Congaree National Park, SC Feb 2006    Jess Riddle
   Apr 03, 2006 08:02 PDT 

Congaree National Park, formerly Congaree Swamp National Monument, lies in
central South Carolina just below the Fall-line. The Fall-line marks the
interface between the rolling hills of the piedmont and the flat, sandy
coastal plain; hence, downstream of the Fall-line rivers slow down, develop
broad floodplains, and deposit vast quantities of rich sediment from the
piedmont and mountains. Most years, the Congaree River floods several
times, so the floodplain forests regularly receive new nutrients and stay
moist. Within the park, the floodplain averages about two miles in width
and contains approximately 11,000 acres of old-growth, the largest remaining
bottomland tract in the eastern U.S. Baldcypress were cut from much of the
forest, and a few high value species were removed from other areas, but most
of the bottomland forest remains undisturbed by logging.

In mid-February, several Ents converged on the Congaree to explore more of
the forest and model some of the giant loblolly pines and cherrybark
oaks. Spring was already clearly in evidence: the elms and red maple were
flowering, silver maple had already set seed, and one spring ephemeral,
butterweed, was just beginning to flower. The rosettes of butterweed leaves
covered the ground adjacent to wet areas. One grass and one sedge species
also covered much of the ground in some areas; however, most of the forest
floor was bare except for leaves, and extensive disturbance by hogs may
ensure spring herbs do not carpet the ground in some wet areas.

At the time of our visit, water levels in the park were low making travel
easier, but water still covered many poorly drained areas. The forests that
inhabit the wet areas vary considerably depending on the depth and structure
of the depressions. Adjacent to the bluff, the five to ten foot high rise
that marks the edge of the floodplain, swamp tupelo dominates the uneven
swampy ground, and Loblolly pines range from absent to abundant in that
forest. Broad flooded areas also occur in abandoned river channels that now
lie scattered throughout the floodplain. Water tupelo and baldcypress
typically form the entire canopy in these areas. Few trees grow in the
understory, but water-elm (Planera aquatica) may be present. Cypress and
tupelo also form a pure mixture in the sloughs or guts that wind through the
floodplain. Sloughs resemble large brown creeks, but the water flow is
imperceptible. Shallower wet areas form on poorly drained higher elevation
areas in the floodplain. In those depressions grow bottomland hardwoods
including overcup oak, laurel oak, persimmon and water hickory.

However, most of the floodplain remains firm dry ground except when the
river overflows its banks. Diverse mixtures of bottomland hardwoods occupy
these better drained regions. Sweetgum, which occasionally forms pure
stands, probably reaches the canopy more often than any other species, but
most areas contain several hardwood species. Ironwood and paw paw are
ubiquitous in the midstory, and likely include more individuals than any
other tree species in the park. American holly is also abundant in the
midstory, but tends to grow in large, discrete groves, except near the
river. Possumhaw or deciduous holly can also become an important component
of the midstory near the river. Spicebush forms the shrub layer in some
areas, but rivercane is far more abundant although still not ubiquitous.

Vines grow throughout the floodplain in impressive numbers regardless of
forest type. Most trees in the park over one foot in diameter have vines
growing up them. Poison ivy in the floodplain always grows up tree trunks
rather than creeping across the ground, but still appears to be the most
common vine species. However, crossvine, supplejack, and grape vines are
also common. The grape vines can exceed 30" in circumference, but trumpet
creeper reaches even larger sizes. However, most trumpet creepers fragment
into several separate living strands before they reach great size.

For our visit, we were fortunate enough to be able to tap into Marcas
Houtchings experience. He has worked at the park for four years and
explored the forests for close to a decade. He was kind enough to volunteer
to show us several of the park's arboreal highlights. Marcas first took my
dad, Will Blozan, and I to a slough that the loggers skipped for some
reason. Ancient cypress stood in a row in the slough and consistently
exceeded 130' in height. We measured a few trees on our way back to the
trail then headed down the River Loop Trail, a trail we had hiked several
times before. A few hours of tree measuring later we arrived at our second
destination, the state champion cherrybark oak. After modeling the tree's
trunk with a monocular, we started going back to camp along the opposite
side of the slough the River Loop Trail paralleled. We stumbled back into
camp well after sunset, but several height records richer.

The second day we planned to focus more on volume modeling, but somehow got
distracted by tall trees along the way. John Eichholz, Will, Marcas, and I
first stopped by a large hornbeam Marcas had found then Marcas showed us one
of the former national co-champion persimmons. We took a short detour to
remeasure a tall persimmon my dad and I had found several years earlier
before heading for our primary target, a loblolly pine grove that had
supported a 173' individual, the tallest loblolly pine yet found. In 2000
or 2001 a microburst hit the grove and snapped the 173' pine, but left
unscathed a 14'7" x 160'+ tree. We planned to model that large pine, but
this trip we found the rest of the grove decimated. Only three pines
remained alive; the largest tree was not among them. Somewhat letdown but
still wanting to model the large pines, we started for the highly visited
former state champion pine. On the way to that tree, we stopped to model
the tallest known cherrybark oak. When we arrived at the large pine, we
quickly set two monoculars to work in the light drizzle. Again, we stumbled
into camp in late twilight well satisfied with the day.

