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Sundarbans
- The good-looking Mangrove wooded area.
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Sundarbans, the largest single hunk
of tidal halophytic mangrove wooded area in the earth, positioned in the
southern part of Bangladesh. It lies on the Ganges-Brahmaputra Delta at the summit
where it merges with the Bay of Bengal. The forest lies a little south to the
Tropic of Cancer between the latitudes 21º30´N and 22º30´N, and longitudes
89º00´E and 89º55´E. With its array of trees and wildlife the forest is a
showpiece of natural history. It is also a centre of economic activities, such
as extraction of timber, fishing and collection of honey. The forest consists
of about 200 islands, separated by about 400 interconnected tidal rivers,
creeks and canal.
The Sundarbans was in the beginning deliberate
(about 200 years ago) to be of about 16,700 sq km. Now it has dwindle to about
1/3 of the unique size. since of the dividing wall of India, Bangladesh
received about 2/3 of the forest; the rest is on the Indian side. It is now
estimated to be about 4,110 sq km, of which about 1,700 sq km is occupied by
waterbodies. The forest lies under two forest divisions, and four
administrative ranges viz Chandra, Sarankhola, Khulna and Burigoalini and has
16 forest stations. It is further divided into 55 compartments and 9 blocks.
The Sundarbans was declared as a Reserve Forest in 1875. About 32,400 hectares
of the Sundarbans have been declared as three wildlife sanctuaries, and came
under the UNESCO World Heritage Site in 1999. These wildlife sanctuaries were
established in 1977 under the Bangladesh natural world (Preservation)
(Amendment) Act, 1974. These are Sundarbans West (9,069 ha), Sundarbans South
(17,878 ha), and Sundarbans East (5,439 ha).
The Bangla declaration ban means
wooded area, and the name Sundarban was coin either from the forests of Sundari
tree ie Sundari-ban, or from the forests of the samudra (sea) ie,
Samudra-ban, or from its association with the primitive tribe Chandra-bandhe
which was corrupted into Sundarban. The generally accepted explanation,
however, is its derivation from the sundari
tree, the most widespread chain of command in these forest.
Geology The country of the Sundarbans is of current origin, raised
by the acknowledgment of sediments formed due to soil erosion in the Himalayas.
The process has been accelerated by tides from the sea face. The substratum
consists mainly of Quaternary Era sediments, sand and silt assorted with maritime
salt put down and clay. Geologists have detected a southeastern slope and
tilting of the Bengal basin during the Tertiary. Because of neo-tectonic
movements during the 10th-12th century AD, the Bengal Basin titled eastward. confirmation
from borehole studies indicate that while the westernside of the Sundarbans is
relatively stable, the southeastern corner is an active sedimentary area and is
fall down.
Soil Soils of the Sundarbans mangrove forest differ from other internal
soils in that they are subjected to the effects of salinity and waterlogging, which
naturally affect the vegetation. In places soils are semi-solid and poorly
consolidated. The pH ranges widely from 5.3 to 8.0. Although the Sundarbans
soil is in general medium textured, sandy loam, deposit loam or clay loam, the
grain size distribution is highly variable. Silt loam is dominant textural
class. Sodium and calcium contents of the soil vary from 5.7 to 29.8 meq/100g
dry soil and are generally low in the eastern region and higher towards the
west. The available potassium comfortable of the soil is low, 0.3-1.3 meq/100g
dry soil. Organic topic content varies between 4% and 10% in dry soil. Soil
salinity increases from east (slight to moderate) to west (highly saline), but
the salinity is not uniform from north to south throughout the wooded area.
Climate Since the forest is located on the south of the Tropic of
Cancer and bounded by the northern limits of the Bay of Bengal, it is
classified as tropical moist forest. The temperatures in the Sundarbans are
fairly equable than those of the adjacent land areas. The average annual
maximum and minimum temperatures vary between 30º and 21ºC. High temperatures
occur from mid-March to mid-June and low in December and January. The mean
maximum temperature for the hottest months has been recorded as 32.4ºC at Patuakhali,
in the east of the Sundarbans.
The mean annual relative humidity
varies from 70% at Satkhira to 80% at Patuakhali. Humidity is highest in
June-October and lowest in February. Annual rainfall in the Sundarbans is in
the range of 1640-2000 mm, rainfall increases from west to the east. Most
rainfall occurs during the monsoon from May to October. Frequent and heavy
showers occur from mid-June to mid-September. Often storm accompanied by tidal
waves result widespread inundation and cause damage to vegetation and animal
life.
Vegetation The vegetation is largely of mangrove type and encompasses
a variety of plants including trees, shrubs, grasses, epiphytes, and lianas.
Being mostly evergreen, they possess more or less similar physiological and
structural adaptations. Most trees have pneumatophores for aerial respiration.
