146-616: Sundarbans (pronounced / s ʌ n ˈ d ɑːr b ə n z / ) is a mangrove area in the delta formed by the confluence of the Ganges , Brahmaputra and Meghna Rivers in the Bay of Bengal . Spread across parts of India and Bangladesh , this forest is the largest Mangrove forest in the world. It spans the area from the Baleswar River in Bangladesh 's division of Khulna to
292-619: A tropical moist broadleaf forest ecoregion of Bangladesh and India. It represents the brackish swamp forests that lie behind the Sundarbans Mangroves , where the salinity is more pronounced. The freshwater ecoregion is an area where the water is only slightly brackish and becomes quite fresh during the rainy season, when the freshwater plumes from the Ganges and the Brahmaputra rivers push the intruding salt water out and bring
438-555: A basis for the development of a bio-inspired method of desalination . Uptake of Na ions is desirable for halophytes to build up osmotic potential , absorb water and sustain turgor pressure . However, excess Na ions may work on toxic element. Therefore, halophytes try to adjust salinity delicately between growth and survival strategies. In this point of view, a novel sustainable desalination method can be derived from halophytes, which are in contact with saline water through their roots. Halophytes exclude salt through their roots, secrete
584-589: A complex salt filtration system and a complex root system to cope with saltwater immersion and wave action. They are adapted to the low-oxygen conditions of waterlogged mud, but are most likely to thrive in the upper half of the intertidal zone . The mangrove biome , often called the mangrove forest or mangal, is a distinct saline woodland or shrubland habitat characterized by depositional coastal environments, where fine sediments (often with high organic content) collect in areas protected from high-energy wave action. Mangrove forests serve as vital habitats for
730-593: A consistent pattern of depleted biodiversity or loss of species in the 20th century, with the ecological quality of the forest declining. Despite preservation commitments from both governments, the Sundarbans are under threat from both natural and human-made causes. In 2007, the landfall of Cyclone Sidr damaged around 40% of the Sundarbans. The forest is also suffering from increased salinity caused by sea level rise due to effects of climate change and reduced freshwater supply. In May 2009, Cyclone Aila devastated
876-468: A critical food source for larger predators like birds, reptiles, and mammals within the ecosystem. Additionally, mangrove forests function as essential nurseries for many commercially important fish species, providing a sheltered environment rich in nutrients during their early life stages. The decomposition of leaves and organic matter in the water further enhances the nutrient content, supporting overall ecosystem productivity. In summary, mangrove forests play
1022-434: A crucial and unbiased role in sustaining biodiversity and ecological balance within coastal food webs. Larger marine organisms benefit from the habitat as a nursery for their offspring. Lemon sharks depend on mangrove creeks to give birth to their pups. The ecosystem provides little competition and minimizes threats of predation to juvenile lemon sharks as they use the cover of mangroves to practice hunting before entering
1168-512: A deposit of silt. It covers 14,600 square kilometres (5,600 sq mi) of the vast Ganges-Brahmaputra Delta , finishing at the mouth of the Bay of Bengal from the northern part of Khulna District and the southern part of North 24 Parganas district in the Indian state of West Bengal. The Sundarbans freshwater swamp forests lie between the upland Lower Gangetic plains moist deciduous forests and
1314-534: A diverse array of aquatic species, offering a unique ecosystem that supports the intricate interplay of marine life and terrestrial vegetation. The saline conditions tolerated by various mangrove species range from brackish water, through pure seawater (3 to 4% salinity), to water concentrated by evaporation to over twice the salinity of ocean seawater (up to 9% salinity). Beginning in 2010, remote sensing technologies and global data have been used to assess areas, conditions and deforestation rates of mangroves around
1460-452: A fundamental environmental index for future reference. Mangrove forests are one of the most carbon-rich biomes, accounting for 11% of the total input of terrestrial carbon into oceans. Viruses are thought to significantly influence local and global biogeochemical cycles , though as of 2019 little information was available about the community structure, genetic diversity and ecological roles of viruses in mangrove ecosystems. Viruses are
1606-470: A given mangrove swamp typically features only a small number of tree species. It is not uncommon for a mangrove forest in the Caribbean to feature only three or four tree species. For comparison, the tropical rainforest biome contains thousands of tree species, but this is not to say mangrove forests lack diversity. Though the trees themselves are few in species, the ecosystem that these trees create provides
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#17327648059641752-622: A global annual deforestation rate estimated at 0.16%, and per-country rates as high as 0.70%. Degradation in quality of remaining mangroves is also an important concern. There is interest in mangrove restoration for several reasons. Mangroves support sustainable coastal and marine ecosystems. They protect nearby areas from tsunamis and extreme weather events. Mangrove forests are also effective at carbon sequestration and storage. The success of mangrove restoration may depend heavily on engagement with local stakeholders, and on careful assessment to ensure that growing conditions will be suitable for
1898-464: A hierarchical, triple layered pore structure in the epidermis and most Na ions are filtered at the first sublayer of the outermost layer. The high blockage of Na ions is attributed to the high surface zeta potential of the first layer. The second layer, which is composed of macroporous structures , also facilitates Na ion filtration. The study provides insights into the mechanism underlying water filtration through halophyte roots and could serve as
2044-411: A higher concentration of white mangroves. Mangrove forests are an important part of the cycling and storage of carbon in tropical coastal ecosystems. Knowing this, scientists seek to reconstruct the environment and investigate changes to the coastal ecosystem over thousands of years using sediment cores. However, an additional complication is the imported marine organic matter that also gets deposited in
2190-480: A home (habitat) for a great variety of other species, including as many as 174 species of marine megafauna . Mangrove plants require a number of physiological adaptations to overcome the problems of low environmental oxygen levels, high salinity , and frequent tidal flooding . Each species has its own solutions to these problems; this may be the primary reason why, on some shorelines, mangrove tree species show distinct zonation. Small environmental variations within
2336-410: A key role in maintaining prey species along coastlines and within mangrove ecosystems. Mangrove forests can decay into peat deposits because of fungal and bacterial processes as well as by the action of termites . It becomes peat in good geochemical , sedimentary, and tectonic conditions. The nature of these deposits depends on the environment and the types of mangroves involved. In Puerto Rico ,
2482-407: A long history to survive against harsh environmental conditions. In this harsh environment, mangroves have evolved a special mechanism to help their offspring survive. Mangrove seeds are buoyant and are therefore suited to water dispersal. Unlike most plants, whose seeds germinate in soil, many mangroves (e.g. red mangrove ) are viviparous , meaning their seeds germinate while still attached to
2628-457: A mangal may lead to greatly differing methods for coping with the environment. Therefore, the mix of species is partly determined by the tolerances of individual species to physical conditions, such as tidal flooding and salinity, but may also be influenced by other factors, such as crabs preying on plant seedlings. Once established, mangrove roots provide an oyster habitat and slow water flow, thereby enhancing sediment deposition in areas where it
