Final answer:
The partly decomposed organic material on a forest floor is called humus, which is created by decomposers breaking down plant and animal matter. In certain wet environments, this material can also be referred to as peat, which may even become coal over time.
Step-by-step explanation:
The term for the partly decomposed organic material on a forest floor is humus. Humus consists of decaying plant and animal matter, the microorganisms involved in this decomposition, and substances resistant to decay like waxes, lignins, and fats. It plays a crucial role in soil structure, providing important nutrients and improving water retention. Decomposers, such as fungi and bacteria, are instrumental in breaking down complex organic material, like dead leaves and wood, into humus.
In certain environments such as swamps or bogs, when decomposition is incomplete due to conditions like lack of oxygen or high acidity, the partly decomposed plant material is known as peat. Over time and under pressure, peat may transform into coal. Peat can be harvested for use as a fuel source or as a soil additive in gardening.
The processes of decay and decomposition contribute significantly to the nutrient cycle within ecosystems, releasing essential elements back into the soil to be used by living plants.