Forest litter and other organic debris in various stages of decomposition on top of the mineral soil; typical of coniferous forests in cool climates, where rate of decomposition is slow and where litter accumulation exceeds decay. | | | | E-F | | | I-K | | | N-O | | | | T-X
the layer of partially and fully decomposed organic materials lying below the litter and immediately above the mineral soil. It corresponds to the fermentation (F) and humus (H) layers of the forest floor. When moss is present, the top of the duff is just below the green portion of the moss.
A soil layer dominated by organic material derived from the decomposition of plant and animal litter and deposited on either an organic or a mineral surface. This layer is distinguished from the litter layer in that the original organic material has undergone sufficient decomposition that the source of this material (e.g., individual plant parts) can no longer be identified.
Layer of decaying forest litter consisting of organics such as needles, leaves, plant and tree materials covering the mineral soil. Duff can smolder for days after a fire. Extinguishing smoldering duff is key to successful mopup operations.
The vegetative matter, such as leaves, twigs, dead logs, etc., that covers the ground in the forest; unconsolidated decomposing and partially decomposed organic material immediately under a layer of leaf litter. Duff forms a layer about 5 cm (2 in.) thick that overlies the soil of a forest floor. Its thermal insulation is an important factor in the formation of permafrost, and the quality and moisture content of duff is significant in considerations of forest fire hazard ( fire weather).