Forest Floor, Definitions and Importance
The forest floor consists of organic residues (leaves, branches, bark, stems) in various stages of decomposition present on the top of the mineral soil.
The amount of organic material in the forest floor depends on the balance between inputs from litter production and outputs from decomposition. Both litter production and decomposition are functions of the site characteristics (e.g., soil water content, temperature, nutrient status) and vegetation present on the site (e.g., coniferous, deciduous). Generally, forest floors are heaviest and deepest in boreal forests and forests where decomposition rates are slow. In contrast, the lightest and thinnest forest floors usually occur in tropical rain forests where decomposition rates are rapid. The forest floor is one of the richest components of the forest ecosystem in terms of organisms since it supports a large number of decomposers and predators, mostly invertebrates, fungi, algae, bacteria, and soil mites. Other important ecosystem roles played by the forest floor include: carbon storage, nutrient cycling and effects on soil moisture and temperature.