South
Carolina Sites |
Jess
Riddle |
Nov
10, 2004 09:21 PST |
|
Bob Leverett wrote: In terms of the areas that you regularly
visit, what are your thoughts on the division sites and
sub-sites for the purpose of applying Rucker height, diameter,
and height/diameter ratios? I ask this question, not because I
can't infer from the detail you provide how you are
"seeing" the sites, but because I've been thinking
about developing the concept of breaking down the
politically-defined sites in Massachusetts into sub-sites, where
a variety of terrain types are represented. |
In general, I see little reason to breaking down the SC sites
into smaller
units. That position results from the fact that multiple
interfaces
coincide to naturally delineate most of the sites. For example,
at
Wadakoe Mountain, geology, topography, and forest type all
correlate well
to form the natural boundaries at the site. The corelations are
not
perfect as seen in the gradual transition of the forest types on
the north
and west lower slopes before the natural boundary of the cleared
fields is
reached. In that case, the field border defines the site edge
since
disturbance history, soil type, and topography all coincide as
the fields
only occupy the large flats along Eastatoe Creek, so the gradual
transition of the forest does not represent a significant
challenge in
defining the site. The mountain could still be subdivided on the
basis of
stream basins or one area that was likely farmed could be
singled out;
however, the similarity of topography, the distributions of
unusual
species, and extent of unusual geology cause me to still think
of the site
as a single unit.
Situations in the Brevard Fault Zone leave greater room for
flexibility in
determining site boundaries. The interface of a large plateau
and steep
slopes coincides with changes in geology and forest type to
precisely
define the upper edge of the sites. Since the soil nutrients
fueling the
high growth of the area appear to be derived only from bedrock
underlying
the steep slopes, the base of the steep slopes would seem like a
natural
boundary; however, the transition to the gentle slopes of the
adjacent
piedmont is gradual, and the downhill movement of material from
the steep
slopes results in a continuum of influence on adjacent soils. In
some
cases, resent human disturbance creates a clear edge, sometimes
coinciding
with the Forest Service property boundary, but for much of the
area, I
have been satisfied with an approximate boundary. The other
question with
demarcating the sites in the faults zone is where does one
section of the
fault end and the next begin. An extension of the plateau of
Station
Mountain separates Station Cove from the series of coves
surrounding
Tamassee Knob, so a physical barrier separates the sites;
however, the
sites are closely related in geology, similar in forest type,
and the
spatial separation is relatively small, so a case for either
distinguishing or grouping the sites could easily be made. The
Lee Branch
area, which shows a gradual trend in forest type along a
north-south axis,
is separated from Station Cove by a slightly large ridge than
separates
Station Cove and Tamassee Knob. The area is geologically closely
related
to Station Cove and the forest at the north end bears a strong
resemblance, but significant differences in the forest exist
even in the
most similar sections; Hence, I've generally treated the entire
Lee Branch
area as a separate site.
Individual coves present a convenient way to subdivide either
Lee Branch
or Tamassee Knob. Some argument could be made for that practice
in the
Lee Branch area on the basis of the apparent gradient in cove
richness
along a geographical axis. So far, I have not reported the site
in that
fashion since the transition between coves is gradual, so any
grouping
would likely be arbitrary. At Tamassee Knob, each cove has a
distinctive
mix of tree species and canopy height, but adjacent coves do not
vary in a
consistent fashion, so the area has not been subdivided.
Comparing
individual coves in the could present a somewhat controlled
method for
looking at the effects of aspect and degree on topographic
sheltering on
the canopy structure, but differences in area and species
richness could
obscure differences. The best argument for a subsite could
probably be
made for the largest cove in the area. The cove has a somewhat
different
structure, is at the mixed mesophytic end of the gradient of
forest types
present in the area, and has one of the few due NE aspects in
the area.
The cove could provide a good comparison to station cove due to
similarities in size, topographic sheltering, age distributions,
and
species occurrence patterns.
This is probably less general than what you were looking for,
but
hopefully enough similarities exist with MTSF to generate some
new ideas
to apply to that area.
Jess Riddle |
Re:
South
Carolina Sites |
Jess
Riddle |
Nov
15, 2004 06:27 PST |
|
Bob
Leverett wrote: Now to South Carolina? Jess, what
is SC's current Rucker index? How does it compare to:
(1) your best mounatin property, (2) Congaree? |
The Rucker Indices for the tallest piedmont site in SC, the
tallest
mountain site in SC, and the state of South Carolina are
followed by a
discussion of that Rucker Indices of superlative sites versus
the Rucker
Indices of their host states.
