
how long it would take to add more open-grown characteristics in a formerly
forest grown tree. Some characteristics like large limbs low to the ground
likely would never be recreated.

Enough rambling for now... What do the rest of you think on this matter?

Ed Frank

Re: Tree Dimension Index
   Feb 01, 2005 20:04 PST 

You covered an awful lot of ground and provided lots of food for thought in
your post.

I have seen large trees that fit several of those circumstances you
described as possible points of origination and I think that the sole survivors of
forest fires or clearcuts could ultimately provide the largest total size
trees of several different species including red oak.........I think white oak
just morphs into a giant green ball given unlimited space but red oaks seem to
reach higher, even in the open.

RE: Tree Dimension Index   Robert Leverett
  Feb 02, 2005 05:47 PST 


   If you walk in forested areas thick with white pine, white ash,
tuliptree seedlings, you will see examples of trees starting out from
the beginning under intense competition. Nothing open grown about those
clusters. I've seen the same with sugar maple seedlings.

    The key to understanding tree form is to actively search for
examples of a species in all stages of development and observe how the
species responds to differing levels of release. Foresters understand
this aspect of tree growth very well, since much of what they do is the
manipulate light levels and competition to control the shape that a tree
takes on as it grows. Calculating the range of ratios of height to crown
spread for a species across the range of growing conditions for trees in
different age classes would indeed produce some interesting ranges. It
would be a real exercise in descriptive statistics. Eventually, we'll
have enough data to put together some interesting charts. I may take on
the cottonwood as a first species to track. Any ideas on experimental

Re: Tree Dimension Index, response    edward coyle
   Feb 02, 2005 07:23 PST 

Ed, Russ,

I didn't know which Ed either, and in truth, I didn't understand what was
meant. If a tree is surrounded by trees, even if they are significantly
younger, it would be forest grown. I would think that if the surrounding
trees were saplings, and the tree cited were a mature specimen, it would
safe to say it was open grown, provided there weren't stumps everywhere. I
don't believe it is that critical a distinction.
To be sure there are many suppositions that could be made when finding a
significantly larger tree within a woods. It might suggest a catastrophic
windfall, fire, or human infestation. Local history might easily shed light
on this. It is a forest grown tree. One of your suggestions, that trees
within a wood provide a buffer for each other, while at the same time
competing for every other aspect of their existence is well founded, in my
experience. Trees on the edge of cuts, through what was formerly dense
woods, will fall over or droop over for no apparent reason. They have not
developed any lateral strength. I understand that trees develop strength in
proportion to resistance they endure during development.
Your wolf tree(s) are different in that they began alone, branched fully,
and had much more area for roots. As the canopy raised, and if it kept up
with that growth, it would be a massive tree. The younger trees providing a
buffer after the main growth spurt.
The tree and roots cannot exceed each other. If the tree puts on a great
deal of vertical growth in order to compete for light, it cannot maintain a
lower canopy. It will shed branches from the center out, and from the bottom
up. The proportion of canopy to mass cannot change, or the tree will
decline. It will always outclass the surrounding trees, however, without
them it would likely fail.
The idea of leaving 'relic' trees after a clearcut seems foolish. A vista
bandage. Unless the tree grew as a loner to begin with, it doesn't have a
chance. If it did, it no longer has its buffer. It would make more sense to
me to save a 'relic patch', leaving the buffer, as opposed to waiting 15
years for one to grow. That's a long time to stand alone.

Are the crowns actually bigger by volume in relation to trunk in an open
grown? Probably. I suspect that it has more to do with a larger root system.
I would guess that if the ratio of crown to trunk were 20% greater, open
grown, it would be 20% shorter than a forest grown example, assuming all
else was equal.
If a tree is within a woods, it is forest grown, and supported. Part of a
system. If it seen in alone anywhere outside of a yard, it was probably
forest grown at some point, or will be. Should we have a class for yard/park
trees instead of open grown, or simply compare tree to tree, looking for the
greatest among them?

I'm done rambling.
Ed C
RE: Tree Dimension Index, response HELLO   Will Blozan
  Feb 02, 2005 19:35 PST 


The whole premise of the relative ranking system idea (we really need to
name this thing) was to have a system inclusive of all growth forms. A fat,
short and wide open-grown tree would score favorably as compared to a slim,
tall forest-grown tree of the same species. I am not interested in weights
or modifications. Apples to apples.

RE: Tree Dimension Index, response HELLO   Edward Frank
  Feb 02, 2005 19:53 PST 


In my mind the question was not so much about the ranking system as it was
a general conversation about how different tree forms can evolve - why do
you get trees in the middle of a forest that have many of the
characteristics of open grown trees, and how long does it take for forest
grown trees exposed by clearing activities to develop some of the
characteristics of open grown trees. I don't think the trees should be
separated in the proposed dimension index. But if people want to sort the
trees in the database for some reason with regard to open grown or forest
grown trees, and some people have expressed the opinion that this is a
worthwhile thing to do, then we should be able to do so.   Considering the
history of a tree when discussing how its form evolved is certainly a valid
discussion point. I may not be experienced enough to have the answers, but
I tried to frame the questions for the rest of you to consider.

