Most wetlands consist of either mosses, grasses or certain types of trees. They are usually classified, according to the soil and plant life found there, as bog, marsh, or swamp. Bogs tend to have more mosses and other specialized plants than grasses or trees and also have spongy peat soils. Their soil is made up almost entirely of organic matter with few minerals. Animal life is uncommon on bogs.
Marshes contain mostly grasses with a small number of trees.
They usually have soils that are very rich in minerals. Marshes tend to be formed by river mouths in river delta areas. Swamps are almost entirely made up of trees. They have a low amount of organic matter in the soil due to minerals preventing the build up of these materials. Swamps are generally found along rivers in low lying areas.