The prominent species is Sundari (Heritiera fomes) and Gewa (Excoecaria
agallocha). Prain (1903) recorded 334 species under 245 genera. Of these 17
are pteridophytes, 87 monocotyledons and the rest are dicotyledons. The plant
species include 35 legumes, 29 grasses, 19 sedges, and 18 euphorbias. Of the 50
true mangrove plant species recorded, the Sundarbans alone contain 35. Almost
all mangrove plant species are evergreen, dwarf, shrubby or tall trees, and
grow gregariously without leaving any space on the floor.
In the Sundarbans the saltwater
forest is situated in the south-western part where Gewa (E. agallocha),
Goran (Ceriops decandra), Keora (Sonneratia apetala), Ora (S.
caseolaris), Passur (Xylocarpus mekongensis), Dhundul (X.
granatum), Bain (Avicennia alba, A. marina, A. officinales), and
other rhizophores, and Hantal (Phoenix pelludosa) dominate. The typical
mangrove species dominate the central part of the forest. The moderate saltwater
forest covers most of the southern parts of Khulna and Bagerhat districts where
Sundari is the dominant species.
There is a thick mat of the nipa palm or 'Golpata' (Nipa
fruticans) by the side of almost all the canals. The moderately
freshwater zone results from the large amount of water, which flows down the
Passur, Haringhata and Burisher, maintaining the surface water at a lower
level of salinity.
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The Sundarbans shows some distinct
phyto-succession, where the newly formed lands are occupied by some pioneer
species viz Leersia hexandra, wild rice (Potresia species), followed by
Avicennia, Sonneratia and Aegiceras. The secondary succession occurs due to
Ceriops, Excoecaria, Bruguiera, Heritiera, Xylocarpus and Rhizophora. Tiger
fern (Achrostichum aureum) mostly covers the ground floor, which is common in
saltwater and moderately saltwater zones. Tigers use these bushes to camouflage
themselves.
Fauna The Sundarbans hosts a large variety of animals. It is the
last stronghold of the THE ROYAL bengal
tiger (Panthera tigris). Within the forest habitats there are
about 50 species of mammals, about 320 species of inland and migratory birds,
about 50 species of reptiles, 8 species of amphibians, and about 400 species of
fish.
Besides the spectacular Royal Bengal
Tiger, the other notable mammalian fauna
are Spotted deer (Cervus axis), Barking deer (Muntiacus muntjak),
Rhesus macaque (Macaca mulatta), Jungle cat (Felis chaus),
Leopard cat (Prionailurus bengalensis), the Indian porcupine (Hystrix
indica), Otter (Lutra perspicillata), and wild boar (Sus scrofa).
deer and wild boar constitute the
main prey for the tiger. Some species including the Bengal tiger are
endangered.
The ecological diversity of the
Sundarbans supports a large variety of birds. Among the total number of species
recorded, most are resident. Over 50 species are known to be migratory and are
mostly represented by the waterfowls. The egrets, storks, herons, bitterns,
sandpipers, curlew, and numerous other waders are seen along the muddy banks.
There are many species of gulls and terns, especially along the seacoast and
the larger waterways. Accipitridae (kites, eagles, vulture, harrier etc) is
represented by about 22 species. Nine species of kingfishers are available in the
forest. The rich avifaunas of the forest include species of woodpeckers,
barbets, owls, bee-eaters, bulbul, shrikes, drongos, starlings, mynas,
babblers, thrush, oriole, flycatchers, and many others.
Of about 50 species of reptiles
the largest member in the Sundarbans is the Estuarine crocodile (Crocodylus porosus), some of which may
attain a length of about seven metres. Although once they were abundant in
this mangrove habitat, their total number is now estimated to be around 250.
Species of lizards, including the Monitor Lizards Varanus, turtles,
and snakes are well-represented. Among the snakes, the King Cobra (Ophiophagus
hannah), Russell's Viper (Vipera russellii), Rock python (Python molurus), Banded
Krait (Bungarus fasciatus) and several species of sea snakes are
notable.
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Only eight species of amphibians
have been reported from the Sundarbans. The green frog (Euphlyctis
hexadactylus) is mostly observed in Chandpai area of the mangrove forest.
The other forest amphibians include the Skipper frog (E. cyanophlyctis),
Cricket frog (Limnonectes limnocharis), Tree frog (Polypedates
maculatus), and the common toad.
The Sundarbans suports nearly 400
species of fishes in its varied aquatic habitats; these include both the
pelagic and demersal fishes. Many species use these habitats as nursery
grounds. No aquaculture or fish farming is allowed in the Sundarbans. The Forest
Department controls the fish catch from the area.
