West Bengal is a state in the eastern region of India along the Bay of Bengal. With over 91 million inhabitants, it is the fourteenth-largest state by area in India. Covering an area of 88,752 km2. Part of the Bengal region of the Indian subcontinent, it borders Bangladesh in the east, and Nepal and Bhutan in the north. It also borders the Indian states of Odisha, Jharkhand, Bihar, Sikkim and Assam. West Bengal includes the Darjeeling Himalayan hill region, the Ganges delta, the Rarh region and the coastal Sundarbans.
The 'India State of Forest Report 2017', recorded forest area in the state is 16,847 km2, while in 2013, forest area was 16,805 km2, which was 18.93% of the state's geographical area, compared to the then national average of 21.23%. Reserves and protected and unclassed forests constitute 59.4%, 31.8% and 8.9%, respectively, of forested areas, as of 2009. Part of the world's largest mangrove forest, the Sundarbans in southern West Bengal.
From a phytogeographic viewpoint, the southern part of West Bengal can be divided into two regions: the Gangetic plain and the littoral mangrove forests of the Sundarbans. The alluvial soil of the Gangetic plain, combined with favourable rainfall, makes this region especially fertile. Much of the vegetation of the western part of the state has similar species composition with the plants of the Chota Nagpur plateau in the adjoining state of Jharkhand. The predominant commercial tree species is Shorea robusta, commonly known as the sal tree. The coastal region of Purba Medinipur exhibits coastal vegetation; the predominant tree is the Casuarina. A notable tree from the Sundarbans is the ubiquitous sundari, from which the forest gets its name.
The distribution of vegetation in northern West Bengal is dictated by elevation and precipitation. For example, the foothills of the Himalayas, the Dooars, are densely wooded with sal and other tropical evergreen trees. Above an elevation of 1,000 metres, the forest becomes predominantly subtropical. In Darjeeling, which is above 1,500 metres, temperate forest trees like oaks, conifers and rhododendrons predominate.
3.26% of the geographical area of West Bengal is protected land, comprising fifteen wildlife sanctuaries and five national parks—Sundarbans National Park, Buxa Tiger Reserve, Gorumara National Park, Neora Valley National Park and Singalila National Park. Extant wildlife includes Indian rhinoceros, Indian elephant, deer, leopard, gaur, tiger and crocodiles, as well as many bird species. Migratory birds come to the state during the winter. The high-altitude forests of Singalila National Park shelter barking deer, red panda, chinkara, takin, serow, pangolin, minivet and kalij pheasants. The Sundarbans are noted for a reserve project devoted to conserving the endangered Bengal tiger, although the forest hosts many other endangered species such as the Gangetic dolphin, river terrapin and estuarine crocodile. The mangrove forest also acts as a natural fish nursery, supporting coastal fishes along the Bay of Bengal. Recognising its special conservation value, the Sundarbans area has been declared a Biosphere Reserve.