Selected Wetland Glossary

Anaerobic: Having no molecular oxygen. Reduced amounts of oxygen are common to many wetlands.

Buffer zone (reserve zone): Regarding wetland protection, a buffer zone is the area beyond the wetland itself that is deemed to vital to the health of the wetland and therefore deserving of protection. Buffer zones have legal standing in many places, including Washington State. In BC the buffer zone concept is enshrined in the Forest Practices Code, where it is called a reserve area.

Conservation: Perhaps once meant leaving things in their natural state. The word ‘preservation’ is now used to describe this. Wetlands in Canada defines conservation as “that aspect of renewable resources management which ensures that utilization is sustainable and which safeguards ecological processes and genetic diversity for the maintenance of the resources concerned.”

Ditch: Any channel that has been specifically dug to facilitate drainage.

Dredging: The excavation of the bottom soil of a wetland. Common practice in estuary areas, especially where sediments fill in shipping lanes in larger rivers, in which case dredging may be a tool in wetland restoration. A practical tool in creating artificial wetlands as well.

Ecosystem: A term coined in 1935 by the Oxford-based ecologist A.G. Tansley as a substitute for terms such as “community,” which he thought were excessively “anthropomorphic or vegetative.” An ecosystem is the sum of the interactions and energy transfers between a given set of organisms and their environment. A geographical unit in which a somewhat defined set of energy transfers occur.

Ecotone: A transition area between two different ecosystems or communities. A small shrub area between a wetland and a forested upland slope would constitute an ecotone.

Estuary: An inlet of the sea reaching a river valley as far as the upper limit of tidal rise where fresh and saline waters mix.

Eutrophic (eutrophication): The process of excessively fast growth of plants (especially algae) resulting from an over-abundance of nutrients in the water, especially nitrogen and phosphorous. The large quantities of biomass created lead to ecosystem succession as a result of the filling in of the water with plant material.

Floodplain: Any area near a body of water that is, or was, occasionally or periodically flooded by the nearby river, lake or ocean.

Forest Practices Code: BC legislation that sets environmental standards for the logging industry. Wetlands are granted some protection under the Code, but many feel that the provisions for buffer zones are insufficient.

Groundwater: Water that is passing through or standing in the soil and underlying strata.

Habitat: Home. The place where any given organism lives and works.

Hummock: A lump in a wetland. In the Arctic it will have an ice core. In Southern environments it will have a core of gravel or dense vegetation.

Hydric soils: Any soil that is sufficiently wet, or wet for a long enough portion of the year to encourage the existence of an anaerobic environment. The presence of hydric soils is a key indicator of wetland habitat.

Hydrologic cycle: The ongoing movement (recycling) of water between the atmosphere, the land, freshwater systems and the oceans. The process varies, but typically might follow the path of: condensation, precipitation, runoff, soil absorption, evaporation, evapo-transpiration from plants, and release through combustion and animal respiration. One could look at wetlands as being devices to slow the hydrologic cycle, thereby making water available to lifeforms that would have otherwise missed out as water sped along to the ocean.

Marshes: These come in many forms, but basically marshes may be thought of as treeless wetlands fed by any of the three main types of shallow water: fresh, brackish or saline. Under the Canadian wetland definition system (in Wetlands of Canada) a marsh is “a mineral wetland or peatland that is periodically inundated by standing or slowly moving water .... The waters are rich in nutrients ... characteristically showing zonal or mosaic surface patterns composed of pools or channels interspersed with clumps of emergent sedges, grasses, rushes, reeds...”

Mire: An English wetland term. Covers all kinds of peatlands.

Mitigation: A term more commonly used in the US. It describes the effort to reduce the negative impact of any human activity on wetlands. It takes the form of avoiding, minimizing, or compensating for the perceived negative effects of a development or activity.

Monitoring: Keeping an eye on wetlands for everything from poaching to dumping; from going to council meetings to tracking natural change and evolution. Land use decisions by councils and the actual land use by people may both be monitored.

Nutrients: Any material, whether organic or not, that may be used by plants and animals to sustain their various metabolic processes. Nutrients range from free-floating chemical compounds to the proteins and carbohydrates digested when an organism eats another organism. Wetlands are generally nutrient-rich, and therefore life-sustaining, ecosystems.

Paludal: Of a marsh; marshy, marsh-like.

Paludification: A useful term describing the process by which a bog or a marsh expands in size due to a rise in the water table. Paludification is a natural process that often results from the wetland’s drainage being impeded by the vegetation that the wetland has produced. This process is somewhat at odds with succession.

Peatlands: A generic term including all types of peat-covered terrain. Many peatlands are a complex of swamps, bogs, and fens.

Ponds: A body of water midway in its lifecycle between a lake and a wetland. Its shoreline will be wetland. Its water content may be seasonal or permanent. Pond succession, resulting from eutrophication, usually indicates that pond-sites will soon be wetland sites.

Salinity: The amount of soluble salt in water.

Salt marsh: A marsh subject to daily or seasonal inflows of brackish or saline water.

Sedimentation: Small solid material dropping out of water. The stuff that settles to the bottom as a result of gravity operating on it. This process happens more readily when water ceases to move quickly, as is almost always the case in wetlands. (The main exception being some river shorelines.)

Succession: The gradual replacement of one kind of ecosystem by another one, i.e., lake becomes pond; pond becomes wetland; wetland becomes scrub forest; etc. Not to be confused with the replacement of wetlands by subdivisions, which has another name.

Upland, upland slope: Uphill from the wetland. By definition it must have good drainage because if it doesn’t it will form part of the wetland itself rather than a drier watershed slope above it. Also, by definition, it has to be sloped, because if it isn’t water will usually pool, and a wetland will form. (See watershed.)

Water table: The upper level of the groundwater or the level below which the soil is saturated with water. So in a wetland the water table may be at or near the surface even if you don’t see any pools of water.