Posts Tagged ‘Congaree Swamp’

William Bartram’s “Magnificent” Forest

April 11, 2011

Portrait of William Bartram.  In his classic Natural History book, Travels, this author and botanist gave us valuable information about the original ecology and landscapes of southeastern North America, many of which either no longer exist or occur as extremely rare remnants.  He traveled through South Carolina, Georgia, Florida, Alabama, Mississippi,  Louisiana, and North Carolina in the 3 years prior to the American Revolution.

A passage from William Bartram’s Travels inspired my trip to the Congaree National Park last week.  I longed to see a forest of giant trees, the kind that used to commonly occur in the southeast until European settlers raped the land.  Though the Congaree has the largest trees in North America east of the California redwoods, the largest trees there are only half the size of the ones Bartram measured in a forest in east central Georgia.  This incredible stretch of woods was 7 miles long (the width is unreported) and existed in  what today is Taliaferro County.  Here’s Bartram’s description of this forest:

Leaving the pleasant town of Wrightsborough, we continued eight or nine miles through a fertile plain and high forest, to the north branch of the Little River, being the largest of the two, crossing which, we entered an extensive fertile plain, bordering on the river, and shaded by trees of vast growth, which at once spoke of its fertility.  Continuing some time through these shady groves, the scene opens, and discloses to view the most magnificent forest I had ever seen.  We rise gradually a sloping bank of twenty or thirty feet in elevation, and immediately entered this sublime forest; the ground is a  perfectly level green plain, thinly planted by nature with the most stately forest trees, such as the gigantic black oak (Q. tinctoria) Liriodendron, Juglans nigra, Platanus, Juglans exalta, Fagus sylvatica, Ulmus sylvatica, Liquid-amber styraciflua, whose mighty trunks, seemingly of an equal heighth, appeared like superb columns…

(I assume “thinly planted by nature” and “level green plain” meant grass grew between the trees.  For those not up to Latin names for trees, the forest consisted of black oak, tulip, black walnut, sycamore, shell bark hickory, beech, elm, and sweetgum.”)

…To keep within the bounds of truth and reality, in describing the magnitude and grandeur of these trees, would, I fear, fail of credibility; yet, I think I can assert, that many of the black oaks measured, eight, nine, ten, and eleven feet in diameter five feet above the ground, as we measured several that were above thirty feet girt, and from whence they ascend perfectly strait, with a gradual taper, forty or fifty feet to the limbs; but, below five or six feet, these trunks would measure a third more in circumference, on account of the projecting jambs, or supports, which are more or less, according to the number of horizontal roots, that they arise from: the Tulip tree, Liquidamber, and Beech, were equally stately…

 

Painting by Philip Juras.  Bartram inspired this artist to create 68 landcape paintings based on descriptions from his book, Travels.   This painting is of a piedmont woodland opening, much like what Bartram describes in his passage on the “magnificent” forest, though I think the trees aren’t as big. Philip Juras’s portfolio will be on display at the Morris Museum of Art in Augusta from May 28-August 14.  I can’t wait to see them in person!

The composition of William Bartram’s magnificent forest puzzles me.  The forest was dominated by “thinly planted” black oaks which implies a forest dependent upon frequent fires for oaks and grasses to grow. Oaks and grasses are fire tolerant but shade intolerant.  However, the other species of trees in this fores are fire intolerant, yet shade tolerant.  I asked Marc Abrams, a forest ecologist from Penn State, about this curious composition of trees.  He explained that Bartram’s description was of a lower slope mixed mesophytic forest with the exception of the black oaks which don’t fit into this kind of forest because it is not pyrogenic.  He had no definitive answer as to how this forest developed.  Reading the next paragraph in Travels, however, gave me an idea.

Not far distant from the terrace, or eminence, overlooking the low grounds of the river, many very magnificent monuments of the power and industry of the ancient inhabitants of these lands are visible.  I observed a stupendous conical pyramid, or artificial mount of earth, vast tetragon terraces, and a large sunken area, of a cubical form, encompassed with banks of earth; and certain traces of a large Indian town, the work of a powerful nation, whose period of grandeur perhaps long preceded the discovery of this continent.

