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TOPIC: 3D tree profile graph
http://groups.google.com/group/entstrees/browse_thread/thread/0d5f7e1228310a9e?hl=en
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== 1 of 1 ==
Date: Fri, Jan 25 2008 9:31 pm
From: "Edward Frank"


ENTS:

Here is another idea that has been misplaced in the shuffle that should be revisited:

RE: Multiple Iterations of the Rucker Index Roman Dial
Jun 02, 2006 23:19 PDT

The recent discussions on the Iterated Rucker prompted me to try and
visualize what was being measured. Thanks to all of you for this,
although it seems pretty painful for many ENTS to revisit the topic!

Generally I like to visualize not just the *mean* of the tallest
specimens of the ten tallest species, but also the tallest specimens of
the ten tallest species lined up from tallest to tenth tallest, like
kids in a big family. In some sense this is a 2 dimensional bar graph
with horizontal axis representing the rank order among species and a
vertical axis as height. Now I guess the Rucker Index is the horizontal
line marking the mean of these heights.

What I would like to see is the data representation for the 10th
Iterated Rucker of a site (i.e. 100 trees?) as a 3D graph. It would
have the same height and among-species rank order axes as used for the
visualization of the Rucker Index data, with an additional
within-species rank order axis as well, giving the heights of the ten
tallest individuals of each species. Now I think that this is not
strictly the data of the iterated Rucker, but perhaps a subset, since
it might (maybe often?) happen that some 11th species shows up in the
2nd (or greater) Iterated Rucker as one of the top ten trees but isn't
among the top ten.

I guess that what I would expect of a "uniform, homogeneous, and smooth"
forest would be a gently tilted plane brushing the tops of these 100
trees arrayed from tallest to shortest in two directions. On the other
hand a very heterogeneous site might be convoluted and not planar at
all, maybe even rumpled. And a crude idea of the Iterated Rucker is the
series of horizontal lines that cut through the tops of the trees
parallel to the among-species axis.

If someone has these data -- the ten tallest specimens of the ten
tallest species at a given site -- I'd like to make (or see) a 3M bar
graph. I understand that these are not exactly the data used for
Iterated Ruckers (perhaps a subset), since it might (maybe often?)
happen that some 11th species shows up in the 2nd Iterated Rucker as one
of the top ten trees in the second rankings.

I also wonder if what we are usually doing with these indices is to try
and capture some of the beauty as well as a quantitative descriptor of
the forests. Has anyone tried making graphs like these already?

Roman Dial
RE: Multiple Iterations of the Rucker Index WAY COOL Will Blozan
Jun 03, 2006 09:25 PDT

Roman,

That is an interesting idea. I will plot some Smokies (heavily sampled!)
trees when I get some time.

Will

Re: Multiple Iterations of the Rucker Index Edward Frank
Jun 03, 2006 18:52 PDT

Roman,

It strikes me that this idea is something completely different from the
entire question of multiple iterations of the Rucker Index. It seems like a
worthwhile approach to pursue. As for data sets capable of performing this
function we actually have several. There is enough data from the Great
Smoky Mountains National Park, Mohawk Trail State Forest, and possibly from
Cook Forest. In any case data could be combined from several areas to create
graphs from broader regions.

I don't think that the numbers used in the proposed grid of ten trees from
ten species is necessarily critical. The graph could be expanded to include
more species than ten, or more examples from each species. There needs to
be some minimum number of data points to make the analysis worthwhile, but
the methodology could be applied to sites with less species or less examples
as well. As a graphical display it does not rely on a specific number of
samples processed in a particular way in order to generate a numerical value
that can be compared between sites, so comparisons between sites with
differing amounts of detail could be made.
This is more like a 3-dimensional tree profile graph.

Ed Frank