Geological Setting
The story of the I’On Swamp begins long ago when a
series of complex geological processes took place that ultimately led to the
formation of this southern freshwater swamp. Due to both uplifting forces in eastern North America and periodic sea level rises and falls driven by glacial cycles, the Atlantic Ocean receded from the coast of what is now South Carolina in a series of “steps”. Each time the ocean receded from the then-current coast of South Carolina, a new
shoreline and a new barrier island system were consequently formed. As this new shoreline
and new barrier island system were formed, the previous shoreline and barrier island
system would be left high and dry on the mainland. This step-like process led to the creation of a series of scarps and terraces. Essentially, a scarp is a narrow, but long, hill formed from
the old sand dune system that was present on what used to be the barrier island
system, while a terrace is a flat, slightly sloping area behind the scarp that
used to be both the back half of the barrier island as well as the shallow marshes
and/or lagoons behind the island.
Figured modified from "Revision of the Pleistocene Dorchester and Summerville Scarps, the inland limits of the Penholoway Terrace, central South Carolina," by W.R. Doar and Ralph Willoughby (South Carolina DNR Geological Survey). |
Human History and Land Use
For the majority of the past several thousand
years, this area had been a mature swamp forest. Swamps are a type of wetland
which are dominated by trees and are
either permanently or seasonally flooded. Ivory-Billed Woodpeckers, American
Alligators, River Otters, and a whole host of other animals lived throughout
this old-growth swamp. The area was not devoid of humans, however. In fact,
Native Americans first began inhabiting South Carolina around 9,000 to 10,000 years
ago. Around 3,500 years ago, tribes began to form more permanent settlements
along the coast of South Carolina right near the I’On Swamp, which is itself
only about five miles from the Atlantic Ocean. It is important to note that
these native peoples did impact and
modify the land, including the I’On Swamp. The idea of Native Americans “living
alongside the land” is a bit of a misconception. We now know that Native Americans did indeed alter the land to benefit them, just not as on a
large-scale manner as people do nowadays.
The greatest environmental impact from the Native
Americans in this region stemmed from their use of fire. Natural wildfires—ones
started through lightning strikes—historically occurred frequently throughout
the Lowcountry of South Carolina, with many habitats in the Lowcountry being
dependent on such wildfires. Some habitats, such as Longleaf Pine savannas,
experienced natural fires as often as 1-5 years. Swamps like the I’On Swamp,
however, experienced natural fires once every 25-100 years. In addition to the natural
wildfires which occurred throughout the Lowcountry, many fires were also started by the Native Americans living in the region. These native peoples made ample use of low-intensity burns to both open
the understory for easier to travel and make the areas more conducive
for hunting, among other reasons. There is no doubt that low-intensity fires started by the native
peoples impacted the I’On Swamp prior to European settlement.
European exploration of the South
Carolina coastal areas began in the 1500’s, but it wasn’t until the mid-1600’s
that European settlers emigrated to the region in significant numbers. In 1670,
British settlers established a city called Charles Town only 20 miles southwest
of the I’On Swamp. Charles Town—which we now know as
Charleston—rapidly grew. This rapid growth led to other
colonists moving out from Charleston to settle the surrounding land. The area immediately around the I’On
Swamp itself began to be earnestly settled in the 1690’s.
It was around this time that the
economy of coastal South Carolina began transitioning from one dominated by fur
trading to one dominated by rice cultivation. From 1700-1860, rice was the crop to grow in coastal South
Carolina. Rice cultivation became the dominant force that impacted the I’On and
other nearby swamps during this period, and the effects can still be seen
today.
Before I dive into how rice cultivation changed the landscape of the I’On Swamp, I want to briefly talk about rice cultivation in the Carolinas. While researching articles for this topic, I relied heavily on Dr. Hayden Smith’s Ph.D dissertation entitled “Rich Swamps and Rice Grounds: The Specialization of Inland Rice Culture in the South Carolina Lowcountry, 1670-1861.” This dissertation was fascinating to read, and is very approachable for those (like me) without any real background knowledge in the topic. If you’re interested in this sort of historical subject, I highly recommend reading the piece, which you can find at this link.
