Sundarbans mangrove forest, Bangladesh. Old leaves of "Sundri" (Heritiera) mangrove trees covered with lichen and moss. This is one of the main and most valuable tree species in the Sundarbans. - - Integrated Resource Development of the Sundarbans Reserved Forest: BGD/84/056. An agreement was made between the Government of Bangladesh and the United Nations Development Programme for implementation of the project by the Ministry of Environment and Forests and for its execution by FAO, and the project document was signed in 1990