Sundarban

World largest mangrove forest  

 General Description

Sundarban is the biggest mangrove forest in the world. Sundarban is in South West part of Bangladesh, in the district of greater Khulna. India shares a bit of the forest with Bangladesh. The total area is about 38,000 square kilo meters. Sundarban is a large block of littoral forests. The beauty lies in its unique natural surrounding. The Sundarbans are a part of the world's largest delta formed by the rivers Ganges,Brahmaputra and Meghna. Thousands of meandering streams, creeks, rivers and estuaries have enhanced its charm. For miles and miles, the lofty treetops form an unbroken canopy, while nearer the ground, works of high and ebb-tide marked on the soil and tree trunks and the many varieties of the natural mangrove forest have much to offer to an inquisitive visitor. 

Sundarban is the natural habitat of the world’s famous Royal Bengal Tiger, spotted deer, crocodiles, jungle fowl, wild boar, lizards and many more. Migratory flock ofSiberian ducks flying over thousands of sail boats loaded with timber, Golpata, fuel wood, honey, shell and fish further add to the serene natural beauty of the Sundarban.

In general, the northern boundary and new depositions are characterized by Baen (Avicennia marina , A. alba, A. officinalis ) flanked by foreshore grassland of Oryza coarctata  (Dhani grass). Baen is gradually replaced by Gewa (Excoecaria agallocha) and then Goran (Ceriops spp.). The southern and eastern associates include Garjan (Rhizophora spp.), Kankra (Bruguiera spp.), and few patches of Sundari (Heritiera fomes) . Hental (Phoenix  spp.) forest exists in relatively high land and compact soil. Dhundul (Xylocarpus granatum), Passur (Xylocarpus mekongensis) and Nipa fruticans  (Golpata) palm swamps are extremely limited. 

 

 Location and history

The Sundarban Reserved Forest (SRF), occupying an area of around 6,017 square kilometres or 600,000 hectares, represents 51 percent of the total reserved forest area of Bangladesh and as such forms a rich and diverse ecosystem with potential for sustainable natural resource management. Man has exploited the Sundarban for centuries but the forest was not given Reserve status by the Forestry Department until 1875.

managed the forest and other natural resources of the SRF through adherence to management plans which it prepares at regular intervals. Early management simply concentrated on revenue collection and the enforcement of felling rules to reduce overcutting, particularly in the eastern portion. The first real professional forest management planning was introduced in the SRF in the early 1900s with the introduction of the Curtis Working Plan.

However, more recently forest resource management has shifted to increase emphasis upon environmental and socio-economic issues.

The following table presents the fractions represented by forest and other land types in the Sundarban.

Famous spots

The main tourist point is Hiron Point (Nilkamal) for watching tiger, deer, monkey, crocodiles, birds and natural beauty. Katka is for watching deer, tiger, crocodiles, varieties of birds and monkey. Morning and evening symphony of wild fowls. Vast expanse of grassy meadows running from Katka to Kachikhali (Tiger Point) provide opportunities for wild tracking. Tin Kona Island for tiger and deer. Dublar Char(Island) for fishermen.  It is a beautiful island where herds of spotted deer are often seen to graze. Here land and water meet in many novel fashions, Wildlife presents many a spectacle. No wonder, you may come across a Royal Bengal Tiger swimming across the streams or the crocodiles basking on the river banks. With the approach of the evening herds of deer make for the darkling glades where boisterous monkeys shower Keora leaves from above for sumptuous meal for the former. For the botanist, the love of nature, the poet and the painter this land provides a variety of wonder for which they all crave.

           

 

Type	Area (km2)	Percent
Forest area	3997	66
Sandbars, grass, bare ground	115	2
Rivers	1905	32
Total SRF (of which 1397 km2 represented by 3 wildlife sanctuaries)	6017	100

                                

 

Species	Area (km2)			Percent (%)
	Production forest	Wildlife sanctuary	Total
Sundri	1801	170	1905	46
Gewa	1056	262	1318	32
Goran	303	345	648	16
Keora	59	24	83	2
Passur	28	0	28	1
Baen	10	2	12	0
Tree plantations	2	0	2	0
Grass, bare ground	46	23	69	2
Sandbars	27	19	46	1
Total	3267	845	4112	100

                                    

 

Although the overall area of forest in the SRF is known, the crucial question is what is the volume by species, what is the growth rate and is the extraction exceeding the growth? This sustainability question is partially answered through reference to the results of various forest inventories.

