ENVIS Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Saturday, September 21, 2019

amphibious plants

'amphibious plants':
    Unique evergreen woody plants thriving in the intertidal salt marshes and brackish waters of estuaries and lagoons along the coasts in the tropical and subtropical latitudes are called mangroves.

1.What is 'mangroves'?


    Unique evergreen woody plants thriving in the intertidal salt marshes and brackish waters of estuaries and lagoons along the coasts in the tropical and subtropical latitudes are called mangroves.

2.What are all the other names for mangroves?


    Mangals, coastal woodlands, tidal forests, oceanic rainforests, amphibious plants, guardian angels ...

3.Are we dependant on mangroves in anyway?


    Yes, many of our coastal-people’s lives depend on mangrove ecosystem for fish food, firewood, medicines, as well as for protection from fiery effects of natural calamities.

4.Are the mangroves benefited by us?


    No, we are cruel to them, overexploiting and destructing them for our endless greedy needs. But they are always patient with us – so self-giving, also dying for us!

5.How mangroves attract us?


    Their unique appearance, adaptations, their uses to us, among other interesting features, attract us:
        They could live well in saltwater (0.5–35 ppt).
        Their thick-leaves, thick-petalled colourful flowers and healthy-happy-looking trees and shrubs captivate our minds.
        Peculiar roots, extensive and complex, totally different from the roots of the other plants.
        We feel ‘quiet and peaceful’ as soon as we enter into any mangrove forest.
        Chirping of the birds and the soft sounds produced by the small creatures, which live below the water level, add to the beauty of the mangroves.
        Dense, nutrient-rich, greenish colour water in the mangrove forest is also very much responsible for the coolness we enjoy in the mangroves.

6.Which is the largest single block of mangrove forest on the earth?


    Sundarbans – ca. 4250 sq. km. It exists in West Bengal, India, and Bangladesh.

7.How many plant species are there in Indian mangrove ecosystems?


    Totally 121 species (35 true mangroves & 86 mangrove associates).
    
8.How many States of our country are fortunate enough to have mangroves and what are they?


    12 states (including union territories)
        (1) Andaman & Nicobar,
        (2) Andhra Pradesh,
        (3) Goa,
        (4) Gujarat,
        (5) Karnataka,
        (6) Kerala,
        (7) Lakshadweep,
        (8) Maharashtra,
        (9) Orissa,
        (10) Pondicherry,
        (11) Tamil Nadu,
        (12) West Bengal
        (Source: <http://www.mangroveindia.org/geogareas.php>, retrieved on March 18, 2009.)


9.What are all the mangrove sites of Tamil Nadu?


    (1) Pichavaram,
    (2) Muthupet,
    (3) Ramnad,
    (4) Pulicat
    (5) Kazhuveli.
    (Source: Annual Report 2007–2008 (Executive Summary), MOE&F, Govt. India, p. 17.)

10.What is the ‘family’ or ‘order’ to which the mangrove plants belong?


    All the mangrove plants are not from the same family or order. They belong to various families among which families Rhizophoraceae and Avicenniaceae have exclusively mangrove plants.

11.Is it possible for the mangrove plants to live in other habitats, or in freshwater?


    No, sometimes they may survive, but they do not appear to be successful in any other habitats other than mangrove habitats – between the high- and low-tide levels.

12.Is it possible for the other plants to live in the mangrove ecosystem?


    Yes, but, generally, they thrive in the zones which are not much influenced by the tides, away from the salt water.

13.How do they succeed living in saline conditions?


    Salts are excreted through leaves. These excreted salt nodules are visible to the naked eyes and are washed by the rain.
    Salts are stored in the leaves, without affecting any other plant part. When the leaves fall off, the stored salts come back to ground.
    Roots of some of the mangrove are capable of eliminating excessive salts.

14.What are the fauna associated with mangrove ecosystem?


    Fish, shrimps, crabs, molluscs, polychaetes, insects and other invertebrates, amphibians, reptiles (mainly crocodiles), birds (both residential and migratory) and mammals (dolphins, monkeys, Bengal tiger in Sunderbans) enjoy living with the mangrove habitats.

15.Why do we need to know about the mangroves?


    If we do not try to know them, at least now, we won’t be able to realize the hard facts, such as, without them:

    * We will suffer even for fish food.
    * The whole earth will suffocate with imbalanced ecosystems and ever accumulating pollutants.
    * Many species will become extinct like Dinosaurs.

    And many more unimaginable dangers we may have to experience.
    Unless we understand them fully, it is not possible to save our environment.

16.How does a mangrove ecosystem work?


    The fallen leaves from mangrove trees are made into pieces, also eaten, by crabs, molluscs and polychaets which live in the burrows of the mangrove-soil. These burrowers help to keep the soil aerated also, by moving the soil constantly to dig burrows.
    The microbes present in the soil transform the pieces of leaves into rich, nutrient, organic soil, which is the great manure for the mangrove plants.
    The burrowing invertebrates also serve as delicacies for the fishes and birds – which are our food too.
    Birds’ excreta serve as good manure to the mangrove plants.
    [Note: Except us, all the other living organisms are helping each other, in turn the whole ecosystem. We, after enjoying everything from mangroves, destroy them thoughtlessly and mercilessly. What a sad-shameful thing to realize!]
    
