Wetlands Glossary



Acre/foot: The amount of water needed to cover one acre of land with one foot of water.

Adaptation: The change of structure or behavior of a plant or animal, which makes it better suited for its environment.

Agriculture: the cultivation and harvest of food crops; farming.

Aeration: to mix air into soil or water to provide oxygen to bacteria, animals, etc.

Algae: a group of simple organisms; tiny green single-celled plants that live in water and produce oxygen.

Alien species: a species of plant or animal that has been introduced into a region or habitat where it is not native; can be harmful to native species and biodiversity.

Alligator: a large reptile that lives in southern coastal wetlands and swamps; an ancient species linked to dinosaurs

Amphibians: a group of animals able to function on land and in water; frogs, toads, salamander.

Anaerobic: a condition of or process requiring no oxygen.

Aquatic: having to do with water.


Bacteria: micro-organisms that multiply through cell division; some bacteria cause disease, while most other bacteria are vital to natural life processes.

Bald Cypress: a large evergreen tree common to southern swamps.

Bald Eagle: the national symbol of the USA; a large, white-headed raptor with a massive beak and strong feet; common in coastal areas and in large wetlands.

Beaver: a furry mammal with a flat hairless tail known for cutting trees and saplings for building dams and lodges to create its own habitat

Benthic: living or found on the bottom of lakes and streams

Biodiversity: a measure of how many different species of plants and animals are present in an ecosystem; high biodiversity is a sign of ecological health and stability.

Bittern: a wading bird common to wetlands; secretive and timid; its call is a thumping croak

Bloodworm: a thread-like, red worm usually found in muddy stream bottoms

Bog: a type of wetland that builds up peat, has no inflows or outflows of water, has acidic water, and supports acid-loving plants and mosses like sphagnum.

Boreal: sub-arctic; between temperate zone and arctic zone.

Bottomland: lowlands along streams and rivers, usually on floodplains and supporting hardwood forests.

Bullfrog: a large amphibian with powerful legs for jumping; usually found in ponds and wetlands.

Bulrush: a group of common grass-like plants found in wetlands


Carnivore: an animal that eats meat

Cattails: a very tall, grass-like plant common to freshwater wetland

Chesapeake Bay: an historic bay stretching between Maryland and Virginia on the Atlantic Coast of North America; it was once an important source of fish and shellfish before suffering from extensive water pollution problems.

Clay: microscopic mineral soil particles; the smallest of three classes: sand, silt, clay.

Clean Water Act: federal law passed in 1972 to improve water quality in streams, rivers and lakes

Community: A place that plants and animals call home, where each has a job to do, and can find all of their needs (energy, shelter, space and water).

Condensation: The process of a substance changing from a gas to a liquid, usually as a result of cooling. Examples: morning dew, or “sweat” on the outside of a glass of ice water.

Conservation: the care and management of natural resources such as soil, air, water and wildlife.

Constructed wetlands: wetlands that are created by humans, sometimes in places where there were no wetlands before.

Consumer: any animal that eats; Primary consumers, like rabbits, eat plants. Secondary consumers, like fox, eat rabbits. Tertiary consumers, like vultures and bacteria, usually eat dead animals.

Coontail: an aquatic plant common to lakes, ponds and wetlands.

Cottonmouth moccasin: a venemous snake found in southern swamps and rivers.

Cottonwood: a fast growing, short-lived tree usually found growing near water.

Cranberry: an evergreen plant that grows in New England wetlands and produces edible fruit.

Crayfish: a freshwater crustacean that looks like a little lobster; also called crawfish and crawdad; common to rivers, streams, lakes and wetlands.

Cypress: a large tree growing to over 100 feet in wet soils and in swamps. Although similar in appearance to the cedar tree, cypress trees drop their needles in the autumn.


Decompose: to breakdown into simple elements; decomposition is a process dead plants and animals go through when exposed to oxygen and bacteria; the result is an organic material returned to the soil.

