What is a wetland, and what does it do? What use is it, and why do we need them? The answers to these questions are more important than a lot of people realize.
A wetland a natural area that holds water, but water is not always present. It provides food shelter and water for plants and animals. A wetland also provides flood control, offers recreation, holds groundwater, cleans water and controls shoreline erosion.
The major types of wetlands are swamps, marshes, bogs, fens and vernal pools. You can add to that, creeks, rivers, ponds, lakes, dunes and swales, flatwoods, floodplain forests, sedge meadows and seeps. Quite a few, aren’t there?
Among the questions I have been asked is, “How do I tell a swamp from a marsh?” They do seem similar, but the way to tell is to look around you. If you’re on the border of a river, pond, lake, or such, you’re in a marsh. If you’re further inland and you see a lot of trees and brush, you’re in a swamp.
The other question is a harder one: “Is this a fen or a bog?” To answer that question, you really have to know what kind of area you’re in. Strictly speaking, in a bog almost all the water comes from rain or snow; it contains few nutrients and is very acidic. It’s also defined as a pond filled with dead plant material.
The fen is formed by rain, snow and groundwater, rich in nutrients. A fen is a future bog.
Vernal pools are neat and wonderful wetlands. Vernal pools are formed mostly during spring rains. They will fill up, and when the water gets warm enough, the eggs from turtles, frogs, toads and salamanders hatch, grow up, make friends and lay more eggs. Then they go away to wherever it is they go.
As the pool dries up, the eggs sink to the bottom, where they remain until the next spring, when it all starts over again.
Those that are tied to a vernal pool seem to evolve at a faster rate than those that are hatched in other water sources. They have to mature before the pool dries.
Wetlands offer flood control. There is normally room in the wetland for flood storage. The vegetation present will slow the velocity of floodwater, helping to slow the flood as it moves downstream toward its destination.
Here are a few figures you can use: 11 species of birds use wetlands. On top of that, 28 species use wetlands during their migration. Thirty-five percent of rare or endangered species of birds are wetland users.
There are about 900 species of vertebrate animals (those with a backbone) that live either on or near a wetland. Plus we have the thousands of invertebrate animals that live in the wetlands (Those are what you see in the Pond Water class through the Parks Department.)
There are economics of wetlands to also consider. We get food such as fish from wetlands; selective harvesting of large trees gets us wood. Although not done much, trapping does provide income and keep populations in check.
The biggest use of wetlands is recreation. Think boating, water skiing, swimming and fishing.
Some studies suggest that a wetland next to a farm field is able to remove up to 80 percent of the chemicals that may wash off.
As you can see, a wetland is an important part of the environment, not only for the birds, animals and plants that grow only there, but also for us as humans.
In Part 2, we’ll discuss the wetland situation not only in the state, but also in Hancock County and the Parks Department. Stay tuned.
Joe Whitfield is a naturalist and gardener for the Greenfield Parks and Recreation Department. He can be reached at email@example.com.