Species listed by first two letters of genus and first two
letters of
specific epithet.
Congaree Swamp NP
PITA 167.2 Pinus taeda = loblolly pine
LIST 157.1 Liquidambar styraciflua = sweetgum
QUPA 154.0 Quercus pagoda = cherrybark oak
PLOC 144.0 Platanus occidentalis = sycamore
TADI 141.0 Taxodium distichum = baldcypress
ULAM 135.0 Ulmus americana = American elm
QUMI 132.8 Quercus michauxii = swamp chestnut oak
PODE 131.0 Populus deltoides = eastern cottonwood
QULY 131.0 Quercus lyrata = overcup oak
DIVI 126.9 Diospyrus virginiana = persimmon
RI 142.00
Central Brevard Fault Zone
LITU 170.2 Tamassee Knob Lirodendron tulipifera = tuliptree
CAGL 168.2 Lee Branch Carya glabra = pignut hickory
CACO 154.2 Station Cove Carya cordiformis = bitternut hickory
QURU 150.0 Lee Branch Quercus rubra = northern red oak
QUMO 143.9 Tamassee Knob Quercus montana (Q. prinus) = chestnut oak
ROPS 143.4 Tamassee Knob Robinia pseudoacacia = black locust
QUAL 141.8 Station Cove Quercus alba = white oak
LIST 141.4 Tamassee Knob Liquidambar styraciflua = sweetgum
ULRU 141.3 Station Cove Ulmus rubra = slippery elm
PIEC 139.9 Tamassee Knob Pinus echinata = shortleaf pine
RI 149.43
South Carolina
LITU 170.2 Tamassee Knob Lirodendron tulipifera = tuliptree
PIST 168.9 Walhalla Fish Hatchery (E. Fork) Pinus strobus = estern white
pine
TSCA 168.9 East Fork Chattooga River Tsuga canadenis = eastern hemlock
CAGL 168.2 Lee Branch Carya glabra = pignut hickory
PITA 167.2 Congaree Swamp NP Pinus taeda = loblolly pine
LIST 157.1 Congaree Swamp NP Liquidambar styraciflua = sweetgum
CACO 154.2 Station Cove Carya cordiformis = bitternut hickory
QUPA 154.0 Congaree Swamp NP Quercus pagoda = cherrybark oak
FRAM 153.4 Wadakoe Mountain Fraxinus americana = white ash
QURU 152.9 Whitewater River Quercus rubra = northern red oak
RI 161.50
State vs Congaree. (161.5/142.00-1) x 100 = 13.7%
State vs Brevard Belt (161.5/149.43-1) x 100 = 8.1%
Looking at the circumstances necessary for a significant
increase in a
Rucker Index, the dominance of MTSF in Massachusetts and the
greater
variety of contributing sites in SC do not seem all that
surprising. A
state could have a much higher RI than the best site in the
state under
one of two conditions or their combination: much taller
individuals of
the same species as at the best site grow found elsewhere in the
state; or
very tall species that do not grow at the best site grow
elsewhere in the
state.
How likely is it that top ten species at the best site would all
approach
their regional maxima? Several months ago, Colby Rucker posted a
well
thought out argument for the best site for a species being the
one that
the species is best adapted to, where it has the greatest
competitive
advantage, and that that would usually not coincide with the
area of
greatest resource ability. That hypothesis could be interpreted
as
implying that height records would require different sites and
thus be
quite spread out spatial; however, sites as trees actually use
them are
much smaller than any of the areas we have defined them, and
disturbances
could shift a specific location from being ideal for one species
to being
nearly ideal for another species. Additionally, even our
relatively
homogeneous sites contain small but significant variations in
moisture
availability, aspect, and soil composition. Consequently, slight
gradients in environmental conditions, microsites, and
disturbance
patchiness on a background of high water and soil nutrients,
physical
requirements of great height growth of all species, could result
in nearly
ideal habitat for several species occurring in a small area that
appears
relatively homogeneous.
How likely is it that all of the tallest species in a state
would all
occur at one location? The distribution of physiographic
provinces within
a state and latitude of the state largely answer that question.