Flora of Sundarban 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. 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.  ·         Forest Sustainability The results of four independent inventories undertaken over the past seventy years would seem to indicate that the overall volume per hectare has decreased. Moreover, closer analysis of three inventories undertaken in 1959, 1983 and 1996 indicate a marked reduction in total standing volume (expressed in millions of cubic metres) for the two principal species of economic importance, Sundri and Gewa. The following table highlights the dramatic decrease.   Species Mean volume/ha (m3/ha) Total standing volume (million m3) Forestal 1959 ODA 1983 FRMP 1996 Forestal 1959 ODA 1983 FRMP 1996 Sundri 34.5 19.9 17.8 13.0 7.9 7.1 Gewa 8.7 4.6 2.1 3.3 1.8 0.8 The reasons for the decline in Sundri, Heriteria fomes is twofold. First, as a valuable timber species with real commercial value, it has been subject to heavy exploitation, both legal and illegal. Second, subtle changes in the ecology of the area, notably increases in salinity and siltation have resulted in hostile anaerobic conditions in which the Sundri finds difficulty in healthy respiration. This has resulted in dieback whereby the tree is progressively defoliated from the top downwards. The decline in Gewa, Excoecaria agallocha is largely attributable to harvesting of around 50,000 m3 per annum as feedstock to Khulna Newsprint Mill for the production of newsprint. Although the mill is scheduled to close, one line continues to operate. In recognition of the importance to manage the forest resources in the SRF on a sustainable basis, the Forest Department imposed a logging moratorium in 1989 on all timber species except Gewa. Diseased Sundri is felled and cleared as part of a sanitation programme and of course illegal logging by fishermen and other collectors continues to have an impact. The main list of sundarban trees are given below. Sl. No Scientific Name Family Vernacular Name Types of Plant 1 Acacia nilotica Leguminosae Babla Tree 2 Acalypha indica Euphprviaceae Muktajhuri Small herb 3 Acalypha indica Euphprviaceae Muktajhuri Small herb 4 Acanthus ilicifolius Acanthaceae Hargoza Scrambling woody, thorny herb 5 Achyranthes aspara Amaranthaceae Upang Rough chaff shrub 6 Acrostichum aureum Pteridaceae Hodo, Tiger fern Gregarious fern 7 Aegialitis rotundifolia Plumbaginaceae Dhalchaka Small tree 8 Aegiceras cornicuiatum Myrsinaceae Khalisha, Khalshi Shrub or small tree 9 Aesclynomene aspara Leguminosae Joloz Shola Grass 10 Aesclynomene indica Leguminosae Joloz Shola Grass 11 Albizia lebbeck Leguminosae Kala koroy Tree 12 Albizia procera Leguminosae Sada koroy Tree 13 Albizia richardiana Leguminosae Raj koroy Tree 14 Amaranthus spinosus Amaranthaceae Kantanote Small spinus shrub 15 Amischophacelus axilaris commelinaceae Kengra Swamp tree 16 Amoora cucullata Meliaceae Amur Small 17 Aponogetom sp. n/a Swampy grass Swampy grass 18 Argemone maxicana Papaveraceae Shialkata Thorny herb 19 Avcennia officinalis Avicenniaceae Baen Tree 20 Avicennia alba Avicenniaceae Morcha bean Small tree 21 Avicennia marina Avicenniaceae Sada bean Small tree 22 Azolla pinanata N/a Blue green algae Algae 23 Barringtonia acutangula Barringtoniaceae Hijal Small tree 24 Barringtonia racemosa Barringtoniaceae Kumba Small tree 25 Blumea lacera Compositae Bon gash Aromatic herb 26 Boerhaavia diffusa Nyctaginaceae Punarnava Small tree 27 Borasus flabellifer Palmae Tal Plam tree 28 Bouca burnanica Anacardiaceae Muriam Small tree 29 Brownloeia tersa Tiliaceae Sundri lata Scandent shrub 30 Bruguiera gymnorrhiza Rhizophoraceae Kankra Tree 31 Bruguiera parviflora Rhizophoraceae Kankra Tree .