This impressive forest apparently was adjacent to an ancient Indian town, probably a large one.  If I recall my archaeology correctly, the mound-building Indians abandoned their towns between 1300AD-1500AD.  Bartram’s magnificent forest may have been this town’s hunting grounds which they managed by periodically burning it to maintain a grassy oak savannah favorable for game such as deer, buffalo, and turkey.  After the Indians abandoned the area, the fire intolerant/shade tolerant species, first establishing themselves alongside the abundant creeks, colonized this woodland, but the black oaks remained, living to a great age, and thus explaining their size.  Black oaks can live to be 250 years old.  The passage was written in 1773; the moundbuilders abandoned the town some time in the previous 150 years, so this stretch of woods was still an oak forest, but eventually was on the way to becoming a forest dominated by shade tolerant beech, sycamore, and elm.

European settlers probably clear cut this forest between 1830-1860 after they kicked the Indians out of the state but before the Civil War stifled the economy.  They also probably ploughed, flattened, and destroyed  the Indian mounds. I’ll have to take a day trip and explore this area some time this summer and see if I can find any remnants of what Bartram saw.

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An addendum to last week’s blog entry–The natural history of the Congaree

Last week, I wrote that as far as I knew there had been no palynological studies determining the age of the Congaree Swamp.  To prove myself wrong, I google searched and did find one–“Palynology and Paleoecology of Late Pleistocene to Holocene, organic rich, paleomeander/rim swamp deposits in South Carolina, and Georgia” by Art Cohen, et. al. from the Geological Society of America 38 (7) Oct. 2006.  Scientists took cores in a place known as Muck swamp within the Congaree.  The oldest zone dated to 21,000 BP, and they found pollen and macrofossils of water lillies, diatoms, algae, spruce, and an evening primrose flower related to a species found in Alaska.  They interpeted this to mean that Muck Swamp was an oxbow lake during this time period.  It must have been an important refuge for waterfowl because during this cool arid climatic stage, wetlands were scarce.  A younger, undated zone contained pollen of oak, hickory, chestnut, and walnut.  They interpet this zone to be a marsh, but it seems more like an upland hardwood forest to me.  Zone 3, dating to about 3500 BP contained pollen of pine, sweetgum, alder, cypress, tupelo, and magnolia. Cypress was the last of the modern day representatives to colonize (or perhaps recolonize) the swamp.

The Congaree National Park, Home of the Giants

April 6, 2011

The Congaree National Park in South Carolina still held some surprises for me, even though I traversed this biggest last stand of bottomland forest in 1988.  Then, it was just a National Monument but in 2003 was upgraded to National Park status.  The park hosts 17 national and/or state record trees, including an 156 foot tall loblolly pine; and record shumard, southern red, and overcup oaks; as well as champion water hickory, Carolina ash, holly, box elder, persimmon, and paw paw.

Loblolly Pine–Pinus taeda

Loblolly pine.  The state record tree located in this park has a circumference of 16 feet.  This one looks to be at about 9 or 10.

The tree on the right is the loblolly pine from the previous photo.  The tree to the left is a red maple.  Some of the stands of loblolly pine in the park were found to be 227 years old.  The same study found that this species sprouts following hurricanes which open up the forest canopy.  The ages of stands corresponded with the history of hurricanes. (I took all the photos for this blog entry.)

This species is also known as old field pine because it reseeds so easily in lots devoid of other trees.  It has become a dominant tree throughout the southeast since much of the cotton and corn fields and horse pastures, which 100 years ago made up the face of the southern lands, were abandoned and went fallow.  Before European settlement it was merely a common component, but today it grows in pure stands as well as mixed with other species.  Therefore, it’s sometimes given the name bull pine due to its predominance.  Not only does it grow in upland locations, but it reaches prodigious size in wet areas from whence it gets its name, loblolly, which means mud puddle.  In the Congaree they grow in wet mud.

Sweetgum–Liquidamber styraciflua

Forked sweetgum trunk.

Another surprise for me.  I didn’t know this species could grow with its root system submerged in water, but I saw plenty of individuals in the Congaree growing in 6-12 inches of water.  Some had roots spread in structures similar to those of cypress and tupelo, enabling them to balance without tipping over in muddy soils.  Sweetgums, like loblolly pines, reseed readily in fields and are a common tree in upland sites.  But they’re adaptible enough to thrive in low muddy land as well.

Cypress–Taxodium distichum and Tupelo– Nyssa sp.

Cypress tree trunk.