There are two main types of
domesticated rice in the world—Asian Rice (Oryza sativa) and African Rice (Oryza
glaberrima). The rice we eat today are cultivars of Asian
Rice, but the rice that was grown in the colonial United States was most likely a cultivar of African Rice, specifically a cultivar called Carolina Gold. African Rice was originally
brought to the Carolina colonies by European explorers and traders that
traveled to Africa. When rice cultivation in the Carolinas began expanding in the early to mid 1700's, the colonists started to utilize enslaved peoples from Africa to work the
rice fields. There were two main reasons for this. First, the colonists needed
more people for labor, and African slaves were sadly a horrific way to satisfy this
need. Second, many of these enslaved peoples came from the Senegambia and
Sierra Leone regions of West Africa. The peoples of West Africa had been
practicing rice cultivation for nearly 2,000 years, and during this time they
had developed a very efficient method for growing the rice using dikes and
flooded fields. Enslaved African peoples brought with them this knowledge of
rice cultivation, which was then implemented in the Carolina Lowcountry.
There were two
main methods of rice cultivation in the Carolina Lowcountry—tidal rice
cultivation and inland rice cultivation. As the name suggests, tidal rice
cultivation relied on the tides, which moved water in and out of impounded rice
fields near the ocean via canals. Inland rice cultivation, on the other hand, relied on
gravity. Inland rice plantations utilized the principle that water flows
downhill from higher elevations to lower elevations. Due to the location of the
I’On Swamp, tides were not a factor in the movement of water. Consequently,
plantations in the I’On Swamp utilized the inland rice cultivation method.
A 200+ year old Wythewood Plantation canal along the I'On Swamp Interpretive Trail. |
As you can see, changing a mature
swamp to a rice plantation alters not only the vegetation of a swamp, but the
entire landscape as well. This level of landscape modification would wreak
havoc on the ecology of an area like the I’On Swamp. Some animals or plants
undoubtedly benefited due to the change from dense swamp forest to a more open
marshland—say, for example, some species of migrating
shorebirds or waterfowl—but the overall impact was negative for the majority of
the species that were originally present.
The peripheries of the I’On Swamp
experienced development for rice cultivation as early as the 1750’s, if not a bit earlier. At this
time, the swamp was known as the Wappetaw Swamp. “Wappetaw” was a Sewee Indian
term meaning “Sweet Water,” and was a name that tribe had given the swamp. From
the 1790’s to the 1810’s, more and more plantations popped up in the area, many
of which were pushing further and further into the swamp. At the same time,
several of the richer plantation owners in the area began buying out some of the
smaller plantations to consolidate land. They did this to both expand their
rice production and—perhaps most importantly—gain more thorough control of
the water for their fields.
As this consolidation occurred, a few “big name” plantations that controlled thousands of acres formed. These were the Fairlawn Plantation in the southern portion of the swamp, the Wythewood Plantation in the northwestern portion, and the Clayfield Plantation in the eastern portion. The early owner of the Clayfield Plantation was Jacob Bond I’On, which is where the current name for the swamp stems from. From what I could gather, most people called this swamp the Wappetaw Swamp during the 1700’s and 1800’s, and the name didn’t transition to the I’On Swamp until the 1900’s. As an interesting aside, this part of the Lowcountry spoke non-rhotic English in the 1700's and early 1800's, meaning that people born and raised in this region did not pronounce the "R" sound in words. Jacob Bond I'On's last name is actually a modification of the name "Iron." This name was modified to reflect how people were pronouncing the name, and the spelling stuck, both with the I'On family, but also the I'On Swamp.
As this consolidation occurred, a few “big name” plantations that controlled thousands of acres formed. These were the Fairlawn Plantation in the southern portion of the swamp, the Wythewood Plantation in the northwestern portion, and the Clayfield Plantation in the eastern portion. The early owner of the Clayfield Plantation was Jacob Bond I’On, which is where the current name for the swamp stems from. From what I could gather, most people called this swamp the Wappetaw Swamp during the 1700’s and 1800’s, and the name didn’t transition to the I’On Swamp until the 1900’s. As an interesting aside, this part of the Lowcountry spoke non-rhotic English in the 1700's and early 1800's, meaning that people born and raised in this region did not pronounce the "R" sound in words. Jacob Bond I'On's last name is actually a modification of the name "Iron." This name was modified to reflect how people were pronouncing the name, and the spelling stuck, both with the I'On family, but also the I'On Swamp.
