What can learn from our sites?   Robert Leverett
  Aug 25, 2002 11:08 PDT 
Colby, Will, Jess, et al:

    My next site to complete for the Rucker Index will be the Mount Holyoke
Range. Eventually, I'll get the Cobble Mountain Reservoir in Mass, the
Claremont pine site in NH, the Tamworth Pines in NH, and a few other sites
in New England that are small in acreage. New York holds enormous potential
as does Pennsylvania. In terms of travel, I can get to eastern New York fast
enough, but Pennsylvania presents logistical problems. Dale will likely
cover western PA and maybe be can collaborate on the eastern side of the

    Next year we should be able to get a good fix on Hartwick Pines and
maybe I can bribe Paul Jost and Lee Frelich with wintergreen creams from
Richardson's Candy Kitchen to assemble a list for the Porkies. When Tom
Diggins gets settled into his Ohio abode, maybe we can get a site or two
from him. I'm keeping my fingers crossed that Will Blozan will head to Joyce
Kilmer and lay to rest where that great site belongs on the charts. Of
course, it is no mean task to construct site indices.

    I'm sure we would all agree that computing these indices is is very
labor intensive. Does this place a practical limit on what we can do? Does
it matter? Beyond personal satisfaction for the few, can we contribute
knowledge valuable to others? Yes, we can - of several types. But we have to
get efficient in the way we cover sites or its all just academic.

    It should be apparent to all that I want to take the Rucker Index Mohawk
Trail State Forest to the limit accuracy and to do this I've had to become
increasingly systematic as I creep towards the upper limits. Without a
system, adding a few more decimal digits pushes me beyond the point of
diminishing returns. However, we are still able to progress satisfactorily
with the Mohawk model because we increasingly know where to look for each
species in terms of growth potential. We are in the process of separating
MTSF into key growing zones based on basic land form, aspect, altitude, and
some site history. The aspect and altitude are easy to determine. Site
history is scattered, but we have some. The land forms have been by trial
and error, but we're really starting to get there and it is here where we
are making our best progress. As of now, the land forms we've classified in
MTSF that significantly affect tree growth (and tree form) include:

        1. Ridge top environments where the land quickly slopes off on two
sides; i.e. a ridge crest.
        2. Plateau environments with shallow depressions and small hill
        3. Mountain/gorge sides:
            a. Concave with boulder field,
            b. Convex, including ridge backbones,
            c. Ledge environments with large benches,
            d. Ledge environments with small benches,
            e. Intermittant rock outcroppings,
            f. Sparse rock cover, lightly undulating surface form, wavy
across the ridge face,
        4. Saddles between peaks (can either be wind funnels or protected
        5. Old river terraces.
        6. Newer river terraces (closer to the parent rivers and usually a
lot larger).
        7. Toe slopes:
            a. Dropping to river or stream,
            b. Dropping to terrace.

    From the above land forms and using topographical maps, we can calculate
the acreage that falls within each terrain class and classify the forest
type(s) associated with each terrain class. For instance, terrain classes 1,
5, and 6 are where most of the white pines grow in MTSF. They grow in other
areas, but don't contribute significant habitat to impact the Rucker Site
Index. The tall pines grow predominately on terrain class 6. The more
acreage that falls in this class with trees in the 120+ year age class, the
more that the species can maintain its effect on the Rucker Site Index.

    Extrapolating this kind of thinking was what led to the table of
reapplied site indicies, updated below.

     1                132.23
     2                127.7
     3                125.38
     4                124.00
     5                123.5
     6                122.5
     7                121.4
     8                120.0
     9                119.08
     10              118.05
     50              112.50
     100            110.50
     200            106.90
     300            104.10
     400            102.70
     500            101.80
     1000            99.60
     2000            97.50
     5000            95.80

    Since each reapplication removes the trees used for that application,
the process does not mirror long term stability of the index, but rather the
depth of the tall tree populations. We wouldn't expect natural events to
remove all the members of each iteration. So, practically speaking over the
long term, what can we expect from the Rucker Site Index for MTSF? I expect
it to vary between 126 and 132.5 (the adelgid and the beech bark disease
will increasingly impact the index as they take out two species that help
maintain teh average.). The MTSF range for the Rucker Site Index represents
a maximum for the Berkshire-Taconic region as a whole. In terms of the past,
my 'guesstimates' may have been slightly conservative. A Pennsylvaina site
could have gone to 134. For New York, MA, etc. I'd still place 133 and the
upper practical limit, but admit to the possibility of a 134.