17.What are the adaptations or unique features of mangrove plants to thrive in salt marshes?


    Cable roots, stilt roots or prop roots – support them in the loose marshy soil.
    Breathing roots or pneumatophores – for air exchange; and prevent soil erosion.
    Knee-like roots, plank roots and buttress roots
    Salt-excreting leaves.
    Salt-accumulating leaves – take the salts with them to the ground when they fall off.
    Viviparity – seedlings grow in the mother plant itself – increase survival rate.

18.What are the uses of mangroves?


    Mangroves contribute all their parts to the other lives on the earth.

    * They are our shore-line ‘guardian angels’ – guarding us from tsunamis, storms and cyclones.
    * They are our beautiful recreation spots – soothe our hearts, quieten our minds, ‘cool’ us even during the hottest days.
    * Protect underground water system – water-table – from salinization.
    * They prevent soil erosion.
    * Very good sources of medicines – both modern and traditional.
    * Our best source of food – capture and culture fisheries.
    * Good source for honey and facilitates apiculture.
    * Useful products from their wood, leaves and roots such as firewood, timber, charcoal, boats, bottle stoppers, toys, match boxes, thatches, mats, baskets, hats, rain caps, cigarette wrapper, paper, fodder, besides many others.
    * They are the best sanctuaries for birds.
    * They provide shelter for the many food fish, shrimp, crab, molluscs, and sometimes crocodiles and dolphins.
    * They help us reducing the CO2 from the atmosphere to a greater extent – carbon sequester.
    * They trap the heavy metals within their substrata.
    * They are ecologists’ or environmentalists’ paradise.
    * They support and protect other ecosystems, such as coral reefs, seagrass beds and sand dune vegetation.
    * Good revenue-source through tourism.

    If we say, ‘their uses are endless’, it won’t be an exaggeration at all.
19.What can we learn about mangroves?


   1.  Their origin and evolution
   2. Distribution on the earth
   3. Whether Indian sages had known well about them?
   4. How to utilize their tranquil-presence for our meditation, learn our psychological movements and healing?
   5. Favourable conditions for their best growth and reproduction
   6. How to be benefitted from them without affecting them?
   7. The cultivable species
   8. Whether they can be grown in pots at home, just for their beautiful presence
   9. More medicinal values
  10. How to protect them?
  11. How to make them happy?
    and much more

20.How the mangroves are affected by us?


    We destroy them to make plain lands for the settlement, business, agriculture and aquaculture purposes.
    [Strange! They themselves are providing us with good quantities of food fishes and other edible organisms. They also provide shelter for many juvenile food fish, shrimp, crab and other invertebrates. They maintain the fishery-balance so as to provide enough sea-protein for us. But what have we done to them? We have killed them with our greed, expecting more delicacies.]
    We cut them for timber, fuel, charcoal and to make boats.
    We are too generous and careless in dumping pollutants and wastes in the mangrove areas.

21.What every one of us have to do to save the mangroves?


   1.  Try to understand the mangroves as much as possible and help others also to understand them.
   2. Be careful not to dispose the wastes carelessly, especially if you are living near coast or any water body.

    [Separate plastics, decomposable wastes, e-wastes, glass materials and papers, and send them for recycling.]

    Do not cut the mangroves and allow others to do that.

    No need to create aquaculture and agriculture fields by destroying mangroves. They themselves do the culture – protect the young fish, shrimp, crab – for us. We just need not be greedy.

    Make sure not to allow the sewage flow into the mangroves.

    Cry for them inwardly, if you find the industrial effluents flowing through the mangroves, and try to do something to avoid it.

    Cattle need not be sent to mangroves for grazing.

    Plant the mangroves as much as possible, as many species as possible.

    Do not use the motor boats for sight-seeing inside mangrove forests.

    When you see the mangroves, try to check whether they are healthy or affected. If more crabs and molluscs are seen over the mangrove soil, you can be positive that the mangrove is more productive. Otherwise, be curious to do something beneficial for them.

    Try to thank them simply for their presence.


22.What is the role of our ENVIS Centre in conserving mangrove forests?


   1. Our objective is to spread knowledge on mangroves and other coastal ecosystems and to implant the importance of them in people’s minds.
   2. We collect scientific information on mangroves.
   3. We disseminate the information in various forms and formats{link please} to the school and college students, scholars, teachers, scientists, ecologists, environmentalists, policy makers and to the common public.
   4. We appreciate feedbacks from all and try to improve ourselves further to contribute to the well-being of mangroves and other coastal ecosystems.

    (Courtesy – scientific facts: Prof. Dr. K. Kathirasan, CAS in Marine Biology, Annamalai University.)