2774-552: A mere 130 km of the ecoregion. Habitat loss in this ecoregion is so extensive, and the remaining habitat is so fragmented, that it is difficult to ascertain the composition of the original vegetation of this ecoregion. According to Champion and Seth (1968), the freshwater swamp forests are characterised by Heritiera minor , Xylocarpus molluccensis , Bruguiera conjugata , Sonneratia apetala , Avicennia officinalis , and Sonneratia caseolaris , with Pandanus tectorius , Hibiscus tiliaceus , and Nipa fruticans along
2920-483: A moist tropical forest demonstrating a whole mosaic of seres , comprising primary colonisation on new accretions to more mature beach forests. Historically vegetation types have been recognised in broad correlation with varying degrees of water salinity, freshwater flushing and physiography. The Sundarbans provides a unique ecosystem and a rich wildlife habitat. According to the 2015 tiger census in Bangladesh, and
3066-435: A network of canals in the Sundarbans and blackened the shoreline. The event was very threatening to trees, plankton, and vast populations of small fishes and dolphins. The event occurred at a protected Sundarbans mangrove area, home to the rare Irrawaddy and Ganges dolphins . Until 15 December 2014 only 50,000 litres (11,000 imp gal; 13,000 US gal) of oil from the area had been cleaned up by local residents,
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#17327648059643212-451: A quiet marine habitat for young organisms. In areas where roots are permanently submerged, the organisms they host include algae , barnacles , oysters , sponges , and bryozoans , which all require a hard surface for anchoring while they filter-feed. Shrimps and mud lobsters use the muddy bottoms as their home. Mangrove crabs eat the mangrove leaves, adding nutrients to the mangal mud for other bottom feeders. In at least some cases,
3358-455: A recent analysis of Pacific Ocean Virome data identified niche-specialised AMGs that contribute to depth-stratified host adaptations. Given that microbes drive global biogeochemical cycles, and a large fraction of microbes is infected by viruses at any given time, viral-encoded AMGs must play important roles in global biogeochemistry and microbial metabolic evolution. Mangrove forests are the only woody halophytes that live in salt water along
3504-537: A remarkable stability to the entire system. During each monsoon season almost all the Bengal Delta is submerged, much of it for half a year. The sediment of the lower delta plain is primarily advected inland by monsoonal coastal setup and cyclonic events. One of the greatest challenges people living on the Ganges Delta may face in coming years is the threat of rising sea levels caused mostly by subsidence in
3650-570: A repertoire of microbial taxa that contribute to important ecological functions in mangrove ecosystems. Like typical terrestrial plants, mangroves depend upon mutually beneficial interactions with microbial communities. In particular, microbes residing in developed roots could help mangroves transform nutrients into usable forms before plant assimilation. These microbes also provide mangroves phytohormones for suppressing phytopathogens or helping mangroves withstand heat and salinity. In turn, root-associated microbes receive carbon metabolites from
3796-435: A significant proportion of the species present in Bangladesh (i.e. about 30% of the reptiles, 37% the birds and 34% of the mammals) and includes many species which are now extinct elsewhere in the country. Two amphibians, 14 reptiles, 25 aves and five mammals are endangered. The Sundarbans is an important wintering area for migrant water birds and is an area suitable for watching and studying avifauna. The management of wildlife
3942-431: A significant role in physical coastal evolution, and for wildlife a variety of habitats have developed which include beaches, estuaries , permanent and semi-permanent swamps, tidal flats, tidal creeks , coastal dunes, back dunes and levees. The mangrove vegetation itself assists in the formation of new landmass and the intertidal vegetation plays a significant role in swamp morphology. The activities of mangrove fauna in
4088-553: A storm barrier, shore stabiliser and energy storage unit. Last but not the least, the Sunderbans provides an aesthetic attraction for local and foreign tourists. The water houseboat in the Sundarbans is also a recent attraction among the tourists. The forest has immense protective and productive functions. Constituting 51% of the total reserved forest estate of Bangladesh, it contributes about 41% of total forest revenue and accounts for about 45% of all timber and fuel wood output of
4234-649: A transition from the marine to freshwater and terrestrial systems, and provide critical habitat for numerous species of small fish, crabs, shrimps and other crustaceans that adapt to feed and shelter, and reproduce among the tangled mass of roots, known as pneumatophores , which grow upward from the anaerobic mud to get the supply of oxygen. A 1991 study has revealed that the Indian part of the Sundarbans supports diverse biological resources including at least 150 species of commercially important fish, 270 species of birds, 42 species of mammals, 35 reptiles and 8 amphibian species, although new ones are being discovered. This represents
4380-402: A week, simulating frequent tropical rainstorms. A 2016 study by Kim et al. investigated the biophysical characteristics of sea water filtration in the roots of the mangrove Rhizophora stylosa from a plant hydrodynamic point of view. R. stylosa can grow even in saline water and the salt level in its roots is regulated within a certain threshold value through filtration. The root possesses
4526-405: A year before arriving in a suitable environment. Once a propagule is ready to root, its density changes so that the elongated shape now floats vertically rather than horizontally. In this position, it is more likely to lodge in the mud and root. If it does not root, it can alter its density and drift again in search of more favorable conditions. The following listings, based on Tomlinson, 2016, give
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4672-462: Is "beautiful forest". Alternatively, it was proposed that the name is a corruption of Samudraban , Shomudrobôn ("Sea Forest"), or Chandra-bandhe , the name of a tribe. However, the likely origin of the word is Sundari or Sundri , the local name of the mangrove species Heritiera fomes abundant in the area. The history of human settlement in the Sundarbans area can be traced back to Mauryan era (4th-2nd century BCE). A ruin of an abandoned city
4818-399: Is 4,143 square kilometres (1,600 sq mi), including exposed sandbars with a total area of 42 square kilometres (16 sq mi); the remaining water area of 1,874 square kilometres (724 sq mi) encompasses rivers, small streams and canals. Rivers in the Sundarbans are meeting places of salt water and freshwater. Thus, it is a region of transition between the freshwater of
4964-631: Is a consistent pattern of depleted biodiversity or loss of species (notably at least six mammals and one important reptile) in the 20th century, and that the "ecological quality of the original mangrove forest is declining". The endangered species that live within the Sundarbans and extinct species that used to be include the Bengal tiger, estuarine crocodile , northern river terrapin ( Batagur baska ), olive ridley sea turtle , Gangetic dolphin , ground turtles, hawksbill sea turtles and king crabs (horse shoe). The Sundarbans hold globally important numbers of
5110-403: Is a medium-sized evergreen tree growing to a height of 15 to 25 metres (49 to 82 ft). The roots are shallow and spreading and send up pneumatophores . The trunk develops buttresses and is grey with vertically fissured bark. Trees with girths of 2 metres (6 ft 7 in) used to be found but these large trees have mostly been harvested for their timber. The trunk has few large branches and
5256-705: Is already occurring. The fine, anoxic sediments under mangroves act as sinks for a variety of heavy (trace) metals which colloidal particles in the sediments have concentrated from the water. Mangrove removal disturbs these underlying sediments, often creating problems of trace metal contamination of seawater and organisms of the area. Mangrove swamps protect coastal areas from erosion , storm surge (especially during tropical cyclones ), and tsunamis . They limit high-energy wave erosion mainly during events such as storm surges and tsunamis. The mangroves' massive root systems are efficient at dissipating wave energy. Likewise, they slow down tidal water so that its sediment