Delta: an area of soil deposits at the mouth of a river where water flows into a gulf or bay; a delta is very rich with nutrients and supports abundant marine life.

Des Plains River Wetland Demonstration Project:

Dilute: To thin down or weaken as by mixing with water.

Dissolved oxygen: Oxygen dissolved in water, required by most aquatic animals.

Diversity: a variety of different types of individuals

Drainage: a system of drains or an area to be drained.

Ducks: a subfamily of birds able to float on water; they have webbed feet and large flat bills for feeding at or just below the surface of water.


Ecosystem: A community of living things and their interrelated physical and chemical environment.

Egret: a long-legged, long-necked bird in the same family as herons and bitterns; their long sharp bill is good for spearing and capturing fish; common to rivers, shorelines and wetlands.

Emergent: a type of plant rooted in shallow water but supporting stems and leaves that reach and grow up out of the water; cattails and arrowhead are emergent plants.

Endangered species: a species of plant or animal which is in danger of disappearing forever, usually because of a massive change or disturbance of its habitat.

Environment: The surroundings of a plant or animal including other plants and animals, climate and location.

Erosion: The removal or wearing away of soil or rock by water, wind, or ice.

Estuary: a wide mouth of a river usually affected by changes in water elevation due to ocean tides; normally these are exceptionally rich in plant and animal life, but river pollution has caused some to become “dead zones”

Eutrophic: water that is extremely rich in nutrients, usually resulting in some loss of aquatic life due to low oxygen levels.

Evaporation: The process of water changing from a liquid to a gas by exposure to heat.

Everglades: a vast shallow river and wetland which drains much of the Florida peninsula

Excess Nutrients: Nutrients are usually elements like nitrogen and phosphorus, or chemicals like ammonia, that help plants grow. Too many nutrients can cause big problems in streams and lakes by causing an explosion of plant growth. Excess nutrients can be washed off of farm fields and lawns into streams, wetlands and lakes during heavy rains. Although excess nutrients are not good for wetlands, wetland plant communities can help use up excess nutrients before the water reaches a stream or lake.


Fen: a type of wetland that builds up peat and receives some drainage from surrounding mineral soils and supports marsh like vegetation.

Filter: To remove or strain solid particles or impurities from a liquid or gas.

Floodplain: the area of land along a stream or river that becomes inundated during high water events usually in the spring.

Fresh water: Clean, unpolluted water without salt; inland waters.

Frog: a family of amphibians with smooth skin and powerful hind legs used for jumping; usually found in or very near water, or in trees.

Fungi: any of various plants that lack stems and leaves and reproduce through spores; vital to decomposition process.


Gator Hole: a hole or depression in the soil created by alligators to keep their skin wet; large gator holes are important habitats for fish, turtles and other aquatic animals.

Glacier: a huge mass of ice and snow which moves extremely slowly (inches per year); able to scrape off and move large amounts of earth.

Gleying of soil: soils which turn gray due to poor drainage and low oxygen.

Great Blue Heron: a large, gray-blue heron common to wetlands, shorelines and streams.

Great Kankakee Marsh: an extinct vast wetland complex which covered much of the northern part of Indiana and extended westward into Illinois; drained for agriculture.

Grebe: a duck-like family of birds with thin necks, small heads, lobed feet, small tails and pointed bills; grebes are diving birds that feed on fish, crustaceans, tadpoles and insects.

Green-winged teal: a cinnamon colored duck-like bird with green patches on its wings; common in fresh water marshes

Groundwater: any water found below the surface of the soil; groundwater can be found at great depths and is extremely slow moving.


Habitat: The environment where a plant or animal grows or lives. The arrangement of food, water, shelter, and space suitable to animals needs.

Hardpan: a compacted layer of clay soil underneath loamy soils which prevents water from draining down through the loam.

Horsetail: a hollow-stemmed, segmented plant found in wet soils.

Hydrologic Cycle: the water cycle: the unending cycle of evaporation, condensation and precipitation; world wide.

