Maximum Dimension List  

TOPIC: Maximum dimensions list

== 1 of 2 ==
Date: Thurs, Jun 19 2008 12:33 pm
From: "Jess Riddle"


On multiple occasions, we have discussed compiling our own big tree
list. Colby Rucker produced the first incarnation of the inventory by
listing the tallest individual trees ENTS had measured in each state
of many different species. The format of that catalog was rather
awkward and it has become out of date, but the list has still proven a
valuable resource. Continuing frustration with the National Register
of Big Trees and a desire to implement the Tree Dimension Index system
for evaluating tree size have spurred additional discussions of an
ENTS' big tree list. These discussions have generated a great deal of
enthusiasm, but years later there is still no evidence that any
progress has been made towards producing such a list. The abundance
of talk and lack of action eventually frustrated me to such an extent
that I just compiled the register myself. Since I am trying to fit
this project into an otherwise full schedule, I may not be entirely
responsive to formatting and procedural suggestions, but I will always
gladly accept data contributions, more details below. I apologize to
those who had already volunteered to put the list together; I couldn't
see any progress that was occurring, and in the process of putting the
catalog together, I realized the compiler needed to be someone who was
already familiar with most of the records and knew about measurements
that had not been posted on the discussion list.

The first draft of the list is accessible at^^^^^^^^^^^, which is an
unlinked webpage. To compile the list, I went through all of the site
descriptions on the website and my own spreadsheets. I'm sure I
missed some trees, and for many others the site descriptions were
missing some of the basic information. Please help fill in those
information gaps; for instance, if the "form" or "date" field is blank
for a tree and you know about the tree, send me the information and
I'll update the list. If you know about a larger individual than the
one listed, please send in the information. Since I'm going to be
getting information from 25 different people (hopefully), the process
will be greatly streamlined if you send the information in a
spreadsheet with the same fields as the master list. Explanations of
all the different fields follow.

Species (latin): I have included only species native to eastern North
America. Since we are the *Eastern* Native Tree Society, they seemed
like a priority, and not listing exotics saved some time. If someone
else wanted to make up a sister list for exotics, that would be great.

Species (common): I need to reformat this column. Right now, sorting
by this column would juxtapose red spruce and red hickory rather than
bringing all the hickories together. Hopefully I'll get around to
that before too long.

Record: This field indicates what dimension the tree is a record for:
"Height", "Circumference" or "Spread". Having those options allows
the spreadsheet to easily be sorted to produced a maximum list for any
one of the those metrics. Spread data is generally lacking, so many
trees were included under maximum spread even if only average spread
data was presented. I think it's still open to debate whether we want
to use maximum spread or average spread.

Cbh: Circumference 4.5' above midslope listed in inches. If a second
tree were close in circumference to the largest, I also included it.
How I defined close was rather arbitrary. Since what elevation to use
as ground is easily determined for small trees and root flair does not
influence their cbh, co-records for small species were only included
if they had exactly the same circumference. For larger species, I
used up to about a five inch spread. We should come of with some more
formal rule for the inclusion of co-record holders.
Only single stemmed, non-coppiced trees qualify for circumference
records. When in doubt, I left a tree off the list. I think this
criteria must be applied stringently to avoid winding up with an
inventory like the National Register of Big Trees. Tracking the
maximum girth of coppices is fine; it's just a different list.

Height: Total vertical height is listed in feet with a two foot
spread for co-records. Only measurements obtained by rangefinder and
clinometer, climbing, or direct pole measurement are included.

Spread (max) and spread (avg): Maximum or average horizontal spread
in feet, respectively.

Form: Since competition can dramatically alter the size and structure
of trees, keeping track of whether the tree grew in a competitive
environment or not has value. The options for this field are open
grown, forest grown or intermediate. Separate circumference records
are included for open and forest grown forms.

Site: A name of a local topographic feature, or in the absence of
nearby topographic names, the name of a nearby man-made feature.

Location: A larger area potentially encompassing multiple sites but
with similar growing conditions. Locations would be the same scale as
areas we track Rucker Indices for. I've included site and location
mainly for internal use, so that we can keep track of which individual
trees are included in the list. For a publicly distributed version of
the list we could replace the "site" and "location" fields with a more
general "area" field that would list administrative units, such as a
national forest, or towns.

Date: when the listed measurements were collected.

Measurer: includes all individuals who measure trees who were present
on the trip when the measurements were collected. This field lists
measurers of the tree, not necessarily the people who located or
nominated the tree.

For this list to be worthwhile, we need input from everyone who has
measurements. For a group focused on trees but with a special
interest in tree measuring, a simple list of tree sizes seems like the
most basic and logical project for the group. If we don't produce a
list this fundamental, I'm not sure why we would expect to become the
leading source of information on tree sizes. Please help ENTS achieve
this basic goal.


