|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|wetland (wět'lānd') Pronunciation Key
A low-lying area of land that is saturated with moisture, especially when regarded as the natural habitat of wildlife. Marshes, swamps, and bogs are examples of wetlands. See more at lacustrine, marine, palustrine, riverine.
Our Living Language : Wetlands are areas such as swamps, bogs, and marshes where water either covers the soil or is present at or near the surface, particularly in the root zone, at least a good portion of the year, including the growing season. In the past, wetlands were generally considered unproductive or undesirable lands—smelly and unhealthful, a breeding ground for mosquitoes and other pests—and many were filled in to create farmland or to develop land for housing and industrial use. More than half of the original wetlands in the continental United States have disappeared in the name of reclamation, disease prevention, and flood control. Scientists now realize that, far from being noxious barrens, wetlands play a key role in the ecosystem. They act as filters, removing pollutants, including metals, from waters. They serve as reservoirs, and they aid flood and erosion control by absorbing excess water. Wetlands are home to a great variety of plant and animal species, some endangered, that have evolved to live in the wetland's unique conditions. The preservation and, where possible, restoration of these vital habitats has become a primary goal of environmentalists around the world.
terrestrial ecosystem characterized by poor drainage and the consequent presence most or all of the time of sluggishly moving or standing water saturating the soil. Wetlands are usually classified, according to soil and plant life, as bog, marsh, or swamp (qq.v.). Because wetlands occur at the interface of a body of water and the land, they are examples of boundary ecosystems.
Learn more about wetland with a free trial on Britannica.com.