Although they may be little known to many people, wetlands are a critical part of the American landscape.

Wetlands are areas of land that are covered with water for at least part of every year. Marshes, swamps and bogs are all types of wetlands.

And the more scientists learn about wetland ecosystems, the more we realize how important it is to protect these fascinating places. Wetlands serve many important functions. They store and hold onto water during floods, then slowly release it over time. They also clean water by slowing down water flow, which allows plants and other organisms to remove harmful deposits.

Wetlands also provide important habitat for many species of animals, plants, and fish. Roughly one-third of the endangered and threatened species in the United States live in wetlands. Other animals use wetland areas foe breeding or raising their young. These animals include birds like the bald eagle, osprey, common loon, and the king rail.

Many freshwater bird species, and most amphibians are depend on wetlands for survival.

And as more becomes known about their importance, more communities are planning growth in ways that preserve wetlands. Here in Dane county for instance, development plans on the north side of Madison included a plan to preserve Cherokee Marsh.

While wetlands are home to many endangered species, these areas are themselves also threatened. Wetlands are fragile. They are often destroyed by human activity—drained for farmland or paved to provide new land for buildings and houses. People also dam or flood wetlands to make ponds and lakes.

Currently, only one hundred million acres of wetlands remain in the United States. This is less than half of what was here four hundred years ago.

Wetlands form important ecosystems. They provide habitats for many species and are critical to purifying and storing water.

[Sources: The World Almanac for Kids; Wisconsin State Journal]