| Lower Gangetic plains moist deciduous forests | |
|---|---|
 | |
 Ecoregion territory (in purple) | |
| Ecology | |
| Realm | Indomalayan |
| Biome | tropical and subtropical moist broadleaf forests |
| Borders | List
|
| Bird species | 380+ |
| Mammal species | 126 |
| Geography | |
| Area | 254,100 km2 (98,100 mi2) |
| Countries | |
| States | |
| Coordinates | 24°02′N89°53′E / 24.033°N 89.883°E /24.033; 89.883 |
| Conservation | |
| Conservation status | Critical/endangered[1] |
| Protected | 2.76% |
TheLower Gangetic Plains moist deciduous forests is atropical and subtropical moist broadleaf forestsecoregion ofBangladesh andIndia. The ecoregion covers an area of 254,100 square kilometres (98,100 sq mi), comprising most of Bangladesh and the Indian states ofWest Bengal,Bihar andTripura, and extending into adjacent states ofOdisha,Uttar Pradesh and a tiny part ofAssam, as well as adjacent westernMyanmar.
The Lower Gangetic Plains moist deciduous forests extends across thealluvial plain of the lowerGanges andBrahmaputra rivers, which form the world's largestriver delta. The ecoregion is currently one of the most densely populated regions on earth, and the forests have largely been replaced withintensive agriculture.
The ecoregion is bounded on the east and northeast by montane tropical rain forests; theMizoram–Manipur–Kachin rain forests covers theChin Hills andChittagong Hills to the east, extending into Myanmar and other states of Northeast India, while theMeghalaya subtropical forests covers the Garo-Khasi-Jaintia Hills of Meghalaya and southern Assam, and almost defines the Bangladesh border withNortheast India. To the north, the ecoregion extends to the base of theHimalayas, where it is bounded by theTerai–Duar savanna and grasslands. The upper portion of the Brahmaputra valley in Assam is home to the humid lowlandBrahmaputra Valley semi-evergreen forests. To the northwest, the forests are bounded by theUpper Gangetic Plains moist deciduous forests. The dryChota Nagpur dry deciduous forests lie on theChota Nagpur Plateau to the southwest. TheSundarbans freshwater swamp forests andSundarbans mangroves ecoregions lie in the swampy, semi-brackish and brackish southern reaches of theGanges-Brahmaputra Delta bordering theBay of Bengal.
The ecoregion is home to several large cities, includingKolkata,Dhaka,Patna, andChittagong.
The climate of the ecoregion is tropical and humid. Most of the annual rainfall comes during the southwest monsoon from June to September.
The natural vegetation is mostly semi-evergreen forest.
The upper canopy is predominantly of deciduous trees, with a lower storey of evergreen trees. Characteristic trees in disturbed forests areBombax ceiba together withAlbizia procera,Duabanga sonneratioides, andSterculia villosa. As forests maturesal (Shorea robusta) becomes predominant, but most of the remaining forests do not mature to climax stage because of human disturbance. Where annual fires occur frequently during the dry season, fire-hardy trees and shrubsZizyphus mauritiana,Madhuca latifolia,Aegle marmelos,Butea monosperma,Terminalia tomentosa, andOchna pumila are common.[1]
Riparian forests are typically anAcacia-Dalbergia association, withAcacia catechu,Dalbergia sissoo,Albizia procera,Bombax ceiba, andSterculia villosa.[1]
The ecoregion is home to 126 native mammal species. They include threatened species like thetiger (Panthera tigris),Asian elephant (Elephas maximus),gaur (Bos gaurus),sloth bear (Melursus ursinus),chousingha (Tetracerus quadricornis),smooth-coated otter (Lutrogale perspicillata), andgreat Indian civet (Viverra zibetha).[1]
The ecoregion is home to 380 species of birds species, including theBengal florican (Houbaropsis bengalensis),lesser florican (Sypheotides indicus),Pallas's fish-eagle (Haliaeetus leucoryphus),swamp francolin (Francolinus gularis),Indian grey hornbill (Ocyceros birostris), andOriental pied hornbill (Anthracoceros albirostris).
The ecoregion has been densely settled for many centuries, yet much forest remained until the early 20th century. Forest clearance accelerated during the 20th century, and by the end of the century, only 3% of the ecoregion remained in natural forest. Remaining forest areas are mostly small patches, except for one large block of forest south ofVaranasi.[2]
In 1997, theWorld Wildlife Fund identified over 40 protected areas in the ecoregion, with a combined area of about 7010 km², or approximately 3% of the ecoregion's area. Over half of these protected areas were smaller than 100 km²[2]
