What's a Wetland? - descriptions and types of wetlands: freshwater marsh, salt marsh, and cypress swamp

Ranger Rick, April, 1996 by Ellen Lambeth, John Dawson

You sure are getting your feet wet in this special issue of Ranger Rick. But you still might have some questions about wetlands. Never fear--Wet Willy's here. So ask away!

A wetland is land that's wet, right, Willy?

Right--at least part of the time. Turn to page 13 to see a wet wetland turn into a not-so-wet wetland. Even when it looks dry, scientists can tell it's a wetland. They check things such as the soil and plants. The yellow and pink wildflowers in the bottom photo on page 13, for example, happen to like their roots in soggy soil.

Just remember these three things from Mr. Mallard's intro to wetlands on page 2: water, mucky soil, and "wet-footed" plants. Got the picture?

Yeah, but are all wetlands the same?

No way! Most folks think of three major wetland groups: swamps, marshes, and bogs. It's easy to tell the difference between the first two. Swamps have mostly trees or shrubs, and marshes have mostly grassy plants. Bogs are spongy, mossy wetlands where dea d plants pile up faster than they can rot away. All those plants form thick layers of peat.

Lakes are wet. Aren't they wetlands too?

Not really--they're too wet. Remember wet-footed plants? Well, lakes are mostly too deep for plants to grow right up out of them. That goes

for oceans and most ponds, rivers, and streams too. But the edges of these bodies of water and waterways . . . now, that's a different story.

Different, how?

The edges are where the water is often shallow enough --or the soil just soggy enough--for wetland plants to take hold. But you can also find wetlands far from any deep water. Mountains may have low spots where water collects. And water seeping up from un derground can make a wetland--even in a desert.

No matter where you find them or what you call them, wetlands make wonderful places to explore. So come along with me, Wet Willy, and check out some wetlands right now. How? Just unfold the next pages to march into a freshwater marsh, slog through a salt marsh, and tromp in a cypress swamp!

When you get to each one, take a good look first. What kinds of plants do you see there? How many different animals can you find? What are they doing? Next, check it all out by reading. And don't miss the list of who's who in each wetland.

FRESHWATER MARSH

The whole country is dotted with freshwater marshes. Some may be no bigger than a kid's wading pool. Other marshes--such as the Everglades in Florida--stretch as far as you can see.

It's easy to guess what makes a wetland a freshwater wetland. (The water doesn't come from the salty ocean.) But what makes it a marsh? NO TREES! There may be a few shrubs here and there. But mostly you'll find grassy plants--such as rushes, reeds, sedges , or wild rice.

Many freshwater marshes form around the edges of lakes and ponds. Over time, a lake or pond may keep shrinking until there's just a wet meadow or a shrub swamp. Those are two other types of wetlands.

If you compared two freshwater marshes in different places, you'd find they have some of the same kinds of plants and animals. Take a close look at the Virginia marsh shown here. It formed when beavers dammed a stream, which flooded the surrounding land. (Also see pages 4-11.) Can you still find any sign of the beavers?

Now look for some tall cattails topped with brown seed heads. See that red-winged blackbird perched in the cattails? He's flashing his bright shoulder patches and singing kong-ka-REEE! Maybe his mate has a nest nearby.

In other spots, you can see ducks, geese, and wading birds. Look, that king rail just caught a crayfish! And don't miss the deer drinking in the distance. Can you tell where a raccoon may have gone fishing for crayfish the night before? (Hint: Look for tr acks in the mud.)

A freshwater marsh is a wonderful place for insects. A dragonfly is resting on a branch--while munching a mosquito. Bet you can find even more insects under the water. They might make a meal for a frog, turtle, or fish. Speaking of fish, that little pumpk inseed had better speed up. A big pickerel is right on its tail!

Who else is at home in this mushy marsh?

1 cattail

2 red-winged blackbird

3 red-shouldered hawk

4 beaver lodge

5 dragonfly

6 Canada geese

7 muskrat

8 northern water snake

9 spotted turtles

10 mallards

11 great blue heron

12 king rail

13 bladderwort

14 water striders

15 backswimmer

16 giant water bug

17 pumpkinseed

18 predaceous diving beetle

19 chain pickerel

20 duckweed

21 golden shiners

22 leopard frog

23 raccoon tracks

24 common yellowthroat

25 arrowhead

SALT MARSH

Follow the U.S. coastline, and you'll find saltwater wetlands. Around Florida's tip, there are shrubby ones called mangrove swamps. But everywhere else, you'll see grassy wetlands. These are the salt marshes.

The water in some salt marshes is nearly as salty as the sea. In places where rivers run into the ocean, the marshes have a mix of fresh and salt water. Either way, tides rule in a salt marsh. At high tide, a large part of the marsh is under water. At low tide, some of the land is visible again.

The plants and animals that live here are used to the daily rising and falling of the water. Shorebirds, for example, poke their beaks into the mud for worms and clams when the tide is out. When the tide comes back in, fish can get to the clams and worms.