Look at all of these cypress knees.  Scientists are unsure whether the cypress knees, which are part of the root system, grow for respiration or balance.

Up close view of a cypress knee.  Cypress trees are closely related to California red woods.

There are a lot of interesting microhabitats within a cypress-tupelo swamp.  Areas flooded in shallow water provide homes for fish, reptiles, amphibians, crayfish, and aquatic insects and spiders.

Flooded land in the cypress-tupelo swamp.

Fallen hollow logs and standing snags provide dens from everything from bats and possums to snakes and birds.

This hollow log is a possum mansion.

This standing snag could be hiding bats or flying squirrels.

When the water recedes lush grass and bamboo cane grow.  I can just imagine such Pleistocene mammals as long-horned bison, horses, and mammoths feeding in these grassy glades which often come about when a mighty old tree topples over allowing more light to reach the forest floor.

Note the grassy glade in the background.  There is plenty of grass and cane for a small population of bison and horses in the Congaree.  Too bad they’ve been extirpated.  The only big game left is deer and feral hogs.

A stand of cane.

When the mighty behemonths do topple over, their roots rip caverns in the forest floor.  Those often fill with water forming deep pools that are free of fish.  Amphibians can breed here without fish preying on their eggs and tadpoles.

Upturned tree root.

Pool formed in a hole from where a tree toppled over.

Beech–Fagus grandifolia

Beech tree canopy

Beech grows on sites that are near water but normally stay high and dry.  I love beech, and I wish I lived in a forest of these beautiful trees.  Their bark is white, the leaves turn a lovely yellow in fall, and they produce delicious little nuts.  Beech trees were common in the south during certain climatic stages of the Pleistocene, and as I mentioned in my blog entry “Pleistocene Passenger Pigeon Populations,” I think it’s a clue that passenger pigeon populations skyrocketed when beech was common because beech can grow and spread from sprouts.  The absence of passenger pigeons feeding allows more oak acorns to survive, and oaks outcompete beech.

The Congaree Swamp is probably as old as the Okefenokee Swamp

No studies on the age of the Congaree Swamp have been conducted as far as I know, but I assume it formed about the same time as the Okefenokee which became a swamp between 7,000-8,000 years ago following the final dissolution of the Canadian glacial Lake Agassiz when the water table rose all across the continent.  Throughout much of the Pleistocene, the region around the Congaree River was likely a mixture of upland oak and pine forests and savannahs with only scattered marshes perhaps near creeks and beaver ponds.  Particularly dry climatic stages even hosted oak scrub and sand dune environments.  It’s possible this region has repeatedly converted and re-converted to swamps with every full blown interglacial.

A comparison between my 1988 trip to the Congaree with my experience in 2011

The park system has considerably upgraded the facilities since I was here last in 1988.  Then, there was a gravel parking lot, and nothing else other than some gray paint marks on trees to demarcate the trails.  I hiked by myself in late July and was impressed with the giant trees.  This was before 1989 when Hurricane Hugo flattened many of the trees, but even then there were quite a few felled trees.  I saw a deer resting on a log, a scarlet king snake, and about a billion orb-weaving spiders that built webs across the entire trail at about 1 foot intervals.  After about 5 hours of enjoying nature, I became paranoid that I didn’t know what trail I was on, and I began jogging because I didn’t want to get lost in the park after dark–I feared the potential threat from feral hogs and rabid raccoons.  I didn’t see a single person while I was there until I got back to my car and met a park ranger.

Today, the Harry Hampton Visitor center is located at the entrance of the park.  It’s an air conditioned haven with clean lavatories.  Though the park is still not crowded, we did cross paths with many people.  Moreover, there is a pleasant 2.4 mile boardwalk which made the park accessible for us because my wife is wheelchair bound.

The lower boardwalk goes through a cypress-tupelo swamp.  The upper boardwalk goes through a bottomland forest dominated by sweetgum, loblolly pine, red maple, river birch, and ash.  I only saw a few oaks here–water, swamp chestnut, and willow; though in other areas of the park they’re more common.  Holly trees are common in the understory, and there are occasional patches of palmetto.  I saw no paw paw trees here, but I remember there were many on the trails.

The trails are now color coded, so there is little danger of becoming confused as to which trail one is on as I did 23 years ago.  The paint marks are on trees for the hiker to follow.