Bangladesh is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 163 million people in an area of 148,460 square kilometres. Bangladesh shares land borders with India to the west, north, and east, and Myanmar to the southeast; to the south it has a coastline along the Bay of Bengal. It is narrowly separated from Nepal and Bhutan by the Siliguri Corridor; and from China by 100 km of the Indian state of Sikkim in the north.
Bangladesh is located in the Indomalayan realm, and lies within four terrestrial ecoregions: Lower Gangetic Plains moist deciduous forests, Mizoram–Manipur–Kachin rain forests, Sundarbans freshwater swamp forests, and Sundarbans mangroves. Its ecology includes a long sea coastline, numerous rivers and tributaries, lakes, wetlands, evergreen forests, semi evergreen forests, hill forests, moist deciduous forests, freshwater swamp forests and flat land with tall grass. The Bangladesh Plain is famous for its fertile alluvial soil which supports extensive cultivation. The country is dominated by lush vegetation, with villages often buried in groves of mango, jackfruit, bamboo, betel nut, coconut and date palm. The country has up to 6000 species of plant life, including 5000 flowering plants. Water bodies and wetland systems provide a habitat for many aquatic plants. Water lilies and lotuses grow vividly during the monsoon season. The country has 50 wildlife sanctuaries.
Bangladesh is home to much of the Sundarbans, the world's largest mangrove forest, covering an area of 6,000 km2 in the southwest littoral region. It is divided into three protected sanctuaries–the South, East and West zones. The forest is a UNESCO World Heritage Site. The northeastern Sylhet region is home to haor wetlands, a unique ecosystem. It also includes tropical and subtropical coniferous forests, a freshwater swamp forest, and mixed deciduous forests. The southeastern Chittagong region covers evergreen and semi-evergreen hilly jungles. Central Bangladesh includes the plainland Sal forest running along with the districts of Gazipur, Tangail and Mymensingh. St. Martin's Island is the only coral reef in the country.
Bangladesh has an abundance of wildlife in its forests, marshes, woodlands and hills. The vast majority of animals dwell within a habitat of 150,000 km2, The Bengal tiger, clouded leopard, saltwater crocodile, black panther and fishing cat are among the chief predators in the Sundarbans. Northern and eastern Bangladesh is home to the Asian elephant, hoolock gibbon, Asian black bear and oriental pied hornbill.
The Chital deer are widely seen in southwestern woodlands. Other animals include the black giant squirrel, capped langur, Bengal fox, sambar deer, jungle cat, king cobra, wild boar, mongooses, pangolins, pythons and water monitors. Bangladesh has one of the largest populations of Irrawaddy dolphins and Ganges dolphins. A 2009 census found 6,000 Irrawaddy dolphins inhabiting the littoral rivers of Bangladesh. The country has numerous species of amphibians, reptiles, marine reptiles and marine mammals, It also has 628 species of birds.
Several animals became extinct in Bangladesh during the last century, including the one-horned and two-horned rhinoceros and common peafowl. The human population is concentrated in urban areas, limiting deforestation to a certain extent. Rapid urban growth has threatened natural habitats. Although many areas are protected under law, some Bangladeshi wildlife is threatened by this growth. Furthermore, access to biocapacity in Bangladesh is low. In 2016, Bangladesh had 0.4 global hectares of biocapacity per person within its territory, or about one fourth of the world average. In contrast, in 2016, they used 0.84 global hectares of biocapacity – their ecological footprint of consumption. As a result, Bangladesh is running a biocapacity deficit.
The government has designated several regions as Ecologically Critical Areas, including wetlands, forests, and rivers. The Sundarbans tiger project and the Bangladesh Bear Project are among the key initiatives to strengthen conservation.