Spring Congaree National Park trip   Jess Riddle
  Apr 02, 2007 18:47 PDT 


The weekend before last, Michael Davie and I rode down to central
South Carolina to meet a few naturalists from North Carolina and to
further explore the remarkable floodplain forests of Congaree National
Park. Most of our previous visits to the park had been in winter, and
the warming weather and longer days of late March had brought some
conspicuous changes to the forest. In the floodplain, the oaks were
flowering, the elms and red maples were beginning to drop seeds, and
the sugarberries were covered with half grown leaves. In the old
loblolly pine plantations that cover the uplands, the southern
crabapples widely scattered throughout the understory were in full
bloom as were the pines overhead. The resulting pollen accumulated in
such densities that foot fall in the pine forest was accompanied by a
little yellow cloud and cars and picnic tables were covered in yellow
swirls. Few herbs grow in the pine forests to add to the pollen
clouds, but spring herbs in the floodplain locally ranged from absent
to 100% coverage. The densest herbaceous layers occurred on swampy or
frequently flooded areas where sedges dominated, or near the river
where butterweed flowers formed a yellow band across the forest.
Butterweed was widespread but less dense in other areas. Nemophila
microcalyx occasionally associated with the butterweed, but other
herbs were generally scarce.

We spent Saturday casually strolling through the floodplain with the
Oak Ridge Trail as our main destination. The trail lives halfway up
to its name; few people would recognize the route winding along
sloughs and guts (essentially stagnant creeks) in the floodplain as a
ridge, but the trail does stay on generally high ground for the
floodplain. However, the path provides one of the best opportunities
in the United States for seeing large individuals of a wide variety of
oak species. Water, willow, overcup, swamp chestnut, shumard, and
cherrybark all reach large diameters and heights along the trail. For
many, the 18' cbh swamp chestnut oak and pair of 20'+ cbh cherrybark
oaks, one a former state champion, highlight the trail. The heights
of the oaks may be even more significant since both the tallest known
water oak and the tallest known cherrybark oak grow within sight of
the trail, 134.0' and 160.2' respectively. However, the impressive
trees along the trail are not limited to oaks; multiple sweetgums
exceed four feet dbh, and the state champion bitternut hickory grows
next to the trail.

Having hiked the trail repeatedly in the past, we were not expecting
to find any new record trees. However, the forest is diverse enough
that paying attention to all species simultaneously is difficult, and
the larger species sometimes distract from the smaller ones. Those
factors may explain why the trees measured on this trip were
previously overlooked since all grow within 20' of the trail. The
first spotted was a 3'6" cbh x 72.3' tall red mulberry, the tallest
ENTS has measured in the state. Nearby on the other side of the trail
grows a winged elm 6'0" cbh x 115.3'. The surprise of the day was a
2'3" cbh x 49.5' sweetleaf. The species is scarce in the floodplain,
and blended in amongst far more common American hollies, which also
sport smooth gray trunks and evergreen leaves. Those dimensions make
the tree large enough to qualify as a state co-champion and the
tallest ENTS has measured.

Obligations back in NC pulled most of the group out of the park on
Saturday evening, but I had enough time to stay explore other parts of
the park on Sunday. Since most of the trails lie in the park's
northwestern quadrant, that section receives by far the most
visitation and exploration, by Ents and others. Since logging
operations only removed baldcypress from most of the northwestern
quadrant, that area retains the most large trees, and the park
established trails to maximize viewing of large trees. Other sections
of the floodplain were clear-cut in the mid 1970's, prompting the
formation of the park. Still other parts were selectively logged for
the most valuable hardwoods, but retain a closed canopy of large
trees, just not the showcase oaks. On Sunday, I decided to explore
some of those less visited, selectively cut areas south of the
Kingsnake Trail.

Sweetgum, sugarberry, green ash, and in the low areas baldcypress,
form much of the very mixed overstory in that section of the park.
The typical midstory species of the floodplain, hornbeam, paw paw,
possumhaw, and American holly, formed a fairly continuous canopy layer
with boxelder replacing American holly closer to the river.

Species                     Cbh   Height
Ash, Green               8'6"   120.1'
Ash, Green               12'11.5" 120.4'
Ash, Green               7'5"   124.2'
Ash, Green               14'4" 124.5'
Ash, Green               8'1"   126.6'
Ash, Green               13'1" 127.7'
Blackgum                  9'7"   98.1'
Buckeye, Red            1'1"   30.7'
Cottonwood, Swamp 8'11" 113.5'
Cottonwood, Swamp 7'10" 116.6'
Elm, Winged              9'4"   119.8'
Green, Hawthorn       2'6.5" 41.1'
Hickory, Water          11'5" 120.2'
Holly, Possumhaw     1'6"   42.7'
Holly, Possumhaw     1'7"   47.8'
Hornbeam                  4'2"   50.8'
Maple, Red                8'11" 130.3'
Mulberry, Red           6'9"   58.8'
Sycamore                   16'2"

Large green ashes were unusually common in this section of the park.
The 14'4" tree is the largest circumference individual of the species
I have seen, but the 13'1" cbh tree is probably larger in volume.

Red buckeye grows on the bluffs bordering the floodplains of many
rivers in the southeastern Coastal Plain, but at Conagree National
Park at least two colonies grow out in the floodplain. They were in
full flower at the time of this trip, and the 30.7' individual is only
slightly shorter than they have been measured in Georgia and

The 116.6' swamp cottonwood is the second tallest ENTS has located,
and the 8'11" cbh individual is the largest circumference one in the
ENTS database. The two trees grow directly adjacent to one another in
a low lying part of the floodplain.

The 9'4" x 119.8' winged elm is by far the largest individual of the
species I have seen and unusually tall, but is not large enough to
qualify as a state champion.

The 47.8' possumhaw is second tallest known, exceeded only by another
tree in the park.

The 130.3' red maple is the second tallest known of the species in SC,
and may be a varietal height record. Unfortunately, I am not certain
which variety the tree is. The tree's location in a low lying part of
the floodplain and relatively smooth bark are consistent with trilobed
red maple (Acer rubrum var. trilobum). However, swamp red maple (var.
drummondii) also grows in the park, and other maples that had already
leafed out had leaves most like the typical variety of red maple (var.
rubrum). All of the red maples known to be taller, growing the
mountains of SC, the Smokies, and Lake Erie gorges, are the typical

The overstory in the park rarely includes sycamore except near the
river, but the section south of Kingsnake trail included many
scattered individuals. The 16'2" tree grows immediately adjacent to
two other sycamore around four feet dbh.

Jess Riddle
RE: Spring Congaree National Park trip   Andrew Joslin
  Apr 03, 2007 09:17 PDT 

You might enjoy this report from a recent tree exploration trip into
Congaree. The account suggests there are sizable Bald Cypress (and
others) yet to be documented:

Andrew Joslin
Jamaica Plain, MA