Hydrology: the study of the movement of water


Insectivorous plants: plants that receive nutrients from insects which are trapped and die inside plant structures; usually found in bogs with acidic water.

Intolerant: Unable to withstand and tolerate unhealthy conditions.

Inundated: being under water

Invertebrates: Animals without a backbone


Juncus: the genus of several species of wetland plants; rushes

Jurisdictional wetland: a wetland that is big enough and of high enough quality to be protected by law.


Kankakee River: now a distinct river channel flowing westward out of northern Indiana into the Illinois River; this river used to be a vast wetland.

Kettle: a bowl-shaped depression or low area formed in the ground by the weight, scraping action, or melt waters of a glacier; very common in the upper Midwest.

Kingfisher: a blue and white bird commonly found near water; feeds on fish


Lake Okeechobee: a large lake in southern Florida which drains into the Everglades.

Landscape: an expanse of natural lands

Loons: a fish-eating, diving bird common to northern lakes.

Loss of wetlands: an environmental concern about changes in wildlife habitat and large scale hydrology.


Macroinvertebrate: a variety of small animals which have no backbones and are able to be seen without the aid of a microscope.

Mallard: a species of duck; the male has a shiny green head and yellow bill.

Mangrove swamps and wetlands:

Marsh: a usually inundated wetland supporting emergent plants adapted to saturated soils.
Meadow wetlands: wet meadows and wet prairies were the normal plant communities found along stream valleys and surrounding wetlands, ponds and lakes.

Migration: the movement of wildlife, especially birds, across thousands of miles; usually occurs in spring and fall.

Mire: (Old Norse, myrr) a wet, soggy place in the ground.

Mitigation wetlands: wetlands constructed by people to make up for wetlands filled and destroyed during land development.

Mosquito: a biting, blood sucking insect that needs standing water for eggs and embryo development; very abundant in wetlands.

Muck: a sticky, wet, black organic soil.

Muskrat: a furry swimming rodent with a hairless tail.


National Wetlands Inventory: An ongoing inventory of all wetlands in the United States carried out by the US Fish & Wildlife Service. The inventory is based on information from aerial photographs; should be finished by 2000.

Nitrogen: an essential nutrient for plant growth; too much nitrogen and other nutrients can cause eutrophic conditions in aquatic habitats, and can lead to low dissolved oxygen and fish kills; nitrogen gas makes up 4/5 of the earth’s atmosphere.

“No Net Loss:” a goal set by the US government in the late 1980s to reduce the number of wetlands lost to agriculture and development.

Nonpoint source: a nonpoint source of pollution does not come out of one point such as a smokestack or a pipe in a streambank. Nonpoint sources of pollution are like fertilizers or soil running off of farm fields, or rainwater running off the surface of parking lots.

Northern harrier: this large raptor used to be called a “marsh hawk.”

Nutrient: an element or substance needed by plants and animals for growth and health.


Okefenokee Swamp: the legendary place of alligators, storks, bears, towering trees and black water in southeastern Georgia.

Organic: not mineral; a product of living organisms; organic soils are made of decomposed plant material.

Otter: a furry, swimming, carnivorous mammal with webbed feet.

Oxbow: a closed loop in a riverbend which gradually fills with plant life and organic soils.

Oxygen: a gas element essential to all life.


Peat: a soil of partially decomposed plants that builds up in poorly drained wetland habitats.
Pesticides: a type of manufactured chemicals used to kill unwanted bacteria, fungus, plants, insects, and animals.

pH: a chemical measurement of the acidity or alkalinity of a substance.

Phosphorus: a chemical element; a waxy, nonmetallic solid; an essential nutrient for plant growth.

Photosynthesis: a nearly miraculous chemical process in which plants convert water, carbon dioxide and sunlight into oxygen and sugars; occurs in the green chlorophyll of plant cells.

Pioneer species: a plant that can grow on newly exposed soils, and will grow until it is overgrown by competing, successional species.

Pitcher plant: a carnivorous plant found in bogs.

