Useful Data   Robert Leverett
  Jun 04, 2004 11:19 PDT 


     The chatter about our impending research at MTSF has probably been
a bit much for those wanting to read about issues more relevant to their
situations. We want to include all ENTS members in the discussions, but
we've agreed among ourselves to move the back and forth chit chat into a
private e-mail stream. The ENTS list should be reserved for material of
broader interest.

     With respect to the current Mohawk project, I often worry about
what the results should be to justify the effort we're making. Given
what is happening to our native species, if our contributions find value
only as historical documentation, then for me, that is sufficient.
However, we will probably obtain results of practical value to the more
curious resource managers. Research results will provide us with
baseline indicators that we don't currently possess. For example, what
can we expect from natural regeneration on good white pine growing sites
at the 100-year mark and over? There is plenty of silvicultural data
collected for highly managed stands, but when it comes to natural
regeneration in specific locations like the Deerfield River corridor,
there are only the tables based on data from who knows where, collected
by who knows who, and actually representing who knows what? There are
lots of people with gut feels about growth rates, but perceptions are
all over the place.

      On state lands we have the Continuous Forest Inventory (CFI).
There are plenty of plots in the state forests that are periodically
monitored. Gary Beluzo knows the exact configuration. So far as I am
aware, CFI is the principal source of information about growth rates in
the public forests. I have seen many of the plots and know many of the
folks who do the monitoring. I have very mixed feelings about CFI and
its value. I have difficulty imagining how data from the plots I've seen
can give good pictures of the growing conditions in the areas they
ostensibly represent. I recall one plot on a dry ridge adjacent to a
mesic area. The difference in growing conditions couldn't be more
exaggerated. The ridge-side had been swept a fire perhaps 70 or 80 years
ago. Loss of top soil and the southeastern exposure makes tree growth
there now very slow. It would be classified as a very poor growing site.
However, fifty yards downslope from the last marked tree in the plot, a
terrace spreads out, covering about 4 acres. The ash growth on the
terrace is spectacular. In adjacent areas, tree growth is intermediate
between these extremes. So what does the CFI data from the plot tell us
about the general area? Well, maybe that was just an example of luck of
the draw. If the numbers from this CFI plot are dumped into a big data
pot and stirred along with hundreds of others, presumably, the averages
will work out, but work out to what? For what? I've seen other CFI plots
that are located in areas that are not representative of the surrounding
species mix or growing conditions, so I am skeptical that so much
unrepresentative data will somehow magically "average out" and do the
intended job of accurately conveying species mix and volume growth at
modest spatial scales. I see no point in applying data to an unusual
place like MTSF because it fits okay somewhere. Are we supposed to dumb
ourselves down to fit some very broad average?   

     BTW, tree height data are not being collected for these CFI plots,
just DBHs. Heights and volumes are presumably statistically derived from
radial growth. Very dangerous! We have documented ad nauseam the
problems associated with height measurements that use the percent scale
of clinometers with fixed baselines - the common forestry method. So,
can we assume that height data incorporated into existing volume models
suffers from errors associated with flawed measurement techniques that
vary with species - better for conifers than hardwoods. Yes, I think we
can assume that. Accurate volume determinations are highly improbable
from current CFI data fed to volume models. Nor do I believe that the
CFI data answers other relevant questions. None of the CFI data has
answered routine questions about MTSF's exemplary white pines.

     From a forestry perspective, I would assume that planners would
want to know the following about the Mohawk pines.

     1. Total acreage within identifiable age classes
     2. Standing basal area and volume within each age class
a. Percentage of basal area and volume by diameter class
b. Average number of stems by diameter class per acre
     3. Average growth rates in each age class
                        a. Radial
                        b. Height
                        c. Volume
     4. Percentage of each age class by volume of single-stemmed versus
multi-stemmed timber.

      At present, DCR may have rough board feet estimates, but nothing
more. So, developing truly tight stand-level baselines for the age
classes will provide DCR with plenty of practical information that they
don't currently have. So, this is presently my personal focus while
other team members focus on other aspects.

      One set of statistics I can develop fairly quickly is average
stand density, i.e. stems per acre. It looks like the average density
over an acreage of 100 to 140 acres is around 50. My present guess is
that the number of mature white pines in Mohawk lies somewhere between
3000 and 5000. There's about 2000 young pines. So the total number of
Mohawk pines lies between 5000 and 7000 - I think. It's a start.


Robert T. Leverett
Cofounder, Eastern Native Tree Society