I have spent many many hours deep in the swamps of Louisiana. Most of the swamps I've seen have been modified by humans in one or more ways - cypress logging, building levees, digging canals, adding water control structures, and impounding and/or draining. There's virtually no remaining intact swamp.
The most dramatic of those on a large scale in my opinion is the widespread cypress logging that took place across the coastal swamps of Louisiana and the rest of the Gulf coast.
Around that time, people developed the pull-boat, which was basically the downfall of cypress stands that were present in those days. The pull-boat allowed trees to be logged much more quickly than before. Intense logging occurred with that mechanical invention, and most virgin (never logged) cypress were logged from 1890-1925. By the 1930s, most cypress mills were going out of business and logging was dwindling... because nothing of worth was left to cut down. Any big trees left standing at that point were hollow and therefore useless to the logger, or otherwise damaged.
To log cypress, workers would visit the sites in the winter, when water levels were lower, and girdle the trees. Girdling is when the bark around the tree is removed, which will ultimately kill the tree [source]. Then, in the spring during high water, loggers would come back, cut the tree down, and then be able to float or pull the logs out of the swamp. To cut the trees down, loggers created notches in the trees that they inserted boards into - called springboards - that they could stand on while cutting the tree down [source].
Loggers effectively clearcut cypress trees from large tracts of land in south Louisiana. I've read descriptions of Manchac, LA (between the Lakes Maurepas and Pontchartrain) that described huge cypress trees as far as the eye can see. Now, there are patches of cypress trees in that area but not nearly what used to be. The marsh is beautiful, but if you look carefully you can tell that something traumatic happened. There are still some sparse standing trees, with marsh underneath and around, but many standing cypress stumps and small canals criss-crossing the remaining marsh.
To log cypress, workers would visit the sites in the winter, when water levels were lower, and girdle the trees. Girdling is when the bark around the tree is removed, which will ultimately kill the tree [source]. Then, in the spring during high water, loggers would come back, cut the tree down, and then be able to float or pull the logs out of the swamp. To cut the trees down, loggers created notches in the trees that they inserted boards into - called springboards - that they could stand on while cutting the tree down [source].
Loggers effectively clearcut cypress trees from large tracts of land in south Louisiana. I've read descriptions of Manchac, LA (between the Lakes Maurepas and Pontchartrain) that described huge cypress trees as far as the eye can see. Now, there are patches of cypress trees in that area but not nearly what used to be. The marsh is beautiful, but if you look carefully you can tell that something traumatic happened. There are still some sparse standing trees, with marsh underneath and around, but many standing cypress stumps and small canals criss-crossing the remaining marsh.
There's many remnants of the effects of cypress logging still visible today. Here's a few:
While you can't see the pattern from the ground, the area is dissected with pull-boat canals. You can see all the straight, unnatural lines that run to one central point. Those are pull-boat canals where the logs were pulled out of the swamp. This is but one example of many that are visible on current aerial photography available to the public.
On the ground in Pearl River, I found an old stump that was girdled. This tree was cut down ~100 years ago, yet this stump still remains. This further proves the point that cypress wood is very very long lasting. Photo by me.
On the Tickfaw River, an old stump that has springboard notches visible. The notches are where loggers inserted the ends of boards (called springboards because they bounced) into the tree to stand on while they cut the tree down. It's hard to picture 100 years ago at this site, before it was logged, or picturing loggers work to cut this tree down. Photo by me.
These are only a few examples of the remnant hints of the cypress logging that took place. I see these scars all the time and they remind me of what used to be, but will never be again (probably).
The hydrology of coastal Louisiana was relatively unaltered by humans in the early 20th century, so forests that were harvested had the opportunity to regrow. Baldcypress seeds need saturated soils but not flooded soils to germinate. Swamps are naturally seasonally flooded, with a portion of the year not flooded which allows seeds to germinate into seedlings. Once seedlings are established they can tolerate the natural flooding regime.
But by the end of the 1930s, the hydrology was dramatically shifted and shifting.
Since then, we've contained the Mississippi River in a prison of levees, and built a few diversion projects to semi-mimic natural floodwater dispersion into wetlands, cut off natural bayous that were river distributaries, extensively dug canals for flood relief, created two flood relief spillways, built interstates/roads over/through the swamps, and dug many many oil and gas exploration canals. I could write pages on all the changes that have happened in the last 100 years so I'll save that for a follow up post.
The point is that the coast is not even remotely the same.
Cypress that regenerated 100 years ago would not be able to do the same in 2018. The hydrology is massively different and seedlings to not seasonally get the non-flooded conditions necessary for adequate growth. Additionally wetlands (swamps included) provide valuable ecosystem services which cannot be easily replicated by humans, nor should they be when the original system is right in front of you.
In the current situation, cypress swamps are semi-stable in my experience. Reconnecting the hydrology would be incredibly beneficial, planting older more tolerant seedlings in marshes is helpful, killing any and all nutria that eat the young trees would be amazing, and those are just the first 3 things I can think of.
The take home message is that even though the hydrology is all messed up, the ecosystem is not properly functioning, and there are many environmental and political hurdles - love the swamp. The swamp is beautiful, it's wonderful, it's home to many beautiful species, and it's iconic. It is not to be feared, drained, destroyed, or logged.
Additional Information:
1800s-era sunken logs are now treasure; here are the men who find them LA Times, 7/13/2014
Video of Louisiana Cypress Logging, 1920s YouTube user foresthistory, 2/3/2009
Battle Brews over Louisiana's Cypress Trees NPR, 5/26/2005
Sinker cypress: treasures of a lost landscape Christopher Aubrey Hurst, LSU thesis, 2005.
>> start at page 29 for a history of cypress in Louisiana
Great Mississippi Flood of 1927 Wikipedia, accessed 10/16/2018
Flood Control Act of 1928 Wikipedia, accessed 10/16/2018
Caernarvon, Louisiana Wikipedia, accessed 10/16/2018
History of Levees FEMA, accessed 10/16/2018
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