Decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients, and the process is called decomposition. Decomposition is one of the important processes in the ecosystem which helps in nutrient cycling. Dead plant remains such as leaves, bark, flowers and dead remains of animals, including faecal matter of animals constitute detritus. This is the raw material for decomposition.
The important steps in the process of decomposition are fragmentation, leaching, catabolism, humification, and mineralization.
The detritivores, like earthworms, break down detritus into smaller particles. This process is called fragmentation.