Among the invertebrates some
molluscs and crustaceans constitute important fisheries resources. About 20
species of shrimps, 8 species of lobsters, 7 species of crabs, several species
of gastropods, and 6 species of pelecypods have been reported from the
Sundarbans. Among the shrimps Penaeus monodon and Metapenaeus monoceros and the
mud crab Scylla serrata are commercially important. Insects are varied, the
most important being the honeybee Apis dorsata. Locally known as 'Mouals', the
professional bee collectors gather honey for three to four months during the
flowering season taking permission from the Forest Department. The forest is
very rich in its spider fauna (Araneae). Nearly 300 species under 22 families
have been recorded from the mangrove forest habitats.
Economic value, tourism and forest
dwellers The most important value of the
Sundarbans lies in its protective role. It helps hold coastlines, reclaim
coastal lands, and settle the silt carried by the rivers. The estuary is a good
breeding centre for many fishes. Several plant-based industries have been
developed here. The most important ones are the newsprint and hardboard mills
in Khulna. The raw material for the former is gewa and for the latter sundari.
Other important plant-based industries are match factories and boat building.
The forest is a good source of fuel, tannins, thatching, wooden articles,
medicinal plants, and fodder. The forest is also a major source of honey and
bee wax. Aegiceras corniculatum, Ceriops decandra, Nipa species, Derris
species, and Hibiscus tiliaceous are the major honey plants.
Most frequently visited sites in the
Sundarbans include Katka, Hiron Point (known commonly as Nilkamal), Dublar Char
and Tiger Point (Kachi Khali). Katka attracts tourists for its landscape and
wildlife. There is a forest rest house here and an observation tower. Hiron
Point also has a rest house and an observation tower. Dublar Char is an island
with a beautiful beach. The other attraction of the island is the fishing
activities that take place every year between mid-October and mid-February.
Fishermen from other places of the country, especially from Chittagong,
assemble here during the period to catch fish and dry them on the sunny beach.
The honey collectors go into the forests during April-May.
Only a few people live permanently
in or around the Sundarbans. They include the bawalis (collectors of
golpata), mouals (honey collectors) and woodcutters. Their dwellings are
usually at the edge of the forest and the houses are built on platforms
supported on 3-5 m high poles of wood or bamboo.
Some people, especially the bedyas (gypsy) live on boats. [Mostafa Kamal
Pasha and Neaz Ahmad Siddiqui]
Sundarbans forest
regeneration Natural regeneration refers to
renewal of a tree crop by natural means, as opposed to artificial regeneration
by means of planting or sowing as done in mangrove plantation. The mangrove of
the Sundarbans is dependent on natural regeneration for its existence. Over the
greater part of the forest, seedling recruitment was sufficient for replacement
of the harvested trees. The average number of seedlings appearing per year was
about 27,750/ha although recruitment densities varied considerably among
different parts of the forests. Heritiera fomes, Excoecaria agallocha
and other species together constituted about 24, 54 and 22 percent of the
recruits (three months old seedlings), respectively.
Salinity of the area apparently
influences the regeneration density which decreases with increasing level of
salinity. There is year to year variation in recruitment. However, salinity
appears to have little influence on these variations. Variation in seedling
recruitment among the three salinity zones seems to be significant. Seedling
recruitment for H. fomes, E. agallocha, and other species shows
highly fluctuating values over the years. Such fluctuation might be due to the
existence of periodicity in the seed production of some species.
Sundarban
Events
Honey
Collection (April- June) After watching
the official opening ceremony of the annual Honey collection season in
Burigoalini, we follow a group of Honey collectors to the western part of the
forest adjoin their search for precious sweetie - a source of revenue that has
survived through the centuries. This is a physically demanding tour, but unique
and unforgettable - A true adventure in the terra firma of the Tiger.
Bobbi
Meal (January) People entering the Sundarban wooded
area to extract forest resources, including fishermen, wood-cutters and honey
collectors, pray for a safe return to Bobbi, the local forest deity. Along the
forest edge permanent shrines are built in her honor. The clay figurines are
replaced and colorfully decorated once a year; a unique festive occasion with
music, theaters and fairs.
Dublin
Rash Purina Mela (Dependant on Lunar Calendar.
normally beginning of November) Dubla Island, situated at the mouth of the Holy
River Ganges, is inhabited by fishermen during the winter months. They are
joined by thousands of Hindu pilgrims for the annual Rash Mela, the festival of
the Rash full moon. After joyous celebrations and fair activities the night
before, the devotees congregate in long lines at the waters edge in the early morning
hours, holding their offerings and awaiting their blessing.
Fishing
with Trained Otters This unique traditional fishing
technique is only found in Bangladesh. Fishermen from the Narail/Gopalganj area
breed and train their otters to amplify the catch. Although they primarily work
in the rivers north of the forest, they also enter the Sundarban wooded area.
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