Wetlands
As at Bushy
Park
Wetlands
Black Swan on
the
southern lake at
Bushy Park
Wetlands.
What is a
Wetland?
A Wetland is an area of land where the water level remains near or above the surface of the ground for most of the year. Plant life is limited to species that can withstand having their roots submerged for long periods of time. Wetlands are usually classified as Swamps, Marshes, or Bogs, according to the type of soil and plant life they contain.
Types
of Wetland
• Swamps are wet areas of land where trees and shrubs grow
and where surface water is present for at least part of the year.
Swamps occur worldwide in lowland and coastal areas, and near slowly
flowing rivers. A wide variety of plants and animals live in swamps.
The moist, usually mineral soil, supports woody trees, shrubs, vines,
and other plant life. Ponds and streams in swamps provide a home
for fish, frogs, snakes and tortoises. Birds and insects also live
in swamps. Swamps may have either fresh water or salt water. Freshwater
swamps have constantly changing water levels that reflect changes
in rainfall. Most freshwater swamps flood during only part of each
year. The water level of saltwater swamps depends on the water level
of the body of salt water that supplies the swamp.
• Marshes are
wet areas where herbaceous plants such as reeds, grasses, rushes,
and sedges grow. Marshes are found in places where the shape of
the land and the nature of the soil combine to produce permanently
moist ground. Marshes provide food or shelter for many kinds of
animals, including fish, frogs and water birds. Most marshes are
covered by fresh water or by salt water. An estuarine marsh is washed
by a tide of salt water part of the time and by fresh water the
rest of the time. Estuarine marshes lie along coasts at places where
fresh water flows into the sea. The mixture of salt and fresh water
provides a rich supply of food that supports an especially large
variety of animal and plant life.
• Bogs are wet areas of spongy land characterized by
acidic soil and the heavy growth of mosses, especially a type called
sphagnum, which absorbs water as a sponge does. Bogs contain almost
no minerals because the primary source of water is rainwater, which
contains few minerals. Consequently, bog plant life consists of
simple plants that can subsist on less nourishing soil like mosses,
sedges, and reeds. A bog also includes other plants and partly decayed
plant life called peat. Most bogs are in cooler regions and appear
relatively dry with only small amounts of shallow water visible.
Animal life is more limited in bogs, with frogs being the most likely
found. Bogs develop in shallow lakes, along slowly moving streams,
and in places that have heavy rainfall and poor water drainage.
