Sunday, December 5, 2010

Getting to Know the Everglades, Part I

View of a non-Everglades cypress swamp from TreePittsburgh.com
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Sometimes, it's hard to explain your own - or my own (the topic here) - ignorance.  Recently, re: Florida, I tried to explain it here and here.  Let's discuss it some more!
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I am a wetland biologist, a hunter, and a fisherman.  I know more about swamps, bogs, glades, and marshes than most people, and sadly, many wetland biologists, will ever know.  I love wetlands, and I've studied them diligently.  So why in the hell did I think that the Everglades would look like the big cypress swamps elsewhere in the Southeast (thinking of the Dismal Swamp and Okefenokee)?  When my father in-law recently took me to see the Everglades, where he grew up hunting, I already envisioned writing some blog posts entitled "The Real Everglades."  Come to find out, I know so little about the place and its ecology, history, and people, that I can't comment accurately on the "real Everglades."  Humbling but very exciting.  So what do the "Real Everglades" look like, at least? Here's one fairly representative view:
Southern edge of the sawgrass prairie, looking (south) into the northern edge of the Mangroves
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Hope you're getting a good laugh at the difference between that photo and the photo of the cypress swamp. Here's a NASA infrared image of the region's vegetation. Obviously that's the Gulf of Mexico to the southwest, and Lake Okechobee to the north.  The bright green signatures (not in the water) are trees. The pinkish-white is concrete, asphalt, gravel, or roofs. Squares are obviously farms. The rest of the vegetation is either dry or wet scrub or prairie. Lots - I mean lots - of wide open space. To my credit, there was historically a gigantic cypress swamp, between Lake Okefenokee and West Palm Beach on the east coast.  Obviously, this has mostly been destroyed and filled, however, a nice sized chunk of real cypress swamp still exists in JW Corbett WMA.  I hope to see it one day!


It is truly a massive area, primarily under control by the National Park Service in two holdings: Everglades National Park (established in 1947) and Big Cypress National Preserve, established in 1974. Additional state wildlife management areas and state forests skirt the Federal properties.  Such massive Federal holdings have not come without controversy, which I'll discuss in a later post.  For now, let's take a very basic look at the lay of the land (and water), mainly from north to south.


To the north and west of the Everglades, and trickling down into Big Cypress, you cannot escape the Pine Savannah / Cabbage Palm Savannah habitats.  These habitats are fire-prone and dry during the summer and fall, and I suspect have been the primary victims of suburban sprawl in Southwest Florida (due to iffy protection as marginal wetlands).  Where the underground is allowed to burn or is intentionally burned, as it is in Myakka State Forest (north and west of the 'Glades, technically), enormous habitat value for quail and other ground-nesting birds exist.  I imagine that unburned savannah probably creates equally great habitat for reptiles.  The picture above is very much what South Florida looked like in 1900.


Let's get this out of the way.  Yes, there are alligators.  Yes, we saw a lot of them.  Yes, they are much bigger than they are in coastal NC, SC, and GA.


As you move south (and lower in grade) into Big Cypress Swamp and the Everglades proper, you can see actual cypress trees.  Again, note (with humor) how this picture differs from the picture at the beginning of this post (my mental image of the Everglades).   Cypress, oak, and pine trees generally only exist on elevated sand strands and islands called hammocks or hummocks, depending on where you're from and who taught you wetland ecology.  I envision them as sand bars or clay strands resulting from the natural drainage of the Everglades leading up to the last ice age.  But my record of guesses and visions on the Everglades has been really poor so far - so please don't take my word for it until I can do a little more reading!

A slough within the sawgrass prairie, or "glade"
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Finally - the namesake (the Glade) of the Everglades - a large treeless wetland surrounded by trees.  There are a variety of prairie types, featuring different soils, hydrology, and vegetation, and I'm just starting to learn them.  The most famous of them all, although I don't yet know if it's the most dominant in the Everglades, is the Sawgrass Prairie. Sawgrass is actually not a grass at all, but is a wetland sedge with pretty nasty blades on it.  The wet prairie is an amazingly valuable habitat to wintering migratory birds. 


These are the first sandhill cranes I have ever seen in the wild - we floated past in an airboat.  I'm not sure whether it's the commonly hunted sandhill crane, or the highly endangered Florida sandhill crane.  Regardless, a huge treat!  We also saw ridiculous numbers of shorebirds, incomprehensible numbers of wading birds, quite a few teal, and some coots and mottled ducks.  All feeding in the wet prairie.  As we move south, the bands of cypress trees give way to entirely wet prairie and sloughs (where the turtles, fish, alligators, and wading birds hang out), and some of those sloughs actually begin showing drainage features to the south (others are connected via drainage canals to the east and west - a separate topic!).  Since the Everglades are already so close to sea level, it's not long before you can see the northern edge of tidal influence....and the mangroves.

I have dreamed about kayaking and fishing the Florida mangroves for years.  It (for a change) was just as I imagined it.  Although it was a bit shallower than I imagined!  There are three species of mangrove trees in Florida - red (dominant), white, and black.  They are very, very aggressive plants and tend to choke out man-made waterways. As a result, this habitat has been about the most successful at restoring itself once it has been left alone.  As you can see from the satellite image, it's not long (in miles) before the mangroves become salty and then give way altogether to the shallow reefs of the Gulf of Mexico.
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I hope this is the beginning of some exciting exploration in South Florida, and I can honestly say that, whatever you think about the Everglades, you can't even imagine it from your couch.  Go see it.

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