Bon-kar a tax on forest products levied during pre-British period. The Mughals were particularly conscious of forest development and conservation. Tree felling was then forbidden without corresponding tree-planting. The government collected considerable revenue through a forest tax called bankar. From rennell’s atlas, the main forest lines in Mughal Bengal can be traced. There were three distinct forest lines until the end of the eighteenth century. The first was the Bengal-end of the central Indian forest line ending in Burdwan, Birbhum, Bishnupur and Midnapore. The second forest line was the extension of the Himalayan foot-hills forest (murang) to north-east Bengal which finally merged with the forests of the Garo and Jaintia hills. The chain included the great Baikanthapur forest on the Tista-Mahananda basin and the madhupur forest range from pabna to sylhet via Atia Pargana of Mymensingh.
The biggest and the most formidable forest line was that of the coastal forests called the sundarbans range. It extended from the chittagong coastline on the east to the Midnapur coastline on the west. The inland extension of the forest from the coastline ranged from 20 to 150 kilometres. These forests were good sources of revenue for the Mughal government. Forest trees were the most important source of energy then. Materials for housing and agricultural implements were also derived from forests. handicrafts, plough-share, irrigation tools, materials for bridges and culverts, for flood control, for rice husking, loom, and oil-press - all came from forests. They also supplied timber for making boats, the greatest means of transport in this riverine country. In addition, forests produced fruits, herbs, roots, honey, important oil bearing stuff, spices and different dyes. Bhoga-kapas, a kind of tree cotton, was produced in forests. The Birbhum and Sylhet forests produced tasar silk, shellac and gum. Wax and honey were other important forest resources. On all these resources taxes were imposed at varying rates, all collectively known as bankar. [Sirajul Islam]