    Now, what might a typical site index range in the Massachusetts
Berkshires be today? Well, the Rucker Index will naturally be all over the
place because of the variety of site conditions and frequency and type of
land use history. A private site that has not undergone recent cutting
(trees are 65+ years old) can be expected to have a Rucker Site Index of
between 85 and 95 out of a potential of perhaps 120 for the good locations
or about 75% of potential. I would guess that poorly managed sites, in the
65+ year age range, will be down to around 60% to 70%. I may be way off on
these numbers and I don't know where the analysis will lead, but I would
hope that we could eventually establish some measures of good forest
stewardship out of them - more realisticly, interest those with the time,
qualifications, and resources to pick up on this type of analysis.

    One of the concerns I've had with the models of forest management that I
see discussed on these lists is that they seem to bring the age of the
forest down to around 60 years old. Even with the best of intentions, I
worry about that becoming the norm, if it hasn't already. Sixty years seems
to me to represent a gross underachievement, thinking like a forest. Where I
go, I see forests that are between 70 and 130 years of age that are
absolutely eye-popping. They are not old growth and my interest in them isn't
related to my OG interests. What I think I'm seeing happening at these sites
has practical applications. For instance, the Ash Flats forest averages
around 200 square feet per acre of basal area (46 sq meters per hectare) and
the Ash Flats canopy averages around 125 feet in height. In places it
exceeds 130. Individual ash trees branch at 65 to 75 feet above ground. They
are straight as arrows and would yield at least four 16-foot saw logs. One
tree I know branches at 80 feet. That's 5 saw logs. Ash Flats got to this
impressive state of development largely by being left alone for a hundred
years. It can now give us a baseline to use as a measure of natural
regeneration. That is a concept beyond the brains of most loggers, but it
should strike resonant chords with plenty of foresters.

    Going beyond Ash Flats, there are areas of MTSF belonging to terrain
classes 3a, 3e, 5, and 7b that could also serve as baselines for comparing
silvicultural success in areas of active timber management. By not
appreciating the value of these recovering forests and what they've produced
in periods of from 70 to 120 years, it seems to me that we are missing the
opportunity to establish natural baselines that aren't already skewed by
poor timber practices in the past. It is all fine and well to have
confidence in one's self that one is doing the right thing in implementing a
cutting plan to mitigate past damage. I realize that is a career in and of
itself, but isn't there a legitimate place for this other body of knowledge?

    If others with silvicultural experience were laying the heavy numbers on
to me, I'd be less inclined to believe that there was a knowledge gap around
rates and limits of natural regeneration. However, what I see as a reaction
to the fast growth places to which I take my friends with silvicultural
experience usually surpasses moderate surprise. That alone says a lot and
the knowledge to be gained at these sites isn't just a slightly different
twist to an already well organized body of silvilultural data.

    Before ENTS began scouring the old growth, big tree, and tall tree
sites, except for the places that had big neon signs in front of them, most
weren't on anybody's radar scopes. For instance, had I asked any of the
UMASS silviculturists about ash growth potential throughout its range, and
locally east and west of the Connecticut River, I would have either been
directed to general tree growth tables (it already happened) or would have
been met with blank stares (it too already happened). Now, shouldn't a
profession concerned with growing trees understand species minimums,
maximums, and averages at a local level where the knowledge can do some
good? Well, there is a gap in the silvicultural knowledge base that applies
to minimums, maximums, and averages for white ash, and other species as
well, that have been growing in areas that aren't being continuously
hammered. For instance, had silviculturists seen Ash Flats 30 years ago
would they have concluded that the trees there were about maxed out - based
on their experience with the species elsewhere? If they did reach that
conclusion, they would have been wrong. Very wrong. Isn't it important for
them to know that so they can tweak their growth models? Or is it better to
continue using outdated growth models and just argue the issue from some
aloof position, taking the assinine turf stance, which is a guaranteed route
to mediocrity.

    No, folks, there is very useful, practical knowledge locked up in the
growth history of the trees in MTSF, MSF, Ice Glen, and elsewhere that has
been obscured by a presumption that the volumes of data that already in
existence has answered all the revelant questions. Not by a long shot.
"Thar's gold in tham thar hills" and it exists in the form of tree growth