Old Wythewood Plantation rice dike (the "trail" running through the right side of the photo). |
The forest began to regrow in any
part of the swamp which were not being used for subsistence farming during this
post-Civil War period. Hardwood trees characteristic of southern bottomland forests—various oaks, tupelos, Sweetgum, etc.—began recolonizing the
abandoned fields and dikes. By 1900, essentially all of the I’On Swamp was reforested
by a young, secondary growth forest. This extensive tract of hardwood trees was
quickly noticed by a booming southeastern timber industry. Between 1900 and 1910, a
large timber company bought most of the old plantation lands in the I'On Swamp. By 1920-1925,
this company had clear-cut nearly all the trees throughout the I’On Swamp.
Various hardwood species regrowing in the I'On Swamp. |
For the rest of this post, I want
to focus on the Ivory-Billed Woodpecker, Carolina Parakeet, and the Bachman’s
Warbler. These three species—all of which are now
extinct—used to inhabit swamps throughout the
southeastern United States, including the I’On Swamp itself. Sadly, most of the
swamps in the southeastern United States have been heavily modified or
completely destroyed by humans over the past 300 years, and these actions have
either directly or indirectly led to the extinction of these three bird
species. I want to explore how human land use of the I’On Swamp over time
impacted these three birds, and how and why they became extirpated (locally
extinct) in the I’On Swamp.
Ivory-Billed Woodpecker
John James Audubon Letters and Drawings, 1805-1892, MS Am 21 (31), Houghton Library, Harvard University |
The Ivory-Billed was known to be
common throughout the swamps in the Lowcountry of South Carolina, and they most
certainly inhabited the I’On Swamp for hundreds, if not several thousands, of
years. Their time in the I’On Swamp probably came to an end between 1750 and 1770
when the swamp experienced the first wave of logging and modification to make
way for rice fields. From historical and contemporary accounts that I’ve read on
the plantations of the I’On Swamp, there were a few sections of the swamp
forest that remained relatively unscathed during this early agricultural time.
It’s possible that these tracts could have harbored a few individuals into the
mid 1800’s, but these tracts were most likely too small for a population of
Ivory-Bills to sustain itself.
The Ivory-Billed Woodpecker,
however, recently jumped back into the public eye after a handful of credible,
but not 100% confirmed, sightings from Louisiana, Arkansas, and Florida came to
light in the early 2000’s. This raised the question as to whether the
Ivory-Billed was truly extinct, or if tiny populations remained in remote and
relatively untouched bottomland swamps around the Southeast. Sadly, even if the
Ivory-Billed Woodpecker is not truly extinct, and a few individuals are indeed
still alive in one or a handful of swamps around the Southeastern US, the
species is still functionally extinct. Any such
population—if one were to truly exist—would be too small to be viable over the
long term.
Carolina Parakeet
Painting by John James Audubon, 1825, New York Historical Society. |
Carolina Parakeets living in the
I’On Swamp probably began facing trouble in the late 1700’s, as the mature
Bald-Cypress trees—whose cavities they nested in—throughout the swamp were cleared to make way for the rice
plantation fields. When did they most likely disappear from the I’On Swamp?
Although I can’t find any specific reports of this species from the swamp, I
would say that the Carolina Parakeet was most likely extirpated from the I’On
Swamp by 1810-1840 based on two details. First, many naturalists noted that
Carolina Parakeet sightings were rarely made outside of Florida by the 1850’s,
which suggests that most of the populations in South Carolina were probably
gone by the early 1800’s. Second, most of the I’On Swamp was already intensely
farmed for rice by 1820-1830, which means that most, if not all, of the
appropriate Carolina Parakeet habitat was gone. No Carolina Parakeet habitat,
no Carolina Parakeets.