For our last day at the park, Marcas and John Torrence, another ranger at
the park, set up a boat trip to see areas they knew about along the
river. Our first stop was an unusual, 26'4" cbh, twin cypress. One stem
had snapped off nine feet above the ground, and with a little help one could
climb inside the tree. Inside, both stems were hollow, and the ground was
14' below the opening. Many people commented the inside looked like a cave;
muck and water stood on the floor while cypress knees and odd fins of wood
grew up all around and were strongly reminiscent of stalagmites. The five
foot elevation difference between ground outside and ground inside the tree
may be the result of centuries of siltation by the river.

The same situation appeared to have occurred in adjacent grove of cypress we
visited. The obviously old cypresses currently grow on dry ground, and
their lower trunks swell much less than usual. The grove is also unusual in
that it still exists. The river would have provided easy access for
loggers, and the grove consists of not just hollow shells but a complete

From there we walked to the state champion bald cypress. The tree grows in
a more typical grove of scattered, remnant, ancient cypress amidst many
younger cypresses. We also tried to visit the state champion American elm,
but we were not able to locate that tree from just the map we had with
us. However, on the way to the tree we walked through an impressive
riverside forest of green ash, sycamore and sugarberry.

Species                  Cbh         Height
Ash, Green              8'8"        131.8'
Baldcypress            26'0"       124.9'
Baldcypress            10'0"       125.0'
Baldcypress            23'9"       133.3'
Baldcypress            8'6.5"      137.1'
Baldcypress            20'1.5"    137.1'
Baldcypress            18'7.5"    139.9'
Baldcypress            Coppice 143.4'
Baldcypress            10'6"       146.7'
Baldcypress            Coppice   147.2'
Beech                     11'0"       112.9'
Beech                     6'10"       115.5'
Beech                     9'10"       122.3'
Beech                     7'11"       126.3'
Boxelder                  5'2"         84.4'
Boxelder                  6'11.5"    94.5'
Bumelia, Gum          9"           35.3'
Cottonwood, Swamp 6'2"        114.9'
Cottonwood, Swamp 7'8"        117.6'
Elm, Winged            6'11"      122.6'
Hickory, Water         11'3"      126.2'
Hickory, Water         12'11"     137.2'
Holly, American        5'3.5"      87.4'
Holly, American        5'3"        92.5'
Holly, American        5'4"        96.6'
Hornbeam, American 4'2"        62.6'
Hornbeam, American 3'7"        65.3'
Hornbeam, American 3'1"        70.3'
Hornbeam, American 2'7.5"     76.1'
Oak, Cherrybark        23'6"     146.5'
Oak, Cherrybark        18'8"     151.3'
Oak, Cherrybark        18'8"     156.8'
Oak, Laurel               12'3"      119.4'
Oak, Laurel               16'7"      122.5'
Oak, Laurel                22'1"     130.1'
Oak, Overcup             14'2"     136.5'
Oak, Overcup             9'6"       143.3'
Oak, Shumard           14'6"      139.1'
Oak, Shumard           17'1"      141.6'
Oak, Shumard           8'6.5"     142.1'
Oak, Shumard           13'10"    157.6'
Oak, Willow               12'4"     144.7'
Paw Paw                   1'3"       47.8'
Paw Paw                   1'3.5"    51.0'
Paw Paw                   1'6.5"    58.8'
Persimmon                7'5"      113.9'
Persimmon                7'4"      114.3'
Persimmon                6'9.5"   131.4'
Possumhaw               3'6"      38.1'
Possumhaw               2'1.5"   49.2'
Redbay                      2'4"      49.3'
Redbay                      2'0"      55.1'
Sugarberry                 7'2"      108.0'
Sugarberry                 7'11"    109.4'
Sugarberry                 8'5"      111.3'
Sugarberry                 9'6"      112.4'
Sugarberry                 6'3"      112.9'
Sugarberry                 6'6"      113.6'
Sugarberry                 5'10"    114.2'
Sugarberry                 8'0"      115.8'
Sugarberry                 9'8"      123.7'
Sugarberry                 13'0"    130.5'
Sugarberry                 11'1"     133.6'
Sweetgum                  11'5"    136.1'
Sweetgum                  14'10" 138.8'
Sweetgum                  5'10"    141.4'
Sweetgum                  13'1"    142.1'
Sweetgum                  9'0"      144.1'
Sweetgum                  10'3"    146.0'
Sweetgum                  10'7"    146.0'
Sweetgum                  9'9"      148.8'
Sweetgum                  8'8"      151.0'
Sweetgum                  9'6"      152.5'
Sweetgum                  9'5"      155.2'
Sweetgum                  9'10"    157.0'
Sycamore                   8'11"    131.5'
Sycamore                  16'0"     133.6'
Sycamore                  14'6"    133.9'
Sycamore                  11'0"    143.3'
Sycamore                   9'5"     153.6'
Tupelo, Water            13'2"     118.8'
Tupelo, Water             9'11"    124.8'

