Tree Height Patterns   John Eichholz
  Nov 14, 2006 09:57 PST 


Here I am, but it is getting hard to keep up with Dale and Cook Forest.
How can he and his team come up with a whole point while we weren't
looking? Great work, Dale.

But seriously, if we are going to produce further improvements in the
data, we ought to structure it to allow analysis like Lee Frelich is

As our corps of tree measurers are aware, tree heights are maximized in
a very localized pattern. Overall, a forest can have many primo sites,
and in the vicinity of any tall tree are often several others of the
same species and sometimes of different species. Move away from that
tree a couple hundred meters and everything changes. In some cases, you
can move a few hundred meters more, into another high growth area, and
the pattern repeats. We gain a sense for where this will happen, but
not only are we sometimes wrong, but we don't know enough about what
makes a site support high tree growth.

One idea I am working with is to consider the local site conditions at
each area that contributes a tree to the Rucker index. In order to
support this research, I am delimiting the topo map for MTSF into
even-sized sections, using the UTM grids on the map. Those are 1km by
1km, there are 15 to 20 of them in the forest, and they could usefully
be further divided into 250m by 250m quadrants. On a first pass, most
of our contiguous high growth areas would each fit into one or two
quadrants. Many quadrants have high growth areas, but fewer quadrants
have Rucker iteration members in them. An initial project would be to
map as many trees from the top 25 iterations onto the grid system as we
can, then look for patterns. We can revisit an area to supplement other
data we have about a quadrant identified in this search. We can make
standard characterizations about the quadrant, and perhaps contrast tree
populations from other quadrants with similar characteristics.

This process of picking areas to go back to is one way I use to increase
the Rucker index. Right now I am looking at a cluster of data showing
high concentrations of tall hemlocks in the area of Black Brook/Cold
River confluence. The tallest hemlocks are located in or next to
streams, within 200' to 300' elevation above the main river. The
tallest trees are located where slopes are 35 degrees or less. While 40
to 45 degree slopes exist adjacent to these areas, mostly at higher
elevations, there is a 20' reduction in maximum observed heights in those
areas. Also present near the tall hemlocks are a significant population
of really nice Yellow Birch, including most of the known examples that
exceed 100' in height. Sugar Maple and to a lesser extent, American
Beech grow quite tall in these areas, but not to record heights. White
Ash does intermix with hemlock, but outside the hemlock areas it grows
much taller. Across Cold River but within sight, is the famous Ash
Flats, with champion White Ash and Bitternut Hickories.    

Of the top 25 hemlocks found, 9 occur in this area. 10 more occur in
the Trout Brook basin, and 4 near the entrance to the park. At least
80% of the tallest Hemlocks found at MTSF occur south of the Cold River,
and would probably lie within the boundaries of 9 quadrants (out of
60-80 total in MTSF.)

Another idea we are working on is time series measurements of selected
trees, to establish growth rates. We have some time series data for
MTSF, but it seems like only the beginning.


RE: Tree Height Patterns
  Nov 14, 2006 12:57 PST 


It just occurred to me that the one thing in common with the corps of tree
measurers (excluding climbers) is that the characterizations of the environment
they occur in, are for the most part ground-based. One of the more influential
determinants for tree height, I'd think, wouldn't be ground-based, but "top-
down", i.e., aspect exposures/topographic exposures/elevation exposures to the
airborne elements (wind events, acid rain/precipitative events, winter climate
extremes, airborne insect/pathogen exposure, etc.).

Some of these influences fall into the realm of Gary's GIS...analysis of
topographic shapes common to existing tall tree areas (eg, northern cove
exposures, lower third of slopes in valleys, etc.), and aspects (varies by
species, I suspect, could provide at least a coarse filter to narrow down


RE: Tree Height Patterns   Gary A. Beluzo
  Nov 15, 2006 00:51 PST 

John, Bob, Don, and all the ENTS,

Yes, GIS is very well suited for applying multivariate search models
(terrain, hydrological, soil,etc)to quickly eliminate large areas that
probably will (and probably won't) support tall trees. The software that I
run on my Dell Inspiron XPS laptop (ARCGIS 9.2) is capable of very
sophisticated 3D as well as 2D visualization, animation, modeling,
geostatistical analysis, geospatial analysis, and---- basically any analysis
that an ENT can dream up, we can write into a query algorithm, and run in
ARCGIS. GIS is great for developing derivative map layers, interpolating
topology, creating masks for map algebra, and superbly presently the results
to the public.

In terms of doing geoanalysis of TREES- the rate limiting step of course is
getting good positional data for a population. This would involve
establishing two or more good GPS benchmarks, determining the relative X,Y,Z
position of each tree to the benchmarks, and then applying a simple
algorithm to determine the absolute coordinates (lat/long or better yet
State Plane Coordinates). Sounds doable but to my knowledge no one in our
group has taken the time to do it yet.

I met with the College IT folks last week and they have made the commitment
to upgrade my ENVGIS lab at the College. We are going to purchase 15 power
PCs, color laser printer, and beefy server. We already have a full license
to ARCGIS 9.2, a 5-foot large bed inkjet printer, digitizer, etc. I have a
sabbatical proposal in for the next academic year so I would have the time.

Bob has suggested mapping the invasives at Robinson State Park as an initial
project. Once we have the invasives mapped we can do a host of geospatial
analyses. If snow limits hiking this winter, I'll be looking for other
project ideas..


Gary A. Beluzo
Professor of Environmental Science
Science, Engineering, and Mathematics Division
Holyoke Community College