== 2 of 2 ==
Date: Thurs, Jun 19 2008 2:32 pm
From: Josh

Thank you, Jess! I just got lost in that spreadsheet for about half
an hour. Including trees that have the maximum recorded combination
of height, girth and spread would also be great. It's nice that you
are making some time to post this summer. I know it probably won't
last into the fall semester, but it's great to have you chime in from


== 2 of 10 ==
Date: Fri, Jun 20 2008 5:03 am


We owe you one, buddy. This was the step that was needed to be taken and you rtook it despite your course load. It is up the the rest of us to support the efffort.


== 3 of 10 ==
Date: Fri, Jun 20 2008 6:33 am
From: "Will Blozan"


You must be commended on this excellent jump start to the ENTS Maximum
Dimension List. It makes sense for you to have done the effort since you are
in close contact with a large portion of the measurers in ENTS who have
found the tallest specimens- you being one of the key players.

I would like to try to come up with a "name" or designation of our list
perhaps beyond "Maximum Dimensions List". People are familiar with the
"National Register of Big Trees" and we could have a similar title. Since it
is not just a list of big trees it may be a bit trickier. I think it should
denote "eastern" and "maximum" somehow. A stand alone title that is
descriptive is a must. I'll throw a few ideas out:

"Eastern Register of Tree Maximums"
"Maximum tree dimensions of eastern trees"
"The ENTS list of tree maxima"

OK, it is harder than I thought...

I also want us to consider the consequences of posting our hard work
spanning over a collective century of top quality work to just anyone. Of
all our ENTS members it is a miniscule fraction who has supplied the data on
the list so this doesn't concern everyone necessarily. But truthfully, the
data are a resource that could be swiped and integrated into a "notch on the
belt" study by unscrupulous "scientists". Think of that horrendous growth
potential "study" done some years ago with "data" taken from the NRBT list.
Who would have thought Michigan would have the tallest trees?

I am admittedly possessive of the work I have done for ENTS since its
inception, especially that of the Tsuga Search Project which cost me dearly.
I very well may be way off base but it is a concern to me. I am not against
the mission of ENTS touting the best of the east and the best information
and techniques possible but the release of such a huge body of work that
anyone could be free to do whatever with sends up a flag. The data we
collect is a goldmine, folks. I think we should guard it but allow
"withdrawals" to those we deem credible. Yet, I have no idea how to do this
or if any of you agree.


== 5 of 10 ==
Date: Fri, Jun 20 2008 10:27 am

While I haven't any entries, I would think that there would be some concern about accessing this database, as there has been about other ENTS' databases. I agree that a general location would be appropriate (although anyone reading this thread would have a head start on locations).
I'd also suggest that the measurer's entries should include what level of equipment/accuracy was employed in determining the maxima.
While the vote count is still out on crown spread determination, my thinking is that it's the volume (say what would be enclosed were the tree to be 'shrinkwrapped') of the crown that creates the 'maximum' impression' and the formula that most aptly measures that should be employed (considers height of crown top, height of crown bottom; breadth and depth (or radius, as appropriate). As part of the tree or site's description, mention of "open-grown" or "in forest" condition would be appropriate.

== 6 of 10 ==
Date: Fri, Jun 20 2008 11:00 am
From: Larry

Jess, Wow! Just looked at the Big Tree Listing, great job! Larry

== 7 of 10 ==
Date: Fri, Jun 20 2008 4:23 pm


I particularly echo your last suggestion, i.e. "As part of the tree or site's description, mention of "open-grown" or "in forest" condition would be appropriate.".


== 8 of 10 ==
Date: Fri, Jun 20 2008 4:58 pm
From: Gary Smith

Jess has the open grown/forest grown category on his list.

Regarding the buttressed conifers, I still struggle with the validity
of cbh instead of stem volume, but I suppose that subject has been
kicked around plenty already.


== 9 of 10 ==
Date: Fri, Jun 20 2008 5:18 pm
From: Randy Brown

I've found one of the best times to hunt is in the second half of leaf
drop after the ashes and maples have dropped. Chestnuts hold their
leaves longer like oaks, but the young ones at least have a finer
branching, limb pattern, making them stand out in the canopy and on
the forest floor or clearcuts (if looking for sprouts).

Technically this time of year when they bloom should be good too, but
that's presuming you can find one
with a clear shot at daylight. I don't hike that much this time of
year (I cycle) so I've never seen a native one flower.

== 10 of 10 ==
Date: Fri, Jun 20 2008 5:56 pm
From: "Edward Frank"


I would envision in the end having a spreadsheet with many more columns incorporating whatever detail we may have for a particular tree. This would be kept by one of the members, and perhaps accessible online with an unlinked and unpublished location known to perhaps ENTS officers and people involved in the measurements. A more generic list with less location information and the basic measurement details would be published on the website.

At this point anyone with measurement data needs to go over the listing Jess has prepared and send him any additional data you may have for additional species or larger or comparable sized specimens for species already on the list. I would send all of the relevant information, all of the measurements you have, including GPS if available. I would also like to see a column for a web address for any tree for which there is a trip report or photo on the ENTS website or other website. The fieldtrip addresses are pretty stable for the ENTS website and will continue to be so for the foreseeable future.