Most rich
site support all or nearly all of the tall species in that
physiographic
province. However, in other physiographic provinces, the same
species may
have vastly different growth potential. For instance, silverbell
grows in
the understory along many southeastern piedmont streams, but
becomes an
overstory species in the southern Appalachians. Also, in the
northeast,
nearly all of the tall species grow well in the mountains; the
coastal
plain of the region has few extremely tall species. Conversely,
in the
south, a host of bottomland species reach great size in the
piedmont and
coastal plain, but cannot survive compete in the mountains.
Going back to the individual sites, MTSF provides excellent
growing
conditions for almost all of the mountain species in
Massachusetts. In
other regions of the state, sycamore, tuliptree, and cottonwood
are the
only additional tall species I know of, and of those I think
sycamore is
the only one that is known to challenge the mountain species in
height in
that region (have I been paying close enough attention to your
e-mails
Bob?). Hence, small improvements in mountain species at other
sites and
sycamore are the only avenues left for Massachusetts to increase
the
state's Rucker Index over MTSF.
The same
general argument applies to Cook SF, but the argument is not
quite as strong. A few broadleaf mountain species, tuliptree in
particular, do not approach their regional maximums in the park,
and
lowland species like sycamore and cottonwood reach more
impressive heights.
In South Carolina, the tallest species different regions of the
state
ensure some of the tallest species of the state stay well
separated, so no
one site can achieve the dominance of some of the northeastern
sites.
Compounding that divide is the fact that the best conifer and
broadleaf
sites in the mountains do not coincide. In spite of those
considerations,
the central section of the Brevard Belt still comes within 10%
of the
state Rucker Index. That situation highlights the fact that the
second-tier tall species are not that much shorter than the
tallest group
of species. 15 feet may seem like a great height difference, but
that
length is still less than 10% of the height of the tallest
species.
North
Carolina has great tree diversity and distinct physiographic
provinces, so the dominance of the Smokies appears to contradict
the
pattern established in looking at the other sites. I attribute
part of
the dominance simply to the fact that the Smokies are a special
area.
Lack of disturbance, and lack of continued disturbance, climate,
geology,
and the resultant high diversity all work in favor of the site.
The other
part of the smokies dominance is probably an artificial artifact
of how we
have set up the situation. The NC side of the park contains
several
distinct high growth areas that are separated by areas of
shorter forest
with different growing conditions, and the high growth regions
are spatial
separated by a few miles. If not for the park boundary, we would
probably
see the area as having several distinct superlative sites rather
than one
large, incomparable site. The other human factor is the paucity
of data
we have form the NC piedmont and costal plain. Will Blozan has
just
recently found one excellent piedmont site giving a specific
example of
the regions potential. How tall can sweetgum, loblolly pine,
cherrybark
oak, and shumard oak grow in the state's floodplains.
Zoar
Valley's dominance in New York points to some holes in this
theory
and the spectacular nature of the site. New York has several
distinct
regions, yet Zoar Valley appears to include excellent habitat
for all of
the tall hardwood species in the state. The lack of conifers
makes the
sites dominance more impressive, but reinforces the fact that
the second
tier of tall species really is not that much shorter than the
tallest
group of species.
Enough half thought through rambling.
Jess Riddle
|
RE:
Questions for Jess and Will |
Will
Blozan |
Nov
16, 2004 19:07 PST |
Jess,
Here are some numbers higher than the lowest you have listed
below from my
3/17/97 trip to Congaree that will update the RI a few points.
All are
lasered heights.
Shumard oak 138.9'
Bitternut 134.8'
Willow oak 130.5' (not in RI)
New RI= 143.6'
Congaree Swamp NP
PITA 167.2 Pinus taeda = loblolly pine
LIST 157.1 Liquidambar styraciflua = sweetgum
QUPA 154.0 Quercus pagoda = cherrybark oak
PLOC 144.0 Platanus occidentalis = sycamore
TADI 141.0 Taxodium distichum = baldcypress
ULAM 135.0 Ulmus americana = American elm
QUMI 132.8 Quercus michauxii = swamp chestnut oak
PODE 131.0 Populus deltoides = eastern cottonwood
QULY 131.0 Quercus lyrata = overcup oak
DIVI 126.9 Diospyrus virginiana = persimmon
RI 142.00 |
|