5402-474: Is characterised by the abundance of sundari ( Heritiera fomes ), gewa ( Excoecaria agallocha ), goran ( Ceriops decandra ) and keora ( Sonneratia apetala ) all of which occur prominently throughout the area. The characteristic tree of the forest is the sundari ( Heritiera littoralis ), from which the name of the forest had probably been derived. It yields a hard wood, used for building houses and making boats, furniture and other things. New forest accretions
5548-638: Is common in places, it has a restricted range and is declining because of the clearing of mangroves for coastal development, rice farming, shrimp ponds and oil palm plantations. It is present in several protected areas in the Sundarbans in Bangladesh as well as in India, but there and elsewhere it is being affected by top dying disease . This causes branches and parts of the crown to die back, and can result in tree mortality. Gall cankers may be present in affected parts and wood-boring insects and fungi also attack
5694-416: Is deposited as the tide comes in, leaving all except fine particles when the tide ebbs. In this way, mangroves build their environments. Because of the uniqueness of mangrove ecosystems and the protection against erosion they provide, they are often the object of conservation programs, including national biodiversity action plans . The unique ecosystem found in the intricate mesh of mangrove roots offers
5840-498: Is essential. Additionally, the intermittent flooding of sea water and resulting sharp transition of mangrove environments may result in substantially different genetic and functional diversity of bacterial and viral communities in mangrove soils compared with those of other systems. Heritiera fomes Heritiera minor Roxb. Heritiera fomes is a species of mangrove tree in the family Malvaceae . Its common names include sunder , sundri , jekanazo and pinlekanazo . It
5986-449: Is estimated to be about 4,260 km (1,640 sq mi), of which about 1,700 km (660 sq mi) is occupied by water bodies in the forms of river, canals and creeks of width varying from a few metres to several kilometres. The Sundarbans is intersected by a complex network of tidal waterways, mudflats and small islands of salt-tolerant mangrove forests. The interconnected network of waterways makes almost every corner of
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6132-678: Is further divided into fifty-five compartments and nine blocks. There are three wildlife sanctuaries established in 1977 under the Bangladesh Wildlife (Preservation) Order, 1973 (P.O. 23 of 1973). The West Bengal part of the forest lies under the district of South & North 24 Parganas. Protected areas cover 15% of the Sundarbans mangroves including Sundarbans National Park and Sajnakhali Wildlife Sanctuary , in West Bengal, Sundarbans East , Sundarbans South and Sundarbans West Wildlife Sanctuaries in Bangladesh. In May 2019,
6278-483: Is grown commercially in plantations. The bark of H. fomes is rich in procyanidins . The ethanol extract has been shown to have antioxidant properties. It also shows antimicrobial activities against Kocuria rhizophila , Staphylococcus aureus , Bacillus subtilis and Pseudomonas aeruginosa and is non-toxic in brine shrimp toxicity tests . The International Union for Conservation of Nature has assessed this mangrove as being " endangered ". Although it
6424-490: Is native to coastal regions of the Indo-Pacific, its range extending from the east coast of India through Bangladesh and Malaysia to Myanmar and Thailand. Compared to other species of mangrove, it grows in less saline environments and on drier ground that gets inundated by the tide only infrequently. It thrives on clayey soils and is the dominant species in these habitats, typically growing on the low banks that form around
6570-601: Is often conspicuously dominated by keora ( Sonneratia apetala ) and tidal forests. It is an indicator species for newly accreted mudbanks and is an important species for wildlife, especially spotted deer ( Axis axis ). There is abundance of dhundul or passur ( Xylocarpus granatum ) and kankra ( Bruguiera gymnorhiza ) though distribution is discontinuous. Among palms, Poresia coaractata , Myriostachya wightiana and golpata ( Nypa fruticans ), and among grasses spear grass ( Imperata cylindrica ) and khagra ( Phragmites karka ) are well distributed. The varieties of
6716-743: Is one of the largest reserves for the Bengal tiger . It is also home to a variety of bird, reptile and invertebrate species, including the salt-water crocodile . The present Sundarbans National Park was declared as the core area of Sundarbans Tiger Reserve in 1973 and a wildlife sanctuary in 1977. On 4 May 1984 it was declared a National Park. Sundarbans West Wildlife Sanctuary is a UNESCO World Heritage Site in Bangladesh. The region supports mangroves, including: sparse stands of Gewa ( Excoecaria agallocha ) and dense stands of Goran ( Ceriops tagal ), with discontinuous patches of Hantal palm ( Phoenix paludosa ) on drier ground, river banks and levees. The fauna of
6862-461: Is reported to be higher than in well-preserved mangroves Studies comparing mangroves in different conservation states show that bacterial composition in disturbed mangrove sediment alters its structure, leading to a functional equilibrium, where the dynamics of chemicals in mangrove soils lead to the remodeling of its microbial structure. Despite many research advancements in mangrove sediment bacterial metagenomics diversity in various conditions over
7008-447: Is restricted to, firstly, the protection of fauna from poaching, and, secondly, designation of some areas as wildlife sanctuaries where no extraction of forest produce is allowed and where the wildlife face few disturbances. Although the fauna of Bangladesh have diminished in recent times and the Sundarbans has not been spared from this decline, the mangrove forest retains several good wildlife habitats and their associated fauna. Of these,
7154-546: Is situated 14 kilometres (8.7 mi) north of the Sundarbans. This project violates the environmental impact assessment guidelines for coal-based thermal power plants. Environmental activists contend that the proposed location of the Rampal Station would violate provisions of the Ramsar Convention . The government of Bangladesh rejected the allegations that the coal-based power plant would adversely affect
7300-492: Is stored in soil and sizable belowground pools of dead roots, aiding in the conservation and recycling of nutrients beneath forests. Although mangroves cover only 0.5% of the earth's coastal area, they account for 10–15% of the coastal sediment carbon storage and 10–11% of the total input of terrestrial carbon into oceans. The disproportionate contribution of mangroves to carbon sequestration is now perceived as an important means to counterbalance greenhouse gas emissions. Despite
7446-631: Is stored in the sediment and the carbon cycle continues. Mangroves are an important source of blue carbon . Globally, mangroves stored 4.19 Gt (9.2 × 10 lb) of carbon in 2012. Two percent of global mangrove carbon was lost between 2000 and 2012, equivalent to a maximum potential of 0.316996250 Gt (6.9885710 × 10 lb) of emissions of carbon dioxide in Earth's atmosphere . Globally, mangroves have been shown to provide measurable economic protections to coastal communities affected by tropical storms. Plant microbiomes play crucial roles in
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#17327648059647592-568: Is the compartment. There are 55 compartments in four Forest Ranges and these are clearly demarcated mainly by natural features such as rivers, canals and creeks. Recently West Bengal Cabinet has approved a new district in South 24 Parganas and proposed district was named Sundarban. The Bangladesh part of the forest lies under two forest divisions, and four administrative ranges viz Chandpai (Khulna District), Sarankhola (Khulna), and Burigoalini ( Satkhira District ) and has sixteen forest stations. It
7738-522: Is the dominant mangrove tree species of the Sundarbans of Bangladesh and India , and comprises about 70% of the trees in the area. H. fomes is a major timber-producing tree. It is threatened by over-harvesting, water diversions in the Ganges Basin , fluctuations in salinity due to upstream and coastal development and top dying disease. The International Union for Conservation of Nature has assessed it as being " endangered ". Heritiera fomes
