Forest floor material includes all organic material present on the forest floor such as duff, moss, litter, peat, twigs, and other woody debris.
Source: Hardy, Colin C., Ottmar, Roger D., Peterson, Janice L., Core, John E., and Seamon, Paula. 2001. Smoke Management Guide for Prescribed and Wildland Fire 2001 Edition. Produced by the National Wildfire coordinating Group Fire Use Working Team.