Brown rot and white rot are the two general types of wood decay caused by fungi. Brown rot results from the action of fungi which destroy the cellulose and leave a dry, brown, crumbly mass of lignin constituents of wood. Wood containing brown rot, even in the earliest visible stages of decay, is so weakened that it will fail in use and must be discarded. Since the cellulose fibers are affected, the value of wood for pulp is lost when brown rot occurs. Forest Insect and Disease Leaflet USDA/USFS accessed 6 Aug 2008
