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Summary
Environment Class 16

REVISION OF THE PREVIOUS CLASS (01:09 PM):

  • Functions of wetlands:
  • Protect coastal areas from shore erosion.
  • It helps in groundwater recharge.
  • It helps in nutrient recycling.

CRITERIA TO CHOOSE RAMSAR SITES (01:12 PM):

  • 9 Criteria are laid down for a given site to be chosen as a Ramsar site if it attracts any one of these criteria:
  • 1). It has representative or unique natural or near natural wetlands.
  • 2). It supports threatened species.
  • 3). It has important plant and animal species that are crucial for maintaining the biodiversity of a particular region.
  • 4). It supports plant and/or animal species that are in the critical stage of their life cycle or is providing refuge to species that are facing some adverse conditions.
  • 5). It regularly supports 20,000 or more water birds.
  • 6). It regularly supports at least 1% of the total population of species or subspecies of water birds.
  • 7). It supports a significant population of a large number of indigenous fish species or subspecies.
  • 8). It is an important breeding ground for fish or is a rich source of food for fish.
  • 9). It regularly supports 1% of the total population of species or subspecies of wetland-dependent nonavian animals.

MONTREUX RECORD (01:32 PM):

  • Montreux Record is a simple register of Ramsar wetlands created at the Brisbane conference in 1996.
  • This register includes those Ramsar wetlands which are undergone ecological changes, are undergoing ecological changes now, or are likely to undergo ecological in the near future primarily because of men's activity.

INDIA'S EFFORTS TO PROTECT WETLANDS (01:38 PM):

  • 1). The National Wetland Conservation Program was launched in 1986.
  • It provides for the protection of catchment areas of wetlands, aforestation of catchment areas, desilting wetlands which are silted, and development of fisheries and wetlands.
  • 2). National Lake Conservation Plan, 2001 was launched to conserve and manage the graded and polluted lakes in urban and semi-urban areas.
  • 3). India has set up the Center for Wetland Conservation and Management in 2021 within the National Center for Sustainable Coastal Management in Chennai.
  • This Center will take up research with regard to all aspects of wetlands including capacity building in people in matters of conservation, protection, and development of wetlands.
  • 4). The National Plan for Conservation of Aquatic Ecosystems was launched in 2015 which merged the National Lake Conservation Plan and the National Wetland Conservation Program.
  • 5). Wetland Conservation and Management Rules of 2010 have been revised in 2017 to provide for more effective conservation of wetlands.
  • These rules transferred the responsibility of identifying and managing wetlands to the states.

MANGROVES FOREST ECOSYSTEM (02:08 PM):

  • The Mangroves are salt-tolerant trees.
  • Mangroves are highly productive ecosystems.
  • Mangrove forests are Tropical forest ecosystems that are always part of the coastal intertidal zones.
  • In coastal areas, they can develop in the deltaic regions close to the coast, inter-tidal regions, and also within some areas of estuaries.
  • Since these plants always are part of saline waters, they have some adaptive structures to filter out this water and also to throw out the salt.
  • For example, the barks and roots are fully porous to filter and throw out saline water and also to capture more oxygen.
  • They have pneumatophores which are specialized roots that grow first grow into the soil and then grow upwards to come out of the water surface to capture more oxygen from the atmosphere.
  • They develop Aerial roots which are called prop roots which grow from the trunk above the water surface to capture more oxygen.
  • Rhizophora is the species that develops these prop roots very well.
  • Still roots or adventitious roots grow above the water surface over a tree trunk and multiply into a network and then grow into the soil to give strong mechanical support to the plant.
  • The plants have a viviparous mode of reproduction where the seeds germinate in the tree trunk, grow into a sapling, and then the sapling is detached from the trunk and falls to the ground to take roots to grow into a plant.

FUNCTIONS/IMPORTANCE OF MANGROVE FORESTS (03:07 PM):

  • 1). They act as natural shelter belts for coastal communities to protect them from possible tsunamis, tidal waves, and tropical cyclones.
  • 2). Protect shorelines/coastal areas from erosion.
  • 3). Since coastal mangroves are also wetlands, they purify river waters when rivers pass/flow through these mangroves into the ocean.
  • 4). Heavy metal can be absorbed by the vegetation of mangroves like water hyacinth, duckweeds, etc., 
  • The slowing down of water by mangrove forests also forces the deposition of heavy elements as sediments and purifying the waters before they enter into the ocean.
  • Therefore marine ecosystem that lives close to the coast like coral reef ecosystems are protected by the mangroves and also the river water and surface runoff are purified before they enter the ocean.
  • 5). The pneumatophores' roots trap sediments which fill up the water body over a period of time.
  • This leads to the development of tidal flats as landforms.
  • 6). The green plants of the mangrove forests start migrating food chains and the organic waste is the basis for the detritus food chain supporting many microorganisms, insects, and many invertebrates which can also support fish and birds.
  • These different food chains create rich biodiversity in these mangrove ecosystems.
  • 7). These ecosystems are rich bird habitats because the fish, insects, and fruits are food for the birds and the dense forest is the nesting ground for birds.
  • 8). The dense vegetation including the algal life becomes a major sink for carbon and therefore this withdrawal of carbon also influences the local climate.
  • 9). They are important recharge and catchment areas for underground water and hence participate in the hydrological cycle.
  • Mangroves forest in India:
  • 1). Sundarbans - has the highest area under the Mangroves.
  • Species:
  • Sunadri trees which are endangered
  • Rhizophora is famous for its aerial roots.
  • Avicennia is famous for its pneumatophorous structure.
  • Fern as border plants.
  • Animals:
  • 356 bird species.
  • 350 fish species including the Ganga dolphins.
  • 50 species of reptiles which are protected under the wildlife act of India.
  • 22 mammal species which are protected are part of Sundarbans (i.e. Sundarban is famous for the Royal Bengal tiger and crocodiles).
  • 2). Bhitarkanika, Orissa - Second biggest mangrove forest in India ( Gahirmatha beach famous for olive ridley turtle).
  • 3). The Gulf of Kutch is famous for dwarf mangrove forests.
  • 4). Pichavaram, Tamil Nadu

ESTUARINE ECOSYSTEM (03:45 PM):

  • Estuaries take the form of drowned river valleys close to the coast, coastal lagoons behind the sand bars, sandbars tidal marshes in inter-tidal regions, and some estuaries and ecosystems within deltas.
  • Estuaries will always have brackish water which results from a mix of seawater with fresh water coming from land.
  • Therefore estuaries will always have more salinity compared to the oceans and logons.
  • Estuaries are much deeper compared to lagoons, particularly if it is a drowned river valley estuary.
  • Estuaries can develop because of subsidence of land close to the coast, and tectonic processes like folding of the crust close to the coast creating basins.
  • Increase in sea level because of tectonic forces which need to submerge coastal areas under seawater creating an estuarine ecosystem. 

THE TOPIC FOR THE NEXT CLASS WILL BE CONTINUATION OF THE SAME TOPIC.