Maximum dimension list start    Jess Riddle
   Jan 25, 2006 19:26 PST 


The two times we have discussed the TDI (Tree Dimension Index, I'll
acquiesce on the name) the system met with general approval and a fair
amount of enthusiasm. If we want the system to move from simply a
good idea to an actual useful tool, we need to develop a list of
maximum dimensions. The system may eventually prove most useful on a
state level, but for the time being, I suggest we focus on using
national dimension records. That list will allow us to see how the
system functions in application and work out any bugs before we
develop a slew of state and other lists. I assume the reference list
will eventually reside on the website, but Ed Frank will need to
advise us on what will work best in that area and what he has the time
and energy to manage. In the mean time, I would be happy to maintain
and build the list as an Excel spreadsheet.

Before the list is posted in a public forum, we will need to resolve a
couple of issues. Lee Frelich recently stated, please correct me if
I'm misrepresenting your statements, that ENTS would be foolish to
informally and publicly present data that might form the basis for a
high quality, peer-reviewed article. Would that issue be a problem
with the maximum dimension list? From my fairly ignorant point of
view, that problem seems unlikely to develop if we include only
minimal contextual information with the measurements and explicitly
state that we should be contacted before the data is reused. However,
the list could function as a more accurate alternative to state and
national big tree lists, which are occasionally cited in scientific
papers. Which brings up the issue of competition or perceived
competition with American Forests. The system and list would parallel
American forests efforts, and consequently, might ruffle some feathers
there. I'm not sure how concerned ENTS is with that potential
friction. Even if those issues are major problems, ENTS can begin
using the list internally. I may be missing other issues. If so,
please bring them up for discussion.

I've tried to start on the list myself, and I've pulled all of the
measurements I've made that I think will be species records and put
them in a spreadsheet. The spread currently contains the following

Species: I'm currently using Latin names for this field for maximum
clarity. If you're unfamiliar with a species Latin name but know an
unambiguous common name, just send me the common name.

Record: This field indicates what dimension the tree is a record for:
"Height", "Circumference" or "Spread". Including this field will
allow us to sort the list to produce lists of record heights, record
circumferences, and record spreads.

Cbh: Circumfernce 4.5' above midslope listed in inches.

Height: Vertical height in feet.

Spread (Max). Maximum horizontal spread in feet. My impression of
the recent discussion on spread measurements was that the group leans
towards maximum spread, but that no strong decision has been made. We
may well want to change this field in the future, but using maximum
spread will work well enough for now.

Form: "Forest", "Intermediate", or "Open". This field may not be
essential, but including it will allow us to see if the formula favors
particular growth forms, although the relationship may be obscured by
our sampling patterns. That information will help us decide if we want
to eventually produce separate open and forest lists.

Site: A name of a local topographic feature, or in the absence of
nearby topographic names, the name of a nearby man-made feature.
Examples include "Clear Creek," "Ocmulgee Flats" and "Big Creek

Location: A large area encompassing many sites, and likely delineated
by an administrative boundary, typically larger than sites used for
Rucker Indices. Examples include "Chattahoochee National Forest",
"Great Smoky Mountains National Park", and "Altamaha River".

State: Postal Code abbreviation.

Date: date of the measurements used for dimensions.

Measurer: Any people involved in measuring the listed tree. I'm
currently using measurers' initials for convenience sake.

Note: Includes information on any champion status, if the tree has
since died or been reduced in dimensions, if a circumference was
measured at a different point, if circumference is not included due to
coppicing, and similar relevant information.

To clarify, each record (row) in the spreadsheet represents an
individual tree, and as many of that tree's dimensions are included as
known. If one tree holds multiple dimension records for the species,
the tree is simply listed repeatedly with only the "Record" field
changing. We can restrict the fields shown publicly if necessary. My
choice of fields (columns) to include may not be ideal, but should be
sufficient to get the system up and running. If I have omitted some
essential field or information that will greatly facilitate future
expansion, please let me know. I have tried to confine the fields to
information measurers have readily available.

I don't want to see this idea stall and the system never be into use.
Please contribute to the maximum dimension list, and help the TDI
system get off the ground.

Jess Riddle

Jess_Max List.xls The initial list from Jess of Species Maximums

Tree Dimension Maximum Spreadsheet in HTML format


Re: Maximum dimension list start   Edward Frank
  Jan 25, 2006 22:42 PST 


Your plan sounds excellent. If you want to post a spreadsheet on the
website, that can be done in a matter of minutes. Excel does export a
functional web page from its save menu that could be posted, but the size of
that file may be prohibitive.

For anything posted to the website, or accessible to the general public, I
would like to see a column listing a common name for each species, if there
is one from a standard public available field guide like Peterson's. I
think this is a must for people not having every latin name memorized like
many on the list appear to have done.

I am wondering, and this might be a stupid question, ENTS people have
measured thousands of trees. To what extent are all of these trees entered
into a single database? Are subset being maintained regionally, or what? Is
each tree in the database identified by a unique tree ID number or
designation? If so then there should be a column for the ENTS tree ID for
the trees listed, so that the data presented on your maximums tables can be
referenced back to the larger data set.

You have my full support in your efforts to make this concept come to
fruitation and email me if there is anything I can do to help..

Ed Frank
Tree Dimension Index   Edward Frank
  Feb 01, 2006 05:50 PST 

Last night Jess Riddle sent me a compilation of measurements he has gathered for use in the Tree Dimension Index. I would encourage others with tree measurement data to contribute to the listing. Initially the list will be for all species across the eastern United States.   If you have data to add to the list, such as larger dimensions for height, girth, or maximum crown spread, please send the information to me and I will compile it into the listing for the Eastern US. Please use the same format (same number of columns in the same order) used in the spreadsheet posted to the website for ease in compiling the information. The TDI uses maximum crown spread as one of the parameters. If you have a large average crown spread number that can be listed in a separate [Spread (ave)] column, but maximum crown is the preferred number.

I know Bob Leverett has been working on an ENTS database. Off-list discussions earlier this year focused on data format and similar mechanics. This database will eventually allow different people to maintain regional datasets in a common format that can be imported into the database. When this is up and running a query like this could simply be typed into the database and the information would be compiled. For now I am working on it by hand. Completion of the Database is rightfully at the top of Bob's list of ongoing projects.

Please contribute your data to this initial compilation of the maximum values for each species. The compiled spreadsheet format will have three rows for each species, one for maximum height, one for maximum girth, one for maximum crown spread (or average). Three lines will be used even if a single tree holds all three records. The individual maximum value will be highlighted in bold text in that row. In any future public posting information on specific locations will not be included on the posted list, but will be maintained in the actual maximum compilation.

Edward Frank