By 1904, the last known wild
individual was observed—and promptly killed. The year 1918 saw the death of the
last captive individual. By 1939, the species was declared officially extinct,
although tantalizing reports of Carolina Parakeets trickled in from Florida,
Georgia and South Carolina between 1930 and 1960. The Santee Swamp was
one site of such reports, with a handful of unconfirmed sightings of Carolina
Parakeets inhabiting the dense, relatively untouched swamp were made throughout
the 1930’s. If you remember, this is the same swamp which harbored Ivory-Billed
Woodpeckers into the 1930’s, and is only 20 miles north of the I’On Swamp as
well. Several credible people, such as bird wardens hired by the National
Audubon Society, reported seeing Carolina Parakeets in the Santee Swamp,
including on Wadmacon Island (the same island where the last confirmed
Ivory-Billed Woodpecker in South Carolina was observed).
Although these sightings were never confirmed, the existence of a small,
remnant population of Carolina Parakeets existing into the 1930’s in the Santee
Swamp seems plausible. Despite such thoughts, they are certainly extinct
now.
Bachman’s Warbler
Painting by John James Audubon, 1833, Reynolda House: Museum of American Art. |
The Bachman’s Warbler was always a
mysterious and hard-to-find species. It was first described by John James
Audubon in 1833 when an individual was discovered in South Carolina. Over the
next few decades, more individuals were recorded in other southern states, but the
species seemingly disappeared from South Carolina. The Bachman’s Warbler was
rediscovered in South Carolina by Arthur T. Wayne, a Victorian ornithologist,
in 1901. The individual that Wayne found had been inhabiting the remnants of
the Fairlawn Plantation, one of the old rice plantations found on the southern
end of the I’On Swamp. As an aside, Arthur T. Wayne lived an absolutely
fascinating life filled with ornithological endeavors. I highly recommend
reading this short, 6-page biography on the man.
Wayne, who lived in the
Charleston area, began systematically searching for more Bachman’s Warblers in the
I’On Swamp, specifically throughout the old Fairlawn Plantation property. In
1906 he found two nests, providing evidence that the warbler did indeed breed in the I’On
Swamp, and didn’t just use the swamp as a migration stopover. Over the next
several years, he found many more individuals and nests.
As I said, the Bachman’s Warbler
was always hard to find, and its ecology is rather misunderstood. There have
been no actual studies ever done on this species prior to its extinction.
Everything we know comes from naturalists in the 1800’s and early 1900’s who
thankfully recorded bits and pieces of information on the species—whether it was the habitat one
was found in, or the behavior of an individual, or what have you.
The last confirmed sighting of a
Bachman’s Warbler was in 1988, and the species is almost certainly extinct. The cause for the
extinction of the species has been subject to debate, and several hypotheses have
been put forth about “the cause.” Nearly
everyone agrees the Bachman’s Warbler went extinct due to habitat destruction,
but no one knows what type of habitat the warbler exactly required. The Bachman’s
Warbler vanished before any thorough studies of its habitat requirements could
be conducted. The little habitat information we do have is confusing and
contradictory, which further complicates matters. For example, some naturalists
found the Bachman’s Warblers in mature swamp forests; others found it in young,
successional swamp forests. If habitat destruction was the killer of the
Bachman’s Warbler, what specific habitat feature was destroyed that the Bachman’s
Warbler relied on?
Although Bachman’s Warblers had
been recorded in mature swamp forests, it seems unlikely that they depended on
such a habitat like the Ivory-Billed Woodpecker did. Between 1948 and 1953,
there were many Bachman’s Warblers observed throughout the I’On Swamp, which—if
you remember—was all but a young, secondary-growth swamp forest at that time
after the period of intense logging between 1900-1920. The prevalence of the
Bachman’s Warbler in the I’On Swamp when it was a young, secondary-growth swamp
forest has made some scientists hypothesize that the species relied on
disturbed, successional areas within swamps, similar to how the Blue-Winged
Warbler and Prairie Warbler rely on similarly disturbed, successional areas
within forests.
Drier areas within the I'On Swamp—like the area pictured above—would have been the site of extensive Giant Cane "canebrakes." Nowadays, such extensive canebrakes have vanished. |
What does that have to with the
Bachman’s Warbler? As it turns out, most of the notes that naturalists recorded
on the habitat of the Bachman’s Warbler mentioned the presence of Giant Cane.
