Preserving our ecosystem
Bangladesh is one of the most densely populated countries in the world. The country was very rich in biodiversity. During the last few decades the country has largely lost its rich biodiversity as a consequence of the rapid reduction in forest area, urbanization, habitat modification, unsustainable natural resources use and collection and climate change.
Ecologically, Bangladesh supports a diverse set of ecosystems. The country has the world's largest mangrove forest. In the Sundarbans, on its south-western part, Royal Bengal tiger lives--this is a rare species of tiger. In its eastern part it has a large tract of evergreen to semi-evergreen hill forests, once very rich in biodiversity but mostly degraded now. Besides, in the north-eastern part, there are many wetlands.
In Bangladesh, some 2,260 species of the plant reported alone from the Chittagong Hill Tracts, which falls between two major floristic regions of Asia. So far an estimated 5,700 species of angiosperms alone, including 68 woody legumes, 130 fibre yielding plants, 500 medicinal plants, 29 orchids, 3 gymnosperms and 1,700 pteridophytes have been recorded.
Bangladesh inland water bodies are known to be the habitat of 266 species of indigenous fish, 13 exotic fish, 56 prawns, about 26 freshwater molluscs. Besides, 150 species of birds live in this land. The marine water bodies (200 nautical miles along the coast) are also remarkable for being the habitat of 442 species of fish. There are at least 36 species of marine shrimps. About 336 species of mollusks, covering 151 genera have identified from the Bay of Bengal. Also, several species of crabs, and 31 species of turtles and tortoises, of which 24 live in freshwater, are found in Bangladesh.
According to the IUCN -2016, the country also possesses a rich faunal diversity. Bangladesh is home to about 138 mammal species, more than 566 species of birds (passerine and non-passerine), 167 species of reptiles, 49 species of amphibians. In addition to that, at least 253 species of fish (inland freshwater), 305 species of butterflies, 305 species of shrimp/prawn, 2,493 species of insects, 362 species of mollusks, 66 species of corals, 15 species of crabs, 19 species of mites, 164 species of algae, 4 species of echinoderms have believed to exist in the country.
A large number of plant and wildlife species have already gone extinct from Bangladesh over the last decades. A substantial number of the country's remaining plants, mammals, birds and reptiles are currently under tremendous threat to be extinct. IUCN has listed a sum of 156 species of mammals, birds, reptiles and amphibians under various degrees of risks in the country.
A reliable statistic on country's plant diversity is still unavailable; nevertheless, it has anticipated that already 10 per cent of the plant species gone extinct. A recent inventory by Bangladesh National Herbarium identified 106 vascular plants with risks of various degrees of threats. The country has also adopted various in-situ and ex-situ conservation measures to maintain its rich biological heritage. Declaration of protected areas, ecologically critical areas, World Heritage Site, Ramsar Sites are among the widely used ways for in situ conservation.
At present, the country has 38 protected areas counting 17 national parks and 21 wildlife sanctuaries distributed across the country. Together with, the protected areas of Bangladesh cover nearly 17.5 per cent of the forest area and 1.8 per cent of the country's total land area. In addition to that, the landscape has seven eco-park, two safari park and botanical gardens which also contribute significantly to the conservation of the territory with dwindling biodiversity.
Major Challenges and crucial threats to biodiversity in Bangladesh are high population density, extreme poverty, and unemployment, climate change and sea-level rise, habitat loss, degradation and fragmentation, illegal poaching, logging and fuel wood collection, environmental pollution and degradation, invasive alien species, limitations in legal and policy framework, lack of political commitments and willingness, lack of public awareness.
The reason behind the richness of this bio diversity is its location in the subtropical belt at the confluence of the two major biotic sub-regions of the Oriental Region-- the Indo-Himalayas and Indo-China. The biodiversity of these two biotic sub-regions overlaps in Bangladesh, making the biodiversity very diverse from all directions.
The species richness of Bangladesh is well recognized when compared with other areas. For example, the total number of bird species in Bangladesh is nearly the same as all of Europe. The five broad types of ecosystems in Bangladesh are coastal and marine ecosystems, inland freshwater ecosystems, terrestrial forest ecosystems, hilly ecosystems and man-made homestead ecosystems.
All of the wildlife and wildlife habitats found in Bangladesh have significant economic value. For the most part, in terms of well-planned tourism, it could play a vital role in development of the Bangladesh economy. The day's most parts of the forest of Bangladesh have now the legal status of protected areas.
According to the Bangladesh wildlife act 1974, there are three defined types of protected areas: National Park, Wildlife Sanctuaries, and Game Reserves. But still, the stunning wildlife of Bangladesh is in continuous threat from a different direction along their numbers are decreasing at an alarming rate. The government should properly implement all of the existing laws and legislation, having to build up trained manpower for the protection of biodiversity.
Biodiversity is a valuable resource of a country. It must be protected from destruction in any way. Otherwise our nature will lose its balance.
The writer is a student, Department of Environmental Science & Engineering, Jatiya Kabi Kazi
Nazrul Islam University,