In the first book of its kind from Bangladesh, the country has been divided into 12 bio-ecological zones, some of which are sub- divided. The numbering of the zones flows from north to south in order to make it user-friendly. In addition to the floral and faunal diversities, there is information on its location, mean annual rainfall and temperature, administrative units and headquarters, physiography, land and soil types, flooding depths, major agricultural land uses and major cultivated crops for each zone.