The three main types of wetlands are swamps, marshes, and peatlands. They can be identified by size, the type of soil, and the plants that live in them, as well as by the type and amount of water they hold. Some located inland are fresh water, while coastal wetlands may be fresh or salt water. Many areas can contain several different types of wetlands. The Great Dismal Swamp in Virginia, which contains both peat bogs and freshwater swamps, is an example.

Swamp

A swamp is a wetland that is characterized by poorly drained soil and plant life dominated by trees. Swamp soil is usually saturated for most of the year. The water can range from 1 inch (2.5 centimeters) to more than 1 foot (30 centimeters) deep.

Because swamp ground is constantly waterlogged, plant life is kept to a minimum. The trees and plants that grow there must...