7884-486: Is the senior most executive officer looking over the administration of the park. The Chief Conservator of Forests (South) & Director, Sundarban Biosphere Reserve is the administrative head of the park at the local level and is assisted by a Deputy Field Director and an Assistant Field Director. The park area is divided into two ranges, overseen by range forest officers. Each range is further sub-divided into beats. The park also has floating watch stations and camps to protect
8030-624: The Bangladesh Navy , and the government of Bangladesh . Some reports indicated that the event killed some wildlife. On 13 December 2014, a dead Irrawaddy dolphin was seen floating on the Harintana-Tembulbunia channel of the Sela River. The Sundarbans plays an important role in the economy of the southwestern region of Bangladesh as well as in the national economy. It is the single largest source of forest produce in
8176-423: The Bengal tiger ( Panthera tigris ). The forest also provides habitat for small wild cats such as the jungle cat ( Felis chaus ), fishing cat ( Prionailurus viverrinus ), and leopard cat ( P. bengalensis ). Several predators dwell in the labyrinth of channels, branches, and roots that poke up into the air. This is the only mangrove ecoregion that harbors the Indo-Pacific region's largest terrestrial predator,
8322-648: The Hooghly River in India 's state of West Bengal . It comprises closed and open mangrove forests , land used for agricultural purpose, mudflats and barren land, and is intersected by multiple tidal streams and channels. Sundarbans is home to the world's largest area of mangrove forests. Four protected areas in the Sundarbans are enlisted as UNESCO World Heritage Sites , viz. Sundarbans West (Bangladesh), Sundarbans South (Bangladesh), Sundarbans East (Bangladesh) and Sundarbans National Park (India). Despite
8468-568: The Malay language manggi-manggi The English usage may reflect a corruption via folk etymology of the words mangrow and grove . The word "mangrove" is used in at least three senses: According to Hogarth (2015), among the recognized mangrove species there are about 70 species in 20 genera from 16 families that constitute the "true mangroves" – species that occur almost exclusively in mangrove habitats. Demonstrating convergent evolution , many of these species found similar solutions to
8614-550: The Mughal Emperor Alamgir II and completed mapping the area in 1764. However, systematic forest management started a century later. The first Forest Management Division to have jurisdiction over the Sundarbans was established in 1869. In 1875 a large portion of the mangrove forests was declared as reserved forests under the Indian Forest Act of 1865 (Act VIII of 1865). The remaining portions of
8760-457: The South 24 Parganas and North 24 Parganas districts . The most abundant tree species are sundri ( Heritiera fomes ) and gewa ( Excoecaria agallocha ). The forests provide habitat to 453 fauna wildlife, including 290 bird, 120 fish, 42 mammal, 35 reptile and eight amphibian species. Despite a total ban on all killing or capture of wildlife other than fish and some invertebrates, there has been
8906-506: The brackish -water Sundarbans mangroves bordering the Bay of Bengal. A victim of large-scale clearing and settlement to support one of the densest human populations in Asia, this ecoregion is under a great threat of extinction. Hundreds of years of habitation and exploitation have exacted a heavy toll on this ecoregion's habitat and biodiversity. There are two protected areas – Narendrapur (110 km) and Ata Danga Baor (20 km) that cover
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#17327648059649052-480: The bulk soil outside the rhizosphere . Furthermore, it was noted that the root episphere, rather than the rhizosphere, was primarily responsible for controlling the entry of specific microbial populations into the root, resulting in the selective enrichment of Proteobacteria in the endosphere. These findings provide new insights into the niche differentiation of root-associated microbial communities, Nevertheless, amplicon-based community profiling may not provide
9198-634: The estuarine crocodile and the Indian python . Mangrove A mangrove is a shrub or tree that grows mainly in coastal saline or brackish water . Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen and remove salt, allowing them to tolerate conditions that kill most plants. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse due to convergent evolution in several plant families. They occur worldwide in
9344-420: The red , white , and black mangroves occupy different ecological niches and have slightly different chemical compositions, so the carbon content varies between the species, as well between the different tissues of the plant (e.g., leaf matter versus roots). In Puerto Rico, there is a clear succession of these three trees from the lower elevations, which are dominated by red mangroves, to farther inland with
9490-640: The tropics and subtropics and even some temperate coastal areas, mainly between latitudes 30° N and 30° S, with the greatest mangrove area within 5° of the equator . Mangrove plant families first appeared during the Late Cretaceous to Paleocene epochs and became widely distributed in part due to the movement of tectonic plates . The oldest known fossils of mangrove palm date to 75 million years ago. Mangroves are salt-tolerant trees, shrubs and ferns also called halophytes , and are adapted to live in harsh coastal conditions. They contain
9636-512: The 2011 tiger census in India, the Sundarbans have about 180 tigers (106 in Bangladesh and 74 in India). Earlier estimates, based on counting unique pugmarks , were much higher. The more recent counts have used camera traps , an improved methodology that yields more accurate results. Tiger attacks were historically common in the area , and are still frequent in the Sundarbans, with around 40 people killed in 2000–2010. Most importantly, mangroves are
9782-608: The Bangladesh Sundarbans. As a result, the salinity of the Bangladesh Sundarbans is much lower than that of the Indian side. A 1990 study noted that there "is no evidence that environmental degradation in the Himalayas or a 'greenhouse' induced rise in sea level have aggravated floods in Bangladesh"; however, a 2007 report by UNESCO, "Case Studies on Climate Change and World Heritage" has stated that an anthropogenic 45-centimetre (18 in) rise in sea level (likely by
9928-436: The Bengal tiger. Unlike in other habitats, tigers live here and swim among the mangrove islands, where they hunt scarce prey such as the chital deer ( Axis axis ), Indian muntjacs ( Muntiacus muntjak ), wild boar ( Sus scrofa ), and Rhesus macaque ( Macaca mulatta ). It is estimated that there are now 180 Bengal tigers and about 30,000 spotted deer in the area. The tigers are known to attack and kill humans who venture into
10074-538: The North Island but become low scrub toward their southern limit. In both instances, the species is referred to as Avicennia marina var. australis , although genetic comparison is clearly needed. In Western Australia, A. marina extends as far south as Bunbury (33° 19'S). In the northern hemisphere, scrubby Avicennia gerrninans in Florida occurs as far north as St. Augustine on the east coast and Cedar Point on
10220-562: The Sundarbans mangroves, are important habitat for the endangered tiger. Additionally, the Mangroves species present in the Sundarban area serve a crucial function as a protective barrier for the millions of inhabitants in and around Kolkata , Khulna and Port of Mongla against the floods that result from the cyclones . It also protects from tsunami and soil erosion for the coastal population. The mangrove-dominated Ganges Delta –
10366-462: The Sundarbans towards the middle of the 20th century, because of extensive poaching and hunting by the British and locals. There are other threatened mammal species, such as the capped langur ( Semnopithecus pileatus ), smooth-coated otter ( Lutrogale perspicillata ), Asian small-clawed otter ( Aonyx cinerea ) and large Indian civet ( Viverra zibetha ). The physical development processes along
10512-521: The Sundarbans with massive casualties. At least 100,000 people were affected by this cyclone. The proposed coal-fired Rampal power station situated 14 km (8.7 mi) north of the Sundarbans at Rampal Upazila of Bagerhat District in Khulna, Bangladesh, is anticipated to further damage this unique mangrove forest according to a 2016 report by UNESCO. Climate change is expected to continue to negatively affect both natural systems and human populations in
