Biodiversity, Floristic Composition and Climate Change in the Sunderbans Presented by Istiak Sobhan 13 April 2011
Area over BD+IND 10,000 km2 Roughly 60% fall in BD Located in the SW part of the country between latitudes 89000/ and 89055/ E and longitudes 21030/ and 23030/N. Total area in BD part of SRF is 577,356 ha of which 175,724 ha is water. The Sundarbans
Biodiversity 3 Protected Areas in Sundarban Reserved Forests (SRF), which constitute the core area of the World Heritage Site, inscribed in 1997. SRF is the 1stRamsar site of the country. The total area of the 798thWorld Heritage Site is about 1,400 km2, of which 490 km2 is water, carrying a very rich biodiversity of flora and fauna. 400 species of fish and crustacean 275 species of birds incl 95 waterfowl 42 species of mammal 50 species of reptiles 8 species of amphibians 25 species of mangroves
Factors influence biodiversity Water resources People living around Landuse in and around the forest Elevation Salinity (soil & water) Natural disaster (Cyclone) Sedimentation
Major river systems Ichhamati-Jamuna system Benta-Kobadak- Kholpetua - Arpangasia system Kobadak sub system Sibsha system Gorai- Rupsha - Pussur System Sela gang system Bhairab subsystem Madhumati-Baleswar system Chitra subsystem
Demography Consists of the three districts Bagerhat, Khulna and Satkhira. The districts cover a total area of 10,660 sq. km. Dependent population mainly in the northern part is about six million (6m).
Livelihood Broadly 17 SRF-adjoining Upazilas, considered as impact zone (SIZ), a band extending 20 km outside the SRF boundary (Popn 1.84m) Variety of NTFP such as fish, honey, wax, nypa leaves, etc. are collected by the inhabitants. Also gather climbers, grasses, medicinal herbs, etc. The 12,000 Km of rivers and creeks produces large quantities of fish, shrimps, crabs, oysters, etc.
Cyclone More than 40% cyclones over the last 100 yrs crossed through the Sundarbans.
Profile of vegetation along the geomorphic gradient
Historical changes in vegetation Geological evidences suggest that the Bengal Basin tilted eastward during the 12th Century because of the neo-tectonic movement (Morgan and McIntire, 1959). The lack of freshwater to the western part has had significant effects on the floristic composition of the forests. For instance, according to some studies of fossil pollen, Heritierafomes was a dominant arborescent species in the Calcutta region about 5000 years ago (Blasco, 1975). The Indian Sundarbans as well as the western part of the Bangladesh Sundarbans no longer support a healthy population of this species.