Ed Frank

TOPIC: Maximum dimensions list

== 1 of 1 ==
Date: Sat, Jun 21 2008 5:10 am


Stem volume is so difficult to calculate. That's basically why CBH is used as a kind of surrogate. As we all know, CBH can be misleading and misused, but very easy to take.


TOPIC: ENTS Maximum Dimension List
From: BVP
To: ENTSTrees
Sent: Tuesday, August 19, 2008 9:27 AM
Subject: [ENTS] Re: ENTS Maximum Dimension List


WOW! What an impressive list!. My hat's off to Jess for taking all
these numbers and compiling them into a single file. Well done!

I just had one comment. Max Spread. I do not feel that this is a
useful number. Max spread is an average of two branches. If you are
going to use an average, use one that is more representative. I
collect four crown radii on most trees. On trees with very large
crowns, such as a live oak, I collect eight crown radii.

A number I do feel IS useful, however, is the length of the longest
branch. This is not an average. This is a number comparable to tree
height, since it is based on the growth of a single appendage.

My two cents,

== 1 of 5 ==
Date: Thurs, Aug 21 2008 10:16 am
From: "Edward Forrest Frank"


I have also expressed in the past that I did not feel that maximum spread was a meaningful number, but my objections....

I also agree that longest limb is a useful measurement.


== 2 of 5 ==
Date: Thurs, Aug 21 2008 12:54 pm
From: "Will Blozan"

Ed, Bob,

I agree with the rational about max spread but I think it has value for
several reasons. It represents what the tree is capable of supporting in on
direction (same as in height) and it is a measure fairly easily accomplished
by most people. Max limb length is a good one and one I plan to collect.

Bob, in the Usis hemlock there is a limb extension out ~38 feet but it is
supported by the fused reiteration and as such would not be a representation
of the max extension of that tree if measured from the trunk. Would you

Will F. Blozan

President, Eastern Native Tree Society

President, Appalachian Arborists, Inc.

== 3 of 5 ==
Date: Thurs, Aug 21 2008 1:13 pm
From: "Edward Forrest Frank"


Max spread is not a measurement of what a tree is capable of supporting in one direction. If the tree had two really long branches and they were 180 degrees apart then the spread would be big. If they were instead 90 degrees apart and their opposite at 180 degrees was a shorter limb, then the max spread would be much smaller. The tree may have exactly the same crown volume, or crown area, and may have exactly the same maximum length of limb, but the value of the maximum spread could be drastically different. Two drastically different values for a single parameter could be obtained when characterizing what is essentially the same crown mass. It isn't measuring anything meaningful biologically or structurally simply the coincidence of two limbs on opposite sides of the tree.

Limb Length is a good idea conceptually, but I am somewhat perplexed about how to apply the measurement. Should it be measured from the branching point from a trunk? What happens when the trunk gets fatter? It could be measured from the center of the base of the trunk, but then what about leaning trees? Branches can branch from other branches - so from what segment should the initial starting place be measured?

I am thinking that the longest limb should be measured from the surface of the trunk where the series of branches and sub-branches begins. This is the point it becomes free supporting, and you do not need to interpolate where the base of the branch might have been been in the past. (You can see the ingrown inward ends of branches in hollow trees.)

BVP thinks that a branch that touches the ground is a separate category, I am not sure if they don't root, but in any case that could be noted.


== 4 of 5 ==
Date: Thurs, Aug 21 2008 4:51 pm
From: "Will Blozan"


A tree viewed mechanically is what I had in mind. A tree with a max limb
length of 80' may not physically be able to support a maximum spread of 160'
plus trunk width (opposing directions). Maybe so, but maybe not. It would be
interesting to survey a species and examine the max branch length and the
ratio of max spread. I doubt 100% (2X max branch length) would ever be
reached which suggests a structural limitation to me. For example in eastern
hemlocks we have measured a maximum branch (or combined structure) extension
around 38 feet. Yet, I doubt there is a single hemlock on earth with a 76
foot spread in one direction across the crown. If so, I would like to see it
and how it was done! That would be one gnarly beast!

I would tend to measure limb length from the point of origin within the
trunk but of course that may be hard to accurately determine so external
trunk/branch intersect is probably best. The inherent strength of the limb
is solely due to the intricate and really awesome connection of the
differing woods (and vascular system) of the trunk wood and branch wood. A
branch is independent both structurally and vascularly from the trunk wood.
They do not join but are separate parts amassed in a very strong lattice of
overlapping growth rings. (Man, if Keslick was still on the list he would
have a field day with this one.)

Trees rule!

Will F. Blozan
President, Eastern Native Tree Society
President, Appalachian Arborists, Inc.

== 5 of 5 ==
Date: Thurs, Aug 21 2008 5:21 pm
From: "Edward Forrest Frank"


Sounds good. You have found some use for the measurement, I will argue no more.