10658-483: The Sundarbans – is a complex ecosystem comprising one of the three largest single tracts of mangrove forests of the world. The larger part is situated in Bangladesh, a smaller portion of it lies in India. The Indian part of the forest is estimated to be about 40 percent, while the Bangladeshi part is 60 percent. To the south the forest meets the Bay of Bengal; to the east it is bordered by the Baleswar River and to
10804-590: The Zoological Society of London (ZSL) found out that the Sunderban coast was retreating up to 200 metres (660 ft) in a year. Agricultural activities had destroyed around 17,179 hectares (42,450 acres) of mangroves within three decades (1975–2010). Shrimp cultivation had destroyed another 7,554 hectares (18,670 acres). Researches from the School of Oceanographic Studies, Jadavpur University, estimated
10950-551: The accumulated salt through their aerial parts and sequester salt in senescent leaves and/or the bark. Mangroves are facultative halophytes and Bruguiera is known for its special ultrafiltration system that can filter approximately 90% of Na ions from the surrounding seawater through the roots. The species also exhibits a high rate of salt rejection. The water-filtering process in mangrove roots has received considerable attention for several decades. Morphological structures of plants and their functions have been evolved through
11096-402: The annual rise in sea level to be 8 millimetres (0.31 in) in 2010. It had doubled from 3.14 millimetres (0.124 in) recorded in 2000. The rising sea levels had also submerged around 7,500 hectares (19,000 acres) of forest areas. This, coupled with an around 1.5 °C (2.7 °F) rise in surface water temperatures and increased levels of salinity have posed a problem for the survival of
11242-443: The canopy is open. The leathery leaves are elliptical and tend to be clustered at the ends of the twigs. The pink or orange bell-shaped flowers are each about 5 mm (0.2 in) across. They form in panicles , each flower being either male or female. The fruit carpels are up to 5 cm (2.0 in) long and 3.8 cm (1.5 in) wide. They ripen between June and August and the seeds germinate readily. Heritiera fomes
11388-433: The coast are influenced by a multitude of factors, comprising wave motions, micro and macro-tidal cycles and long shore currents typical to the coastal tract. The shore currents vary greatly along with the monsoon . These are also affected by cyclonic action. Erosion and accretion through these forces maintains varying levels, as yet not properly measured, of physiographic change whilst the mangrove vegetation itself provides
11534-429: The coastal population in cyclone -prone Bangladesh. Part of the Sundarbans is shielded from tidal inflow by leaves and there one finds villages and agriculture. During the monsoon season, the low lying agricultural lands are waterlogged and the summer crop ( kharif crop ) is therefore mainly deepwater rice or floating rice. In the dry winter season the land is normally uncropped and used for cattle grazing. However,
11680-400: The country. A number of industries (e.g., newsprint mill, match factory, hardboard, boat building, furniture making) are based on raw materials obtained from the Sundarbans ecosystem. Non-timber forest products and plantations help generate considerable employment and income opportunities for at least half a million poor coastal people. It provides natural protection to life and properties of
11826-494: The country. The forest provides raw materials for wood-based industries. In addition to traditional forest produce like timber, fuelwood, pulpwood etc., large-scale harvest of non-wood forest products such as thatching materials, honey , beeswax, fish, crustacean and mollusc resources of the forest takes place regularly. The vegetated tidal lands of the Sundarbans function as an essential habitat, produces nutrients and purifies water. The forest also traps nutrient and sediment, acts as
11972-444: The critically endangered masked finfoot and are important wintering sites for the spoon-billed sandpiper and the Indian skimmer . Some species such as hog deer ( Axis porcinus ), water buffalos ( Bubalus bubalis ), barasingha or swamp deer ( Cervus duvauceli ), Javan rhinoceros ( Rhinoceros sondaicus ), Indian rhinoceros ( Rhinoceros unicornis ) and the mugger crocodile ( Crocodylus palustris ) started to become extinct in
12118-542: The deltaic islands where low velocity of river and tidal current occurs. The flats are exposed in low tides and submerged in high tides, thus being changed morphologically even in one tidal cycle. The tides are so large that approximately one third of the land disappears and reappears every day. The interior parts of the mudflats serve as a perfect home for mangroves. Sundarbans features two ecoregions — "Sundarbans freshwater swamp forests" (IM0162) and "Sundarbans mangroves" (IM1406). The Sundarbans freshwater swamp forests are
12264-509: The ecological importance of mangrove ecosystem, knowledge on mangrove biodiversity is notably limited. Previous reports mainly investigated the biodiversity of mangrove fauna, flora and bacterial communities. Particularly, little information is available about viral communities and their roles in mangrove soil ecosystems. In view of the importance of viruses in structuring and regulating host communities and mediating element biogeochemical cycles, exploring viral communities in mangrove ecosystems
12410-516: The edges of saucer-shaped, newly emerged islands. It is the dominant mangrove species in the area and its local name, sundari, gives the Sundarbans region its name. Timber produced from Heritiera fomes is hard, fine-grained, tough and elastic. The heartwood is dark red or reddish brown and the sapwood is a paler reddish brown. The timber has many uses; in bridge building, house construction, boat building and joinery , as utility poles and tool handles, making hardboard and as firewood . The tree
12556-491: The end of the 21st century, according to the Intergovernmental Panel on Climate Change), combined with other forms of anthropogenic stress on the Sundarbans, could lead to the destruction of 75 percent of the Sundarbans mangroves. Already, Lohachara Island and New Moore Island/South Talpatti Island have disappeared under the sea, and Ghoramara Island is half submerged. In a study conducted in 2012,
12702-411: The export of carbon fixed in mangroves is important in coastal food webs. Mangrove forests contribute significantly to coastal ecosystems by fostering complex and diverse food webs . The intricate root systems of mangroves create a habitat conducive to the proliferation of microorganisms, crustaceans, and small fish, forming the foundational tiers of the food chain. This abundance of organisms serves as
12848-573: The food web of the ocean. Mangrove plantations in Vietnam, Thailand, Philippines, and India host several commercially important species of fish and crustaceans. The mangrove food chain extends beyond the marine ecosystem. Coastal bird species inhabit the tidal ecosystems feeding off small marine organisms and wetland insects. Common bird families found in mangroves around the world are egrets , kingfishers , herons , and hornbills , among many others dependent on ecological range. Bird predation plays
12994-420: The forest accessible by boat. The area is known for the Bengal tiger ( Panthera tigris ), as well as numerous fauna including species of birds, chital , crocodiles and snakes. The fertile soils of the delta have been subject to intensive human use for centuries, and the ecoregion has been mostly converted to intensive agriculture, with few enclaves of forest remaining. The remaining forests, taken together with
13140-399: The forest, with around 40 deaths recorded in 2000–2010. Forest inventories reveal a decline in standing volume of the two main commercial mangrove species – sundari ( Heritiera spp.) and gewa ( Excoecaria agallocha ) — by 40% and 45% respectively between 1959 and 1983. Despite a total ban on all killing or capture of wildlife other than fish and some invertebrates , it appears that there
13286-494: The forests that exist in Sundarbans include mangrove scrub, littoral forest , saltwater mixed forest , brackish water mixed forest and swamp forest . Besides the forest, there are extensive areas of brackish water and freshwater marshes , intertidal mudflats , sandflats , sand dunes with typical dune vegetation, open grassland on sandy soils and raised areas supporting a variety of terrestrial shrubs and trees. Since Prain's report there have been considerable changes in
