Chapter –Iii Classification and Distribution of Wetlands
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CHAPTER –III CLASSIFICATION AND DISTRIBUTION OF WETLANDS 69 CHAPTER –III CLASSIFICATION AND DISTRIBUTION OF WETLANDS 3.1. Definition of Wetland: “Wetlands encompasses a wide array of “wetlands” also called marshes, bogs, swamps, fens, pocosins, and other names” (Tiner, 1999).Wetlands are neither truly aquatic nor terrestrial, generally depending on seasonal variability. Thus, wetlands reveal vast diversity according to their genesis, geographical location, water regime, dominant plants, animals and soil. Because of their transitional nature, the boundaries of wetlands are also difficult to delineate. Based on multifaceted observations and diverse objective and orientation, different individuals, institutions, agencies and countries have given different definitions for wetlands. Wetlands are defined differently by countries in their domestic legislations (MOEF, 2009). Most of the countries have given a narrow definition in order to limit the field and scope of wetland protection. There is a lot of controversy regarding the definition of a wetland not only in our country but also all over the world. 3.1.1. Definition of Wetland before Ramsar Convention: One of the most well accepted early definitions of wetland was given by S.P. Shaw & C.G. Fredine (1956) who suggested the term Wetlands as ‘lowlands covered with shallow and sometimes temporary or intermittent waters.’ These are referred to by such names as marshes, swamps, bogs, wet meadows, potholes, sloughs, and river-overflow lands. Shallow lakes and ponds, usually with emergent vegetation as a conspicuous feature, are included in the definition, but the permanent waters of the streams, reservoirs and deep lakes are not included. Neither are water areas that are so temporary as to have little or no effect on the development of moist soil vegetation” 3.1.2. Definition of Wetland after Ramsar Convention: The first World Convention on Wetlands was held on 2 February 1971 in Ramsar city, Iran. The Ramsar Convention took a broad approach in determining the wetlands which come under its mandate in Articles 1.1 and 2.1 as shown below: 3.1.2.1. Article-1.1: Under the text of the Convention (Article1.1), wetlands are defined as an “ area of marsh, fen, peat land or water, whether natural or artificial, permanent or temporary, with water 70 that is static or flowing, fresh, brackish or salty, including areas of marine water, the depth of which at low tide does not exceed six metres.” 3.1.2.2. Article-2.1: In addition, to serve the purpose of protecting coherent sites, the Article 2.1 provides the wetlands as: “May incorporate riparian and coastal zones adjacent to the wetlands, and islands or bodies of marine water deeper than six metres at low tide lying within the wetlands”. 3.1.2.3. Other Notable Definitions: Space application centre (ISRO) defineswetlands as: “All submerged or water-saturated lands, natural or man-made, inland or coastal, permanent or temporary, static or dynamic, vegetated or non-vegetated, which necessarily have a land-water interface”. The US Department of Interior Fish and Wildlife Service Authority adopted the following definition of Cowrdin in 1979 to prepare a status of wetlands in the USA: “Wetlands are lands, transitional between terrestrial and aquatic systems, where the water table is usually at or near the surface, or the land is covered by the shallow water”. The notification of the Government of India in the Ministry of environment and Forest, S.O number 114 (E) dated 19th February, 1991 described that, wetland is an area or of marsh, fen, peat land or water; 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 meters and includes all inland waters such as lakes, reservoir, tanks, backwaters, lagoon, creeks, estuaries and manmade wetland and zone of direct influence on wetlands that is to say the drainage area or catchment region of the wetlands as determined by the authority but does not include main river channels, paddy fields and the coastal wetland.” The Kerala Conservation of Paddy Land and Wetland Act, 2008 (Section 2(XVII) defines wetland as: “… land lying between terrestrial and aquatic systems, where the water table is usually at or near the surface or which is covered by shallow water or characterized by the presence of sluggishly moving or standing water, saturating the soil with water and 71 includes backwaters, estuary, fens, lagoons, mangroves, marshes, salt marshes and swamp forests but does not include paddy lands and rivers”. Shaler (1890), who defined it in a report, gave one of the earliest definitions of wetland in his article “General Account of the Freshwater Morasses of the United States” as “all areas… in which the natural declivity is insufficient, when the forest cover is removed, to reduce the soil to the measure of dryness necessary for agriculture. Wherever any unprofitable until the land is necessary to secure this desiccation, the area is classified as swamp”. “…… areas of seasonally, intermittently, or permanently waterlogged soils or inundated land, whether natural or artificial, fresh or saline, e.g., waterlogged soils, ponds, billabongs, lakes, swamps, tidal flats, estuaries, rivers and their tributaries.” (Semeniuk, 1995). Wetlands form the transitional zone between land and water, where saturation with water is the dominant factor determining the nature of soil development and the types of plant and animal communities living in and on it (Cowardin et al, 1979). Wetlands are “land permanently or temporarily underwater or waterlogged. Temporary wetlands must have surface water or waterlogging of sufficient frequency and/or duration to affect the biota. Thus the occurrence, at least sometimes, of hydrophytic vegetation or use by water birds is necessary attributes. This wide definition includes some areas, whose wetland nature is arguably, notably land subject to inundation but having little or no hydrophytic vegetation and bare ‘dry lakes’ in the arid interior” (Paijmans et al, 1985). “A wetland is an ecosystem that depends on constant or recurrent, shallow inundation, or saturation at or near the surface of the substrate. The minimum essential characteristics of a wetland are recurrent, sustained inundation, or saturation at or near the surface and the presence of physical, chemical, and biological features reflective or recurrent, sustained inundation or saturation. Common diagnostic features of wetlands are hydric soils and hydrophytic vegetation. These features will be present except where specific physiochemical, biotic or anthropogenic factors have removed them or prevented their development” (NRC, 1995). 72 3.2. Classification of Wetland: 3.2.1. Ramsar Classification of Wetland: The wetland types scheduled under, are from the “The Ramsar Classification System for Wetland Type” as accepted by Recommendation 4.7 and amended by Resolutions VI.5 and VII.11 of the 1990 Conference of the Contracting Parties. The categories scheduled herein are proposed to provide only a very broad framework to aid rapid identification of the main wetland habitats represented at each site. The Ramsar Convention developed a new and more widespread wetland classification system (adopted in 1990 and modified in 1996) (Table-3.1). Table3.1:Ramsar Classification System for Wetland Type Code Marine/Coastal Wetlands A Permanent shallow marine waters; in most cases, less than six metres deep at low tide; including sea bays and straits B Marines btidal aquatic beds; including kelp beds, sea-grass beds, and tropical marine meadows. C Coral reefs. D Rocky marine shores; including rocky offshore islands, sea cliffs. E Sand, shingle or pebble shores; including sand bars, spits and sandy islets; dune systems and humid dune slacks. F Estuarine waters; permanent water of estuaries and estuarine systems of deltas. G Intertidal mud, sand or salt flats. H Intertidal marshes; including salt marshes, salt meadows, saltings, raised salt marshes; tidal brackish and freshwater marshes. I Intertidal forested wetlands; including mangrove swamps, nipah swamps and tidal freshwater swamp forests. J Coastal brackish/saline lagoons; brackish to saline lagoons with at least one relatively narrow connection to the sea. K Coastal freshwater lagoons; including freshwater delta lagoons. Zk(a) Karst and other subterranean hydrological systems, marine/coastal Inland Wetlands L Permanent inland deltas. M Permanent rivers/streams/creeks; including waterfalls. N Seasonal/intermittent/irregular rivers/streams/creeks. O Permanent freshwater lakes (over 8 ha); including large oxbow lakes. P Seasonal/intermittent freshwater lakes (over 8 ha); including floodplain lakes. Q Permanent saline/brackish/alkaline lakes. 73 R Seasonal/intermittent saline/brackish/alkaline lakes and flats. Sp Permanent saline/brackish/alkaline marshes/pools. Ss Seasonal/intermittent saline/brackish/alkaline marshes/pools. Tp Permanent freshwater marshes/pools; ponds (below 8 ha), marshes and swamps on inorganic soils; with emergent vegetation water-logged for at least most of the growing season. Ts Seasonal/intermittent freshwater marshes/pools on inorganic soils; including sloughs, potholes, seasonally flooded meadows and sedge marshes. U Non-forested peatlands; including shrub or open bogs, swamps and fens. Va Alpine wetlands; including alpine meadows, temporary waters from snowmelt. Vt Tundra wetlands; including tundra pools, temporary waters from snowmelt.