Pollution: solids, liquids and gases that, when put into soil, water or air, will harm plants, animals and the natural environment.

Pothole: a shallow, marshlike pond found in the Dakotas and central Canada; Prairie Potholes


Quercus: the genus of species of oak trees


Redwing: a blackbird common to wetlands; used to be called the “red-winged blackbird.”

Reptiles: snakes, lizard, turtles, dragons and alligators

Riparian wetlands: wetlands that occur along streams and river channels.

Roseate Spoonbill: a large rose-colored heron like bird with a bill like a spoon or spatula; flies with its neck outstretched.

Runoff: Water that drains or flows off the surface of the land after a rain.

Rush: a group of wetland plants with round, hollow stems


Sagittaria: the genus of a wetland plant species; common name is Arrowhead due to the shape of the large leaves.

Salamander: a four-legged, slick-skinned amphibian with a long plump tail; common to moist woodlands; breed and lay eggs in wetlands and vernal pools.

Salix: the genus of species of willow trees

Sandhill crane: a very large, long-legged, buff colored bird common to large wetlands and floodplains; can usually be seen during the growing season at FermiLab or Nelson Lake Marsh.

Sandpiper: a small long-legged bird common to mudflats and shallow wetlands.

Section 404: the section of the Clean Water Act which regulates the excavation and fill of wetlands.

Sedge: a large group of grass-like plants normally found in wet soils; many have triangular stems.

Sediment: mineral and organic particles which settle on the bottom from still waters of a stream or lake.

Seep wetlands: normally found on the side or at the base of a hill or slope; where ground water emerges from the soil surface through a layer of sand and gravel exposed on the side of a hill.

Soils: scientists work with more than 7,000 different soils; the texture, structure, and color of a soil is used to tell it apart from other soils.

Sora: a small, short-billed wading bird common to marshes and wet meadows; makes a very distinctive call: a descending whinny.

Southern deepwater swamp: large wooded blackwater wetlands common to Gulf Coast states.

Species: A population of individual plants or animals that are alike, and that are able to reproduce fertile offspring under natural conditions.

Stormwater: urban runoff from lawns, street and parking lots which usually enters a system of underground pipes to be deposited in a stream or river; polluted

Succession: The gradual and continuous replacement of one plant community by another. Succession will change a farm field into a prairie or mature forest over many decades.

Sundew: a species of insectivorous plant found in bogs.

Suspended Solids: Particles of soil and organic matter carried and suspended in moving water. Large particles like sand will drop out of the moving water quickly when it is slowed down. Small particles like clay will stay suspended in water until the water completely stops for a long time.

Swamp: an area of deep wetlands with large towering trees.


Teal: a type of surface-feeding marsh duck; green-winged and blue-winged.

Tidal wetlands: wetlands which are affected and depend on the incoming and outgoing tides on ocean coastlines, bays and estuaries.

Tolerant: The ability to resist the effects of something.

Transpiration: The process of water passing from a plant to the atmosphere.

Turtles: a reptile with a soft body inside a hard shell; usually associated with water.


US Army Corps of Engineers: a department of the US Army which controls all open waters (navigable rivers, lakes, etc.) of the USA

US Environmental Protection Agency: a federal agency created in 1972 to protect the soil, air and water resources of the USA

US Fish & Wildlife Service: a bureau of the US Department of the Interior which oversees the management and protection of wild animals and plants.


Vegetation: a variety of plants covering an area

Vernal pool: a short lived pool of water found in woodlands and prairies during spring time rains.


Wastewater: water which has been used; usually carries some form of pollution.

Water Conservation: Methods used to reduce the amount of water needed for homes, lawns, farming, and industry, thus increasing water supplies for long-term economic and social benefits.

Water Cycle: The continuous circulation of water in systems throughout the planet, involving condensation, precipitation, runoff, evaporation and transpiration.


Wetland: Any land area that tends to be regularly wet or flooded, and supports wetland vegetation.