*Rucker Index 151.01'*
Loblolly Pine     168.9'
Cherrybark Oak 160.2'
Shumard Oak    157.6'
Sweetgum         157.0'
Sycamore         153.6'
Baldcypress      147.2'
Willow Oak        144.7'
Overcup Oak      143.3'
Swamp Chestnut Oak 140.3'
Bitternut Hickory 137.3'

The 26' circumference baldcypress is the current South Carolina state
champion. Previously, the tallest confirmed baldcypress was a 144.7' tree
growing in a ravine in Virginia, and the tallest in the Congaree was 141.0'

The larger boxelder is a potential state co-champion and the tallest found
thus far in the east.

The swamp cottonwood also sets a new ENTS height record.

The height record winged elm, a 131.1' that grew in the Congaree, died
during the year since it was measured. The tree appeared healthy last year,
but some disease, most likely elm yellows, has killed the
tree. Consequently, the 122.6' tree is now the tallest known living winged

The 137.2' water hickory is the tallest ENTS knows of, but the species has
only been measured at a few sites.

The 96.6' American holly is the second tallest known, and the tallest so far
found in the Congaree.

The 76.1' hornbeam is also the second tallest known of the species. The
tallest individual also resides in the Congaree.

The 23'6" cbh cherrybark oak is the South Carolina state champion. The
tree's asymmetrical crown yields branch spreads of 88' and 150'. The tree's
huge, stabilizing, buttressing roots radiate out from the trunk like fins
and inflate the tree's circumference. At the top of the basal flair,
10.5'above the ground, the circumference is 16'4". From that level,
the trunk
gradually tapers down to slightly over 10' in circumference at 75' above the
ground. Consequently, that lower trunk contains approximately 1066 ft^3 of

The tallest known cherrybark oak, 160.2', has a more modest cbh of 20'4.5",
but remains 13'8" in circumference just below the point of major
branching. That slightly slower taper allows the tree to amass 913 ft^3 of
wood over the first 52' of the trunk. Above that level, the trunk splits
into tree leads, each at least 2'4" in diameter, and ascends over 100
additional feet.

The 156.8' cherrybark oak is the second tallest found so far.

Exceptionally large buttress roots support the largest laurel oak. Two
cracks stretch up the tree's trunk, and the trunk has entirely rotted away
at ground level leaving the tree standing only on its roots. However, the
tree still maintains a full crown that spreads 80', and has enough points by
the American Forests system to qualify as a national champion. The tree is
also the tallest of the few laurel oaks ENTS has measured.

Previously, ENTS had measured overcup oaks to only approximately 130'.

The former height record for shumard oak was 140.0', so that record was
shattered by 17.6'. The 17'1" cbh tree is a potential state champion since
the former record holder in the Congaree fell.

The willow oak ties the tallest ENTS has measured.

This may sound like a broken record by know, but the 58.8' paw paw is the
tallest ENTS has measured.

The 7'5" persimmon is a former national co-champion, and the 131.4' tree is
the current height record holder.

The former state champion loblolly pine has a 15'9" cbh, and the tree's flat
topped crown rises 143.5' above the ground. The tree's trunk remains over
10' in circumference for the first 75', and is still over eight feet in
circumference 100' above the ground. That long stem gives the tree a trunk
volume of 1144 ft^3.

The 3'6" possumhaw shows substantial crown die-back. In its prime, the tree
may have qualified as a national co-champion. The 49.2' tree exceeds the
former height record by five feet.

Previously, the tallest known sugarberry was 118.4', and the tallest known
in the Congaree was 111.6'. We suspected taller individuals were present in
the Congaree, so John Eichholz focused on the species during this trip. The
first day of searching yielded several tall individuals comparable to
previous finds, all of the individuals listed above less than 115', but no
significantly taller individuals. That day was spent near the trails, and
miles from the river. On the following day, when we ventured near the
river, we found all of the individuals listed above over 115'. The
riverside individuals were also far larger in volume than the more inland
trees, and the 13' cbh tree is a new potential state co-champion. The
133.6' tree breaks the old height record by 15.2'.

The former height record for sweetgum was 152.7'.

The 153.6' sycamore was previously measured at 144' tall. All other
sycamores listed grow near the river.

The 151.01' Rucker Index slightly surpass that of the central Brevard Fault
Zone (150.57') and is the second highest of any eastern US site.

Jess Riddle, Will Blozan, John Eichholz, Marcas Houtchings, and Doug Riddle