Most of the lands in Bangladesh have been formed by river alluvium from the Ganges, Brahmaputra, and their tributaries. Geographically, the country falls near the Indo-Burma region, one of the global biodiversity hotspots, and has large seasonal variability. Bangladesh's wide range of ecosystems include hills, forests (evergreen and semi-evergreen forests, dry-deciduous and moist-deciduous forests), grasslands, reedlands, floodplains, rivers, low-lying islands (Charlands), ox-bow lakes (baors), river-back swamps (haors), open woodlands (village groves), low-lying deep depressions (beels), ponds, canals, ditches, estuary, coastal mudflats, coastal