13432-517: The forests were declared a reserve forest the following year and the forest, which was so far administered by the civil administration district, was placed under the control of the Forest Department. A Forest Division, which is the basic forest management and administration unit, was created in 1879 with the headquarters in today Khulna , Bangladesh. The first management plan was written for the period 1893–1898. The Sundarban forest lies in
13578-535: The former, the Rhizophoraceae are of minor importance. Ecological succession is generally defined as the successive occupation of a site by different plant communities. In an accreting mudflats the outer community along the sequence represents the pioneer community which is gradually replaced by the next community representing the seral stages and finally by a climax community typical of the climatic zone. Robert Scott Troup suggested that succession began in
13724-413: The fringing banks. The Sundarbans Mangroves ecoregion on the coast forms the seaward fringe of the delta and is the world's largest mangrove ecosystem, with 20,400 square kilometres (7,900 sq mi) of an area covered. The dominant mangrove species Heritiera fomes is locally known as sundri or sundari . Mangrove forests are not home to a great variety of plants. They have a thick canopy, and
13870-405: The functional characteristics of root-associated microbial communities in plant growth and biogeochemical cycling. Unraveling functional patterns across the four root compartments holds a great potential for understanding functional mechanisms responsible for mediating root–microbe interactions in support of enhancing mangrove ecosystem functioning. The diversity of bacteria in disturbed mangroves
14016-402: The health and productivity of mangroves. Many researchers have successfully applied knowledge acquired about plant microbiomes to produce specific inocula for crop protection. Such inocula can stimulate plant growth by releasing phytohormones and enhancing uptake of some mineral nutrients (particularly phosphorus and nitrogen). However, most of the plant microbiome studies have focused on
14162-626: The importance of root-associated bacteria and fungi for mangrove growth and health. Recent studies have investigated the detailed structure of root-associated microbial communities at a continuous fine-scale in other plants, where a microhabitat was divided into four root compartments: endosphere, episphere, rhizosphere, and nonrhizosphere or bulk soil . Moreover, the microbial communities in each compartment have been reported to have unique characteristics. Root exudates selectively enrich adapted microbial populations; however, these exudates were found to exert only marginal impacts on microbes in
14308-455: The indigenous flora and fauna. The Sundari trees are exceptionally sensitive to salinity and are being threatened with extinction. Loss of the mangrove forest will result in the loss of the protective biological shield against cyclones and tsunamis. This may put the surrounding coastal communities at high risk. Moreover, the submergence of land mass have rendered up to 6,000 families homeless and around 70,000 people are immediately threatened with
14454-544: The intense and large-scale exploitation, this still is one of the largest contiguous areas of mangroves in the world. Another threat comes from deforestation and water diversion from the rivers inland, which causes far more silt to be brought to the estuary, clogging up the waterways. The Directorate of Forest is responsible for the administration and management of Sundarban National Park in West Bengal. The Principal Chief Conservator of Forests (PCCF), Wildlife & Bio-Diversity & ex-officio Chief Wildlife Warden, West Bengal
14600-405: The intertidal mudflats develop micromorphological features that trap and hold sediments to create a substratum for mangrove seeds. The morphology and evolution of the eolian dunes is controlled by an abundance of xerophytic and halophytic plants. Creepers, grasses and sedges stabilise sand dunes and uncompacted sediments. The Sunderbans mudflats (Banerjee, 1998) are found at the estuary and on
14746-475: The land is only occasionally flooded by tides, Heritiera fomes begins to appear. A total of 245 genera and 334 plant species were recorded by David Prain in 1903. While most of the mangroves in other parts of the world are characterised by members of the Rhizophoraceae , Avicenneaceae or Combretaceae , the mangroves of Bangladesh are dominated by the Malvaceae and Euphorbiaceae . The Sundarbans flora
14892-413: The lands near the villages are irrigated from ponds that were filled up during monsoon, and vegetable crops ( Rabi crops ) can be grown here. Some farms and mangrove areas are being cleared for aquaculture . The Sundarbans has a population of over 4 million but much of it is mostly free of permanent human habitation. Despite human habitations and a century of economic exploitation of the forest well into
15038-559: The late 1940s, the Sundarbans retained a forest closure of about 70% according to the Overseas Development Administration (ODA) of the United Kingdom in 1980. The Sundarbans area is one of the most densely populated areas in the world, and the population is increasing. As a result, half of this ecoregion's mangrove forests have been cut down to supply fuelwood and other natural resources. Despite
15184-492: The limited fresh water available in salty intertidal soils, mangroves limit the amount of water they lose through their leaves. They can restrict the opening of their stomata (pores on the leaf surfaces, which exchange carbon dioxide gas and water vapor during photosynthesis). They also vary the orientation of their leaves to avoid the harsh midday sun and so reduce evaporation from the leaves. A captive red mangrove grows only if its leaves are misted with fresh water several times
15330-466: The limits of distribution, the formation is represented by scrubby, usually monotypic Avicennia -dominated vegetation, as at Westonport Bay and Corner Inlet, Victoria, Australia. The latter locality is the highest latitude (38° 45'S) at which mangroves occur naturally. The mangroves in New Zealand, which extend as far south as 37°, are of the same type; they start as low forest in the northern part of
15476-505: The local authorities in Bangladesh killed 4 tiger poachers in a shootout in the Sunderbans mangrove area where currently 114 tigers dwell. The Sundarban National Park is a National Park , Tiger Reserve , and a Biosphere Reserve in West Bengal, India. It is part of the Sundarbans on the Ganges Delta , and adjacent to the Sundarbans Reserve Forest in Bangladesh. The delta is densely covered by mangrove forests, and
15622-472: The major limitation to the number of species able to thrive in their habitat. High tide brings in salt water, and when the tide recedes, solar evaporation of the seawater in the soil leads to further increases in salinity. The return of tide can flush out these soils, bringing them back to salinity levels comparable to that of seawater. At low tide, organisms are also exposed to increases in temperature and reduced moisture before being then cooled and flooded by
15768-535: The mangrove species in each listed plant genus and family. Mangrove environments in the Eastern Hemisphere harbor six times as many species of trees and shrubs as do mangroves in the New World. Genetic divergence of mangrove lineages from terrestrial relatives, in combination with fossil evidence, suggests mangrove diversity is limited by evolutionary transition into the stressful marine environment, and
15914-403: The model plant Arabidopsis thaliana and economically important crop plants, such as rice , barley , wheat , maize and soybean . There is less information on the microbiomes of tree species. Plant microbiomes are determined by plant-related factors (e.g., genotype , organ, species, and health status) and environmental factors (e.g., land use, climate, and nutrient availability). Two of
16060-488: The most abundant biological entities on earth, present in virtually all ecosystems. By lysing their hosts, that is, by rupturing their cell membranes, viruses control host abundance and affect the structure of host communities. Viruses also influence their host diversity and evolution through horizontal gene transfer , selection for resistance and manipulation of bacterial metabolisms . Importantly, marine viruses affect local and global biogeochemical cycles through
