Wetlands

Wetlands

Wetlands are taken to mean areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres (Article 1.1 of the Ramsar Convention on Wetlands, 1971).

Inundated (waterlogged) lands can be developed under the influence of various factors, as such lands are located in depressions, and rain and other runoffs regularly fill those. Some of inundated areas are located practically at the same level as groundwater and are fed from below. Other types of inundated lands are located near to rivers or other water bodies which always overflow. In coastal zones, those are filled due to occurring flood tides.

Some inundated lands are formed because of minor external effects. So, beavers turn depressions into swamps or sections of woodland into waterlogged areas by constructing dams in streams. People also make lands wet. For example, an organization engaged in improving the condition of wildlife can make certain areas inundated to create habitat for fish and wildlife.

There are many types of swamps, marshes, overflow lands, and other inundated lands. And all of inundated lands have a series of features that distinguish them from other habitats. The majority of ecologists define inundated lands as areas the soil of which becomes waterlogged, at least periodically, or the surface of which is covered with water sustaining the life of plants and animals adapted to living in aquatic environment.

Marine: coastal lagoons; offshore zones the depth of which at low tides does not exceed six meters, together with islands located in shallow water; riparian wet lowlands flooded with seawater at high tides and upsurges (marshes); and beaches, cliffs, and other natural complexes close to seashore.
Estuarial: deltas with river branches, arms, their doabs, overflow lands, estuary shallow areas in the sea (delta fronts).
Lake: natural water bodies differing in size, origin, and other characteristics, located in slight depressions in the ground, permanent or temporary, static or flowing, with water with different salt content (load), including saline, as well as connected with local lakes.
River: rivers, streams, temporary watercourses together with floodplains and other valley complexes.
Swamped: marshes (overmoistened areas with peat layer at least 0.3 m thick) of different types, including lowland bogs (fens), mesotrophic (transitional) and upland, as well as the woodlands, scrubs that surround swamps, and other palces.

In addition, there are artificial wetlands such as ponds made for various economic purposes, reservoirs, channels for irrigation and water supply, fields filled with water.

Why do wetlands attract so much attention? Because their role in natural processes and in the life of the human society is extremely important and diverse. Among critical ecological functions of wetlands are the following:

accumulating and storing fresh water;
regulating surface and subsurface runoffs;
maintaining groundwater level;
purifying of water, blocking contaminants;
restoring oxygen to the atmosphere;
extracting carbon from the atmosphere and collect;
stabilizing climatic conditions, particularly rainfall and temperature;
controlling erosion, stabilizing the position of water fronts; and
serving as a habitat for many types of plants and animals, including rare and economically significant ones.

Classification of wetlands for the purpose of inventory of those

The wetland kingdom	Wetland type	Wetland class	Wetland group
1. Sea	1. Open shallow marine areas	1. Littoral	1. Stony 2. Sandy
	1. Open shallow marine areas	2. Sublittoral	1. Stony 2. Sandy
	2. Bays and straits	1. Exposed during low tides (watten, nyashi)	1. Sandy 2. Silty 3. Silty with sandy ridges
		2. Deep-water bays
		3. Shallow-water bays	1. With underwater angiosperms and charophytes meadows 2. With underwater meadows composed of other algae 3. Without mature vegetation (bare bottom)
		4. Desalinated-water bays	1. With underwater meadows of angiosperms and charophytes 2. With underwater meadows composed of other algae 3. With bushes of emergent vegetation 5. With bare bottom
		5. Lagoons	1. Salty 2. Desalinated
	3. River mouths	1. Estuaries 2. Deltas
	4. Sea coasts	1. Small islands	1. Rock-ribbed 2. Non-rock-ribbed
		2. Costs of continents and mainlands	1. Meadow 2. Sandy 3. Pebble beaches 4. Rocky 5. Marshes
2. Valley	5. Rivers and their valleys	1. Lowland type	1. With the developed system of dead channels and channels, of meadow boggy type 2. The same, of forest type 3. With the undeveloped system of dead channels and channels, of meadow boggy type 4. The same, of forest type 5. Lake and reservoir deltas
		2. Mountain type
		3. Streams	1. Meadow 2. Forest 3. Tundra
	6. Reservoirs	1. Lowland type with stable level
		2. Plain type, with stable level	1. Regular seasonal fluctuations of level 2. Multiple random fluctuations of level
		3. Mountain type
3. Watershed and drainless areas	7. Lake groups	1. Stable	1. Eutrophic 2. Mesotrophic 3. Oligotrophic 4. Complex
		2. Cryogenic	1. Tundra 2. Taiga and meadow
		3. Of arid areas, unstable	1. Freshwater 2. Saline 3. Complex
	8. Particular lakes	1. Stable	1. Saline 2. Brackish 3. Freshwater eutrophic type 4. Oligotrophic 5. Dystrophic
	8. Particular lakes	2. With variable water level	1. Saline 2. Brackish 3. Freshwater 4. Variable salinity и
	9. Swamps	1. Lowland and transitional moor	1. Having many lakes 2. Having few or no lakes
	9. Swamps	2. Upland moor	1. Having many lakes 2. Having few or no lakes
	10. Intermittent water bodies		1. Tundra 2. Forest 3. Meadow 4. Steppe 5. Desert
	11. Artificial reservoirs	1. Ponds	1. Fish rearing 2. Domestic 3. Mill and beaver 4. Flooded opencast mines
	11. Artificial reservoirs	2. Irrigation systems	1. Rice fields 2. Drainage systems 3. Water bodies for discharge 4. Filtration water bodies

* - Classification by Yu.A. Isakov (1968), improved by V.G. Krivchenko and V.G. Vinogradov (1996)

Wetlands are significant for people to a considerable extent because of their ecological role. The human being depends to a large extent on the condition of those, because they:

serve as the main source of drinking and pure water;
maintaining the groundwater table, mainly determine the productivity of agricultural lands;
serve as the basis for some types of animal husbandry (poultry farming, fur farming, haymaking, valuable additional fertilizing – sapropel);
provide farms/households with fuel, construction materials, fertilizers (wood, reed, turf);
function as raw materials sources (fishing, hunting, berrying);
provide great opportunities for tourism, use of recreational and balneological purposes;
serve as the necessary environment for the livelihood of the indigenous peoples that preserve traditional way of housekeeping.

Source: Wikipedia