This is even more prevalent when reading descriptions of where nests were
found; nearly all of them mention the nests being either in Giant Cane plants, or
being in the same vicinity of Giant Cane. Many of their nests even contained
leaves from Giant Cane. This suggests that the Bachman’s Warbler might have been
a bamboo specialist, a niche that many birds across the world utilize. If this
is true, then it makes sense that the Bachman’s Warbler disappeared as the
Giant Cane canebrakes became less and less extensive throughout the Southeast.
Is the decline of Giant Cane the
sole reason for the extinction of the Bachman’s Warbler? Probably not. Although
it might be the main contributor to the destruction of the species, other
factors probably exacerbated the decline. The destruction of swamps across the
southeast, the destruction of their wintering habitats in Cuba, and potentially
unknown factors might have all helped drive the Bachman’s Warbler to
extinction.
The I’On Swamp Today
Visiting the I’On Swamp today can
be a difficult endeavor. The swamp is large, and only a few gravel and dirt roads
allow access. Only one trail exists in the whole of the swamp. That trail—the 2.5 mile I’On Swamp Interpretive Trail—is part of the Francis
Marion National Forest trail system. The I’On Swamp Interpretive Trail
offers the easiest way for visitors to get “into” the swamp, but—at only 2.5 miles—it allows visitors a tiny glimpse of the swamp. Short of bushwhacking
through the swamp, the trail is the best choice visitors have to see the swamp.
Nearly the entirety of the I’On
Swamp Interpretive Trail runs atop ancient dikes that once belonged to the
Wythewood Plantation, one of the main rice plantations that used to call the
swamp home. As you walk along the nearly 300-year-old dikes, you can’t help but
marvel at the engineering feat they represent. At the same time, you can’t help
but feel an overwhelming sorrow when you realize that enslaved peoples from
Africa were the ones who toiled away to make these extensive dikes. The colonial and
early American rice industry was the second most dangerous industry for
enslaved peoples to find themselves part of, second only to the sugar cane
industry. Between the harsh owners, never-ending work, the oppressive heat of
the Carolina Lowcountry, rampant diseases, and dangerous wildlife, being a rice
plantation slave was an absolutely brutal, and many times short, affair.
Injuries and deaths were commonplace. The mortality rate of enslaved peoples
working on rice plantations is mind-numbing to consider. At some rice plantations,
almost 90% of children died before they reached 16 years old. Many adults did
not make it past 30. The profit margins on rice were so high that an enslaved
person only had to work for one season for the owner to make back the cost of
the slave, so slaves were viewed as a highly dispensable commodity. Although
this mentality seems unfathomable today, it was sadly common throughout the
Lowcountry in the 1700’s and 1800’s.
Today the I’On Swamp looks like a very young, secondary growth swamp forest. When Hurricane Hugo slammed South Carolina in 1989, the winds knocked down essentially all of the trees in the eastern section of Francis Marion NF, including the I'On Swamp. Consequently, most of the I'On Swamp's forest is only 28 years old. Despite the young age, the forest is still impressive. Dwarf Palmettos cover the ground. Red Maples and Black Tupelos take hold in the drier areas. Bald-Cypresses dot the wetter areas, where their knees jut up through the shallow, tannin-stained water. Alligators bask along the banks of the ancient dikes, and River Otters swim through the canals. The place feels natural on the surface, but—while it is still natural to a certain extent, true—the I’On Swamp is scarred. Animals which should call the swamp home are forever gone. Plants which should be easily found throughout the swamp are uncommon and nowhere near as extensive as they used to be. The water flows in unnatural channels and canals, separated by earthen banks that shouldn’t be there. The landscape has been forever changed, and a sorrow hangs in the air—not only because the land will never be as it once was, but also because so many lives were unnecessarily lost here.
Despite the scars, the I’On Swamp is nevertheless a
fascinating place. Go visit the swamp if you’re in the Lowcountry of South Carolina. Walk along the
ancient rice field dikes as you travel through the swamp forest. Look for
animals and plants, and enjoy the landscape. But while you do, don’t forget to
take a few moments to reflect on all the history bound up in this swamp.