16206-400: The newly accreted land created by fresh deposits of eroded soil. The pioneer vegetation on these newly accreted sites is Sonneratia , followed by Avicennia and Nypa . As the ground is elevated as a result of soil deposition, other trees make their appearance. The most prevalent, though one of the late species to appear, is Excoecaria . As the level of land rises through accretion and
16352-427: The north there is a sharp interface with intensively cultivated land. The natural drainage in the upstream areas, other than the main river channels, is everywhere impeded by extensive embankments and polders . The Sundarbans was originally measured (about 200 years ago) to be of about 16,700 square kilometres (6,400 sq mi). Now it has dwindled into about one-third of its original size. The total land area today
16498-614: The number of mangrove lineages has increased steadily over the Tertiary with little global extinction. Mangroves are a type of tropical vegetation with some outliers established in subtropical latitudes, notably in South Florida and southern Japan, as well as South Africa, New Zealand and Victoria (Australia). These outliers result either from unbroken coastlines and island chains or from reliable supplies of propagules floating on warm ocean currents from rich mangrove regions. "At
16644-473: The parent tree. Once germinated, the seedling grows either within the fruit (e.g. Aegialitis , Avicennia and Aegiceras ), or out through the fruit (e.g. Rhizophora , Ceriops , Bruguiera and Nypa ) to form a propagule (a ready-to-go seedling) which can produce its own food via photosynthesis . The mature propagule then drops into the water, which can transport it great distances. Propagules can survive desiccation and remain dormant for over
16790-429: The past few years, bridging the research gap and expanding our knowledge towards the relationship between microbes mainly constituted of bacteria and its nutrient cycles in the mangrove sediment and direct and indirect impacts on mangrove growth and stand-structures as coastal barriers and other ecological service providers. Thus, based on studies by Lai et al.'s systematic review, here they suggest sampling improvements and
16936-927: The plant via root exudates , thus close associations between the plant and microbes are established for their mutual benefits. The taxonomic class level shows that most Proteobacteria were reported to come from Gammaproteobacteria, followed by Deltaproteobacteria and Alphaproteobacteria. The diverse function and the phylogenic variation of Gammaproteobacteria, which consisted of orders such as Alteromonadales and Vibrionales, are found in marine and coastal regions and are high in abundance in mangrove sediments functioning as nutrient recyclers. Members of Deltaproteobacteria found in mangrove soil are mostly sulfur-related, consisting of Desulfobacterales , Desulfuromonadales , Desulfovibrionales , and Desulfarculales among others. Highly diverse microbial communities (mainly bacteria and fungi ) have been found to inhabit and function in mangrove roots. For example, diazotrophic bacteria in
17082-453: The plant was exposed. In a frequently cited concept that has become known as the "sacrificial leaf", salt which does accumulate in the shoot (sprout) then concentrates in old leaves, which the plant then sheds. However, recent research on the Red mangrove Rhizophora mangle suggests that the older, yellowing leaves have no more measurable salt content than the other, greener leaves. Because of
17228-549: The plant-related factors, plant species, and genotypes, have been shown to play significant roles in shaping rhizosphere and plant microbiomes, as tree genotypes and species are associated with specific microbial communities . Different plant organs also have specific microbial communities depending on plant-associated factors (plant genotype, available nutrients, and organ-specific physicochemical conditions) and environmental conditions (associated with aboveground and underground surfaces and disturbances). Mangrove roots harbour
17374-765: The property from poachers. The park receives financial aid from the State Government as well as the Ministry of Environment and Forests under various Plan and Non-Plan Budgets. Additional funding is received under the Project Tiger from the Central Government. In 2001, a grant of US$ 20,000 was received as a preparatory assistance for promotion between India and Bangladesh from the World Heritage Fund . A new Khulna Forest Circle
17520-574: The protected status, the Indian Sundarbans were considered endangered in a 2020 assessment under the IUCN Red List of Ecosystems framework. The Sundarbans mangrove forest covers an area of about 10,277 km (3,968 sq mi), of which forests in Bangladesh's Khulna Division extend over 6,017 km (2,323 sq mi) and in West Bengal's Presidency division , they extend over 4,260 km (1,640 sq mi) across
17666-447: The region According to a report created by UNESCO, the landfall of Cyclone Sidr damaged around 40% of Sundarbans in 2007. In August 2010, a memorandum of understanding was signed between Bangladesh Power Development Board (BPDB) and India's state-owned National Thermal Power Corporation (NTPC) where they designated to implement the coal-fired Rampal power station by 2016. The proposed project, on an area of over 1,834 acres of land,
17812-575: The region and partly by climate change. In many of the Bangladesh's mangrove wetlands, freshwater reaching the mangroves was considerably reduced from the 1970s because of diversion of freshwater in the upstream area by neighbouring India through the use of the Farakka Barrage bordering Rajshahi , Bangladesh. Also, the Bengal Basin is slowly tilting towards the east because of neo- tectonic movement, forcing greater freshwater input to
17958-409: The region, resulting in further ecosystem degradation and climate migration . Experts examining the region recommend further focus on mangrove restoration and management and advocating for adaptation of human populations, through processes like managed retreat and investments in resilient infrastructure. The literal meaning of Sundarbans ( Bengali : সুন্দরবন , romanized : Sundôrbôn )
18104-731: The release of substantial amounts of organic carbon and nutrients from hosts and assist microbes in driving biogeochemical cycles with auxiliary metabolic genes (AMGs). It is presumed AMGs augment viral-infected host metabolism and facilitate the production of new viruses. AMGs have been extensively explored in marine cyanophages and include genes involved in photosynthesis, carbon turnover, phosphate uptake and stress response. Cultivation-independent metagenomic analysis of viral communities has identified additional AMGs that are involved in motility, central carbon metabolism, photosystem I, energy metabolism, iron–sulphur clusters, anti-oxidation and sulphur and nitrogen cycling. Interestingly,
18250-404: The rest of the plant. One study found that roots of the Indian mangrove Avicennia officinalis exclude 90% to 95% of the salt in water taken up by the plant, depositing the excluded salt in the cortex of the root. An increase in the production of suberin and in the activity of a gene regulating cytochrome P450 were observed in correlation with an increase in the salinity of the water to which
18396-708: The rivers originating from the Ganges and the saline water of the Bay of Bengal. The Sundarbans along the Bay of Bengal has evolved over the millennia through natural deposition of upstream sediments accompanied by intertidal segregation. The physiography is dominated by deltaic formations that include innumerable drainage lines associated with surface and subaqueous levees, splays and tidal flats. There are also marginal marshes above mean tide level, tidal sandbars and islands with their networks of tidal channels, subaqueous distal bars and proto-delta clays and silt sediments. The Sundarbans' floor varies from 0.9 to 2.11 metres (3.0 to 6.9 ft) above sea level. Biotic factors here play
18542-485: The same. This is causing the flight of human capital to the mainland, about 13% in the decade of 2000–2010. A 2015 ethnographic study, conducted by a team of researchers from Heidelberg university in Germany, found a crisis brewing in the Sunderbans. The study contended that poor planning on the part of the India and Bangladesh governments coupled with natural ecological changes were forcing the flight of human capital from
