Flat Top Mountain, GA   Jess Riddle
  Jan 15, 2007 14:15 PST 


"The appropriately named Flat Top Mountain rises to approximately
3720' in the southeastern part of the Cohutta Mountains in
northcentral Georgia. The level area on top of the mountain was large
enough to support a small community at one time, but the slopes on all
sides drop away steeply. Those features may in part account for the
fact that the highest recorded annual rainfall in Georgia occurred on
the mountain, slightly over 100". That climate and metasedimentary
bedrock contribute to the rich coves that occur on the north side of
the mountain. Among those coves, botanists have recognized Devilsden
Branch as an exceptional botanical site for decades. Another unnamed
cove on the north side of the mountain between Williamson Cove and
Postelle Creek may also warrant some superlatives. Second-growth
[tuliptrees] constitute most of the canopy throughout the cove, but
basswood, white ash, black cherry, northern red oak, and yellow
buckeye are also common. Yellowwood occurs in the midstory, and much
of the area has an unusually dense understory. An exceptional amount
of paw paw mixed with some spicebush forms the understory in the upper
part of the stand giving way to pure spicebush in the lower reaches.
As expected from the composition of the woody layers, the stand
features a diverse herbaceous layer. Unusually widespread pale
jewelweed and sweet cicely associate with foam flower, black cohosh,
blue cohosh, may apple, violets, wild ginger, and other species.

In the middle of the cove at around 2700' elevation, an unusual level
area, perhaps three acres in extent, supports an exceptional stand of
tuliptrees. Not a single individual of another species reaches the
canopy, but a few small basswoods and yellowwoods do pierce the
continuous cover of spicebush on the base of the stand. The
composition of the stand reminds one of old field sites in Smokies,
but this stand presents a much different appearance due to the crown
structure of the tuliptrees, sometimes entirely folded over and
consistently asymmetrical. Those features and bark characteristics
suggest the stand originated about 125 years ago, older than the
surrounding forest, but little thinning has occurred. Consequently,
the crowns remain narrow and most trees in the stands interior only
have circumferences of six or seven feet, although trees around the
stands edge probably reach 10 to 11' cbh. Trees reach much more
impressive heights than circumferences with any tree under about 140'
being overtopped and likely dying. The stand likely contains over a
dozen tuliptrees that exceed 150' tall, as many as have thus far been
found [elsewhere] in Georgia, and some could exceed the current state
height record of 159'. Due to the high density, basal area probably
around 200 ft^2 per acre, and the great height, this stand may contain
the greatest biomass per unit area of any stand in north Georgia. The
hardwoods in Sosebee Cove might only be slightly lower, and white pine
stands in the Chattooga watershed may be able to reach similar biomass
densities; however, neither likely equals this stand at this time."

Those were my impressions after first visiting the unnamed cove in
summer 2005. Over the holidays, my dad and I returned to the cove,
and the old-field tuliptree grove in particular, to take advantage of
the leafless canopy conditions for measuring and to further explore
the area. Shadows, the ubiquitous haze of fine spicebush twigs
obscuring the tree bases, and overlapping crowns all made measuring in
the grove unusually difficult for an entirely deciduous forest.
Consequently, the tuliptrees listed below are generally the most
easily visible trees in the grove, but not necessarily the tallest.

Cbh    Height
NA     157.3'
6'3"    158.5'
9'11" 158.9'
6'7"    159.0'
8'2"    159.2'
9'8"    160.0'
6'0"    160.5'
7'10" 165.1'
7'3"    166.0'
7'8"    166.0'
8'1"    167.6'

Six of these eleven tuliptrees exceed the former state height record
of 159.4'. While the lower part of the grove appears to have a
slightly lower canopy, many more trees in the upper part of the grove
reach heights comparable to those listed above. The 167.6' tree and
the 165.1' tree were singled out for measurement due to their more
vigorous and ascending crowns, but the two 166' trees did not stand
out at all. Hence, a slightly taller tree could easily remain
anonymous within the grove. In addition to the tuliptrees, a 4'6"cbh
basswood growing on the edge of the grove is a new state height
champion at 137.2'.

After sampling the tuliptree grove, we hiked east over a ridge into
Williamson Cove. White pine, chestnut oak, red maple, and other
hardwoods mix on the short, east and southeast facing slope we
descended into the cove, but an unusually pure stand of tuliptrees
occupies the much broader, north facing slope on the cove's opposite
side. A few basswoods and northern red oaks grow on the upper slope,
cut black locust stumps sit scattered, and two northern red oaks reach
the canopy on the lower slope, but ever other canopy tree on the north
facing side of Williamson Cove is a tuliptree. That dominance makes
the forest reminiscent of the old-field grove in the adjacent cove,
but road beds cutting across the slope and an absence of rock piles
suggest a logging rather than a farming origin. The tuliptrees in
Williamson cove also differs in being younger, probably well under 100
years old, but they also reach exceptional heights and have a blanket
of spicebush growing beneath them. Many of the tuliptrees in the cove
have so far reached approximately 150' tall, but a few slightly
larger, and probably slightly older trees, grow amongst them. The two
of those larger tuliptrees that we measured are 8'10" cbh x 164.5'
tall and 8'11" cbh x 169.1', so the state height record from the other
cove lasted only a few hours after replacing a tree that had held the
record for over five years.

Anticipating more tall trees, we crossed another ridge into the
botanically best known watershed in the area. Hemlocks, still without
adelgid, line the lower part of Devilsden Branch, but rapidly give way
to hardwoods where the stream forks into several coves. Again,
tuliptree dominates the coves, but not to near the extent as in
Williamson Cove. Northern red oaks, bitternut hickory, yellow
buckeye, and black cherry share the overstory. The lower canopy
layers feature more species unusual in north Georgia including
yellowwood, yellow birch, and mountain maple. The coves were
obviously cleared in the early 1900's except for a pair of tuliptrees
and a few buckeyes, the latter bear the legacy of there formerly
exposed setting in the form of broken crowns. However, one buckeye
grew through the last century unscathed, and has now reached 12'3.5"
cbh x 141.3' tall, the second tallest measured in Georgia. The larger
of the remnant tuliptrees is 12'4" cbh x 156.1' tall, and a black gum
farther down in the cove also reached the noteworthy size of 7'7" cbh
x 106.2' tall.

Combined, the coves on the north side of Flat Top Mountain support
eight tuliptrees over 160' tall, the eight tallest known hardwoods in
Georgia, and certainly more than that number remain to be measured; in
addition to trees bypassed in these initial surveys of the unnamed
cove and Williamson Cove, other parts of Devilsden Branch and two
large north facing coves in the adjacent Polecat Branch watershed have
the potential to support similar forests. What makes this plethora of
new tall tuliptrees especially surprisingly is that north Georgia
seemed like a known quantity. ENTS had spent literally hundreds of
days in the forests all across north Georgia, and had found only about
a dozen tuliptrees exceeding 150'.

Jess & Doug Riddle