Ed Frank
RE: Tree Dimension Index, response HELLO   Paul Jost
  Feb 02, 2005 20:02 PST 


I agree. Since we are normalizing against the maximums, we are
relatively form independent and scale factors would add human bias
beyond the balance of a pure average. As far as naming goes, since it
is really all about the percentage of the growth potential and could
have two or three variables, how about the PGP-2 index or the PGP-3
index. It is more intuitive than naming it after someone and it really
isn't a (hyper)volume although it could use three variables in the
calculation. As long as it is a 100% scale, the number of variables
isn't critical but should be noted.

Paul Jost
RE: Tree Dimension Index, response HELLO   edward coyle
  Feb 02, 2005 20:58 PST 


Sounds simple and fair.

Ed C
RE: Tree Dimension Index, response HELLO   Darian Copiz
  Feb 03, 2005 06:35 PST 


It sounds good that there seems to be a consensus on lumping different
growing conditions together. As Ed had said, comparing tree to tree. I
have noticed that there generally is a strong bias on the listserve
toward forest grown specimens and height (maybe because by others this
is marginalized?). I would be happy to see the preservation of
objectivity. Another possible suggestion for a name is IMP, Index of
Maximum Potential.

More on tree rating systems   Robert Leverett
  Feb 03, 2005 07:50 PST 


   Good points. There does appears to be a forest-grown bias. However,
that is in part a reaction to the inclusion of coppiced and
multi-stemmed trees in the champion tree lists. Most of us are as drawn
to the compelling forms of trees like the amazing Angel Oak as we are to
the towering Smoky Mountain tuliptrees. We just want to see the
individual measurements done correctly and sensible interpretations put
on the results of formula-based calculations. My personal preference is
to see where a tree falls on different evaluations systems. However, the
he new percentile the AF, and the ENTS points systems arrayed side by side
can create confusion for those looking for a simple result.

   Although others must speak their pieces, I do believe that the vast
majority of ENTS members are satisfied with dealing with the complexity
of tree forms on a variety of levels. In making comparisons, I like to
draw parallels to baseball. The many statistics compiled on baseball
players allow pundits to consider different aspects of a player's game.
Not many in baseball feel the need to adopt a contrived point-based
weighting system to compare players and pronounce one as the all around
greatest. Individual champions of home runs, batting average, etc. are
recognized though.

   In terms of performance in a specific area, such as home runs, there
was a temptation in the past to declare Babe Ruth as the greatest home
run hitter of all times. The Bambino's 714 life time total and his 60 in
a single season records looked as though they would stand forever. Then
Roger Marris, a very good, but not great hitter, broke Ruth's single
season record with 61, albeit in a slightly longer playing season, 163
games versus 154. Then Hank Aaron surpassed Ruth's lifetime total with
755. Still many people continued to proclaim Ruth the greatest overall.
Now Barry Bonds holds the single season best (ignoring steroids for the
moment) with 73 and is virtually certain to surpass Ruth's lifetime
total in 2005 and Aaron's lifetime total in 2006. In the popularity
department, Bonds now only has to sneeze to get another MVP award.

   Comparisons within the sports world have grown increasingly
sophisticated as a result of more data, more comparisons, and the
rapidity with which new data can be incorporated into the data banks and
comparisons regenerated. We are moving in that direction in ENTS -
although with almost complete dependence on poor Ed Frank.

   The continuing practice of crowning a single tree as an overall
champion of its species may have outlived its usefulness by diverting
attention from a broader assessment of each species and its potential.
Will's point about the hemlocks of the Porkies - giants in their own
right is well taken. What is truly most important is the focus we put on
understanding tree growth and potential. Champion tree lists, competing
formulas, form indices, etc. are merely the tools we use to keep the
focus on the objects of our affection.

RE: Tree Dimension Index - Tree Shapes   Edward Frank
  Feb 03, 2005 12:42 PST 


You are of course right about the dense growth of seedlings on the forest
floor. I have seen many examples. It was a poor choice of words, I was
thinking more along the line of openings in the canopy, rather than

I don't really have any suggestions for experimental design. I believe
that my proposal for using a ternary diagram to plot tree shapes would be a
useful graphical representation of differences in tree shapes within or
between species and would show changes in form with age.    The weighting
factors could be tailored for an individual set of data to better represent
the variation found within that set. Ideally the plots of individual tree
shapes would form clusters on the chart, or perhaps a band with trees of
differing ages and characteristics forming a progressive continuum across
portions of the graph.

Ed Frank