18688-421: The sanctuary is very diverse with some 40 species of mammals, 260 species of birds and 35 species of reptiles. The greatest of these being the Bengal tiger of which an estimated 350 remain in the Bangladesh Sundarbans. Other large mammals are wild boar , chital horin ( spotted deer ), Indian otter and macaque monkey . Five species of marine turtles frequent the coastal zone and two endangered reptiles are present –
18834-411: The sediment due to the tidal flushing of mangrove forests. Termites play an important role in the formation of peat from mangrove materials. They process fallen leaf litter , root systems and wood from mangroves into peat to build their nests, and stabilise the chemistry of this peat that represents approximately 2% of above ground carbon storage in mangroves. As the nests are buried over time this carbon
18980-465: The soil like straws for breathing. These "breathing tubes" typically reach heights of up to 30 cm (12 in), and in some species, over 3 m (9.8 ft). The roots also contain wide aerenchyma to facilitate transport within the plants. Because the soil is perpetually waterlogged, little free oxygen is available. Anaerobic bacteria liberate nitrogen gas, soluble ferrum (iron), inorganic phosphates , sulfides , and methane , which make
19126-503: The soil much less nutritious. Pneumatophores ( aerial roots ) allow mangroves to absorb gases directly from the atmosphere, and other nutrients such as iron, from the inhospitable soil. Mangroves store gases directly inside the roots, processing them even when the roots are submerged during high tide. Red mangroves exclude salt by having significantly impermeable roots that are highly suberised (impregnated with suberin ), acting as an ultrafiltration mechanism to exclude sodium salts from
19272-757: The species chosen. The International Day for the Conservation of the Mangrove Ecosystem is celebrated every year on 26 July. Etymology of the English term mangrove can only be speculative and is disputed. The term may have come to English from the Portuguese mangue or the Spanish mangle . Further back, it may be traced to South America and Cariban and Arawakan languages such as Taíno . Other possibilities include
19418-460: The status of various mangrove species and taxonomic revision of the man-grove flora. However, very little exploration of the botanical nature of the Sundarbans has been made to keep up with these changes. Differences in vegetation have been explained in terms of freshwater and low salinity influences in the Northeast and variations in drainage and siltation . The Sundarbans has been classified as
19564-435: The tide. Thus, for a plant to survive in this environment, it must tolerate broad ranges of salinity, temperature, and moisture, as well as several other key environmental factors—thus only a select few species make up the mangrove tree community. About 110 species are considered mangroves, in the sense of being trees that grow in such a saline swamp, though only a few are from the mangrove plant genus, Rhizophora . However,
19710-463: The tiger and dolphin are target species for planning wildlife management and tourism development. There are high profile and vulnerable mammals living in two contrasting environments, and their statuses and management are strong indicators of the general condition and management of wildlife. Some species are protected by legislation, notably by the Bangladesh Wildlife (Preservation) Order, 1973 (P.O. 23 of 1973). The Sundarbans are an important habitat for
19856-767: The tropical conditions of variable salinity, tidal range (inundation), anaerobic soils, and intense sunlight. Plant biodiversity is generally low in a given mangrove. The greatest biodiversity of mangroves occurs in Southeast Asia , particularly in the Indonesian archipelago . The red mangrove ( Rhizophora mangle ) survives in the most inundated areas, props itself above the water level with stilt or prop roots and then absorbs air through lenticels in its bark. The black mangrove ( Avicennia germinans ) lives on higher ground and develops many specialized root-like structures called pneumatophores , which stick up out of
20002-402: The undergrowth is mostly seedlings of the mangrove trees. Besides the sundari , other tree species in the forest include Avicennia , Xylocarpus mekongensis , Xylocarpus granatum , Sonneratia apetala , Bruguiera gymnorhiza , Ceriops decandra , Aegiceras corniculatum , Rhizophora mucronata , and Nypa fruticans palms. Twenty-six of the fifty broad mangrove species found in
20148-529: The vast delta on the Bay of Bengal formed by the super-confluence of the Hooghly , Padma (both are distributaries of Ganges ), Brahmaputra and Meghna rivers across southern Bangladesh . The seasonally flooded Sundarbans freshwater swamp forest lies inland from the mangrove forests on the coastal fringe. The forest covers 10,277 km (3,968 sq mi) of which about 6,017 km (2,323 sq mi) are in Bangladesh. The Indian part of Sundarbans
20294-579: The vicinity of mangrove roots could perform biological nitrogen fixation , which provides 40–60% of the total nitrogen required by mangroves; the soil attached to mangrove roots lacks oxygen but is rich in organic matter, providing an optimal microenvironment for sulfate-reducing bacteria and methanogens , ligninolytic , cellulolytic , and amylolytic fungi are prevalent in the mangrove root environment; rhizosphere fungi could help mangroves survive in waterlogged and nutrient-restricted environments. These studies have provided increasing evidence to support
20440-642: The west. There are records of A. germinans and Rhizophora mangle for Bermuda, presumably supplied by the Gulf Stream. In southern Japan, Kandelia obovata occurs to about 31 °N (Tagawa in Hosakawa et al., 1977, but initially referred to as K. candel )." Mangrove forests , also called mangrove swamps or mangals , are found in tropical and subtropical tidal areas. Areas where mangroves occur include estuaries and marine shorelines. The intertidal existence to which these trees are adapted represents
20586-413: The world grow well in the Sundarbans. The commonly identifiable vegetation types in the dense Sundarbans mangrove forests are salt water mixed forest, mangrove scrub, brackish water mixed forest, littoral forest, wet forest and wet alluvial grass forests. The Bangladesh mangrove vegetation of the Sundarbans differs greatly from other non-deltaic coastal mangrove forests and upland forests associations. Unlike
20732-459: The world's largest mangrove forest. On 9 December 2014 an oil-tanker named Southern Star VII , carrying 358,000 litres (79,000 imp gal; 95,000 US gal) of furnace oil , was sunk in the Sela river of Sundarbans after it had been hit by a cargo vessel. The oil spread over 350 km (140 sq mi) area after the clash, as of 17 December. The slick spread to a second river and
20878-403: The world's subtropical and tropical coastlines. Mangroves are one of the most productive and ecologically important ecosystems on earth. The rates of primary production of mangroves equal those of tropical humid evergreen forests and coral reefs. As a globally relevant component of the carbon cycle, mangroves sequester approximately 24 million metric tons of carbon each year. Most mangrove carbon
21024-550: The world. In 2018, the Global Mangrove Watch Initiative released a new global baseline which estimates the total mangrove forest area of the world as of 2010 at 137,600 km (53,100 sq mi), spanning 118 countries and territories. A 2022 study on losses and gains of tidal wetlands estimates a 3,700 km (1,400 sq mi) net decrease in global mangrove extent from 1999 to 2019. Mangrove loss continues due to human activity, with
21170-550: Was created in Bangladesh back in 1993 to preserve the forest, and Chief Conservators of Forests have been posted since. The direct administrative head of the Division is the Divisional Forest Officer, based at Khulna, who has a number of professional, subprofessional and support staff and logistic supports for the implementation of necessary management and administrative activities. The basic unit of management
21316-692: Was found in the Baghmara Forest Block that is attributed to Chand Sadagar , a pre-Mauryan semi-historical figure in Bengali folklore. Archaeological excavation at Kapilmuni , Paikgacha Upazilla , north of the Sundarbans in Bangladesh, revealed ruins of urban settlement dating back to the early middle ages . During the Mughal period, forest tracts were leased out by the local rulers for establishing settlements. In 1757, The British East India Company obtained proprietary rights over Sundarbans from
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